| Message ID | 20240303150115.133633-11-brgl@bgdev.pl (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | firmware: qcom: implement support for and enable SHM bridge | expand |
On Sun, Mar 03, 2024 at 04:01:13PM +0100, Bartosz Golaszewski wrote: > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > > SHM Bridge is a safety mechanism allowing to limit the amount of memory > shared between the kernel and the TrustZone to regions explicitly marked > as such. > > Add a variant of the tzmem allocator that configures the memory pools as > SHM bridges. It also enables the SHM bridge globally so non-SHM bridge > memory will no longer work with SCM calls. > > If enabled at build-time, it will still be checked for availability at > run-time. If the architecture doesn't support SHM Bridge, the allocator > will fall back to the generic mode. > > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > Tested-by: Andrew Halaney <ahalaney@redhat.com> # sc8280xp-lenovo-thinkpad-x13s > Tested-by: Deepti Jaggi <quic_djaggi@quicinc.com> #sa8775p-ride > Reviewed-by: Elliot Berman <quic_eberman@quicinc.com> > --- > drivers/firmware/qcom/Kconfig | 10 +++++ > drivers/firmware/qcom/qcom_tzmem.c | 65 +++++++++++++++++++++++++++++- > 2 files changed, 74 insertions(+), 1 deletion(-) > > diff --git a/drivers/firmware/qcom/Kconfig b/drivers/firmware/qcom/Kconfig > index 4634f8cecc7b..7f6eb4174734 100644 > --- a/drivers/firmware/qcom/Kconfig > +++ b/drivers/firmware/qcom/Kconfig > @@ -28,6 +28,16 @@ config QCOM_TZMEM_MODE_GENERIC > Use the generic allocator mode. The memory is page-aligned, non-cachable > and physically contiguous. > > +config QCOM_TZMEM_MODE_SHMBRIDGE > + bool "SHM Bridge" > + help > + Use Qualcomm Shared Memory Bridge. The memory has the same alignment as > + in the 'Generic' allocator but is also explicitly marked as an SHM Bridge > + buffer. > + > + With this selected, all buffers passed to the TrustZone must be allocated > + using the TZMem allocator or else the TrustZone will refuse to use them. > + > endchoice > > config QCOM_SCM_DOWNLOAD_MODE_DEFAULT > diff --git a/drivers/firmware/qcom/qcom_tzmem.c b/drivers/firmware/qcom/qcom_tzmem.c > index 23f364afa6ca..244615e8c505 100644 > --- a/drivers/firmware/qcom/qcom_tzmem.c > +++ b/drivers/firmware/qcom/qcom_tzmem.c > @@ -67,7 +67,70 @@ static void qcom_tzmem_cleanup_area(struct qcom_tzmem_area *area) > > } > > -#endif /* CONFIG_QCOM_TZMEM_MODE_GENERIC */ > +#elif IS_ENABLED(CONFIG_QCOM_TZMEM_MODE_SHMBRIDGE) > + > +#include <linux/firmware/qcom/qcom_scm.h> > + > +#define QCOM_SHM_BRIDGE_NUM_VM_SHIFT 9 > + > +static bool qcom_tzmem_using_shm_bridge; > + > +static int qcom_tzmem_init(void) > +{ > + int ret; > + > + ret = qcom_scm_shm_bridge_enable(); > + if (ret == -EOPNOTSUPP) { > + dev_info(qcom_tzmem_dev, "SHM Bridge not supported\n"); > + return 0; > + } > + > + if (!ret) > + qcom_tzmem_using_shm_bridge = true; > + > + return ret; > +} > + > +static int qcom_tzmem_init_area(struct qcom_tzmem_area *area) > +{ > + u64 pfn_and_ns_perm, ipfn_and_s_perm, size_and_flags, ns_perms; > + int ret; > + > + if (!qcom_tzmem_using_shm_bridge) > + return 0; > + > + ns_perms = (QCOM_SCM_PERM_WRITE | QCOM_SCM_PERM_READ); Above expr can be replaced with QCOM_SCM_PERM_RW. https://elixir.bootlin.com/linux/v6.8-rc7/source/include/linux/firmware/qcom/qcom_scm.h#L59 Regards Kuldeep
diff --git a/drivers/firmware/qcom/Kconfig b/drivers/firmware/qcom/Kconfig index 4634f8cecc7b..7f6eb4174734 100644 --- a/drivers/firmware/qcom/Kconfig +++ b/drivers/firmware/qcom/Kconfig @@ -28,6 +28,16 @@ config QCOM_TZMEM_MODE_GENERIC Use the generic allocator mode. The memory is page-aligned, non-cachable and physically contiguous. +config QCOM_TZMEM_MODE_SHMBRIDGE + bool "SHM Bridge" + help + Use Qualcomm Shared Memory Bridge. The memory has the same alignment as + in the 'Generic' allocator but is also explicitly marked as an SHM Bridge + buffer. + + With this selected, all buffers passed to the TrustZone must be allocated + using the TZMem allocator or else the TrustZone will refuse to use them. + endchoice config QCOM_SCM_DOWNLOAD_MODE_DEFAULT diff --git a/drivers/firmware/qcom/qcom_tzmem.c b/drivers/firmware/qcom/qcom_tzmem.c index 23f364afa6ca..244615e8c505 100644 --- a/drivers/firmware/qcom/qcom_tzmem.c +++ b/drivers/firmware/qcom/qcom_tzmem.c @@ -67,7 +67,70 @@ static void qcom_tzmem_cleanup_area(struct qcom_tzmem_area *area) } -#endif /* CONFIG_QCOM_TZMEM_MODE_GENERIC */ +#elif IS_ENABLED(CONFIG_QCOM_TZMEM_MODE_SHMBRIDGE) + +#include <linux/firmware/qcom/qcom_scm.h> + +#define QCOM_SHM_BRIDGE_NUM_VM_SHIFT 9 + +static bool qcom_tzmem_using_shm_bridge; + +static int qcom_tzmem_init(void) +{ + int ret; + + ret = qcom_scm_shm_bridge_enable(); + if (ret == -EOPNOTSUPP) { + dev_info(qcom_tzmem_dev, "SHM Bridge not supported\n"); + return 0; + } + + if (!ret) + qcom_tzmem_using_shm_bridge = true; + + return ret; +} + +static int qcom_tzmem_init_area(struct qcom_tzmem_area *area) +{ + u64 pfn_and_ns_perm, ipfn_and_s_perm, size_and_flags, ns_perms; + int ret; + + if (!qcom_tzmem_using_shm_bridge) + return 0; + + ns_perms = (QCOM_SCM_PERM_WRITE | QCOM_SCM_PERM_READ); + pfn_and_ns_perm = (u64)area->paddr | ns_perms; + ipfn_and_s_perm = (u64)area->paddr | ns_perms; + size_and_flags = area->size | (1 << QCOM_SHM_BRIDGE_NUM_VM_SHIFT); + + u64 *handle __free(kfree) = kzalloc(sizeof(*handle), GFP_KERNEL); + if (!handle) + return -ENOMEM; + + ret = qcom_scm_shm_bridge_create(qcom_tzmem_dev, pfn_and_ns_perm, + ipfn_and_s_perm, size_and_flags, + QCOM_SCM_VMID_HLOS, handle); + if (ret) + return ret; + + area->priv = no_free_ptr(handle); + + return 0; +} + +static void qcom_tzmem_cleanup_area(struct qcom_tzmem_area *area) +{ + u64 *handle = area->priv; + + if (!qcom_tzmem_using_shm_bridge) + return; + + qcom_scm_shm_bridge_delete(qcom_tzmem_dev, *handle); + kfree(handle); +} + +#endif /* CONFIG_QCOM_TZMEM_MODE_SHMBRIDGE */ static int qcom_tzmem_pool_add_memory(struct qcom_tzmem_pool *pool, size_t size, gfp_t gfp)