| Message ID | 20241101091735.1465-10-shiju.jose@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | EDAC: Scrub: introduce generic EDAC RAS control feature driver + CXL/ACPI-RAS2 drivers | expand |
On Fri, Nov 1, 2024 at 10:18 AM <shiju.jose@huawei.com> wrote: > > From: Shiju Jose <shiju.jose@huawei.com> > > Add support for ACPI RAS2 feature table (RAS2) defined in the > ACPI 6.5 Specification, section 5.2.21. > Driver contains RAS2 Init, which extracts the RAS2 table and driver > adds auxiliary device for each memory feature which binds to the > RAS2 memory driver. > > Driver uses PCC mailbox to communicate with the ACPI HW and the > driver adds OSPM interfaces to send RAS2 commands. > > Co-developed-by: A Somasundaram <somasundaram.a@hpe.com> > Signed-off-by: A Somasundaram <somasundaram.a@hpe.com> > Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: Shiju Jose <shiju.jose@huawei.com> In case my ACK on this is needed Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> and please route this along with the rest of the series. Thanks! > --- > drivers/acpi/Kconfig | 11 ++ > drivers/acpi/Makefile | 1 + > drivers/acpi/ras2.c | 409 +++++++++++++++++++++++++++++++++++++++ > include/acpi/ras2_acpi.h | 45 +++++ > 4 files changed, 466 insertions(+) > create mode 100755 drivers/acpi/ras2.c > create mode 100644 include/acpi/ras2_acpi.h > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig > index d67f63d93b2a..ceae55704a14 100644 > --- a/drivers/acpi/Kconfig > +++ b/drivers/acpi/Kconfig > @@ -284,6 +284,17 @@ config ACPI_CPPC_LIB > If your platform does not support CPPC in firmware, > leave this option disabled. > > +config ACPI_RAS2 > + bool "ACPI RAS2 driver" > + select AUXILIARY_BUS > + select MAILBOX > + select PCC > + help > + The driver adds support for ACPI RAS2 feature table(extracts RAS2 > + table from OS system table) and OSPM interfaces to send RAS2 > + commands via PCC mailbox subspace. Driver adds platform device for > + the RAS2 memory features which binds to the RAS2 memory driver. > + > config ACPI_PROCESSOR > tristate "Processor" > depends on X86 || ARM64 || LOONGARCH || RISCV > diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile > index 61ca4afe83dc..84e2a2519bae 100644 > --- a/drivers/acpi/Makefile > +++ b/drivers/acpi/Makefile > @@ -100,6 +100,7 @@ obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o > obj-$(CONFIG_ACPI_BGRT) += bgrt.o > obj-$(CONFIG_ACPI_CPPC_LIB) += cppc_acpi.o > obj-$(CONFIG_ACPI_SPCR_TABLE) += spcr.o > +obj-$(CONFIG_ACPI_RAS2) += ras2.o > obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o > obj-$(CONFIG_ACPI_PPTT) += pptt.o > obj-$(CONFIG_ACPI_PFRUT) += pfr_update.o pfr_telemetry.o > diff --git a/drivers/acpi/ras2.c b/drivers/acpi/ras2.c > new file mode 100755 > index 000000000000..56ad7667ce81 > --- /dev/null > +++ b/drivers/acpi/ras2.c > @@ -0,0 +1,409 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Implementation of ACPI RAS2 driver. > + * > + * Copyright (c) 2024 HiSilicon Limited. > + * > + * Support for RAS2 - ACPI 6.5 Specification, section 5.2.21 > + * > + * Driver contains ACPI RAS2 init, which extracts the ACPI RAS2 table and > + * get the PCC channel subspace for communicating with the ACPI compliant > + * HW platform which supports ACPI RAS2. Driver adds platform devices > + * for each RAS2 memory feature which binds to the memory ACPI RAS2 driver. > + */ > + > +#define pr_fmt(fmt) "ACPI RAS2: " fmt > + > +#include <linux/delay.h> > +#include <linux/export.h> > +#include <linux/ktime.h> > +#include <linux/platform_device.h> > +#include <acpi/pcc.h> > +#include <acpi/ras2_acpi.h> > + > +/* Data structure for PCC communication */ > +struct ras2_pcc_subspace { > + int pcc_subspace_id; > + struct mbox_client mbox_client; > + struct pcc_mbox_chan *pcc_chan; > + struct acpi_ras2_shared_memory __iomem *pcc_comm_addr; > + bool pcc_channel_acquired; > + ktime_t deadline; > + unsigned int pcc_mpar; > + unsigned int pcc_mrtt; > + struct list_head elem; > + u16 ref_count; > +}; > + > +/* > + * Arbitrary Retries for PCC commands because the > + * remote processor could be much slower to reply. > + */ > +#define RAS2_NUM_RETRIES 600 > + > +#define RAS2_FEATURE_TYPE_MEMORY 0x00 > + > +/* global variables for the RAS2 PCC subspaces */ > +static DEFINE_MUTEX(ras2_pcc_subspace_lock); > +static LIST_HEAD(ras2_pcc_subspaces); > + > +static int ras2_report_cap_error(u32 cap_status) > +{ > + switch (cap_status) { > + case ACPI_RAS2_NOT_VALID: > + case ACPI_RAS2_NOT_SUPPORTED: > + return -EPERM; > + case ACPI_RAS2_BUSY: > + return -EBUSY; > + case ACPI_RAS2_FAILED: > + case ACPI_RAS2_ABORTED: > + case ACPI_RAS2_INVALID_DATA: > + return -EINVAL; > + default: /* 0 or other, Success */ > + return 0; > + } > +} > + > +static int ras2_check_pcc_chan(struct ras2_pcc_subspace *pcc_subspace) > +{ > + struct acpi_ras2_shared_memory __iomem *generic_comm_base = pcc_subspace->pcc_comm_addr; > + ktime_t next_deadline = ktime_add(ktime_get(), pcc_subspace->deadline); > + u32 cap_status; > + u16 status; > + u32 ret; > + > + while (!ktime_after(ktime_get(), next_deadline)) { > + /* > + * As per ACPI spec, the PCC space will be initialized by > + * platform and should have set the command completion bit when > + * PCC can be used by OSPM > + */ > + status = readw_relaxed(&generic_comm_base->status); > + if (status & RAS2_PCC_CMD_ERROR) { > + cap_status = readw_relaxed(&generic_comm_base->set_capabilities_status); > + ret = ras2_report_cap_error(cap_status); > + > + status &= ~RAS2_PCC_CMD_ERROR; > + writew_relaxed(status, &generic_comm_base->status); > + return ret; > + } > + if (status & RAS2_PCC_CMD_COMPLETE) > + return 0; > + /* > + * Reducing the bus traffic in case this loop takes longer than > + * a few retries. > + */ > + msleep(10); > + } > + > + return -EIO; > +} > + > +/** > + * ras2_send_pcc_cmd() - Send RAS2 command via PCC channel > + * @ras2_ctx: pointer to the RAS2 context structure > + * @cmd: command to send > + * > + * Returns: 0 on success, an error otherwise > + */ > +int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd) > +{ > + struct ras2_pcc_subspace *pcc_subspace = ras2_ctx->pcc_subspace; > + struct acpi_ras2_shared_memory *generic_comm_base = pcc_subspace->pcc_comm_addr; > + static ktime_t last_cmd_cmpl_time, last_mpar_reset; > + struct mbox_chan *pcc_channel; > + unsigned int time_delta; > + static int mpar_count; > + int ret; > + > + guard(mutex)(&ras2_pcc_subspace_lock); > + ret = ras2_check_pcc_chan(pcc_subspace); > + if (ret < 0) > + return ret; > + pcc_channel = pcc_subspace->pcc_chan->mchan; > + > + /* > + * Handle the Minimum Request Turnaround Time(MRTT) > + * "The minimum amount of time that OSPM must wait after the completion > + * of a command before issuing the next command, in microseconds" > + */ > + if (pcc_subspace->pcc_mrtt) { > + time_delta = ktime_us_delta(ktime_get(), last_cmd_cmpl_time); > + if (pcc_subspace->pcc_mrtt > time_delta) > + udelay(pcc_subspace->pcc_mrtt - time_delta); > + } > + > + /* > + * Handle the non-zero Maximum Periodic Access Rate(MPAR) > + * "The maximum number of periodic requests that the subspace channel can > + * support, reported in commands per minute. 0 indicates no limitation." > + * > + * This parameter should be ideally zero or large enough so that it can > + * handle maximum number of requests that all the cores in the system can > + * collectively generate. If it is not, we will follow the spec and just > + * not send the request to the platform after hitting the MPAR limit in > + * any 60s window > + */ > + if (pcc_subspace->pcc_mpar) { > + if (mpar_count == 0) { > + time_delta = ktime_ms_delta(ktime_get(), last_mpar_reset); > + if (time_delta < 60 * MSEC_PER_SEC) { > + dev_dbg(ras2_ctx->dev, > + "PCC cmd not sent due to MPAR limit"); > + return -EIO; > + } > + last_mpar_reset = ktime_get(); > + mpar_count = pcc_subspace->pcc_mpar; > + } > + mpar_count--; > + } > + > + /* Write to the shared comm region. */ > + writew_relaxed(cmd, &generic_comm_base->command); > + > + /* Flip CMD COMPLETE bit */ > + writew_relaxed(0, &generic_comm_base->status); > + > + /* Ring doorbell */ > + ret = mbox_send_message(pcc_channel, &cmd); > + if (ret < 0) { > + dev_err(ras2_ctx->dev, > + "Err sending PCC mbox message. cmd:%d, ret:%d\n", > + cmd, ret); > + return ret; > + } > + > + /* > + * If Minimum Request Turnaround Time is non-zero, we need > + * to record the completion time of both READ and WRITE > + * command for proper handling of MRTT, so we need to check > + * for pcc_mrtt in addition to CMD_READ > + */ > + if (cmd == RAS2_PCC_CMD_EXEC || pcc_subspace->pcc_mrtt) { > + ret = ras2_check_pcc_chan(pcc_subspace); > + if (pcc_subspace->pcc_mrtt) > + last_cmd_cmpl_time = ktime_get(); > + } > + > + if (pcc_channel->mbox->txdone_irq) > + mbox_chan_txdone(pcc_channel, ret); > + else > + mbox_client_txdone(pcc_channel, ret); > + > + return ret >= 0 ? 0 : ret; > +} > +EXPORT_SYMBOL_GPL(ras2_send_pcc_cmd); > + > +static int ras2_register_pcc_channel(struct ras2_mem_ctx *ras2_ctx, int pcc_subspace_id) > +{ > + struct ras2_pcc_subspace *pcc_subspace; > + struct acpi_pcct_hw_reduced *ras2_ss; > + struct pcc_mbox_chan *pcc_chan; > + struct mbox_client *mbox_cl; > + > + if (pcc_subspace_id < 0) > + return -EINVAL; > + > + mutex_lock(&ras2_pcc_subspace_lock); > + list_for_each_entry(pcc_subspace, &ras2_pcc_subspaces, elem) { > + if (pcc_subspace->pcc_subspace_id == pcc_subspace_id) { > + ras2_ctx->pcc_subspace = pcc_subspace; > + pcc_subspace->ref_count++; > + mutex_unlock(&ras2_pcc_subspace_lock); > + return 0; > + } > + } > + mutex_unlock(&ras2_pcc_subspace_lock); > + > + pcc_subspace = kcalloc(1, sizeof(*pcc_subspace), GFP_KERNEL); > + if (!pcc_subspace) > + return -ENOMEM; > + mbox_cl = &pcc_subspace->mbox_client; > + mbox_cl->knows_txdone = true; > + > + pcc_chan = pcc_mbox_request_channel(mbox_cl, pcc_subspace_id); > + if (IS_ERR(pcc_chan)) { > + kfree(pcc_subspace); > + return PTR_ERR(pcc_chan); > + } > + ras2_ss = pcc_chan->mchan->con_priv; > + *pcc_subspace = (struct ras2_pcc_subspace) { > + .pcc_subspace_id = pcc_subspace_id, > + .pcc_chan = pcc_chan, > + .pcc_comm_addr = acpi_os_ioremap(ras2_ss->base_address, > + ras2_ss->length), > + .deadline = ns_to_ktime(RAS2_NUM_RETRIES * > + ras2_ss->latency * > + NSEC_PER_USEC), > + .pcc_mrtt = ras2_ss->min_turnaround_time, > + .pcc_mpar = ras2_ss->max_access_rate, > + .mbox_client = { > + .knows_txdone = true, > + }, > + .pcc_channel_acquired = true, > + }; > + mutex_lock(&ras2_pcc_subspace_lock); > + list_add(&pcc_subspace->elem, &ras2_pcc_subspaces); > + pcc_subspace->ref_count++; > + mutex_unlock(&ras2_pcc_subspace_lock); > + ras2_ctx->pcc_subspace = pcc_subspace; > + ras2_ctx->pcc_comm_addr = pcc_subspace->pcc_comm_addr; > + ras2_ctx->dev = pcc_chan->mchan->mbox->dev; > + > + return 0; > +} > + > +static DEFINE_IDA(ras2_ida); > +static void ras2_remove_pcc(struct ras2_mem_ctx *ras2_ctx) > +{ > + struct ras2_pcc_subspace *pcc_subspace = ras2_ctx->pcc_subspace; > + > + guard(mutex)(&ras2_pcc_subspace_lock); > + if (pcc_subspace->ref_count > 0) > + pcc_subspace->ref_count--; > + if (!pcc_subspace->ref_count) { > + list_del(&pcc_subspace->elem); > + pcc_mbox_free_channel(pcc_subspace->pcc_chan); > + kfree(pcc_subspace); > + } > +} > + > +static void ras2_release(struct device *device) > +{ > + struct auxiliary_device *auxdev = container_of(device, struct auxiliary_device, dev); > + struct ras2_mem_ctx *ras2_ctx = container_of(auxdev, struct ras2_mem_ctx, adev); > + > + ida_free(&ras2_ida, auxdev->id); > + ras2_remove_pcc(ras2_ctx); > + kfree(ras2_ctx); > +} > + > +static struct ras2_mem_ctx *ras2_add_aux_device(char *name, int channel) > +{ > + struct ras2_mem_ctx *ras2_ctx; > + int id, ret; > + > + ras2_ctx = kzalloc(sizeof(*ras2_ctx), GFP_KERNEL); > + if (!ras2_ctx) > + return ERR_PTR(-ENOMEM); > + > + mutex_init(&ras2_ctx->lock); > + > + ret = ras2_register_pcc_channel(ras2_ctx, channel); > + if (ret < 0) { > + pr_debug("failed to register pcc channel ret=%d\n", ret); > + goto ctx_free; > + } > + > + id = ida_alloc(&ras2_ida, GFP_KERNEL); > + if (id < 0) { > + ret = id; > + goto pcc_free; > + } > + ras2_ctx->id = id; > + ras2_ctx->adev.id = id; > + ras2_ctx->adev.name = RAS2_MEM_DEV_ID_NAME; > + ras2_ctx->adev.dev.release = ras2_release; > + ras2_ctx->adev.dev.parent = ras2_ctx->dev; > + > + ret = auxiliary_device_init(&ras2_ctx->adev); > + if (ret) > + goto ida_free; > + > + ret = auxiliary_device_add(&ras2_ctx->adev); > + if (ret) { > + auxiliary_device_uninit(&ras2_ctx->adev); > + return ERR_PTR(ret); > + } > + > + return ras2_ctx; > + > +ida_free: > + ida_free(&ras2_ida, id); > +pcc_free: > + ras2_remove_pcc(ras2_ctx); > +ctx_free: > + kfree(ras2_ctx); > + return ERR_PTR(ret); > +} > + > +static int __init ras2_acpi_init(void) > +{ > + struct acpi_table_header *pAcpiTable = NULL; > + struct acpi_ras2_pcc_desc *pcc_desc_list; > + struct acpi_table_ras2 *pRas2Table; > + struct ras2_mem_ctx *ras2_ctx; > + int pcc_subspace_id; > + acpi_size ras2_size; > + acpi_status status; > + u8 count = 0, i; > + int ret = 0; > + > + status = acpi_get_table("RAS2", 0, &pAcpiTable); > + if (ACPI_FAILURE(status) || !pAcpiTable) { > + pr_err("ACPI RAS2 driver failed to initialize, get table failed\n"); > + return -EINVAL; > + } > + > + ras2_size = pAcpiTable->length; > + if (ras2_size < sizeof(struct acpi_table_ras2)) { > + pr_err("ACPI RAS2 table present but broken (too short #1)\n"); > + ret = -EINVAL; > + goto free_ras2_table; > + } > + > + pRas2Table = (struct acpi_table_ras2 *)pAcpiTable; > + if (pRas2Table->num_pcc_descs <= 0) { > + pr_err("ACPI RAS2 table does not contain PCC descriptors\n"); > + ret = -EINVAL; > + goto free_ras2_table; > + } > + > + pcc_desc_list = (struct acpi_ras2_pcc_desc *)(pRas2Table + 1); > + /* Double scan for the case of only one actual controller */ > + pcc_subspace_id = -1; > + count = 0; > + for (i = 0; i < pRas2Table->num_pcc_descs; i++, pcc_desc_list++) { > + if (pcc_desc_list->feature_type != RAS2_FEATURE_TYPE_MEMORY) > + continue; > + if (pcc_subspace_id == -1) { > + pcc_subspace_id = pcc_desc_list->channel_id; > + count++; > + } > + if (pcc_desc_list->channel_id != pcc_subspace_id) > + count++; > + } > + /* > + * Workaround for the client platform with multiple scrub devices > + * but uses single PCC subspace for communication. > + */ > + if (count == 1) { > + /* Add auxiliary device and bind ACPI RAS2 memory driver */ > + ras2_ctx = ras2_add_aux_device(RAS2_MEM_DEV_ID_NAME, pcc_subspace_id); > + if (IS_ERR(ras2_ctx)) { > + ret = PTR_ERR(ras2_ctx); > + goto free_ras2_table; > + } > + acpi_put_table(pAcpiTable); > + return 0; > + } > + > + pcc_desc_list = (struct acpi_ras2_pcc_desc *)(pRas2Table + 1); > + count = 0; > + for (i = 0; i < pRas2Table->num_pcc_descs; i++, pcc_desc_list++) { > + if (pcc_desc_list->feature_type != RAS2_FEATURE_TYPE_MEMORY) > + continue; > + pcc_subspace_id = pcc_desc_list->channel_id; > + /* Add auxiliary device and bind ACPI RAS2 memory driver */ > + ras2_ctx = ras2_add_aux_device(RAS2_MEM_DEV_ID_NAME, pcc_subspace_id); > + if (IS_ERR(ras2_ctx)) { > + ret = PTR_ERR(ras2_ctx); > + goto free_ras2_table; > + } > + } > + > +free_ras2_table: > + acpi_put_table(pAcpiTable); > + return ret; > +} > +late_initcall(ras2_acpi_init) > diff --git a/include/acpi/ras2_acpi.h b/include/acpi/ras2_acpi.h > new file mode 100644 > index 000000000000..7b32407ae2af > --- /dev/null > +++ b/include/acpi/ras2_acpi.h > @@ -0,0 +1,45 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * RAS2 ACPI driver header file > + * > + * (C) Copyright 2014, 2015 Hewlett-Packard Enterprises > + * > + * Copyright (c) 2024 HiSilicon Limited > + */ > + > +#ifndef _RAS2_ACPI_H > +#define _RAS2_ACPI_H > + > +#include <linux/acpi.h> > +#include <linux/auxiliary_bus.h> > +#include <linux/mailbox_client.h> > +#include <linux/mutex.h> > +#include <linux/types.h> > + > +#define RAS2_PCC_CMD_COMPLETE BIT(0) > +#define RAS2_PCC_CMD_ERROR BIT(2) > + > +/* RAS2 specific PCC commands */ > +#define RAS2_PCC_CMD_EXEC 0x01 > + > +#define RAS2_AUX_DEV_NAME "ras2" > +#define RAS2_MEM_DEV_ID_NAME "acpi_ras2_mem" > + > +/* Data structure RAS2 table */ > +struct ras2_mem_ctx { > + struct auxiliary_device adev; > + /* Lock to provide mutually exclusive access to PCC channel */ > + struct mutex lock; > + int id; > + u8 instance; > + bool bg; > + u64 base, size; > + u8 scrub_cycle_hrs, min_scrub_cycle, max_scrub_cycle; > + struct device *dev; > + struct device *scrub_dev; > + void *pcc_subspace; > + struct acpi_ras2_shared_memory __iomem *pcc_comm_addr; > +}; > + > +int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd); > +#endif /* _RAS2_ACPI_H */ > -- > 2.34.1 >
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index d67f63d93b2a..ceae55704a14 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -284,6 +284,17 @@ config ACPI_CPPC_LIB If your platform does not support CPPC in firmware, leave this option disabled. +config ACPI_RAS2 + bool "ACPI RAS2 driver" + select AUXILIARY_BUS + select MAILBOX + select PCC + help + The driver adds support for ACPI RAS2 feature table(extracts RAS2 + table from OS system table) and OSPM interfaces to send RAS2 + commands via PCC mailbox subspace. Driver adds platform device for + the RAS2 memory features which binds to the RAS2 memory driver. + config ACPI_PROCESSOR tristate "Processor" depends on X86 || ARM64 || LOONGARCH || RISCV diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 61ca4afe83dc..84e2a2519bae 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -100,6 +100,7 @@ obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o obj-$(CONFIG_ACPI_BGRT) += bgrt.o obj-$(CONFIG_ACPI_CPPC_LIB) += cppc_acpi.o obj-$(CONFIG_ACPI_SPCR_TABLE) += spcr.o +obj-$(CONFIG_ACPI_RAS2) += ras2.o obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o obj-$(CONFIG_ACPI_PPTT) += pptt.o obj-$(CONFIG_ACPI_PFRUT) += pfr_update.o pfr_telemetry.o diff --git a/drivers/acpi/ras2.c b/drivers/acpi/ras2.c new file mode 100755 index 000000000000..56ad7667ce81 --- /dev/null +++ b/drivers/acpi/ras2.c @@ -0,0 +1,409 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of ACPI RAS2 driver. + * + * Copyright (c) 2024 HiSilicon Limited. + * + * Support for RAS2 - ACPI 6.5 Specification, section 5.2.21 + * + * Driver contains ACPI RAS2 init, which extracts the ACPI RAS2 table and + * get the PCC channel subspace for communicating with the ACPI compliant + * HW platform which supports ACPI RAS2. Driver adds platform devices + * for each RAS2 memory feature which binds to the memory ACPI RAS2 driver. + */ + +#define pr_fmt(fmt) "ACPI RAS2: " fmt + +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/ktime.h> +#include <linux/platform_device.h> +#include <acpi/pcc.h> +#include <acpi/ras2_acpi.h> + +/* Data structure for PCC communication */ +struct ras2_pcc_subspace { + int pcc_subspace_id; + struct mbox_client mbox_client; + struct pcc_mbox_chan *pcc_chan; + struct acpi_ras2_shared_memory __iomem *pcc_comm_addr; + bool pcc_channel_acquired; + ktime_t deadline; + unsigned int pcc_mpar; + unsigned int pcc_mrtt; + struct list_head elem; + u16 ref_count; +}; + +/* + * Arbitrary Retries for PCC commands because the + * remote processor could be much slower to reply. + */ +#define RAS2_NUM_RETRIES 600 + +#define RAS2_FEATURE_TYPE_MEMORY 0x00 + +/* global variables for the RAS2 PCC subspaces */ +static DEFINE_MUTEX(ras2_pcc_subspace_lock); +static LIST_HEAD(ras2_pcc_subspaces); + +static int ras2_report_cap_error(u32 cap_status) +{ + switch (cap_status) { + case ACPI_RAS2_NOT_VALID: + case ACPI_RAS2_NOT_SUPPORTED: + return -EPERM; + case ACPI_RAS2_BUSY: + return -EBUSY; + case ACPI_RAS2_FAILED: + case ACPI_RAS2_ABORTED: + case ACPI_RAS2_INVALID_DATA: + return -EINVAL; + default: /* 0 or other, Success */ + return 0; + } +} + +static int ras2_check_pcc_chan(struct ras2_pcc_subspace *pcc_subspace) +{ + struct acpi_ras2_shared_memory __iomem *generic_comm_base = pcc_subspace->pcc_comm_addr; + ktime_t next_deadline = ktime_add(ktime_get(), pcc_subspace->deadline); + u32 cap_status; + u16 status; + u32 ret; + + while (!ktime_after(ktime_get(), next_deadline)) { + /* + * As per ACPI spec, the PCC space will be initialized by + * platform and should have set the command completion bit when + * PCC can be used by OSPM + */ + status = readw_relaxed(&generic_comm_base->status); + if (status & RAS2_PCC_CMD_ERROR) { + cap_status = readw_relaxed(&generic_comm_base->set_capabilities_status); + ret = ras2_report_cap_error(cap_status); + + status &= ~RAS2_PCC_CMD_ERROR; + writew_relaxed(status, &generic_comm_base->status); + return ret; + } + if (status & RAS2_PCC_CMD_COMPLETE) + return 0; + /* + * Reducing the bus traffic in case this loop takes longer than + * a few retries. + */ + msleep(10); + } + + return -EIO; +} + +/** + * ras2_send_pcc_cmd() - Send RAS2 command via PCC channel + * @ras2_ctx: pointer to the RAS2 context structure + * @cmd: command to send + * + * Returns: 0 on success, an error otherwise + */ +int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd) +{ + struct ras2_pcc_subspace *pcc_subspace = ras2_ctx->pcc_subspace; + struct acpi_ras2_shared_memory *generic_comm_base = pcc_subspace->pcc_comm_addr; + static ktime_t last_cmd_cmpl_time, last_mpar_reset; + struct mbox_chan *pcc_channel; + unsigned int time_delta; + static int mpar_count; + int ret; + + guard(mutex)(&ras2_pcc_subspace_lock); + ret = ras2_check_pcc_chan(pcc_subspace); + if (ret < 0) + return ret; + pcc_channel = pcc_subspace->pcc_chan->mchan; + + /* + * Handle the Minimum Request Turnaround Time(MRTT) + * "The minimum amount of time that OSPM must wait after the completion + * of a command before issuing the next command, in microseconds" + */ + if (pcc_subspace->pcc_mrtt) { + time_delta = ktime_us_delta(ktime_get(), last_cmd_cmpl_time); + if (pcc_subspace->pcc_mrtt > time_delta) + udelay(pcc_subspace->pcc_mrtt - time_delta); + } + + /* + * Handle the non-zero Maximum Periodic Access Rate(MPAR) + * "The maximum number of periodic requests that the subspace channel can + * support, reported in commands per minute. 0 indicates no limitation." + * + * This parameter should be ideally zero or large enough so that it can + * handle maximum number of requests that all the cores in the system can + * collectively generate. If it is not, we will follow the spec and just + * not send the request to the platform after hitting the MPAR limit in + * any 60s window + */ + if (pcc_subspace->pcc_mpar) { + if (mpar_count == 0) { + time_delta = ktime_ms_delta(ktime_get(), last_mpar_reset); + if (time_delta < 60 * MSEC_PER_SEC) { + dev_dbg(ras2_ctx->dev, + "PCC cmd not sent due to MPAR limit"); + return -EIO; + } + last_mpar_reset = ktime_get(); + mpar_count = pcc_subspace->pcc_mpar; + } + mpar_count--; + } + + /* Write to the shared comm region. */ + writew_relaxed(cmd, &generic_comm_base->command); + + /* Flip CMD COMPLETE bit */ + writew_relaxed(0, &generic_comm_base->status); + + /* Ring doorbell */ + ret = mbox_send_message(pcc_channel, &cmd); + if (ret < 0) { + dev_err(ras2_ctx->dev, + "Err sending PCC mbox message. cmd:%d, ret:%d\n", + cmd, ret); + return ret; + } + + /* + * If Minimum Request Turnaround Time is non-zero, we need + * to record the completion time of both READ and WRITE + * command for proper handling of MRTT, so we need to check + * for pcc_mrtt in addition to CMD_READ + */ + if (cmd == RAS2_PCC_CMD_EXEC || pcc_subspace->pcc_mrtt) { + ret = ras2_check_pcc_chan(pcc_subspace); + if (pcc_subspace->pcc_mrtt) + last_cmd_cmpl_time = ktime_get(); + } + + if (pcc_channel->mbox->txdone_irq) + mbox_chan_txdone(pcc_channel, ret); + else + mbox_client_txdone(pcc_channel, ret); + + return ret >= 0 ? 0 : ret; +} +EXPORT_SYMBOL_GPL(ras2_send_pcc_cmd); + +static int ras2_register_pcc_channel(struct ras2_mem_ctx *ras2_ctx, int pcc_subspace_id) +{ + struct ras2_pcc_subspace *pcc_subspace; + struct acpi_pcct_hw_reduced *ras2_ss; + struct pcc_mbox_chan *pcc_chan; + struct mbox_client *mbox_cl; + + if (pcc_subspace_id < 0) + return -EINVAL; + + mutex_lock(&ras2_pcc_subspace_lock); + list_for_each_entry(pcc_subspace, &ras2_pcc_subspaces, elem) { + if (pcc_subspace->pcc_subspace_id == pcc_subspace_id) { + ras2_ctx->pcc_subspace = pcc_subspace; + pcc_subspace->ref_count++; + mutex_unlock(&ras2_pcc_subspace_lock); + return 0; + } + } + mutex_unlock(&ras2_pcc_subspace_lock); + + pcc_subspace = kcalloc(1, sizeof(*pcc_subspace), GFP_KERNEL); + if (!pcc_subspace) + return -ENOMEM; + mbox_cl = &pcc_subspace->mbox_client; + mbox_cl->knows_txdone = true; + + pcc_chan = pcc_mbox_request_channel(mbox_cl, pcc_subspace_id); + if (IS_ERR(pcc_chan)) { + kfree(pcc_subspace); + return PTR_ERR(pcc_chan); + } + ras2_ss = pcc_chan->mchan->con_priv; + *pcc_subspace = (struct ras2_pcc_subspace) { + .pcc_subspace_id = pcc_subspace_id, + .pcc_chan = pcc_chan, + .pcc_comm_addr = acpi_os_ioremap(ras2_ss->base_address, + ras2_ss->length), + .deadline = ns_to_ktime(RAS2_NUM_RETRIES * + ras2_ss->latency * + NSEC_PER_USEC), + .pcc_mrtt = ras2_ss->min_turnaround_time, + .pcc_mpar = ras2_ss->max_access_rate, + .mbox_client = { + .knows_txdone = true, + }, + .pcc_channel_acquired = true, + }; + mutex_lock(&ras2_pcc_subspace_lock); + list_add(&pcc_subspace->elem, &ras2_pcc_subspaces); + pcc_subspace->ref_count++; + mutex_unlock(&ras2_pcc_subspace_lock); + ras2_ctx->pcc_subspace = pcc_subspace; + ras2_ctx->pcc_comm_addr = pcc_subspace->pcc_comm_addr; + ras2_ctx->dev = pcc_chan->mchan->mbox->dev; + + return 0; +} + +static DEFINE_IDA(ras2_ida); +static void ras2_remove_pcc(struct ras2_mem_ctx *ras2_ctx) +{ + struct ras2_pcc_subspace *pcc_subspace = ras2_ctx->pcc_subspace; + + guard(mutex)(&ras2_pcc_subspace_lock); + if (pcc_subspace->ref_count > 0) + pcc_subspace->ref_count--; + if (!pcc_subspace->ref_count) { + list_del(&pcc_subspace->elem); + pcc_mbox_free_channel(pcc_subspace->pcc_chan); + kfree(pcc_subspace); + } +} + +static void ras2_release(struct device *device) +{ + struct auxiliary_device *auxdev = container_of(device, struct auxiliary_device, dev); + struct ras2_mem_ctx *ras2_ctx = container_of(auxdev, struct ras2_mem_ctx, adev); + + ida_free(&ras2_ida, auxdev->id); + ras2_remove_pcc(ras2_ctx); + kfree(ras2_ctx); +} + +static struct ras2_mem_ctx *ras2_add_aux_device(char *name, int channel) +{ + struct ras2_mem_ctx *ras2_ctx; + int id, ret; + + ras2_ctx = kzalloc(sizeof(*ras2_ctx), GFP_KERNEL); + if (!ras2_ctx) + return ERR_PTR(-ENOMEM); + + mutex_init(&ras2_ctx->lock); + + ret = ras2_register_pcc_channel(ras2_ctx, channel); + if (ret < 0) { + pr_debug("failed to register pcc channel ret=%d\n", ret); + goto ctx_free; + } + + id = ida_alloc(&ras2_ida, GFP_KERNEL); + if (id < 0) { + ret = id; + goto pcc_free; + } + ras2_ctx->id = id; + ras2_ctx->adev.id = id; + ras2_ctx->adev.name = RAS2_MEM_DEV_ID_NAME; + ras2_ctx->adev.dev.release = ras2_release; + ras2_ctx->adev.dev.parent = ras2_ctx->dev; + + ret = auxiliary_device_init(&ras2_ctx->adev); + if (ret) + goto ida_free; + + ret = auxiliary_device_add(&ras2_ctx->adev); + if (ret) { + auxiliary_device_uninit(&ras2_ctx->adev); + return ERR_PTR(ret); + } + + return ras2_ctx; + +ida_free: + ida_free(&ras2_ida, id); +pcc_free: + ras2_remove_pcc(ras2_ctx); +ctx_free: + kfree(ras2_ctx); + return ERR_PTR(ret); +} + +static int __init ras2_acpi_init(void) +{ + struct acpi_table_header *pAcpiTable = NULL; + struct acpi_ras2_pcc_desc *pcc_desc_list; + struct acpi_table_ras2 *pRas2Table; + struct ras2_mem_ctx *ras2_ctx; + int pcc_subspace_id; + acpi_size ras2_size; + acpi_status status; + u8 count = 0, i; + int ret = 0; + + status = acpi_get_table("RAS2", 0, &pAcpiTable); + if (ACPI_FAILURE(status) || !pAcpiTable) { + pr_err("ACPI RAS2 driver failed to initialize, get table failed\n"); + return -EINVAL; + } + + ras2_size = pAcpiTable->length; + if (ras2_size < sizeof(struct acpi_table_ras2)) { + pr_err("ACPI RAS2 table present but broken (too short #1)\n"); + ret = -EINVAL; + goto free_ras2_table; + } + + pRas2Table = (struct acpi_table_ras2 *)pAcpiTable; + if (pRas2Table->num_pcc_descs <= 0) { + pr_err("ACPI RAS2 table does not contain PCC descriptors\n"); + ret = -EINVAL; + goto free_ras2_table; + } + + pcc_desc_list = (struct acpi_ras2_pcc_desc *)(pRas2Table + 1); + /* Double scan for the case of only one actual controller */ + pcc_subspace_id = -1; + count = 0; + for (i = 0; i < pRas2Table->num_pcc_descs; i++, pcc_desc_list++) { + if (pcc_desc_list->feature_type != RAS2_FEATURE_TYPE_MEMORY) + continue; + if (pcc_subspace_id == -1) { + pcc_subspace_id = pcc_desc_list->channel_id; + count++; + } + if (pcc_desc_list->channel_id != pcc_subspace_id) + count++; + } + /* + * Workaround for the client platform with multiple scrub devices + * but uses single PCC subspace for communication. + */ + if (count == 1) { + /* Add auxiliary device and bind ACPI RAS2 memory driver */ + ras2_ctx = ras2_add_aux_device(RAS2_MEM_DEV_ID_NAME, pcc_subspace_id); + if (IS_ERR(ras2_ctx)) { + ret = PTR_ERR(ras2_ctx); + goto free_ras2_table; + } + acpi_put_table(pAcpiTable); + return 0; + } + + pcc_desc_list = (struct acpi_ras2_pcc_desc *)(pRas2Table + 1); + count = 0; + for (i = 0; i < pRas2Table->num_pcc_descs; i++, pcc_desc_list++) { + if (pcc_desc_list->feature_type != RAS2_FEATURE_TYPE_MEMORY) + continue; + pcc_subspace_id = pcc_desc_list->channel_id; + /* Add auxiliary device and bind ACPI RAS2 memory driver */ + ras2_ctx = ras2_add_aux_device(RAS2_MEM_DEV_ID_NAME, pcc_subspace_id); + if (IS_ERR(ras2_ctx)) { + ret = PTR_ERR(ras2_ctx); + goto free_ras2_table; + } + } + +free_ras2_table: + acpi_put_table(pAcpiTable); + return ret; +} +late_initcall(ras2_acpi_init) diff --git a/include/acpi/ras2_acpi.h b/include/acpi/ras2_acpi.h new file mode 100644 index 000000000000..7b32407ae2af --- /dev/null +++ b/include/acpi/ras2_acpi.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * RAS2 ACPI driver header file + * + * (C) Copyright 2014, 2015 Hewlett-Packard Enterprises + * + * Copyright (c) 2024 HiSilicon Limited + */ + +#ifndef _RAS2_ACPI_H +#define _RAS2_ACPI_H + +#include <linux/acpi.h> +#include <linux/auxiliary_bus.h> +#include <linux/mailbox_client.h> +#include <linux/mutex.h> +#include <linux/types.h> + +#define RAS2_PCC_CMD_COMPLETE BIT(0) +#define RAS2_PCC_CMD_ERROR BIT(2) + +/* RAS2 specific PCC commands */ +#define RAS2_PCC_CMD_EXEC 0x01 + +#define RAS2_AUX_DEV_NAME "ras2" +#define RAS2_MEM_DEV_ID_NAME "acpi_ras2_mem" + +/* Data structure RAS2 table */ +struct ras2_mem_ctx { + struct auxiliary_device adev; + /* Lock to provide mutually exclusive access to PCC channel */ + struct mutex lock; + int id; + u8 instance; + bool bg; + u64 base, size; + u8 scrub_cycle_hrs, min_scrub_cycle, max_scrub_cycle; + struct device *dev; + struct device *scrub_dev; + void *pcc_subspace; + struct acpi_ras2_shared_memory __iomem *pcc_comm_addr; +}; + +int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd); +#endif /* _RAS2_ACPI_H */