diff mbox series

[v3,4/4] optee: support restricted memory allocation

Message ID 20241128150927.1377981-5-jens.wiklander@linaro.org (mailing list archive)
State New
Headers show
Series TEE subsystem for restricted dma-buf allocations | expand

Commit Message

Jens Wiklander Nov. 28, 2024, 3:09 p.m. UTC
Add support in the OP-TEE backend driver for restricted memory
allocation.

The restricted memory can be allocated from a static carveout, but also
be dynamically allocated from CMA and turned into restricted memory by
OP-TEE, inaccessible by the kernel. The restricted memory configuration
is depends on the platform and is probed by driver.

A restricted memory pool is allocated during probe if a static carveout
is available. The restricted memory pools for dynamically allocated
restrict memory are instantiated when requested by user-space. This
instantiation can fail if OP-TEE doesn't support the requested use-case
of restricted memory.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 drivers/tee/optee/Makefile        |   1 +
 drivers/tee/optee/core.c          |   1 +
 drivers/tee/optee/ffa_abi.c       | 135 ++++++++++-
 drivers/tee/optee/optee_private.h |  33 ++-
 drivers/tee/optee/rstmem.c        | 380 ++++++++++++++++++++++++++++++
 drivers/tee/optee/smc_abi.c       | 138 ++++++++++-
 6 files changed, 683 insertions(+), 5 deletions(-)
 create mode 100644 drivers/tee/optee/rstmem.c

Comments

Sumit Garg Dec. 3, 2024, 8:19 a.m. UTC | #1
Hi Jens,

On Thu, 28 Nov 2024 at 20:39, Jens Wiklander <jens.wiklander@linaro.org> wrote:
>
> Add support in the OP-TEE backend driver for restricted memory
> allocation.
>
> The restricted memory can be allocated from a static carveout, but also
> be dynamically allocated from CMA and turned into restricted memory by
> OP-TEE, inaccessible by the kernel. The restricted memory configuration
> is depends on the platform and is probed by driver.
>
> A restricted memory pool is allocated during probe if a static carveout
> is available. The restricted memory pools for dynamically allocated
> restrict memory are instantiated when requested by user-space. This
> instantiation can fail if OP-TEE doesn't support the requested use-case
> of restricted memory.

Can we split this patch into smaller reviewable pieces as follows?

- Patch 1: Adds support for static carveout using SMC ABI
- Patch 2: Adds support for dynamic CMA pool using SMC ABI
- Patch 3: Adds support for both using FF-A ABI

-Sumit

>
> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> ---
>  drivers/tee/optee/Makefile        |   1 +
>  drivers/tee/optee/core.c          |   1 +
>  drivers/tee/optee/ffa_abi.c       | 135 ++++++++++-
>  drivers/tee/optee/optee_private.h |  33 ++-
>  drivers/tee/optee/rstmem.c        | 380 ++++++++++++++++++++++++++++++
>  drivers/tee/optee/smc_abi.c       | 138 ++++++++++-
>  6 files changed, 683 insertions(+), 5 deletions(-)
>  create mode 100644 drivers/tee/optee/rstmem.c
>
> diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile
> index a6eff388d300..498969fb8e40 100644
> --- a/drivers/tee/optee/Makefile
> +++ b/drivers/tee/optee/Makefile
> @@ -4,6 +4,7 @@ optee-objs += core.o
>  optee-objs += call.o
>  optee-objs += notif.o
>  optee-objs += rpc.o
> +optee-objs += rstmem.o
>  optee-objs += supp.o
>  optee-objs += device.o
>  optee-objs += smc_abi.o
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index c75fddc83576..f4fa494789a4 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -182,6 +182,7 @@ void optee_remove_common(struct optee *optee)
>         tee_device_unregister(optee->teedev);
>
>         tee_shm_pool_free(optee->pool);
> +       optee_rstmem_pools_uninit(optee);
>         optee_supp_uninit(&optee->supp);
>         mutex_destroy(&optee->call_queue.mutex);
>         rpmb_dev_put(optee->rpmb_dev);
> diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> index 02e6175ac5f0..f500cf101c8d 100644
> --- a/drivers/tee/optee/ffa_abi.c
> +++ b/drivers/tee/optee/ffa_abi.c
> @@ -672,6 +672,122 @@ static int optee_ffa_do_call_with_arg(struct tee_context *ctx,
>         return optee_ffa_yielding_call(ctx, &data, rpc_arg, system_thread);
>  }
>
> +static int do_call_lend_rstmem(struct optee *optee, u64 cookie, u32 use_case)
> +{
> +       struct optee_shm_arg_entry *entry;
> +       struct optee_msg_arg *msg_arg;
> +       struct tee_shm *shm;
> +       u_int offs;
> +       int rc;
> +
> +       msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
> +       if (IS_ERR(msg_arg))
> +               return PTR_ERR(msg_arg);
> +
> +       msg_arg->cmd = OPTEE_MSG_CMD_ASSIGN_RSTMEM;
> +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
> +       msg_arg->params[0].u.value.a = cookie;
> +       msg_arg->params[0].u.value.b = use_case;
> +
> +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> +       if (rc)
> +               goto out;
> +       if (msg_arg->ret != TEEC_SUCCESS) {
> +               rc = -EINVAL;
> +               goto out;
> +       }
> +
> +out:
> +       optee_free_msg_arg(optee->ctx, entry, offs);
> +       return rc;
> +}
> +
> +static int optee_ffa_lend_rstmem(struct optee *optee, struct tee_shm *rstmem,
> +                                u16 *end_points, unsigned int ep_count)
> +{
> +       struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
> +       const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
> +       const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
> +       struct ffa_send_direct_data data;
> +       struct ffa_mem_region_attributes *mem_attr;
> +       struct ffa_mem_ops_args args = {
> +               .use_txbuf = true,
> +               .tag = rstmem->use_case,
> +       };
> +       struct page *page;
> +       struct scatterlist sgl;
> +       unsigned int n;
> +       int rc;
> +
> +       mem_attr = kcalloc(ep_count, sizeof(*mem_attr), GFP_KERNEL);
> +       for (n = 0; n < ep_count; n++) {
> +               mem_attr[n].receiver = end_points[n];
> +               mem_attr[n].attrs = FFA_MEM_RW;
> +       }
> +       args.attrs = mem_attr;
> +       args.nattrs = ep_count;
> +
> +       page = phys_to_page(rstmem->paddr);
> +       sg_init_table(&sgl, 1);
> +       sg_set_page(&sgl, page, rstmem->size, 0);
> +
> +       args.sg = &sgl;
> +       rc = mem_ops->memory_lend(&args);
> +       kfree(mem_attr);
> +       if (rc)
> +               return rc;
> +
> +       rc = do_call_lend_rstmem(optee, args.g_handle, rstmem->use_case);
> +       if (rc)
> +               goto err_reclaim;
> +
> +       rc = optee_shm_add_ffa_handle(optee, rstmem, args.g_handle);
> +       if (rc)
> +               goto err_unreg;
> +
> +       rstmem->sec_world_id = args.g_handle;
> +
> +       return 0;
> +
> +err_unreg:
> +       data = (struct ffa_send_direct_data){
> +               .data0 = OPTEE_FFA_RELEASE_RSTMEM,
> +               .data1 = (u32)args.g_handle,
> +               .data2 = (u32)(args.g_handle >> 32),
> +       };
> +       msg_ops->sync_send_receive(ffa_dev, &data);
> +err_reclaim:
> +       mem_ops->memory_reclaim(args.g_handle, 0);
> +       return rc;
> +}
> +
> +static int optee_ffa_reclaim_rstmem(struct optee *optee, struct tee_shm *rstmem)
> +{
> +       struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
> +       const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
> +       const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
> +       u64 global_handle = rstmem->sec_world_id;
> +       struct ffa_send_direct_data data = {
> +               .data0 = OPTEE_FFA_RELEASE_RSTMEM,
> +               .data1 = (u32)global_handle,
> +               .data2 = (u32)(global_handle >> 32)
> +       };
> +       int rc;
> +
> +       optee_shm_rem_ffa_handle(optee, global_handle);
> +       rstmem->sec_world_id = 0;
> +
> +       rc = msg_ops->sync_send_receive(ffa_dev, &data);
> +       if (rc)
> +               pr_err("Release SHM id 0x%llx rc %d\n", global_handle, rc);
> +
> +       rc = mem_ops->memory_reclaim(global_handle, 0);
> +       if (rc)
> +               pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
> +
> +       return rc;
> +}
> +
>  /*
>   * 6. Driver initialization
>   *
> @@ -785,7 +901,10 @@ static void optee_ffa_get_version(struct tee_device *teedev,
>                 .gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM |
>                             TEE_GEN_CAP_MEMREF_NULL,
>         };
> +       struct optee *optee = tee_get_drvdata(teedev);
>
> +       if (optee->rstmem_pools)
> +               v.gen_caps |= TEE_GEN_CAP_RSTMEM;
>         *vers = v;
>  }
>
> @@ -804,6 +923,8 @@ static const struct tee_driver_ops optee_ffa_clnt_ops = {
>         .cancel_req = optee_cancel_req,
>         .shm_register = optee_ffa_shm_register,
>         .shm_unregister = optee_ffa_shm_unregister,
> +       .rstmem_alloc = optee_rstmem_alloc,
> +       .rstmem_free = optee_rstmem_free,
>  };
>
>  static const struct tee_desc optee_ffa_clnt_desc = {
> @@ -820,6 +941,8 @@ static const struct tee_driver_ops optee_ffa_supp_ops = {
>         .supp_send = optee_supp_send,
>         .shm_register = optee_ffa_shm_register, /* same as for clnt ops */
>         .shm_unregister = optee_ffa_shm_unregister_supp,
> +       .rstmem_alloc = optee_rstmem_alloc,
> +       .rstmem_free = optee_rstmem_free,
>  };
>
>  static const struct tee_desc optee_ffa_supp_desc = {
> @@ -833,6 +956,8 @@ static const struct optee_ops optee_ffa_ops = {
>         .do_call_with_arg = optee_ffa_do_call_with_arg,
>         .to_msg_param = optee_ffa_to_msg_param,
>         .from_msg_param = optee_ffa_from_msg_param,
> +       .lend_rstmem = optee_ffa_lend_rstmem,
> +       .reclaim_rstmem = optee_ffa_reclaim_rstmem,
>  };
>
>  static void optee_ffa_remove(struct ffa_device *ffa_dev)
> @@ -937,11 +1062,17 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
>             (sec_caps & OPTEE_FFA_SEC_CAP_RPMB_PROBE))
>                 optee->in_kernel_rpmb_routing = true;
>
> +       if (sec_caps & OPTEE_FFA_SEC_CAP_RSTMEM) {
> +               rc = optee_rstmem_pools_init(optee);
> +               if (rc)
> +                       goto err_free_pool;
> +       }
> +
>         teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
>                                   optee);
>         if (IS_ERR(teedev)) {
>                 rc = PTR_ERR(teedev);
> -               goto err_free_pool;
> +               goto err_free_rstmem_pools;
>         }
>         optee->teedev = teedev;
>
> @@ -1020,6 +1151,8 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
>         tee_device_unregister(optee->teedev);
>  err_free_pool:
>         tee_shm_pool_free(pool);
> +err_free_rstmem_pools:
> +       optee_rstmem_pools_uninit(optee);
>  err_free_optee:
>         kfree(optee);
>         return rc;
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 20eda508dbac..dd2a3a2224bc 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -174,9 +174,14 @@ struct optee;
>   * @do_call_with_arg:  enters OP-TEE in secure world
>   * @to_msg_param:      converts from struct tee_param to OPTEE_MSG parameters
>   * @from_msg_param:    converts from OPTEE_MSG parameters to struct tee_param
> + * @lend_rstmem:       lends physically contiguous memory as restricted
> + *                     memory, inaccessible by the kernel
> + * @reclaim_rstmem:    reclaims restricted memory previously lent with
> + *                     @lend_rstmem() and makes it accessible by the
> + *                     kernel again
>   *
>   * These OPs are only supposed to be used internally in the OP-TEE driver
> - * as a way of abstracting the different methogs of entering OP-TEE in
> + * as a way of abstracting the different methods of entering OP-TEE in
>   * secure world.
>   */
>  struct optee_ops {
> @@ -191,6 +196,23 @@ struct optee_ops {
>                               size_t num_params,
>                               const struct optee_msg_param *msg_params,
>                               bool update_out);
> +       int (*lend_rstmem)(struct optee *optee, struct tee_shm *rstmem,
> +                          u16 *end_points, unsigned int ep_count);
> +       int (*reclaim_rstmem)(struct optee *optee, struct tee_shm *rstmem);
> +};
> +
> +/**
> + * struct optee_rstmem_pools - restricted memory pools
> + * @mutex:     serializes write access to @xa when adding a new pool.
> + * @xa:                XArray of struct tee_shm_pool where the index is the
> + *             use case ID TEE_IOC_UC_* supplied for TEE_IOC_RSTMEM_ALLOC.
> + */
> +struct optee_rstmem_pools {
> +       /*
> +        * Serializes write access to @xa when adding a new pool.
> +        */
> +       struct mutex mutex;
> +       struct xarray xa;
>  };
>
>  /**
> @@ -206,6 +228,7 @@ struct optee_ops {
>   * @notif:             notification synchronization struct
>   * @supp:              supplicant synchronization struct for RPC to supplicant
>   * @pool:              shared memory pool
> + * @rstmem_pool:       restricted memory pool for secure data path
>   * @mutex:             mutex protecting @rpmb_dev
>   * @rpmb_dev:          current RPMB device or NULL
>   * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices
> @@ -230,6 +253,7 @@ struct optee {
>         struct optee_notif notif;
>         struct optee_supp supp;
>         struct tee_shm_pool *pool;
> +       struct optee_rstmem_pools *rstmem_pools;
>         /* Protects rpmb_dev pointer */
>         struct mutex rpmb_dev_mutex;
>         struct rpmb_dev *rpmb_dev;
> @@ -286,6 +310,9 @@ void optee_supp_init(struct optee_supp *supp);
>  void optee_supp_uninit(struct optee_supp *supp);
>  void optee_supp_release(struct optee_supp *supp);
>
> +int optee_rstmem_pools_init(struct optee *optee);
> +void optee_rstmem_pools_uninit(struct optee *optee);
> +
>  int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params,
>                     struct tee_param *param);
>  int optee_supp_send(struct tee_context *ctx, u32 ret, u32 num_params,
> @@ -378,6 +405,10 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
>  int optee_do_bottom_half(struct tee_context *ctx);
>  int optee_stop_async_notif(struct tee_context *ctx);
>
> +int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
> +                      u32 flags, u32 use_case, size_t size);
> +void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm);
> +
>  /*
>   * Small helpers
>   */
> diff --git a/drivers/tee/optee/rstmem.c b/drivers/tee/optee/rstmem.c
> new file mode 100644
> index 000000000000..cf300929171f
> --- /dev/null
> +++ b/drivers/tee/optee/rstmem.c
> @@ -0,0 +1,380 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024, Linaro Limited
> + */
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/cma.h>
> +#include <linux/dma-map-ops.h>
> +#include <linux/errno.h>
> +#include <linux/genalloc.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/tee_core.h>
> +#include <linux/types.h>
> +#include "optee_private.h"
> +
> +struct optee_rstmem_cma_pool {
> +       struct tee_shm_pool pool;
> +       struct page *page;
> +       struct optee *optee;
> +       size_t page_count;
> +       u16 *end_points;
> +       u_int end_point_count;
> +       u_int align;
> +       refcount_t refcount;
> +       struct tee_shm rstmem;
> +       /* Protects when initializing and tearing down this struct */
> +       struct mutex mutex;
> +};
> +
> +static struct optee_rstmem_cma_pool *
> +to_rstmem_cma_pool(struct tee_shm_pool *pool)
> +{
> +       return container_of(pool, struct optee_rstmem_cma_pool, pool);
> +}
> +
> +static int init_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> +{
> +       struct cma *cma = dev_get_cma_area(&rp->optee->teedev->dev);
> +       int rc;
> +
> +       rp->page = cma_alloc(cma, rp->page_count, rp->align, true/*no_warn*/);
> +       if (!rp->page)
> +               return -ENOMEM;
> +
> +       /*
> +        * TODO unmap the memory range since the physical memory will
> +        * become inaccesible after the lend_rstmem() call.
> +        */
> +
> +       rp->rstmem.paddr = page_to_phys(rp->page);
> +       rp->rstmem.size = rp->page_count * PAGE_SIZE;
> +       rc = rp->optee->ops->lend_rstmem(rp->optee, &rp->rstmem,
> +                                        rp->end_points, rp->end_point_count);
> +       if (rc)
> +               goto err_release;
> +
> +       rp->pool.private_data = gen_pool_create(PAGE_SHIFT, -1);
> +       if (!rp->pool.private_data) {
> +               rc = -ENOMEM;
> +               goto err_reclaim;
> +       }
> +
> +       rc = gen_pool_add(rp->pool.private_data, rp->rstmem.paddr,
> +                         rp->rstmem.size, -1);
> +       if (rc)
> +               goto err_free_pool;
> +
> +       refcount_set(&rp->refcount, 1);
> +       return 0;
> +
> +err_free_pool:
> +       gen_pool_destroy(rp->pool.private_data);
> +err_reclaim:
> +       rp->optee->ops->reclaim_rstmem(rp->optee, &rp->rstmem);
> +err_release:
> +       cma_release(cma, rp->page, rp->page_count);
> +       rp->rstmem.paddr = 0;
> +       rp->rstmem.size = 0;
> +       rp->rstmem.sec_world_id = 0;
> +       return rc;
> +}
> +
> +static int get_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> +{
> +       int rc = 0;
> +
> +       if (!refcount_inc_not_zero(&rp->refcount)) {
> +               mutex_lock(&rp->mutex);
> +               if (rp->pool.private_data) {
> +                       /*
> +                        * Another thread has already initialized the pool
> +                        * before us, or the pool was just about to be torn
> +                        * down. Either way we only need to increase the
> +                        * refcount and we're done.
> +                        */
> +                       refcount_inc(&rp->refcount);
> +               } else {
> +                       rc = init_cma_rstmem(rp);
> +               }
> +               mutex_unlock(&rp->mutex);
> +       }
> +
> +       return rc;
> +}
> +
> +static void release_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> +{
> +       gen_pool_destroy(rp->pool.private_data);
> +       rp->optee->ops->reclaim_rstmem(rp->optee, &rp->rstmem);
> +       cma_release(dev_get_cma_area(&rp->optee->teedev->dev), rp->page,
> +                   rp->page_count);
> +
> +       rp->pool.private_data = NULL;
> +       rp->page = NULL;
> +       rp->rstmem.paddr = 0;
> +       rp->rstmem.size = 0;
> +       rp->rstmem.sec_world_id = 0;
> +}
> +
> +static void put_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> +{
> +       if (refcount_dec_and_test(&rp->refcount)) {
> +               mutex_lock(&rp->mutex);
> +               if (rp->pool.private_data)
> +                       release_cma_rstmem(rp);
> +               mutex_unlock(&rp->mutex);
> +       }
> +}
> +
> +static int rstmem_pool_op_cma_alloc(struct tee_shm_pool *pool,
> +                                   struct tee_shm *shm, size_t size,
> +                                   size_t align)
> +{
> +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> +       size_t sz = ALIGN(size, PAGE_SIZE);
> +       phys_addr_t pa;
> +       int rc;
> +
> +       rc = get_cma_rstmem(rp);
> +       if (rc)
> +               return rc;
> +
> +       pa = gen_pool_alloc(rp->pool.private_data, sz);
> +       if (!pa) {
> +               put_cma_rstmem(rp);
> +               return -ENOMEM;
> +       }
> +
> +       shm->size = sz;
> +       shm->paddr = pa;
> +       shm->offset = pa - page_to_phys(rp->page);
> +       shm->sec_world_id = rp->rstmem.sec_world_id;
> +
> +       return 0;
> +}
> +
> +static void rstmem_pool_op_cma_free(struct tee_shm_pool *pool,
> +                                   struct tee_shm *shm)
> +{
> +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> +
> +       gen_pool_free(rp->pool.private_data, shm->paddr, shm->size);
> +       shm->size = 0;
> +       shm->paddr = 0;
> +       shm->offset = 0;
> +       shm->sec_world_id = 0;
> +       put_cma_rstmem(rp);
> +}
> +
> +static void pool_op_cma_destroy_pool(struct tee_shm_pool *pool)
> +{
> +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> +
> +       mutex_destroy(&rp->mutex);
> +       kfree(rp);
> +}
> +
> +static struct tee_shm_pool_ops rstmem_pool_ops_cma = {
> +       .alloc = rstmem_pool_op_cma_alloc,
> +       .free = rstmem_pool_op_cma_free,
> +       .destroy_pool = pool_op_cma_destroy_pool,
> +};
> +
> +static int get_rstmem_config(struct optee *optee, u32 use_case,
> +                            size_t *min_size, u_int *min_align,
> +                            u16 *end_points, u_int *ep_count)
> +{
> +       struct tee_param params[2] = {
> +               [0] = {
> +                       .attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT,
> +                       .u.value.a = use_case,
> +               },
> +               [1] = {
> +                       .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT,
> +               },
> +       };
> +       struct optee_shm_arg_entry *entry;
> +       struct tee_shm *shm_param = NULL;
> +       struct optee_msg_arg *msg_arg;
> +       struct tee_shm *shm;
> +       u_int offs;
> +       int rc;
> +
> +       if (end_points && *ep_count) {
> +               params[1].u.memref.size = *ep_count * sizeof(*end_points);
> +               shm_param = tee_shm_alloc_priv_buf(optee->ctx,
> +                                                  params[1].u.memref.size);
> +               if (IS_ERR(shm_param))
> +                       return PTR_ERR(shm_param);
> +               params[1].u.memref.shm = shm_param;
> +       }
> +
> +       msg_arg = optee_get_msg_arg(optee->ctx, ARRAY_SIZE(params), &entry,
> +                                   &shm, &offs);
> +       if (IS_ERR(msg_arg)) {
> +               rc = PTR_ERR(msg_arg);
> +               goto out_free_shm;
> +       }
> +       msg_arg->cmd = OPTEE_MSG_CMD_GET_RSTMEM_CONFIG;
> +
> +       rc = optee->ops->to_msg_param(optee, msg_arg->params,
> +                                     ARRAY_SIZE(params), params,
> +                                     false /*!update_out*/);
> +       if (rc)
> +               goto out_free_msg;
> +
> +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> +       if (rc)
> +               goto out_free_msg;
> +       if (msg_arg->ret && msg_arg->ret != TEEC_ERROR_SHORT_BUFFER) {
> +               rc = -EINVAL;
> +               goto out_free_msg;
> +       }
> +
> +       rc = optee->ops->from_msg_param(optee, params, ARRAY_SIZE(params),
> +                                       msg_arg->params, true /*update_out*/);
> +       if (rc)
> +               goto out_free_msg;
> +
> +       if (!msg_arg->ret && end_points &&
> +           *ep_count < params[1].u.memref.size / sizeof(u16)) {
> +               rc = -EINVAL;
> +               goto out_free_msg;
> +       }
> +
> +       *min_size = params[0].u.value.a;
> +       *min_align = params[0].u.value.b;
> +       *ep_count = params[1].u.memref.size / sizeof(u16);
> +
> +       if (msg_arg->ret == TEEC_ERROR_SHORT_BUFFER) {
> +               rc = -ENOSPC;
> +               goto out_free_msg;
> +       }
> +
> +       if (end_points)
> +               memcpy(end_points, tee_shm_get_va(shm_param, 0),
> +                      params[1].u.memref.size);
> +
> +out_free_msg:
> +       optee_free_msg_arg(optee->ctx, entry, offs);
> +out_free_shm:
> +       if (shm_param)
> +               tee_shm_free(shm_param);
> +       return rc;
> +}
> +
> +static struct tee_shm_pool *alloc_rstmem_pool(struct optee *optee, u32 use_case)
> +{
> +       struct optee_rstmem_cma_pool *rp;
> +       size_t min_size;
> +       int rc;
> +
> +       rp = kzalloc(sizeof(*rp), GFP_KERNEL);
> +       if (!rp)
> +               return ERR_PTR(-ENOMEM);
> +       rp->rstmem.use_case = use_case;
> +
> +       rc = get_rstmem_config(optee, use_case, &min_size, &rp->align, NULL,
> +                              &rp->end_point_count);
> +       if (rc) {
> +               if (rc != -ENOSPC)
> +                       goto err;
> +               rp->end_points = kcalloc(rp->end_point_count,
> +                                        sizeof(*rp->end_points), GFP_KERNEL);
> +               if (!rp->end_points) {
> +                       rc = -ENOMEM;
> +                       goto err;
> +               }
> +               rc = get_rstmem_config(optee, use_case, &min_size, &rp->align,
> +                                      rp->end_points, &rp->end_point_count);
> +               if (rc)
> +                       goto err_kfree_eps;
> +       }
> +
> +       rp->pool.ops = &rstmem_pool_ops_cma;
> +       rp->optee = optee;
> +       rp->page_count = min_size / PAGE_SIZE;
> +       mutex_init(&rp->mutex);
> +
> +       return &rp->pool;
> +
> +err_kfree_eps:
> +       kfree(rp->end_points);
> +err:
> +       kfree(rp);
> +       return ERR_PTR(rc);
> +}
> +
> +int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
> +                      u32 flags, u32 use_case, size_t size)
> +{
> +       struct optee *optee = tee_get_drvdata(ctx->teedev);
> +       struct tee_shm_pool *pool;
> +       int rc;
> +
> +       if (!optee->rstmem_pools)
> +               return -EINVAL;
> +       if (flags)
> +               return -EINVAL;
> +
> +       pool = xa_load(&optee->rstmem_pools->xa, use_case);
> +       if (!pool) {
> +               pool = alloc_rstmem_pool(optee, use_case);
> +               if (IS_ERR(pool))
> +                       return PTR_ERR(pool);
> +               rc = xa_insert(&optee->rstmem_pools->xa, use_case, pool,
> +                              GFP_KERNEL);
> +               if (rc) {
> +                       pool->ops->destroy_pool(pool);
> +                       return rc;
> +               }
> +       }
> +
> +       return pool->ops->alloc(pool, shm, size, 0);
> +}
> +
> +void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm)
> +{
> +       struct optee *optee = tee_get_drvdata(ctx->teedev);
> +       struct tee_shm_pool *pool;
> +
> +       pool = xa_load(&optee->rstmem_pools->xa, shm->use_case);
> +       if (pool)
> +               pool->ops->free(pool, shm);
> +       else
> +               pr_err("Can't find pool for use_case %u\n", shm->use_case);
> +}
> +
> +int optee_rstmem_pools_init(struct optee *optee)
> +{
> +       struct optee_rstmem_pools *pools;
> +
> +       pools = kmalloc(sizeof(*pools), GFP_KERNEL);
> +       if (!pools)
> +               return -ENOMEM;
> +
> +       mutex_init(&pools->mutex);
> +       xa_init(&pools->xa);
> +       optee->rstmem_pools = pools;
> +       return 0;
> +}
> +
> +void optee_rstmem_pools_uninit(struct optee *optee)
> +{
> +       if (optee->rstmem_pools) {
> +               struct tee_shm_pool *pool;
> +               u_long idx;
> +
> +               xa_for_each(&optee->rstmem_pools->xa, idx, pool) {
> +                       xa_erase(&optee->rstmem_pools->xa, idx);
> +                       pool->ops->destroy_pool(pool);
> +               }
> +
> +               xa_destroy(&optee->rstmem_pools->xa);
> +               mutex_destroy(&optee->rstmem_pools->mutex);
> +               kfree(optee->rstmem_pools);
> +               optee->rstmem_pools = NULL;
> +       }
> +}
> diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> index d1f79947f58a..7fa7d9d14c94 100644
> --- a/drivers/tee/optee/smc_abi.c
> +++ b/drivers/tee/optee/smc_abi.c
> @@ -1001,6 +1001,67 @@ static int optee_smc_do_call_with_arg(struct tee_context *ctx,
>         return rc;
>  }
>
> +static int optee_smc_lend_rstmem(struct optee *optee, struct tee_shm *rstmem,
> +                                u16 *end_points, unsigned int ep_count)
> +{
> +       struct optee_shm_arg_entry *entry;
> +       struct optee_msg_arg *msg_arg;
> +       struct tee_shm *shm;
> +       u_int offs;
> +       int rc;
> +
> +       msg_arg = optee_get_msg_arg(optee->ctx, 2, &entry, &shm, &offs);
> +       if (IS_ERR(msg_arg))
> +               return PTR_ERR(msg_arg);
> +
> +       msg_arg->cmd = OPTEE_MSG_CMD_LEND_RSTMEM;
> +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
> +       msg_arg->params[0].u.value.a = OPTEE_MSG_RSTMEM_SECURE_VIDEO_PLAY;
> +       msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
> +       msg_arg->params[1].u.tmem.buf_ptr = rstmem->paddr;
> +       msg_arg->params[1].u.tmem.size = rstmem->size;
> +       msg_arg->params[1].u.tmem.shm_ref = (u_long)rstmem;
> +
> +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> +       if (rc)
> +               goto out;
> +       if (msg_arg->ret != TEEC_SUCCESS) {
> +               rc = -EINVAL;
> +               goto out;
> +       }
> +
> +out:
> +       optee_free_msg_arg(optee->ctx, entry, offs);
> +       return rc;
> +}
> +
> +static int optee_smc_reclaim_rstmem(struct optee *optee, struct tee_shm *rstmem)
> +{
> +       struct optee_shm_arg_entry *entry;
> +       struct optee_msg_arg *msg_arg;
> +       struct tee_shm *shm;
> +       u_int offs;
> +       int rc;
> +
> +       msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
> +       if (IS_ERR(msg_arg))
> +               return PTR_ERR(msg_arg);
> +
> +       msg_arg->cmd = OPTEE_MSG_CMD_RECLAIM_RSTMEM;
> +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
> +       msg_arg->params[0].u.rmem.shm_ref = (u_long)rstmem;
> +
> +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> +       if (rc)
> +               goto out;
> +       if (msg_arg->ret != TEEC_SUCCESS)
> +               rc = -EINVAL;
> +
> +out:
> +       optee_free_msg_arg(optee->ctx, entry, offs);
> +       return rc;
> +}
> +
>  /*
>   * 5. Asynchronous notification
>   */
> @@ -1201,6 +1262,8 @@ static void optee_get_version(struct tee_device *teedev,
>                 v.gen_caps |= TEE_GEN_CAP_REG_MEM;
>         if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
>                 v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
> +       if (optee->rstmem_pools)
> +               v.gen_caps |= TEE_GEN_CAP_RSTMEM;
>         *vers = v;
>  }
>
> @@ -1223,6 +1286,8 @@ static const struct tee_driver_ops optee_clnt_ops = {
>         .cancel_req = optee_cancel_req,
>         .shm_register = optee_shm_register,
>         .shm_unregister = optee_shm_unregister,
> +       .rstmem_alloc = optee_rstmem_alloc,
> +       .rstmem_free = optee_rstmem_free,
>  };
>
>  static const struct tee_desc optee_clnt_desc = {
> @@ -1239,6 +1304,8 @@ static const struct tee_driver_ops optee_supp_ops = {
>         .supp_send = optee_supp_send,
>         .shm_register = optee_shm_register_supp,
>         .shm_unregister = optee_shm_unregister_supp,
> +       .rstmem_alloc = optee_rstmem_alloc,
> +       .rstmem_free = optee_rstmem_free,
>  };
>
>  static const struct tee_desc optee_supp_desc = {
> @@ -1252,6 +1319,9 @@ static const struct optee_ops optee_ops = {
>         .do_call_with_arg = optee_smc_do_call_with_arg,
>         .to_msg_param = optee_to_msg_param,
>         .from_msg_param = optee_from_msg_param,
> +       .lend_rstmem = optee_smc_lend_rstmem,
> +       .reclaim_rstmem = optee_smc_reclaim_rstmem,
> +       //.alloc_rstmem_pool = optee_smc_alloc_rstmem_pool,
>  };
>
>  static int enable_async_notif(optee_invoke_fn *invoke_fn)
> @@ -1619,6 +1689,62 @@ static inline int optee_load_fw(struct platform_device *pdev,
>  }
>  #endif
>
> +static int optee_sdp_pool_init(struct optee *optee)
> +{
> +       bool dyn_sdp = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_RSTMEM;
> +       bool sdp = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP;
> +       struct tee_shm_pool *pool;
> +       int rc;
> +
> +       /*
> +        * optee_sdp_pools_init() must be called if secure world has any
> +        * SDP capability. If the static carvout is available initialize
> +        * and add a pool for that. If there's an error from secure world
> +        * we complain but don't call optee_sdp_pools_uninit() unless we
> +        * know that there is no SDP capability left.
> +        */
> +       if (!dyn_sdp && !sdp)
> +               return 0;
> +
> +       rc = optee_rstmem_pools_init(optee);
> +       if (rc)
> +               return rc;
> +
> +       if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP) {
> +               union {
> +                       struct arm_smccc_res smccc;
> +                       struct optee_smc_get_sdp_config_result result;
> +               } res;
> +
> +               optee->smc.invoke_fn(OPTEE_SMC_GET_SDP_CONFIG, 0, 0, 0, 0, 0, 0,
> +                                    0, &res.smccc);
> +               if (res.result.status != OPTEE_SMC_RETURN_OK) {
> +                       pr_err("Secure Data Path service not available\n");
> +                       if (!dyn_sdp)
> +                               goto err;
> +                       return 0;
> +               }
> +
> +               pool = tee_rstmem_gen_pool_alloc(res.result.start,
> +                                                res.result.size);
> +               if (IS_ERR(pool)) {
> +                       rc = PTR_ERR(pool);
> +                       goto err;
> +               }
> +               rc = xa_insert(&optee->rstmem_pools->xa,
> +                              TEE_IOC_UC_SECURE_VIDEO_PLAY, pool, GFP_KERNEL);
> +               if (rc) {
> +                       pool->ops->destroy_pool(pool);
> +                       goto err;
> +               }
> +       }
> +
> +       return 0;
> +err:
> +       optee_rstmem_pools_uninit(optee);
> +       return rc;
> +}
> +
>  static int optee_probe(struct platform_device *pdev)
>  {
>         optee_invoke_fn *invoke_fn;
> @@ -1714,7 +1840,7 @@ static int optee_probe(struct platform_device *pdev)
>         optee = kzalloc(sizeof(*optee), GFP_KERNEL);
>         if (!optee) {
>                 rc = -ENOMEM;
> -               goto err_free_pool;
> +               goto err_free_shm_pool;
>         }
>
>         optee->ops = &optee_ops;
> @@ -1726,10 +1852,14 @@ static int optee_probe(struct platform_device *pdev)
>             (sec_caps & OPTEE_SMC_SEC_CAP_RPMB_PROBE))
>                 optee->in_kernel_rpmb_routing = true;
>
> +       rc = optee_sdp_pool_init(optee);
> +       if (rc)
> +               goto err_free_optee;
> +
>         teedev = tee_device_alloc(&optee_clnt_desc, NULL, pool, optee);
>         if (IS_ERR(teedev)) {
>                 rc = PTR_ERR(teedev);
> -               goto err_free_optee;
> +               goto err_rstmem_pools_uninit;
>         }
>         optee->teedev = teedev;
>
> @@ -1836,9 +1966,11 @@ static int optee_probe(struct platform_device *pdev)
>         tee_device_unregister(optee->supp_teedev);
>  err_unreg_teedev:
>         tee_device_unregister(optee->teedev);
> +err_rstmem_pools_uninit:
> +       optee_rstmem_pools_uninit(optee);
>  err_free_optee:
>         kfree(optee);
> -err_free_pool:
> +err_free_shm_pool:
>         tee_shm_pool_free(pool);
>         if (memremaped_shm)
>                 memunmap(memremaped_shm);
> --
> 2.43.0
>
Jens Wiklander Dec. 5, 2024, 10:57 a.m. UTC | #2
Hi Sumit,

On Tue, Dec 3, 2024 at 9:19 AM Sumit Garg <sumit.garg@linaro.org> wrote:
>
> Hi Jens,
>
> On Thu, 28 Nov 2024 at 20:39, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > Add support in the OP-TEE backend driver for restricted memory
> > allocation.
> >
> > The restricted memory can be allocated from a static carveout, but also
> > be dynamically allocated from CMA and turned into restricted memory by
> > OP-TEE, inaccessible by the kernel. The restricted memory configuration
> > is depends on the platform and is probed by driver.
> >
> > A restricted memory pool is allocated during probe if a static carveout
> > is available. The restricted memory pools for dynamically allocated
> > restrict memory are instantiated when requested by user-space. This
> > instantiation can fail if OP-TEE doesn't support the requested use-case
> > of restricted memory.
>
> Can we split this patch into smaller reviewable pieces as follows?
>
> - Patch 1: Adds support for static carveout using SMC ABI
> - Patch 2: Adds support for dynamic CMA pool using SMC ABI
> - Patch 3: Adds support for both using FF-A ABI

OK, I'll split it.

Thanks,
Jens

>
> -Sumit
>
> >
> > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> > ---
> >  drivers/tee/optee/Makefile        |   1 +
> >  drivers/tee/optee/core.c          |   1 +
> >  drivers/tee/optee/ffa_abi.c       | 135 ++++++++++-
> >  drivers/tee/optee/optee_private.h |  33 ++-
> >  drivers/tee/optee/rstmem.c        | 380 ++++++++++++++++++++++++++++++
> >  drivers/tee/optee/smc_abi.c       | 138 ++++++++++-
> >  6 files changed, 683 insertions(+), 5 deletions(-)
> >  create mode 100644 drivers/tee/optee/rstmem.c
> >
> > diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile
> > index a6eff388d300..498969fb8e40 100644
> > --- a/drivers/tee/optee/Makefile
> > +++ b/drivers/tee/optee/Makefile
> > @@ -4,6 +4,7 @@ optee-objs += core.o
> >  optee-objs += call.o
> >  optee-objs += notif.o
> >  optee-objs += rpc.o
> > +optee-objs += rstmem.o
> >  optee-objs += supp.o
> >  optee-objs += device.o
> >  optee-objs += smc_abi.o
> > diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> > index c75fddc83576..f4fa494789a4 100644
> > --- a/drivers/tee/optee/core.c
> > +++ b/drivers/tee/optee/core.c
> > @@ -182,6 +182,7 @@ void optee_remove_common(struct optee *optee)
> >         tee_device_unregister(optee->teedev);
> >
> >         tee_shm_pool_free(optee->pool);
> > +       optee_rstmem_pools_uninit(optee);
> >         optee_supp_uninit(&optee->supp);
> >         mutex_destroy(&optee->call_queue.mutex);
> >         rpmb_dev_put(optee->rpmb_dev);
> > diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> > index 02e6175ac5f0..f500cf101c8d 100644
> > --- a/drivers/tee/optee/ffa_abi.c
> > +++ b/drivers/tee/optee/ffa_abi.c
> > @@ -672,6 +672,122 @@ static int optee_ffa_do_call_with_arg(struct tee_context *ctx,
> >         return optee_ffa_yielding_call(ctx, &data, rpc_arg, system_thread);
> >  }
> >
> > +static int do_call_lend_rstmem(struct optee *optee, u64 cookie, u32 use_case)
> > +{
> > +       struct optee_shm_arg_entry *entry;
> > +       struct optee_msg_arg *msg_arg;
> > +       struct tee_shm *shm;
> > +       u_int offs;
> > +       int rc;
> > +
> > +       msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
> > +       if (IS_ERR(msg_arg))
> > +               return PTR_ERR(msg_arg);
> > +
> > +       msg_arg->cmd = OPTEE_MSG_CMD_ASSIGN_RSTMEM;
> > +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
> > +       msg_arg->params[0].u.value.a = cookie;
> > +       msg_arg->params[0].u.value.b = use_case;
> > +
> > +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> > +       if (rc)
> > +               goto out;
> > +       if (msg_arg->ret != TEEC_SUCCESS) {
> > +               rc = -EINVAL;
> > +               goto out;
> > +       }
> > +
> > +out:
> > +       optee_free_msg_arg(optee->ctx, entry, offs);
> > +       return rc;
> > +}
> > +
> > +static int optee_ffa_lend_rstmem(struct optee *optee, struct tee_shm *rstmem,
> > +                                u16 *end_points, unsigned int ep_count)
> > +{
> > +       struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
> > +       const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
> > +       const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
> > +       struct ffa_send_direct_data data;
> > +       struct ffa_mem_region_attributes *mem_attr;
> > +       struct ffa_mem_ops_args args = {
> > +               .use_txbuf = true,
> > +               .tag = rstmem->use_case,
> > +       };
> > +       struct page *page;
> > +       struct scatterlist sgl;
> > +       unsigned int n;
> > +       int rc;
> > +
> > +       mem_attr = kcalloc(ep_count, sizeof(*mem_attr), GFP_KERNEL);
> > +       for (n = 0; n < ep_count; n++) {
> > +               mem_attr[n].receiver = end_points[n];
> > +               mem_attr[n].attrs = FFA_MEM_RW;
> > +       }
> > +       args.attrs = mem_attr;
> > +       args.nattrs = ep_count;
> > +
> > +       page = phys_to_page(rstmem->paddr);
> > +       sg_init_table(&sgl, 1);
> > +       sg_set_page(&sgl, page, rstmem->size, 0);
> > +
> > +       args.sg = &sgl;
> > +       rc = mem_ops->memory_lend(&args);
> > +       kfree(mem_attr);
> > +       if (rc)
> > +               return rc;
> > +
> > +       rc = do_call_lend_rstmem(optee, args.g_handle, rstmem->use_case);
> > +       if (rc)
> > +               goto err_reclaim;
> > +
> > +       rc = optee_shm_add_ffa_handle(optee, rstmem, args.g_handle);
> > +       if (rc)
> > +               goto err_unreg;
> > +
> > +       rstmem->sec_world_id = args.g_handle;
> > +
> > +       return 0;
> > +
> > +err_unreg:
> > +       data = (struct ffa_send_direct_data){
> > +               .data0 = OPTEE_FFA_RELEASE_RSTMEM,
> > +               .data1 = (u32)args.g_handle,
> > +               .data2 = (u32)(args.g_handle >> 32),
> > +       };
> > +       msg_ops->sync_send_receive(ffa_dev, &data);
> > +err_reclaim:
> > +       mem_ops->memory_reclaim(args.g_handle, 0);
> > +       return rc;
> > +}
> > +
> > +static int optee_ffa_reclaim_rstmem(struct optee *optee, struct tee_shm *rstmem)
> > +{
> > +       struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
> > +       const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
> > +       const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
> > +       u64 global_handle = rstmem->sec_world_id;
> > +       struct ffa_send_direct_data data = {
> > +               .data0 = OPTEE_FFA_RELEASE_RSTMEM,
> > +               .data1 = (u32)global_handle,
> > +               .data2 = (u32)(global_handle >> 32)
> > +       };
> > +       int rc;
> > +
> > +       optee_shm_rem_ffa_handle(optee, global_handle);
> > +       rstmem->sec_world_id = 0;
> > +
> > +       rc = msg_ops->sync_send_receive(ffa_dev, &data);
> > +       if (rc)
> > +               pr_err("Release SHM id 0x%llx rc %d\n", global_handle, rc);
> > +
> > +       rc = mem_ops->memory_reclaim(global_handle, 0);
> > +       if (rc)
> > +               pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
> > +
> > +       return rc;
> > +}
> > +
> >  /*
> >   * 6. Driver initialization
> >   *
> > @@ -785,7 +901,10 @@ static void optee_ffa_get_version(struct tee_device *teedev,
> >                 .gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM |
> >                             TEE_GEN_CAP_MEMREF_NULL,
> >         };
> > +       struct optee *optee = tee_get_drvdata(teedev);
> >
> > +       if (optee->rstmem_pools)
> > +               v.gen_caps |= TEE_GEN_CAP_RSTMEM;
> >         *vers = v;
> >  }
> >
> > @@ -804,6 +923,8 @@ static const struct tee_driver_ops optee_ffa_clnt_ops = {
> >         .cancel_req = optee_cancel_req,
> >         .shm_register = optee_ffa_shm_register,
> >         .shm_unregister = optee_ffa_shm_unregister,
> > +       .rstmem_alloc = optee_rstmem_alloc,
> > +       .rstmem_free = optee_rstmem_free,
> >  };
> >
> >  static const struct tee_desc optee_ffa_clnt_desc = {
> > @@ -820,6 +941,8 @@ static const struct tee_driver_ops optee_ffa_supp_ops = {
> >         .supp_send = optee_supp_send,
> >         .shm_register = optee_ffa_shm_register, /* same as for clnt ops */
> >         .shm_unregister = optee_ffa_shm_unregister_supp,
> > +       .rstmem_alloc = optee_rstmem_alloc,
> > +       .rstmem_free = optee_rstmem_free,
> >  };
> >
> >  static const struct tee_desc optee_ffa_supp_desc = {
> > @@ -833,6 +956,8 @@ static const struct optee_ops optee_ffa_ops = {
> >         .do_call_with_arg = optee_ffa_do_call_with_arg,
> >         .to_msg_param = optee_ffa_to_msg_param,
> >         .from_msg_param = optee_ffa_from_msg_param,
> > +       .lend_rstmem = optee_ffa_lend_rstmem,
> > +       .reclaim_rstmem = optee_ffa_reclaim_rstmem,
> >  };
> >
> >  static void optee_ffa_remove(struct ffa_device *ffa_dev)
> > @@ -937,11 +1062,17 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> >             (sec_caps & OPTEE_FFA_SEC_CAP_RPMB_PROBE))
> >                 optee->in_kernel_rpmb_routing = true;
> >
> > +       if (sec_caps & OPTEE_FFA_SEC_CAP_RSTMEM) {
> > +               rc = optee_rstmem_pools_init(optee);
> > +               if (rc)
> > +                       goto err_free_pool;
> > +       }
> > +
> >         teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
> >                                   optee);
> >         if (IS_ERR(teedev)) {
> >                 rc = PTR_ERR(teedev);
> > -               goto err_free_pool;
> > +               goto err_free_rstmem_pools;
> >         }
> >         optee->teedev = teedev;
> >
> > @@ -1020,6 +1151,8 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> >         tee_device_unregister(optee->teedev);
> >  err_free_pool:
> >         tee_shm_pool_free(pool);
> > +err_free_rstmem_pools:
> > +       optee_rstmem_pools_uninit(optee);
> >  err_free_optee:
> >         kfree(optee);
> >         return rc;
> > diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> > index 20eda508dbac..dd2a3a2224bc 100644
> > --- a/drivers/tee/optee/optee_private.h
> > +++ b/drivers/tee/optee/optee_private.h
> > @@ -174,9 +174,14 @@ struct optee;
> >   * @do_call_with_arg:  enters OP-TEE in secure world
> >   * @to_msg_param:      converts from struct tee_param to OPTEE_MSG parameters
> >   * @from_msg_param:    converts from OPTEE_MSG parameters to struct tee_param
> > + * @lend_rstmem:       lends physically contiguous memory as restricted
> > + *                     memory, inaccessible by the kernel
> > + * @reclaim_rstmem:    reclaims restricted memory previously lent with
> > + *                     @lend_rstmem() and makes it accessible by the
> > + *                     kernel again
> >   *
> >   * These OPs are only supposed to be used internally in the OP-TEE driver
> > - * as a way of abstracting the different methogs of entering OP-TEE in
> > + * as a way of abstracting the different methods of entering OP-TEE in
> >   * secure world.
> >   */
> >  struct optee_ops {
> > @@ -191,6 +196,23 @@ struct optee_ops {
> >                               size_t num_params,
> >                               const struct optee_msg_param *msg_params,
> >                               bool update_out);
> > +       int (*lend_rstmem)(struct optee *optee, struct tee_shm *rstmem,
> > +                          u16 *end_points, unsigned int ep_count);
> > +       int (*reclaim_rstmem)(struct optee *optee, struct tee_shm *rstmem);
> > +};
> > +
> > +/**
> > + * struct optee_rstmem_pools - restricted memory pools
> > + * @mutex:     serializes write access to @xa when adding a new pool.
> > + * @xa:                XArray of struct tee_shm_pool where the index is the
> > + *             use case ID TEE_IOC_UC_* supplied for TEE_IOC_RSTMEM_ALLOC.
> > + */
> > +struct optee_rstmem_pools {
> > +       /*
> > +        * Serializes write access to @xa when adding a new pool.
> > +        */
> > +       struct mutex mutex;
> > +       struct xarray xa;
> >  };
> >
> >  /**
> > @@ -206,6 +228,7 @@ struct optee_ops {
> >   * @notif:             notification synchronization struct
> >   * @supp:              supplicant synchronization struct for RPC to supplicant
> >   * @pool:              shared memory pool
> > + * @rstmem_pool:       restricted memory pool for secure data path
> >   * @mutex:             mutex protecting @rpmb_dev
> >   * @rpmb_dev:          current RPMB device or NULL
> >   * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices
> > @@ -230,6 +253,7 @@ struct optee {
> >         struct optee_notif notif;
> >         struct optee_supp supp;
> >         struct tee_shm_pool *pool;
> > +       struct optee_rstmem_pools *rstmem_pools;
> >         /* Protects rpmb_dev pointer */
> >         struct mutex rpmb_dev_mutex;
> >         struct rpmb_dev *rpmb_dev;
> > @@ -286,6 +310,9 @@ void optee_supp_init(struct optee_supp *supp);
> >  void optee_supp_uninit(struct optee_supp *supp);
> >  void optee_supp_release(struct optee_supp *supp);
> >
> > +int optee_rstmem_pools_init(struct optee *optee);
> > +void optee_rstmem_pools_uninit(struct optee *optee);
> > +
> >  int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params,
> >                     struct tee_param *param);
> >  int optee_supp_send(struct tee_context *ctx, u32 ret, u32 num_params,
> > @@ -378,6 +405,10 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
> >  int optee_do_bottom_half(struct tee_context *ctx);
> >  int optee_stop_async_notif(struct tee_context *ctx);
> >
> > +int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
> > +                      u32 flags, u32 use_case, size_t size);
> > +void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm);
> > +
> >  /*
> >   * Small helpers
> >   */
> > diff --git a/drivers/tee/optee/rstmem.c b/drivers/tee/optee/rstmem.c
> > new file mode 100644
> > index 000000000000..cf300929171f
> > --- /dev/null
> > +++ b/drivers/tee/optee/rstmem.c
> > @@ -0,0 +1,380 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) 2024, Linaro Limited
> > + */
> > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> > +
> > +#include <linux/cma.h>
> > +#include <linux/dma-map-ops.h>
> > +#include <linux/errno.h>
> > +#include <linux/genalloc.h>
> > +#include <linux/slab.h>
> > +#include <linux/string.h>
> > +#include <linux/tee_core.h>
> > +#include <linux/types.h>
> > +#include "optee_private.h"
> > +
> > +struct optee_rstmem_cma_pool {
> > +       struct tee_shm_pool pool;
> > +       struct page *page;
> > +       struct optee *optee;
> > +       size_t page_count;
> > +       u16 *end_points;
> > +       u_int end_point_count;
> > +       u_int align;
> > +       refcount_t refcount;
> > +       struct tee_shm rstmem;
> > +       /* Protects when initializing and tearing down this struct */
> > +       struct mutex mutex;
> > +};
> > +
> > +static struct optee_rstmem_cma_pool *
> > +to_rstmem_cma_pool(struct tee_shm_pool *pool)
> > +{
> > +       return container_of(pool, struct optee_rstmem_cma_pool, pool);
> > +}
> > +
> > +static int init_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > +       struct cma *cma = dev_get_cma_area(&rp->optee->teedev->dev);
> > +       int rc;
> > +
> > +       rp->page = cma_alloc(cma, rp->page_count, rp->align, true/*no_warn*/);
> > +       if (!rp->page)
> > +               return -ENOMEM;
> > +
> > +       /*
> > +        * TODO unmap the memory range since the physical memory will
> > +        * become inaccesible after the lend_rstmem() call.
> > +        */
> > +
> > +       rp->rstmem.paddr = page_to_phys(rp->page);
> > +       rp->rstmem.size = rp->page_count * PAGE_SIZE;
> > +       rc = rp->optee->ops->lend_rstmem(rp->optee, &rp->rstmem,
> > +                                        rp->end_points, rp->end_point_count);
> > +       if (rc)
> > +               goto err_release;
> > +
> > +       rp->pool.private_data = gen_pool_create(PAGE_SHIFT, -1);
> > +       if (!rp->pool.private_data) {
> > +               rc = -ENOMEM;
> > +               goto err_reclaim;
> > +       }
> > +
> > +       rc = gen_pool_add(rp->pool.private_data, rp->rstmem.paddr,
> > +                         rp->rstmem.size, -1);
> > +       if (rc)
> > +               goto err_free_pool;
> > +
> > +       refcount_set(&rp->refcount, 1);
> > +       return 0;
> > +
> > +err_free_pool:
> > +       gen_pool_destroy(rp->pool.private_data);
> > +err_reclaim:
> > +       rp->optee->ops->reclaim_rstmem(rp->optee, &rp->rstmem);
> > +err_release:
> > +       cma_release(cma, rp->page, rp->page_count);
> > +       rp->rstmem.paddr = 0;
> > +       rp->rstmem.size = 0;
> > +       rp->rstmem.sec_world_id = 0;
> > +       return rc;
> > +}
> > +
> > +static int get_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > +       int rc = 0;
> > +
> > +       if (!refcount_inc_not_zero(&rp->refcount)) {
> > +               mutex_lock(&rp->mutex);
> > +               if (rp->pool.private_data) {
> > +                       /*
> > +                        * Another thread has already initialized the pool
> > +                        * before us, or the pool was just about to be torn
> > +                        * down. Either way we only need to increase the
> > +                        * refcount and we're done.
> > +                        */
> > +                       refcount_inc(&rp->refcount);
> > +               } else {
> > +                       rc = init_cma_rstmem(rp);
> > +               }
> > +               mutex_unlock(&rp->mutex);
> > +       }
> > +
> > +       return rc;
> > +}
> > +
> > +static void release_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > +       gen_pool_destroy(rp->pool.private_data);
> > +       rp->optee->ops->reclaim_rstmem(rp->optee, &rp->rstmem);
> > +       cma_release(dev_get_cma_area(&rp->optee->teedev->dev), rp->page,
> > +                   rp->page_count);
> > +
> > +       rp->pool.private_data = NULL;
> > +       rp->page = NULL;
> > +       rp->rstmem.paddr = 0;
> > +       rp->rstmem.size = 0;
> > +       rp->rstmem.sec_world_id = 0;
> > +}
> > +
> > +static void put_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > +       if (refcount_dec_and_test(&rp->refcount)) {
> > +               mutex_lock(&rp->mutex);
> > +               if (rp->pool.private_data)
> > +                       release_cma_rstmem(rp);
> > +               mutex_unlock(&rp->mutex);
> > +       }
> > +}
> > +
> > +static int rstmem_pool_op_cma_alloc(struct tee_shm_pool *pool,
> > +                                   struct tee_shm *shm, size_t size,
> > +                                   size_t align)
> > +{
> > +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > +       size_t sz = ALIGN(size, PAGE_SIZE);
> > +       phys_addr_t pa;
> > +       int rc;
> > +
> > +       rc = get_cma_rstmem(rp);
> > +       if (rc)
> > +               return rc;
> > +
> > +       pa = gen_pool_alloc(rp->pool.private_data, sz);
> > +       if (!pa) {
> > +               put_cma_rstmem(rp);
> > +               return -ENOMEM;
> > +       }
> > +
> > +       shm->size = sz;
> > +       shm->paddr = pa;
> > +       shm->offset = pa - page_to_phys(rp->page);
> > +       shm->sec_world_id = rp->rstmem.sec_world_id;
> > +
> > +       return 0;
> > +}
> > +
> > +static void rstmem_pool_op_cma_free(struct tee_shm_pool *pool,
> > +                                   struct tee_shm *shm)
> > +{
> > +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > +
> > +       gen_pool_free(rp->pool.private_data, shm->paddr, shm->size);
> > +       shm->size = 0;
> > +       shm->paddr = 0;
> > +       shm->offset = 0;
> > +       shm->sec_world_id = 0;
> > +       put_cma_rstmem(rp);
> > +}
> > +
> > +static void pool_op_cma_destroy_pool(struct tee_shm_pool *pool)
> > +{
> > +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > +
> > +       mutex_destroy(&rp->mutex);
> > +       kfree(rp);
> > +}
> > +
> > +static struct tee_shm_pool_ops rstmem_pool_ops_cma = {
> > +       .alloc = rstmem_pool_op_cma_alloc,
> > +       .free = rstmem_pool_op_cma_free,
> > +       .destroy_pool = pool_op_cma_destroy_pool,
> > +};
> > +
> > +static int get_rstmem_config(struct optee *optee, u32 use_case,
> > +                            size_t *min_size, u_int *min_align,
> > +                            u16 *end_points, u_int *ep_count)
> > +{
> > +       struct tee_param params[2] = {
> > +               [0] = {
> > +                       .attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT,
> > +                       .u.value.a = use_case,
> > +               },
> > +               [1] = {
> > +                       .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT,
> > +               },
> > +       };
> > +       struct optee_shm_arg_entry *entry;
> > +       struct tee_shm *shm_param = NULL;
> > +       struct optee_msg_arg *msg_arg;
> > +       struct tee_shm *shm;
> > +       u_int offs;
> > +       int rc;
> > +
> > +       if (end_points && *ep_count) {
> > +               params[1].u.memref.size = *ep_count * sizeof(*end_points);
> > +               shm_param = tee_shm_alloc_priv_buf(optee->ctx,
> > +                                                  params[1].u.memref.size);
> > +               if (IS_ERR(shm_param))
> > +                       return PTR_ERR(shm_param);
> > +               params[1].u.memref.shm = shm_param;
> > +       }
> > +
> > +       msg_arg = optee_get_msg_arg(optee->ctx, ARRAY_SIZE(params), &entry,
> > +                                   &shm, &offs);
> > +       if (IS_ERR(msg_arg)) {
> > +               rc = PTR_ERR(msg_arg);
> > +               goto out_free_shm;
> > +       }
> > +       msg_arg->cmd = OPTEE_MSG_CMD_GET_RSTMEM_CONFIG;
> > +
> > +       rc = optee->ops->to_msg_param(optee, msg_arg->params,
> > +                                     ARRAY_SIZE(params), params,
> > +                                     false /*!update_out*/);
> > +       if (rc)
> > +               goto out_free_msg;
> > +
> > +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> > +       if (rc)
> > +               goto out_free_msg;
> > +       if (msg_arg->ret && msg_arg->ret != TEEC_ERROR_SHORT_BUFFER) {
> > +               rc = -EINVAL;
> > +               goto out_free_msg;
> > +       }
> > +
> > +       rc = optee->ops->from_msg_param(optee, params, ARRAY_SIZE(params),
> > +                                       msg_arg->params, true /*update_out*/);
> > +       if (rc)
> > +               goto out_free_msg;
> > +
> > +       if (!msg_arg->ret && end_points &&
> > +           *ep_count < params[1].u.memref.size / sizeof(u16)) {
> > +               rc = -EINVAL;
> > +               goto out_free_msg;
> > +       }
> > +
> > +       *min_size = params[0].u.value.a;
> > +       *min_align = params[0].u.value.b;
> > +       *ep_count = params[1].u.memref.size / sizeof(u16);
> > +
> > +       if (msg_arg->ret == TEEC_ERROR_SHORT_BUFFER) {
> > +               rc = -ENOSPC;
> > +               goto out_free_msg;
> > +       }
> > +
> > +       if (end_points)
> > +               memcpy(end_points, tee_shm_get_va(shm_param, 0),
> > +                      params[1].u.memref.size);
> > +
> > +out_free_msg:
> > +       optee_free_msg_arg(optee->ctx, entry, offs);
> > +out_free_shm:
> > +       if (shm_param)
> > +               tee_shm_free(shm_param);
> > +       return rc;
> > +}
> > +
> > +static struct tee_shm_pool *alloc_rstmem_pool(struct optee *optee, u32 use_case)
> > +{
> > +       struct optee_rstmem_cma_pool *rp;
> > +       size_t min_size;
> > +       int rc;
> > +
> > +       rp = kzalloc(sizeof(*rp), GFP_KERNEL);
> > +       if (!rp)
> > +               return ERR_PTR(-ENOMEM);
> > +       rp->rstmem.use_case = use_case;
> > +
> > +       rc = get_rstmem_config(optee, use_case, &min_size, &rp->align, NULL,
> > +                              &rp->end_point_count);
> > +       if (rc) {
> > +               if (rc != -ENOSPC)
> > +                       goto err;
> > +               rp->end_points = kcalloc(rp->end_point_count,
> > +                                        sizeof(*rp->end_points), GFP_KERNEL);
> > +               if (!rp->end_points) {
> > +                       rc = -ENOMEM;
> > +                       goto err;
> > +               }
> > +               rc = get_rstmem_config(optee, use_case, &min_size, &rp->align,
> > +                                      rp->end_points, &rp->end_point_count);
> > +               if (rc)
> > +                       goto err_kfree_eps;
> > +       }
> > +
> > +       rp->pool.ops = &rstmem_pool_ops_cma;
> > +       rp->optee = optee;
> > +       rp->page_count = min_size / PAGE_SIZE;
> > +       mutex_init(&rp->mutex);
> > +
> > +       return &rp->pool;
> > +
> > +err_kfree_eps:
> > +       kfree(rp->end_points);
> > +err:
> > +       kfree(rp);
> > +       return ERR_PTR(rc);
> > +}
> > +
> > +int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
> > +                      u32 flags, u32 use_case, size_t size)
> > +{
> > +       struct optee *optee = tee_get_drvdata(ctx->teedev);
> > +       struct tee_shm_pool *pool;
> > +       int rc;
> > +
> > +       if (!optee->rstmem_pools)
> > +               return -EINVAL;
> > +       if (flags)
> > +               return -EINVAL;
> > +
> > +       pool = xa_load(&optee->rstmem_pools->xa, use_case);
> > +       if (!pool) {
> > +               pool = alloc_rstmem_pool(optee, use_case);
> > +               if (IS_ERR(pool))
> > +                       return PTR_ERR(pool);
> > +               rc = xa_insert(&optee->rstmem_pools->xa, use_case, pool,
> > +                              GFP_KERNEL);
> > +               if (rc) {
> > +                       pool->ops->destroy_pool(pool);
> > +                       return rc;
> > +               }
> > +       }
> > +
> > +       return pool->ops->alloc(pool, shm, size, 0);
> > +}
> > +
> > +void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm)
> > +{
> > +       struct optee *optee = tee_get_drvdata(ctx->teedev);
> > +       struct tee_shm_pool *pool;
> > +
> > +       pool = xa_load(&optee->rstmem_pools->xa, shm->use_case);
> > +       if (pool)
> > +               pool->ops->free(pool, shm);
> > +       else
> > +               pr_err("Can't find pool for use_case %u\n", shm->use_case);
> > +}
> > +
> > +int optee_rstmem_pools_init(struct optee *optee)
> > +{
> > +       struct optee_rstmem_pools *pools;
> > +
> > +       pools = kmalloc(sizeof(*pools), GFP_KERNEL);
> > +       if (!pools)
> > +               return -ENOMEM;
> > +
> > +       mutex_init(&pools->mutex);
> > +       xa_init(&pools->xa);
> > +       optee->rstmem_pools = pools;
> > +       return 0;
> > +}
> > +
> > +void optee_rstmem_pools_uninit(struct optee *optee)
> > +{
> > +       if (optee->rstmem_pools) {
> > +               struct tee_shm_pool *pool;
> > +               u_long idx;
> > +
> > +               xa_for_each(&optee->rstmem_pools->xa, idx, pool) {
> > +                       xa_erase(&optee->rstmem_pools->xa, idx);
> > +                       pool->ops->destroy_pool(pool);
> > +               }
> > +
> > +               xa_destroy(&optee->rstmem_pools->xa);
> > +               mutex_destroy(&optee->rstmem_pools->mutex);
> > +               kfree(optee->rstmem_pools);
> > +               optee->rstmem_pools = NULL;
> > +       }
> > +}
> > diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> > index d1f79947f58a..7fa7d9d14c94 100644
> > --- a/drivers/tee/optee/smc_abi.c
> > +++ b/drivers/tee/optee/smc_abi.c
> > @@ -1001,6 +1001,67 @@ static int optee_smc_do_call_with_arg(struct tee_context *ctx,
> >         return rc;
> >  }
> >
> > +static int optee_smc_lend_rstmem(struct optee *optee, struct tee_shm *rstmem,
> > +                                u16 *end_points, unsigned int ep_count)
> > +{
> > +       struct optee_shm_arg_entry *entry;
> > +       struct optee_msg_arg *msg_arg;
> > +       struct tee_shm *shm;
> > +       u_int offs;
> > +       int rc;
> > +
> > +       msg_arg = optee_get_msg_arg(optee->ctx, 2, &entry, &shm, &offs);
> > +       if (IS_ERR(msg_arg))
> > +               return PTR_ERR(msg_arg);
> > +
> > +       msg_arg->cmd = OPTEE_MSG_CMD_LEND_RSTMEM;
> > +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
> > +       msg_arg->params[0].u.value.a = OPTEE_MSG_RSTMEM_SECURE_VIDEO_PLAY;
> > +       msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
> > +       msg_arg->params[1].u.tmem.buf_ptr = rstmem->paddr;
> > +       msg_arg->params[1].u.tmem.size = rstmem->size;
> > +       msg_arg->params[1].u.tmem.shm_ref = (u_long)rstmem;
> > +
> > +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> > +       if (rc)
> > +               goto out;
> > +       if (msg_arg->ret != TEEC_SUCCESS) {
> > +               rc = -EINVAL;
> > +               goto out;
> > +       }
> > +
> > +out:
> > +       optee_free_msg_arg(optee->ctx, entry, offs);
> > +       return rc;
> > +}
> > +
> > +static int optee_smc_reclaim_rstmem(struct optee *optee, struct tee_shm *rstmem)
> > +{
> > +       struct optee_shm_arg_entry *entry;
> > +       struct optee_msg_arg *msg_arg;
> > +       struct tee_shm *shm;
> > +       u_int offs;
> > +       int rc;
> > +
> > +       msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
> > +       if (IS_ERR(msg_arg))
> > +               return PTR_ERR(msg_arg);
> > +
> > +       msg_arg->cmd = OPTEE_MSG_CMD_RECLAIM_RSTMEM;
> > +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
> > +       msg_arg->params[0].u.rmem.shm_ref = (u_long)rstmem;
> > +
> > +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> > +       if (rc)
> > +               goto out;
> > +       if (msg_arg->ret != TEEC_SUCCESS)
> > +               rc = -EINVAL;
> > +
> > +out:
> > +       optee_free_msg_arg(optee->ctx, entry, offs);
> > +       return rc;
> > +}
> > +
> >  /*
> >   * 5. Asynchronous notification
> >   */
> > @@ -1201,6 +1262,8 @@ static void optee_get_version(struct tee_device *teedev,
> >                 v.gen_caps |= TEE_GEN_CAP_REG_MEM;
> >         if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
> >                 v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
> > +       if (optee->rstmem_pools)
> > +               v.gen_caps |= TEE_GEN_CAP_RSTMEM;
> >         *vers = v;
> >  }
> >
> > @@ -1223,6 +1286,8 @@ static const struct tee_driver_ops optee_clnt_ops = {
> >         .cancel_req = optee_cancel_req,
> >         .shm_register = optee_shm_register,
> >         .shm_unregister = optee_shm_unregister,
> > +       .rstmem_alloc = optee_rstmem_alloc,
> > +       .rstmem_free = optee_rstmem_free,
> >  };
> >
> >  static const struct tee_desc optee_clnt_desc = {
> > @@ -1239,6 +1304,8 @@ static const struct tee_driver_ops optee_supp_ops = {
> >         .supp_send = optee_supp_send,
> >         .shm_register = optee_shm_register_supp,
> >         .shm_unregister = optee_shm_unregister_supp,
> > +       .rstmem_alloc = optee_rstmem_alloc,
> > +       .rstmem_free = optee_rstmem_free,
> >  };
> >
> >  static const struct tee_desc optee_supp_desc = {
> > @@ -1252,6 +1319,9 @@ static const struct optee_ops optee_ops = {
> >         .do_call_with_arg = optee_smc_do_call_with_arg,
> >         .to_msg_param = optee_to_msg_param,
> >         .from_msg_param = optee_from_msg_param,
> > +       .lend_rstmem = optee_smc_lend_rstmem,
> > +       .reclaim_rstmem = optee_smc_reclaim_rstmem,
> > +       //.alloc_rstmem_pool = optee_smc_alloc_rstmem_pool,
> >  };
> >
> >  static int enable_async_notif(optee_invoke_fn *invoke_fn)
> > @@ -1619,6 +1689,62 @@ static inline int optee_load_fw(struct platform_device *pdev,
> >  }
> >  #endif
> >
> > +static int optee_sdp_pool_init(struct optee *optee)
> > +{
> > +       bool dyn_sdp = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_RSTMEM;
> > +       bool sdp = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP;
> > +       struct tee_shm_pool *pool;
> > +       int rc;
> > +
> > +       /*
> > +        * optee_sdp_pools_init() must be called if secure world has any
> > +        * SDP capability. If the static carvout is available initialize
> > +        * and add a pool for that. If there's an error from secure world
> > +        * we complain but don't call optee_sdp_pools_uninit() unless we
> > +        * know that there is no SDP capability left.
> > +        */
> > +       if (!dyn_sdp && !sdp)
> > +               return 0;
> > +
> > +       rc = optee_rstmem_pools_init(optee);
> > +       if (rc)
> > +               return rc;
> > +
> > +       if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP) {
> > +               union {
> > +                       struct arm_smccc_res smccc;
> > +                       struct optee_smc_get_sdp_config_result result;
> > +               } res;
> > +
> > +               optee->smc.invoke_fn(OPTEE_SMC_GET_SDP_CONFIG, 0, 0, 0, 0, 0, 0,
> > +                                    0, &res.smccc);
> > +               if (res.result.status != OPTEE_SMC_RETURN_OK) {
> > +                       pr_err("Secure Data Path service not available\n");
> > +                       if (!dyn_sdp)
> > +                               goto err;
> > +                       return 0;
> > +               }
> > +
> > +               pool = tee_rstmem_gen_pool_alloc(res.result.start,
> > +                                                res.result.size);
> > +               if (IS_ERR(pool)) {
> > +                       rc = PTR_ERR(pool);
> > +                       goto err;
> > +               }
> > +               rc = xa_insert(&optee->rstmem_pools->xa,
> > +                              TEE_IOC_UC_SECURE_VIDEO_PLAY, pool, GFP_KERNEL);
> > +               if (rc) {
> > +                       pool->ops->destroy_pool(pool);
> > +                       goto err;
> > +               }
> > +       }
> > +
> > +       return 0;
> > +err:
> > +       optee_rstmem_pools_uninit(optee);
> > +       return rc;
> > +}
> > +
> >  static int optee_probe(struct platform_device *pdev)
> >  {
> >         optee_invoke_fn *invoke_fn;
> > @@ -1714,7 +1840,7 @@ static int optee_probe(struct platform_device *pdev)
> >         optee = kzalloc(sizeof(*optee), GFP_KERNEL);
> >         if (!optee) {
> >                 rc = -ENOMEM;
> > -               goto err_free_pool;
> > +               goto err_free_shm_pool;
> >         }
> >
> >         optee->ops = &optee_ops;
> > @@ -1726,10 +1852,14 @@ static int optee_probe(struct platform_device *pdev)
> >             (sec_caps & OPTEE_SMC_SEC_CAP_RPMB_PROBE))
> >                 optee->in_kernel_rpmb_routing = true;
> >
> > +       rc = optee_sdp_pool_init(optee);
> > +       if (rc)
> > +               goto err_free_optee;
> > +
> >         teedev = tee_device_alloc(&optee_clnt_desc, NULL, pool, optee);
> >         if (IS_ERR(teedev)) {
> >                 rc = PTR_ERR(teedev);
> > -               goto err_free_optee;
> > +               goto err_rstmem_pools_uninit;
> >         }
> >         optee->teedev = teedev;
> >
> > @@ -1836,9 +1966,11 @@ static int optee_probe(struct platform_device *pdev)
> >         tee_device_unregister(optee->supp_teedev);
> >  err_unreg_teedev:
> >         tee_device_unregister(optee->teedev);
> > +err_rstmem_pools_uninit:
> > +       optee_rstmem_pools_uninit(optee);
> >  err_free_optee:
> >         kfree(optee);
> > -err_free_pool:
> > +err_free_shm_pool:
> >         tee_shm_pool_free(pool);
> >         if (memremaped_shm)
> >                 memunmap(memremaped_shm);
> > --
> > 2.43.0
> >
diff mbox series

Patch

diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile
index a6eff388d300..498969fb8e40 100644
--- a/drivers/tee/optee/Makefile
+++ b/drivers/tee/optee/Makefile
@@ -4,6 +4,7 @@  optee-objs += core.o
 optee-objs += call.o
 optee-objs += notif.o
 optee-objs += rpc.o
+optee-objs += rstmem.o
 optee-objs += supp.o
 optee-objs += device.o
 optee-objs += smc_abi.o
diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index c75fddc83576..f4fa494789a4 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -182,6 +182,7 @@  void optee_remove_common(struct optee *optee)
 	tee_device_unregister(optee->teedev);
 
 	tee_shm_pool_free(optee->pool);
+	optee_rstmem_pools_uninit(optee);
 	optee_supp_uninit(&optee->supp);
 	mutex_destroy(&optee->call_queue.mutex);
 	rpmb_dev_put(optee->rpmb_dev);
diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
index 02e6175ac5f0..f500cf101c8d 100644
--- a/drivers/tee/optee/ffa_abi.c
+++ b/drivers/tee/optee/ffa_abi.c
@@ -672,6 +672,122 @@  static int optee_ffa_do_call_with_arg(struct tee_context *ctx,
 	return optee_ffa_yielding_call(ctx, &data, rpc_arg, system_thread);
 }
 
+static int do_call_lend_rstmem(struct optee *optee, u64 cookie, u32 use_case)
+{
+	struct optee_shm_arg_entry *entry;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+	int rc;
+
+	msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
+	if (IS_ERR(msg_arg))
+		return PTR_ERR(msg_arg);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_ASSIGN_RSTMEM;
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
+	msg_arg->params[0].u.value.a = cookie;
+	msg_arg->params[0].u.value.b = use_case;
+
+	rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
+	if (rc)
+		goto out;
+	if (msg_arg->ret != TEEC_SUCCESS) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+out:
+	optee_free_msg_arg(optee->ctx, entry, offs);
+	return rc;
+}
+
+static int optee_ffa_lend_rstmem(struct optee *optee, struct tee_shm *rstmem,
+				 u16 *end_points, unsigned int ep_count)
+{
+	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
+	const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
+	const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
+	struct ffa_send_direct_data data;
+	struct ffa_mem_region_attributes *mem_attr;
+	struct ffa_mem_ops_args args = {
+		.use_txbuf = true,
+		.tag = rstmem->use_case,
+	};
+	struct page *page;
+	struct scatterlist sgl;
+	unsigned int n;
+	int rc;
+
+	mem_attr = kcalloc(ep_count, sizeof(*mem_attr), GFP_KERNEL);
+	for (n = 0; n < ep_count; n++) {
+		mem_attr[n].receiver = end_points[n];
+		mem_attr[n].attrs = FFA_MEM_RW;
+	}
+	args.attrs = mem_attr;
+	args.nattrs = ep_count;
+
+	page = phys_to_page(rstmem->paddr);
+	sg_init_table(&sgl, 1);
+	sg_set_page(&sgl, page, rstmem->size, 0);
+
+	args.sg = &sgl;
+	rc = mem_ops->memory_lend(&args);
+	kfree(mem_attr);
+	if (rc)
+		return rc;
+
+	rc = do_call_lend_rstmem(optee, args.g_handle, rstmem->use_case);
+	if (rc)
+		goto err_reclaim;
+
+	rc = optee_shm_add_ffa_handle(optee, rstmem, args.g_handle);
+	if (rc)
+		goto err_unreg;
+
+	rstmem->sec_world_id = args.g_handle;
+
+	return 0;
+
+err_unreg:
+	data = (struct ffa_send_direct_data){
+		.data0 = OPTEE_FFA_RELEASE_RSTMEM,
+		.data1 = (u32)args.g_handle,
+		.data2 = (u32)(args.g_handle >> 32),
+	};
+	msg_ops->sync_send_receive(ffa_dev, &data);
+err_reclaim:
+	mem_ops->memory_reclaim(args.g_handle, 0);
+	return rc;
+}
+
+static int optee_ffa_reclaim_rstmem(struct optee *optee, struct tee_shm *rstmem)
+{
+	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
+	const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
+	const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
+	u64 global_handle = rstmem->sec_world_id;
+	struct ffa_send_direct_data data = {
+		.data0 = OPTEE_FFA_RELEASE_RSTMEM,
+		.data1 = (u32)global_handle,
+		.data2 = (u32)(global_handle >> 32)
+	};
+	int rc;
+
+	optee_shm_rem_ffa_handle(optee, global_handle);
+	rstmem->sec_world_id = 0;
+
+	rc = msg_ops->sync_send_receive(ffa_dev, &data);
+	if (rc)
+		pr_err("Release SHM id 0x%llx rc %d\n", global_handle, rc);
+
+	rc = mem_ops->memory_reclaim(global_handle, 0);
+	if (rc)
+		pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
+
+	return rc;
+}
+
 /*
  * 6. Driver initialization
  *
@@ -785,7 +901,10 @@  static void optee_ffa_get_version(struct tee_device *teedev,
 		.gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM |
 			    TEE_GEN_CAP_MEMREF_NULL,
 	};
+	struct optee *optee = tee_get_drvdata(teedev);
 
+	if (optee->rstmem_pools)
+		v.gen_caps |= TEE_GEN_CAP_RSTMEM;
 	*vers = v;
 }
 
@@ -804,6 +923,8 @@  static const struct tee_driver_ops optee_ffa_clnt_ops = {
 	.cancel_req = optee_cancel_req,
 	.shm_register = optee_ffa_shm_register,
 	.shm_unregister = optee_ffa_shm_unregister,
+	.rstmem_alloc = optee_rstmem_alloc,
+	.rstmem_free = optee_rstmem_free,
 };
 
 static const struct tee_desc optee_ffa_clnt_desc = {
@@ -820,6 +941,8 @@  static const struct tee_driver_ops optee_ffa_supp_ops = {
 	.supp_send = optee_supp_send,
 	.shm_register = optee_ffa_shm_register, /* same as for clnt ops */
 	.shm_unregister = optee_ffa_shm_unregister_supp,
+	.rstmem_alloc = optee_rstmem_alloc,
+	.rstmem_free = optee_rstmem_free,
 };
 
 static const struct tee_desc optee_ffa_supp_desc = {
@@ -833,6 +956,8 @@  static const struct optee_ops optee_ffa_ops = {
 	.do_call_with_arg = optee_ffa_do_call_with_arg,
 	.to_msg_param = optee_ffa_to_msg_param,
 	.from_msg_param = optee_ffa_from_msg_param,
+	.lend_rstmem = optee_ffa_lend_rstmem,
+	.reclaim_rstmem = optee_ffa_reclaim_rstmem,
 };
 
 static void optee_ffa_remove(struct ffa_device *ffa_dev)
@@ -937,11 +1062,17 @@  static int optee_ffa_probe(struct ffa_device *ffa_dev)
 	    (sec_caps & OPTEE_FFA_SEC_CAP_RPMB_PROBE))
 		optee->in_kernel_rpmb_routing = true;
 
+	if (sec_caps & OPTEE_FFA_SEC_CAP_RSTMEM) {
+		rc = optee_rstmem_pools_init(optee);
+		if (rc)
+			goto err_free_pool;
+	}
+
 	teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
 				  optee);
 	if (IS_ERR(teedev)) {
 		rc = PTR_ERR(teedev);
-		goto err_free_pool;
+		goto err_free_rstmem_pools;
 	}
 	optee->teedev = teedev;
 
@@ -1020,6 +1151,8 @@  static int optee_ffa_probe(struct ffa_device *ffa_dev)
 	tee_device_unregister(optee->teedev);
 err_free_pool:
 	tee_shm_pool_free(pool);
+err_free_rstmem_pools:
+	optee_rstmem_pools_uninit(optee);
 err_free_optee:
 	kfree(optee);
 	return rc;
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index 20eda508dbac..dd2a3a2224bc 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -174,9 +174,14 @@  struct optee;
  * @do_call_with_arg:	enters OP-TEE in secure world
  * @to_msg_param:	converts from struct tee_param to OPTEE_MSG parameters
  * @from_msg_param:	converts from OPTEE_MSG parameters to struct tee_param
+ * @lend_rstmem:	lends physically contiguous memory as restricted
+ *			memory, inaccessible by the kernel
+ * @reclaim_rstmem:	reclaims restricted memory previously lent with
+ *			@lend_rstmem() and makes it accessible by the
+ *			kernel again
  *
  * These OPs are only supposed to be used internally in the OP-TEE driver
- * as a way of abstracting the different methogs of entering OP-TEE in
+ * as a way of abstracting the different methods of entering OP-TEE in
  * secure world.
  */
 struct optee_ops {
@@ -191,6 +196,23 @@  struct optee_ops {
 			      size_t num_params,
 			      const struct optee_msg_param *msg_params,
 			      bool update_out);
+	int (*lend_rstmem)(struct optee *optee, struct tee_shm *rstmem,
+			   u16 *end_points, unsigned int ep_count);
+	int (*reclaim_rstmem)(struct optee *optee, struct tee_shm *rstmem);
+};
+
+/**
+ * struct optee_rstmem_pools - restricted memory pools
+ * @mutex:	serializes write access to @xa when adding a new pool.
+ * @xa:		XArray of struct tee_shm_pool where the index is the
+ *		use case ID TEE_IOC_UC_* supplied for TEE_IOC_RSTMEM_ALLOC.
+ */
+struct optee_rstmem_pools {
+	/*
+	 * Serializes write access to @xa when adding a new pool.
+	 */
+	struct mutex mutex;
+	struct xarray xa;
 };
 
 /**
@@ -206,6 +228,7 @@  struct optee_ops {
  * @notif:		notification synchronization struct
  * @supp:		supplicant synchronization struct for RPC to supplicant
  * @pool:		shared memory pool
+ * @rstmem_pool:	restricted memory pool for secure data path
  * @mutex:		mutex protecting @rpmb_dev
  * @rpmb_dev:		current RPMB device or NULL
  * @rpmb_scan_bus_done	flag if device registation of RPMB dependent devices
@@ -230,6 +253,7 @@  struct optee {
 	struct optee_notif notif;
 	struct optee_supp supp;
 	struct tee_shm_pool *pool;
+	struct optee_rstmem_pools *rstmem_pools;
 	/* Protects rpmb_dev pointer */
 	struct mutex rpmb_dev_mutex;
 	struct rpmb_dev *rpmb_dev;
@@ -286,6 +310,9 @@  void optee_supp_init(struct optee_supp *supp);
 void optee_supp_uninit(struct optee_supp *supp);
 void optee_supp_release(struct optee_supp *supp);
 
+int optee_rstmem_pools_init(struct optee *optee);
+void optee_rstmem_pools_uninit(struct optee *optee);
+
 int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params,
 		    struct tee_param *param);
 int optee_supp_send(struct tee_context *ctx, u32 ret, u32 num_params,
@@ -378,6 +405,10 @@  void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
 int optee_do_bottom_half(struct tee_context *ctx);
 int optee_stop_async_notif(struct tee_context *ctx);
 
+int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
+		       u32 flags, u32 use_case, size_t size);
+void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm);
+
 /*
  * Small helpers
  */
diff --git a/drivers/tee/optee/rstmem.c b/drivers/tee/optee/rstmem.c
new file mode 100644
index 000000000000..cf300929171f
--- /dev/null
+++ b/drivers/tee/optee/rstmem.c
@@ -0,0 +1,380 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024, Linaro Limited
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cma.h>
+#include <linux/dma-map-ops.h>
+#include <linux/errno.h>
+#include <linux/genalloc.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/tee_core.h>
+#include <linux/types.h>
+#include "optee_private.h"
+
+struct optee_rstmem_cma_pool {
+	struct tee_shm_pool pool;
+	struct page *page;
+	struct optee *optee;
+	size_t page_count;
+	u16 *end_points;
+	u_int end_point_count;
+	u_int align;
+	refcount_t refcount;
+	struct tee_shm rstmem;
+	/* Protects when initializing and tearing down this struct */
+	struct mutex mutex;
+};
+
+static struct optee_rstmem_cma_pool *
+to_rstmem_cma_pool(struct tee_shm_pool *pool)
+{
+	return container_of(pool, struct optee_rstmem_cma_pool, pool);
+}
+
+static int init_cma_rstmem(struct optee_rstmem_cma_pool *rp)
+{
+	struct cma *cma = dev_get_cma_area(&rp->optee->teedev->dev);
+	int rc;
+
+	rp->page = cma_alloc(cma, rp->page_count, rp->align, true/*no_warn*/);
+	if (!rp->page)
+		return -ENOMEM;
+
+	/*
+	 * TODO unmap the memory range since the physical memory will
+	 * become inaccesible after the lend_rstmem() call.
+	 */
+
+	rp->rstmem.paddr = page_to_phys(rp->page);
+	rp->rstmem.size = rp->page_count * PAGE_SIZE;
+	rc = rp->optee->ops->lend_rstmem(rp->optee, &rp->rstmem,
+					 rp->end_points, rp->end_point_count);
+	if (rc)
+		goto err_release;
+
+	rp->pool.private_data = gen_pool_create(PAGE_SHIFT, -1);
+	if (!rp->pool.private_data) {
+		rc = -ENOMEM;
+		goto err_reclaim;
+	}
+
+	rc = gen_pool_add(rp->pool.private_data, rp->rstmem.paddr,
+			  rp->rstmem.size, -1);
+	if (rc)
+		goto err_free_pool;
+
+	refcount_set(&rp->refcount, 1);
+	return 0;
+
+err_free_pool:
+	gen_pool_destroy(rp->pool.private_data);
+err_reclaim:
+	rp->optee->ops->reclaim_rstmem(rp->optee, &rp->rstmem);
+err_release:
+	cma_release(cma, rp->page, rp->page_count);
+	rp->rstmem.paddr = 0;
+	rp->rstmem.size = 0;
+	rp->rstmem.sec_world_id = 0;
+	return rc;
+}
+
+static int get_cma_rstmem(struct optee_rstmem_cma_pool *rp)
+{
+	int rc = 0;
+
+	if (!refcount_inc_not_zero(&rp->refcount)) {
+		mutex_lock(&rp->mutex);
+		if (rp->pool.private_data) {
+			/*
+			 * Another thread has already initialized the pool
+			 * before us, or the pool was just about to be torn
+			 * down. Either way we only need to increase the
+			 * refcount and we're done.
+			 */
+			refcount_inc(&rp->refcount);
+		} else {
+			rc = init_cma_rstmem(rp);
+		}
+		mutex_unlock(&rp->mutex);
+	}
+
+	return rc;
+}
+
+static void release_cma_rstmem(struct optee_rstmem_cma_pool *rp)
+{
+	gen_pool_destroy(rp->pool.private_data);
+	rp->optee->ops->reclaim_rstmem(rp->optee, &rp->rstmem);
+	cma_release(dev_get_cma_area(&rp->optee->teedev->dev), rp->page,
+		    rp->page_count);
+
+	rp->pool.private_data = NULL;
+	rp->page = NULL;
+	rp->rstmem.paddr = 0;
+	rp->rstmem.size = 0;
+	rp->rstmem.sec_world_id = 0;
+}
+
+static void put_cma_rstmem(struct optee_rstmem_cma_pool *rp)
+{
+	if (refcount_dec_and_test(&rp->refcount)) {
+		mutex_lock(&rp->mutex);
+		if (rp->pool.private_data)
+			release_cma_rstmem(rp);
+		mutex_unlock(&rp->mutex);
+	}
+}
+
+static int rstmem_pool_op_cma_alloc(struct tee_shm_pool *pool,
+				    struct tee_shm *shm, size_t size,
+				    size_t align)
+{
+	struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
+	size_t sz = ALIGN(size, PAGE_SIZE);
+	phys_addr_t pa;
+	int rc;
+
+	rc = get_cma_rstmem(rp);
+	if (rc)
+		return rc;
+
+	pa = gen_pool_alloc(rp->pool.private_data, sz);
+	if (!pa) {
+		put_cma_rstmem(rp);
+		return -ENOMEM;
+	}
+
+	shm->size = sz;
+	shm->paddr = pa;
+	shm->offset = pa - page_to_phys(rp->page);
+	shm->sec_world_id = rp->rstmem.sec_world_id;
+
+	return 0;
+}
+
+static void rstmem_pool_op_cma_free(struct tee_shm_pool *pool,
+				    struct tee_shm *shm)
+{
+	struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
+
+	gen_pool_free(rp->pool.private_data, shm->paddr, shm->size);
+	shm->size = 0;
+	shm->paddr = 0;
+	shm->offset = 0;
+	shm->sec_world_id = 0;
+	put_cma_rstmem(rp);
+}
+
+static void pool_op_cma_destroy_pool(struct tee_shm_pool *pool)
+{
+	struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
+
+	mutex_destroy(&rp->mutex);
+	kfree(rp);
+}
+
+static struct tee_shm_pool_ops rstmem_pool_ops_cma = {
+	.alloc = rstmem_pool_op_cma_alloc,
+	.free = rstmem_pool_op_cma_free,
+	.destroy_pool = pool_op_cma_destroy_pool,
+};
+
+static int get_rstmem_config(struct optee *optee, u32 use_case,
+			     size_t *min_size, u_int *min_align,
+			     u16 *end_points, u_int *ep_count)
+{
+	struct tee_param params[2] = {
+		[0] = {
+			.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT,
+			.u.value.a = use_case,
+		},
+		[1] = {
+			.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT,
+		},
+	};
+	struct optee_shm_arg_entry *entry;
+	struct tee_shm *shm_param = NULL;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+	int rc;
+
+	if (end_points && *ep_count) {
+		params[1].u.memref.size = *ep_count * sizeof(*end_points);
+		shm_param = tee_shm_alloc_priv_buf(optee->ctx,
+						   params[1].u.memref.size);
+		if (IS_ERR(shm_param))
+			return PTR_ERR(shm_param);
+		params[1].u.memref.shm = shm_param;
+	}
+
+	msg_arg = optee_get_msg_arg(optee->ctx, ARRAY_SIZE(params), &entry,
+				    &shm, &offs);
+	if (IS_ERR(msg_arg)) {
+		rc = PTR_ERR(msg_arg);
+		goto out_free_shm;
+	}
+	msg_arg->cmd = OPTEE_MSG_CMD_GET_RSTMEM_CONFIG;
+
+	rc = optee->ops->to_msg_param(optee, msg_arg->params,
+				      ARRAY_SIZE(params), params,
+				      false /*!update_out*/);
+	if (rc)
+		goto out_free_msg;
+
+	rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
+	if (rc)
+		goto out_free_msg;
+	if (msg_arg->ret && msg_arg->ret != TEEC_ERROR_SHORT_BUFFER) {
+		rc = -EINVAL;
+		goto out_free_msg;
+	}
+
+	rc = optee->ops->from_msg_param(optee, params, ARRAY_SIZE(params),
+					msg_arg->params, true /*update_out*/);
+	if (rc)
+		goto out_free_msg;
+
+	if (!msg_arg->ret && end_points &&
+	    *ep_count < params[1].u.memref.size / sizeof(u16)) {
+		rc = -EINVAL;
+		goto out_free_msg;
+	}
+
+	*min_size = params[0].u.value.a;
+	*min_align = params[0].u.value.b;
+	*ep_count = params[1].u.memref.size / sizeof(u16);
+
+	if (msg_arg->ret == TEEC_ERROR_SHORT_BUFFER) {
+		rc = -ENOSPC;
+		goto out_free_msg;
+	}
+
+	if (end_points)
+		memcpy(end_points, tee_shm_get_va(shm_param, 0),
+		       params[1].u.memref.size);
+
+out_free_msg:
+	optee_free_msg_arg(optee->ctx, entry, offs);
+out_free_shm:
+	if (shm_param)
+		tee_shm_free(shm_param);
+	return rc;
+}
+
+static struct tee_shm_pool *alloc_rstmem_pool(struct optee *optee, u32 use_case)
+{
+	struct optee_rstmem_cma_pool *rp;
+	size_t min_size;
+	int rc;
+
+	rp = kzalloc(sizeof(*rp), GFP_KERNEL);
+	if (!rp)
+		return ERR_PTR(-ENOMEM);
+	rp->rstmem.use_case = use_case;
+
+	rc = get_rstmem_config(optee, use_case, &min_size, &rp->align, NULL,
+			       &rp->end_point_count);
+	if (rc) {
+		if (rc != -ENOSPC)
+			goto err;
+		rp->end_points = kcalloc(rp->end_point_count,
+					 sizeof(*rp->end_points), GFP_KERNEL);
+		if (!rp->end_points) {
+			rc = -ENOMEM;
+			goto err;
+		}
+		rc = get_rstmem_config(optee, use_case, &min_size, &rp->align,
+				       rp->end_points, &rp->end_point_count);
+		if (rc)
+			goto err_kfree_eps;
+	}
+
+	rp->pool.ops = &rstmem_pool_ops_cma;
+	rp->optee = optee;
+	rp->page_count = min_size / PAGE_SIZE;
+	mutex_init(&rp->mutex);
+
+	return &rp->pool;
+
+err_kfree_eps:
+	kfree(rp->end_points);
+err:
+	kfree(rp);
+	return ERR_PTR(rc);
+}
+
+int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
+		       u32 flags, u32 use_case, size_t size)
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	struct tee_shm_pool *pool;
+	int rc;
+
+	if (!optee->rstmem_pools)
+		return -EINVAL;
+	if (flags)
+		return -EINVAL;
+
+	pool = xa_load(&optee->rstmem_pools->xa, use_case);
+	if (!pool) {
+		pool = alloc_rstmem_pool(optee, use_case);
+		if (IS_ERR(pool))
+			return PTR_ERR(pool);
+		rc = xa_insert(&optee->rstmem_pools->xa, use_case, pool,
+			       GFP_KERNEL);
+		if (rc) {
+			pool->ops->destroy_pool(pool);
+			return rc;
+		}
+	}
+
+	return pool->ops->alloc(pool, shm, size, 0);
+}
+
+void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm)
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	struct tee_shm_pool *pool;
+
+	pool = xa_load(&optee->rstmem_pools->xa, shm->use_case);
+	if (pool)
+		pool->ops->free(pool, shm);
+	else
+		pr_err("Can't find pool for use_case %u\n", shm->use_case);
+}
+
+int optee_rstmem_pools_init(struct optee *optee)
+{
+	struct optee_rstmem_pools *pools;
+
+	pools = kmalloc(sizeof(*pools), GFP_KERNEL);
+	if (!pools)
+		return -ENOMEM;
+
+	mutex_init(&pools->mutex);
+	xa_init(&pools->xa);
+	optee->rstmem_pools = pools;
+	return 0;
+}
+
+void optee_rstmem_pools_uninit(struct optee *optee)
+{
+	if (optee->rstmem_pools) {
+		struct tee_shm_pool *pool;
+		u_long idx;
+
+		xa_for_each(&optee->rstmem_pools->xa, idx, pool) {
+			xa_erase(&optee->rstmem_pools->xa, idx);
+			pool->ops->destroy_pool(pool);
+		}
+
+		xa_destroy(&optee->rstmem_pools->xa);
+		mutex_destroy(&optee->rstmem_pools->mutex);
+		kfree(optee->rstmem_pools);
+		optee->rstmem_pools = NULL;
+	}
+}
diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
index d1f79947f58a..7fa7d9d14c94 100644
--- a/drivers/tee/optee/smc_abi.c
+++ b/drivers/tee/optee/smc_abi.c
@@ -1001,6 +1001,67 @@  static int optee_smc_do_call_with_arg(struct tee_context *ctx,
 	return rc;
 }
 
+static int optee_smc_lend_rstmem(struct optee *optee, struct tee_shm *rstmem,
+				 u16 *end_points, unsigned int ep_count)
+{
+	struct optee_shm_arg_entry *entry;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+	int rc;
+
+	msg_arg = optee_get_msg_arg(optee->ctx, 2, &entry, &shm, &offs);
+	if (IS_ERR(msg_arg))
+		return PTR_ERR(msg_arg);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_LEND_RSTMEM;
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
+	msg_arg->params[0].u.value.a = OPTEE_MSG_RSTMEM_SECURE_VIDEO_PLAY;
+	msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
+	msg_arg->params[1].u.tmem.buf_ptr = rstmem->paddr;
+	msg_arg->params[1].u.tmem.size = rstmem->size;
+	msg_arg->params[1].u.tmem.shm_ref = (u_long)rstmem;
+
+	rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
+	if (rc)
+		goto out;
+	if (msg_arg->ret != TEEC_SUCCESS) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+out:
+	optee_free_msg_arg(optee->ctx, entry, offs);
+	return rc;
+}
+
+static int optee_smc_reclaim_rstmem(struct optee *optee, struct tee_shm *rstmem)
+{
+	struct optee_shm_arg_entry *entry;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+	int rc;
+
+	msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
+	if (IS_ERR(msg_arg))
+		return PTR_ERR(msg_arg);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_RECLAIM_RSTMEM;
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
+	msg_arg->params[0].u.rmem.shm_ref = (u_long)rstmem;
+
+	rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
+	if (rc)
+		goto out;
+	if (msg_arg->ret != TEEC_SUCCESS)
+		rc = -EINVAL;
+
+out:
+	optee_free_msg_arg(optee->ctx, entry, offs);
+	return rc;
+}
+
 /*
  * 5. Asynchronous notification
  */
@@ -1201,6 +1262,8 @@  static void optee_get_version(struct tee_device *teedev,
 		v.gen_caps |= TEE_GEN_CAP_REG_MEM;
 	if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
 		v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
+	if (optee->rstmem_pools)
+		v.gen_caps |= TEE_GEN_CAP_RSTMEM;
 	*vers = v;
 }
 
@@ -1223,6 +1286,8 @@  static const struct tee_driver_ops optee_clnt_ops = {
 	.cancel_req = optee_cancel_req,
 	.shm_register = optee_shm_register,
 	.shm_unregister = optee_shm_unregister,
+	.rstmem_alloc = optee_rstmem_alloc,
+	.rstmem_free = optee_rstmem_free,
 };
 
 static const struct tee_desc optee_clnt_desc = {
@@ -1239,6 +1304,8 @@  static const struct tee_driver_ops optee_supp_ops = {
 	.supp_send = optee_supp_send,
 	.shm_register = optee_shm_register_supp,
 	.shm_unregister = optee_shm_unregister_supp,
+	.rstmem_alloc = optee_rstmem_alloc,
+	.rstmem_free = optee_rstmem_free,
 };
 
 static const struct tee_desc optee_supp_desc = {
@@ -1252,6 +1319,9 @@  static const struct optee_ops optee_ops = {
 	.do_call_with_arg = optee_smc_do_call_with_arg,
 	.to_msg_param = optee_to_msg_param,
 	.from_msg_param = optee_from_msg_param,
+	.lend_rstmem = optee_smc_lend_rstmem,
+	.reclaim_rstmem = optee_smc_reclaim_rstmem,
+	//.alloc_rstmem_pool = optee_smc_alloc_rstmem_pool,
 };
 
 static int enable_async_notif(optee_invoke_fn *invoke_fn)
@@ -1619,6 +1689,62 @@  static inline int optee_load_fw(struct platform_device *pdev,
 }
 #endif
 
+static int optee_sdp_pool_init(struct optee *optee)
+{
+	bool dyn_sdp = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_RSTMEM;
+	bool sdp = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP;
+	struct tee_shm_pool *pool;
+	int rc;
+
+	/*
+	 * optee_sdp_pools_init() must be called if secure world has any
+	 * SDP capability. If the static carvout is available initialize
+	 * and add a pool for that. If there's an error from secure world
+	 * we complain but don't call optee_sdp_pools_uninit() unless we
+	 * know that there is no SDP capability left.
+	 */
+	if (!dyn_sdp && !sdp)
+		return 0;
+
+	rc = optee_rstmem_pools_init(optee);
+	if (rc)
+		return rc;
+
+	if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP) {
+		union {
+			struct arm_smccc_res smccc;
+			struct optee_smc_get_sdp_config_result result;
+		} res;
+
+		optee->smc.invoke_fn(OPTEE_SMC_GET_SDP_CONFIG, 0, 0, 0, 0, 0, 0,
+				     0, &res.smccc);
+		if (res.result.status != OPTEE_SMC_RETURN_OK) {
+			pr_err("Secure Data Path service not available\n");
+			if (!dyn_sdp)
+				goto err;
+			return 0;
+		}
+
+		pool = tee_rstmem_gen_pool_alloc(res.result.start,
+						 res.result.size);
+		if (IS_ERR(pool)) {
+			rc = PTR_ERR(pool);
+			goto err;
+		}
+		rc = xa_insert(&optee->rstmem_pools->xa,
+			       TEE_IOC_UC_SECURE_VIDEO_PLAY, pool, GFP_KERNEL);
+		if (rc) {
+			pool->ops->destroy_pool(pool);
+			goto err;
+		}
+	}
+
+	return 0;
+err:
+	optee_rstmem_pools_uninit(optee);
+	return rc;
+}
+
 static int optee_probe(struct platform_device *pdev)
 {
 	optee_invoke_fn *invoke_fn;
@@ -1714,7 +1840,7 @@  static int optee_probe(struct platform_device *pdev)
 	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
 	if (!optee) {
 		rc = -ENOMEM;
-		goto err_free_pool;
+		goto err_free_shm_pool;
 	}
 
 	optee->ops = &optee_ops;
@@ -1726,10 +1852,14 @@  static int optee_probe(struct platform_device *pdev)
 	    (sec_caps & OPTEE_SMC_SEC_CAP_RPMB_PROBE))
 		optee->in_kernel_rpmb_routing = true;
 
+	rc = optee_sdp_pool_init(optee);
+	if (rc)
+		goto err_free_optee;
+
 	teedev = tee_device_alloc(&optee_clnt_desc, NULL, pool, optee);
 	if (IS_ERR(teedev)) {
 		rc = PTR_ERR(teedev);
-		goto err_free_optee;
+		goto err_rstmem_pools_uninit;
 	}
 	optee->teedev = teedev;
 
@@ -1836,9 +1966,11 @@  static int optee_probe(struct platform_device *pdev)
 	tee_device_unregister(optee->supp_teedev);
 err_unreg_teedev:
 	tee_device_unregister(optee->teedev);
+err_rstmem_pools_uninit:
+	optee_rstmem_pools_uninit(optee);
 err_free_optee:
 	kfree(optee);
-err_free_pool:
+err_free_shm_pool:
 	tee_shm_pool_free(pool);
 	if (memremaped_shm)
 		memunmap(memremaped_shm);