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[81.98.232.178]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47a9e4d8410sm55607342f8f.15.2026.07.09.14.08.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jul 2026 14:08:05 -0700 (PDT) From: shijujose2008@gmail.com To: rafael@kernel.org, bp@alien8.de, akpm@linux-foundation.org, rppt@kernel.org, dferguson@amperecomputing.com, linux-edac@vger.kernel.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, tony.luck@intel.com, lenb@kernel.org, Yazen.Ghannam@amd.com, mchehab@kernel.org, ashok.raj@oss.qualcomm.com Cc: jic23@kernel.org, linuxarm@huawei.com, rientjes@google.com, jiaqiyan@google.com, Jon.Grimm@amd.com, dave.hansen@linux.intel.com, naoya.horiguchi@nec.com, james.morse@arm.com, jthoughton@google.com, somasundaram.a@hpe.com, erdemaktas@google.com, pgonda@google.com, duenwen@google.com, gthelen@google.com, wschwartz@amperecomputing.com, wbs@os.amperecomputing.com, nifan.cxl@gmail.com, tanxiaofei@huawei.com, prime.zeng@hisilicon.com, roberto.sassu@huawei.com, kangkang.shen@futurewei.com, wanghuiqiang@huawei.com, shijujose2008@gmail.com Subject: [PATCH v22 1/2] ACPI:RAS2: Add driver for the ACPI RAS2 feature table Date: Thu, 9 Jul 2026 22:07:49 +0100 Message-Id: <20260709210750.424659-2-shijujose2008@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260709210750.424659-1-shijujose2008@gmail.com> References: <20260709210750.424659-1-shijujose2008@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: EF53C18000B X-Stat-Signature: n7r4mr74x1sxhmcwnt5oup9kggujmmur X-HE-Tag: 1783631287-276733 X-HE-Meta: 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 alAaCqxI 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Shiju Jose ACPI 6.5 Specification, section 5.2.21, defined RAS2 feature table (RAS2). Driver adds support for RAS2 feature table, which provides interfaces for platform RAS features, e.g., for HW-based memory scrubbing, and logical to PA translation service. RAS2 uses PCC channel subspace for communicating with the ACPI compliant HW platform. Co-developed-by: A Somasundaram Signed-off-by: A Somasundaram Co-developed-by: Jonathan Cameron Signed-off-by: Jonathan Cameron Tested-by: Daniel Ferguson Reviewed-by: Ashok Raj Signed-off-by: Shiju Jose --- drivers/acpi/Kconfig | 11 + drivers/acpi/Makefile | 1 + drivers/acpi/bus.c | 3 + drivers/acpi/ras2.c | 502 ++++++++++++++++++++++++++++++++++++++++++ include/acpi/ras2.h | 57 +++++ 5 files changed, 574 insertions(+) create mode 100644 drivers/acpi/ras2.c create mode 100644 include/acpi/ras2.h diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index f165d14cf61a..539ff143ccc5 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -294,6 +294,17 @@ 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 + depends on MAILBOX + depends on PCC + help + Add support for the RAS2 feature table and provide interfaces for + platform RAS features, such as hardware-based memory scrubbing. + + If unsure, select N. + config ACPI_PROCESSOR tristate "Processor" depends on X86 || ARM64 || LOONGARCH || RISCV diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index d1b0affb844f..abfec6745724 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -105,6 +105,7 @@ 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/bus.c b/drivers/acpi/bus.c index a30a904f6535..8d6a0b773bc5 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -31,6 +31,7 @@ #include #include #include +#include #include "internal.h" @@ -1610,6 +1611,8 @@ static int __init acpi_init(void) acpi_debugger_init(); acpi_setup_sb_notify_handler(); acpi_viot_init(); + acpi_ras2_init(); + return 0; } diff --git a/drivers/acpi/ras2.c b/drivers/acpi/ras2.c new file mode 100644 index 000000000000..b66700e0e7d3 --- /dev/null +++ b/drivers/acpi/ras2.c @@ -0,0 +1,502 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ACPI RAS2 feature table driver. + * + * Copyright (c) 2024-2026 HiSilicon Limited. + * + * Support for RAS2 table - ACPI 6.5 Specification, section 5.2.21, which + * provides interfaces for platform RAS features, e.g., for HW-based memory + * scrubbing, and logical to physical address translation service. RAS2 uses + * PCC channel subspace for communicating with the ACPI compliant HW platform. + */ + +#undef pr_fmt +#define pr_fmt(fmt) "ACPI RAS2: " fmt + +#include +#include +#include +#include +#include +#include + +/** + * struct ras2_sspcc - Data structure for PCC communication + * @mbox_client: struct mbox_client object + * @pcc_chan: Pointer to struct pcc_mbox_chan + * @comm_addr: Pointer to RAS2 PCC shared memory region + * @elem: List for registered RAS2 PCC channel subspaces + * @pcc_lock: PCC lock to provide mutually exclusive access + * to PCC channel subspace + * @deadline_us: Poll PCC status register timeout in microsecs + * for PCC command completion + * @pcc_mpar: Maximum Periodic Access Rate (MPAR) for PCC channel + * @pcc_mrtt: Minimum Request Turnaround Time (MRTT) in microsecs + * OS must wait after completion of a PCC command before + * issuing next command + * @last_cmd_cmpl_time: Completion time of last PCC command + * @last_mpar_reset: Time of last MPAR count reset + * @mpar_count: MPAR count + * @pcc_id: Identifier of the RAS2 platform communication channel + * @last_cmd: Last PCC command + * @kref: kref object + */ +struct ras2_sspcc { + struct mbox_client mbox_client; + struct pcc_mbox_chan *pcc_chan; + struct acpi_ras2_shmem __iomem *comm_addr; + struct list_head elem; + struct mutex pcc_lock; + u64 deadline_us; + unsigned int pcc_mpar; + unsigned int pcc_mrtt; + ktime_t last_cmd_cmpl_time; + ktime_t last_mpar_reset; + int mpar_count; + int pcc_id; + u16 last_cmd; + struct kref kref; +}; + +/* + * Arbitrary retries for PCC commands because the remote processor could be + * much slower to reply. Keep it high enough to cover emulators where the + * processors run painfully slow. + */ +#define PCC_NUM_RETRIES 600ULL +#define PCC_CHNL_DEFAULT_LATENCY 1000 +#define PCC_MIN_POLL_USECS 3 + +#define RAS2_MAX_NUM_PCC_DESCS 100 +#define RAS2_FEAT_TYPE_MEMORY 0x00 + +/* Static variables for the RAS2 PCC subspaces */ +static DEFINE_MUTEX(ras2_pcc_list_lock); +static LIST_HEAD(ras2_sspcc); + +static int check_pcc_chan(struct ras2_sspcc *sspcc) +{ + struct acpi_ras2_shmem __iomem *gen_comm_base = sspcc->comm_addr; + u32 cap_status; + u16 status; + int rc; + + /* + * As per ACPI spec, the PCC space will be initialized by the + * platform and should have set the command completion bit when + * PCC can be used by OSPM. + * + * Poll PCC status register every PCC_MIN_POLL_USECS for maximum of + * PCC_NUM_RETRIES * PCC channel latency until PCC command complete + * bit is set. + */ + rc = readw_relaxed_poll_timeout(&gen_comm_base->status, status, + status & PCC_STATUS_CMD_COMPLETE, + PCC_MIN_POLL_USECS, sspcc->deadline_us); + if (rc) { + pr_warn("PCC ID: 0x%x: PCC check channel timeout for last command: 0x%x rc=%d\n", + sspcc->pcc_id, sspcc->last_cmd, rc); + + return rc; + } + + if (status & PCC_STATUS_ERROR) { + pr_warn("PCC ID: 0x%x: Error in executing last command: 0x%x\n", + sspcc->pcc_id, sspcc->last_cmd); + status &= ~PCC_STATUS_ERROR; + iowrite16(status, &gen_comm_base->status); + iowrite32(0x0, &gen_comm_base->set_caps_status); + return -EIO; + } + + /* Ensure get updated PCC status */ + rmb(); + cap_status = ioread32(&gen_comm_base->set_caps_status); + switch (cap_status) { + case ACPI_RAS2_NOT_VALID: + case ACPI_RAS2_NOT_SUPPORTED: + rc = -EPERM; + break; + case ACPI_RAS2_BUSY: + rc = -EBUSY; + break; + case ACPI_RAS2_FAILED: + case ACPI_RAS2_ABORTED: + case ACPI_RAS2_INVALID_DATA: + rc = -EINVAL; + break; + default: + rc = 0; + } + + iowrite32(0x0, &gen_comm_base->set_caps_status); + + return rc; +} + +/** + * ras2_send_pcc_cmd() - Send RAS2 command via PCC channel + * @ras2_ctx: pointer to the RAS2 context structure + * @cmd: RAS2 command to send + * + * Returns: 0 on success, an error otherwise + */ +int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd) +{ + struct acpi_ras2_shmem __iomem *gen_comm_base; + struct mbox_chan *pcc_channel; + struct ras2_sspcc *sspcc; + s64 time_delta; + u16 val; + int rc; + + if (!ras2_ctx) + return -EINVAL; + + lockdep_assert_held(ras2_ctx->pcc_lock); + sspcc = ras2_ctx->sspcc; + gen_comm_base = sspcc->comm_addr; + + rc = check_pcc_chan(sspcc); + if (rc < 0) + return rc; + + pcc_channel = sspcc->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 (sspcc->pcc_mrtt) { + time_delta = ktime_us_delta(ktime_get(), sspcc->last_cmd_cmpl_time); + if (sspcc->pcc_mrtt > time_delta) + fsleep(sspcc->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, follow the spec and + * just not send the request to the platform after hitting the MPAR + * limit in any 60s window. + */ + if (sspcc->pcc_mpar) { + if (!sspcc->mpar_count) { + time_delta = ktime_ms_delta(ktime_get(), sspcc->last_mpar_reset); + if ((time_delta < 60 * MSEC_PER_SEC) && sspcc->last_mpar_reset) { + dev_dbg(ras2_ctx->dev, + "PCC command 0x%x not sent due to MPAR limit", cmd); + return -EIO; + } + sspcc->last_mpar_reset = ktime_get(); + sspcc->mpar_count = sspcc->pcc_mpar; + } + sspcc->mpar_count--; + } + + /* Write to the shared comm region */ + iowrite16(cmd, &gen_comm_base->command); + + /* Flip CMD COMPLETE bit */ + iowrite16(0, &gen_comm_base->status); + + /* Ring doorbell */ + rc = mbox_send_message(pcc_channel, &cmd); + /* + * mbox_send_message() returns a non-negative integer for successful submission + * and a negative value on failure. + */ + if (rc < 0) { + dev_warn(ras2_ctx->dev, + "Error sending PCC mbox message command: 0x%x, rc:%d\n", cmd, rc); + /* Restore CMD COMPLETE bit on error */ + val = ioread16(&gen_comm_base->status); + val |= PCC_STATUS_CMD_COMPLETE; + iowrite16(val, &gen_comm_base->status); + return rc; + } else { + rc = 0; + } + + sspcc->last_cmd = cmd; + + /* + * If Minimum Request Turnaround Time is non-zero, need to record the + * completion time of both READ and WRITE commands for proper handling + * of MRTT, so need to check for pcc_mrtt in addition to PCC_CMD_EXEC_RAS2. + */ + if (cmd == PCC_CMD_EXEC_RAS2 || sspcc->pcc_mrtt) { + rc = check_pcc_chan(sspcc); + if (sspcc->pcc_mrtt) + sspcc->last_cmd_cmpl_time = ktime_get(); + } + + if (!pcc_channel->mbox->txdone_irq) + mbox_client_txdone(pcc_channel, rc); + + return rc; +} +EXPORT_SYMBOL_FOR_MODULES(ras2_send_pcc_cmd, "acpi_ras2"); + +static void ras2_list_pcc_release(struct kref *kref) +{ + struct ras2_sspcc *sspcc = + container_of(kref, struct ras2_sspcc, kref); + + guard(mutex)(&ras2_pcc_list_lock); + list_del(&sspcc->elem); + pcc_mbox_free_channel(sspcc->pcc_chan); + kfree(sspcc); +} + +static void ras2_sspcc_put(struct ras2_sspcc *sspcc) +{ + kref_put(&sspcc->kref, &ras2_list_pcc_release); +} + +static struct ras2_sspcc *ras2_sspcc_get(int pcc_id) +{ + struct ras2_sspcc *sspcc; + + guard(mutex)(&ras2_pcc_list_lock); + list_for_each_entry(sspcc, &ras2_sspcc, elem) { + if (sspcc->pcc_id != pcc_id) + continue; + + if (!kref_get_unless_zero(&sspcc->kref)) + break; + + return sspcc; + } + + return NULL; +} + +static int register_pcc_channel(struct ras2_mem_ctx *ras2_ctx, int pcc_id) +{ + struct pcc_mbox_chan *pcc_chan; + struct ras2_sspcc *sspcc; + + if (pcc_id < 0) + return -EINVAL; + + sspcc = ras2_sspcc_get(pcc_id); + if (sspcc) { + ras2_ctx->sspcc = sspcc; + ras2_ctx->comm_addr = sspcc->comm_addr; + ras2_ctx->dev = + sspcc->pcc_chan->mchan->mbox->dev; + ras2_ctx->pcc_lock = &sspcc->pcc_lock; + return 0; + } + + sspcc = kzalloc(sizeof(*sspcc), GFP_KERNEL); + if (!sspcc) + return -ENOMEM; + + pcc_chan = pcc_mbox_request_channel(&sspcc->mbox_client, pcc_id); + if (IS_ERR(pcc_chan)) { + kfree(sspcc); + return PTR_ERR(pcc_chan); + } + + if (!pcc_chan->shmem) { + pcc_mbox_free_channel(pcc_chan); + kfree(sspcc); + return -EINVAL; + } + + sspcc->pcc_id = pcc_id; + sspcc->pcc_chan = pcc_chan; + sspcc->comm_addr = pcc_chan->shmem; + if (pcc_chan->latency) + sspcc->deadline_us = PCC_NUM_RETRIES * pcc_chan->latency; + else + sspcc->deadline_us = PCC_NUM_RETRIES * PCC_CHNL_DEFAULT_LATENCY; + sspcc->pcc_mrtt = pcc_chan->min_turnaround_time; + sspcc->pcc_mpar = pcc_chan->max_access_rate; + sspcc->mbox_client.knows_txdone = true; + + mutex_init(&sspcc->pcc_lock); + kref_init(&sspcc->kref); + + mutex_lock(&ras2_pcc_list_lock); + list_add(&sspcc->elem, &ras2_sspcc); + mutex_unlock(&ras2_pcc_list_lock); + + ras2_ctx->sspcc = sspcc; + ras2_ctx->comm_addr = sspcc->comm_addr; + ras2_ctx->dev = pcc_chan->mchan->mbox->dev; + ras2_ctx->pcc_lock = &sspcc->pcc_lock; + + return 0; +} + +static DEFINE_IDA(ras2_ida); +static void ras2_release(struct device *device) +{ + struct auxiliary_device *auxdev = to_auxiliary_dev(device); + struct ras2_mem_ctx *ras2_ctx = container_of(auxdev, struct ras2_mem_ctx, adev); + + ida_free(&ras2_ida, auxdev->id); + ras2_sspcc_put(ras2_ctx->sspcc); + kfree(ras2_ctx); +} + +static struct ras2_mem_ctx *add_aux_device(char *name, int channel, u32 pxm_inst) +{ + struct ras2_mem_ctx *ras2_ctx; + u32 comp_nid; + int id, rc; + + comp_nid = pxm_to_node(pxm_inst); + if (comp_nid == NUMA_NO_NODE) { + pr_debug("Invalid NUMA node, channel=%d pxm_inst=%d\n", channel, pxm_inst); + return ERR_PTR(-ENXIO); + } + + ras2_ctx = kzalloc(sizeof(*ras2_ctx), GFP_KERNEL); + if (!ras2_ctx) + return ERR_PTR(-ENOMEM); + + ras2_ctx->sys_comp_nid = comp_nid; + + rc = register_pcc_channel(ras2_ctx, channel); + if (rc < 0) { + pr_debug("Failed to register PCC channel=%d pxm_inst=%d rc=%d\n", channel, + pxm_inst, rc); + goto ctx_free; + } + + id = ida_alloc(&ras2_ida, GFP_KERNEL); + if (id < 0) { + rc = id; + goto pcc_free; + } + + ras2_ctx->adev.id = id; + ras2_ctx->adev.name = name; + ras2_ctx->adev.dev.release = ras2_release; + ras2_ctx->adev.dev.parent = ras2_ctx->dev; + + rc = auxiliary_device_init(&ras2_ctx->adev); + if (rc) + goto ida_free; + + rc = auxiliary_device_add(&ras2_ctx->adev); + if (rc) { + auxiliary_device_uninit(&ras2_ctx->adev); + return ERR_PTR(rc); + } + + return ras2_ctx; + +ida_free: + ida_free(&ras2_ida, id); +pcc_free: + ras2_sspcc_put(ras2_ctx->sspcc); +ctx_free: + kfree(ras2_ctx); + + return ERR_PTR(rc); +} + +static void remove_aux_device(struct ras2_mem_ctx *ras2_ctx) +{ + if (!ras2_ctx) + return; + + auxiliary_device_delete(&ras2_ctx->adev); + auxiliary_device_uninit(&ras2_ctx->adev); +} + +static int parse_ras2_table(struct acpi_table_ras2 *ras2_tab) +{ + struct acpi_ras2_pcc_desc *pcc_desc_list; + struct ras2_mem_ctx **pctx_list; + struct ras2_mem_ctx *ras2_ctx; + u16 tot_tbl_len; + u16 i; + + if (ras2_tab->header.length < sizeof(*ras2_tab)) { + pr_warn(FW_WARN "ACPI RAS2 table present but broken (too short, size=%u)\n", + ras2_tab->header.length); + return -EINVAL; + } + + if (!ras2_tab->num_pcc_descs || ras2_tab->num_pcc_descs > RAS2_MAX_NUM_PCC_DESCS) { + pr_warn(FW_WARN "No/Invalid number of PCC descs(%d) in ACPI RAS2 table\n", + ras2_tab->num_pcc_descs); + return -EINVAL; + } + + tot_tbl_len = sizeof(*ras2_tab) + ras2_tab->num_pcc_descs * sizeof(*pcc_desc_list); + if (ras2_tab->header.length < tot_tbl_len) { + pr_warn(FW_WARN "RAS2 table is not large enough to contain PCC descs=%d size=%u)\n", + ras2_tab->num_pcc_descs, ras2_tab->header.length); + return -EINVAL; + } + + pctx_list = kcalloc(ras2_tab->num_pcc_descs, sizeof(*pctx_list), GFP_KERNEL); + if (!pctx_list) + return -ENOMEM; + + pcc_desc_list = (struct acpi_ras2_pcc_desc *)(ras2_tab + 1); + for (i = 0; i < ras2_tab->num_pcc_descs; i++, pcc_desc_list++) { + if (pcc_desc_list->feature_type != RAS2_FEAT_TYPE_MEMORY) + continue; + + ras2_ctx = add_aux_device(RAS2_MEM_DEV_ID_NAME, pcc_desc_list->channel_id, + pcc_desc_list->instance); + /* Invalid NUMA node, continue parsing next node */ + if (PTR_ERR(ras2_ctx) == -ENXIO) + continue; + + if (IS_ERR(ras2_ctx)) { + pr_warn("Failed to add RAS2 auxiliary device rc=%ld\n", PTR_ERR(ras2_ctx)); + for (; i > 0; i--) { + if (pctx_list[i - 1]) + remove_aux_device(pctx_list[i - 1]); + } + kfree(pctx_list); + return PTR_ERR(ras2_ctx); + } + pctx_list[i] = ras2_ctx; + } + kfree(pctx_list); + + return 0; +} + +/** + * acpi_ras2_init - RAS2 driver initialization function. + * + * Extracts the ACPI RAS2 table and retrieves ID for the PCC channel subspace + * for communicating with the ACPI compliant HW platform. Driver adds an + * auxiliary device, which binds to the memory ACPI RAS2 driver, for each RAS2 + * memory feature. + * + * Returns: none. + */ +void __init acpi_ras2_init(void) +{ + struct acpi_table_ras2 *ras2_tab; + acpi_status status; + + status = acpi_get_table(ACPI_SIG_RAS2, 0, (struct acpi_table_header **)&ras2_tab); + if (ACPI_FAILURE(status)) { + pr_debug("Failed to get table, %s\n", acpi_format_exception(status)); + return; + } + + if (parse_ras2_table(ras2_tab)) + pr_debug("Failed to parse RAS2 table\n"); + + acpi_put_table((struct acpi_table_header *)ras2_tab); +} diff --git a/include/acpi/ras2.h b/include/acpi/ras2.h new file mode 100644 index 000000000000..f4574e8e0a12 --- /dev/null +++ b/include/acpi/ras2.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * ACPI RAS2 (RAS Feature Table) methods. + * + * Copyright (c) 2024-2026 HiSilicon Limited + */ + +#ifndef _ACPI_RAS2_H +#define _ACPI_RAS2_H + +#include +#include +#include +#include +#include + +struct device; + +/* + * ACPI spec 6.5 Table 5.82: PCC command codes used by + * RAS2 platform communication channel. + */ +#define PCC_CMD_EXEC_RAS2 0x01 + +#define RAS2_AUX_DEV_NAME "ras2" +#define RAS2_MEM_DEV_ID_NAME "acpi_ras2_mem" + +/** + * struct ras2_mem_ctx - Context for RAS2 memory features + * @adev: Auxiliary device object + * @comm_addr: Pointer to RAS2 PCC shared memory region + * @dev: Pointer to device backing struct mbox_controller for PCC + * @sspcc: Pointer to local data structure for PCC communication + * @pcc_lock: Pointer to PCC lock to provide mutually exclusive access + * to PCC channel subspace + * @sys_comp_nid: Node ID of the system component that the RAS feature + * is associated with. See ACPI spec 6.5 Table 5.80: RAS2 + * Platform Communication Channel Descriptor format, + * Field: Instance + */ +struct ras2_mem_ctx { + struct auxiliary_device adev; + struct acpi_ras2_shmem __iomem *comm_addr; + struct device *dev; + void *sspcc; + struct mutex *pcc_lock; + u32 sys_comp_nid; +}; + +#ifdef CONFIG_ACPI_RAS2 +void __init acpi_ras2_init(void); +int ras2_send_pcc_cmd(struct ras2_mem_ctx *ras2_ctx, u16 cmd); +#else +static inline void acpi_ras2_init(void) { } +#endif + +#endif /* _ACPI_RAS2_H */ -- 2.25.1