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, for eg. 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 Signed-off-by: Shiju Jose --- drivers/acpi/Kconfig | 12 ++ drivers/acpi/Makefile | 1 + drivers/acpi/bus.c | 3 + drivers/acpi/ras2.c | 398 ++++++++++++++++++++++++++++++++++++++++++ include/acpi/ras2.h | 57 ++++++ 5 files changed, 471 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 ca00a5dbcf75..bfa9f3f4def5 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -293,6 +293,18 @@ 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 + depends on NUMA_KEEP_MEMINFO + help + This driver adds support for RAS2 feature table provides interfaces + for platform RAS features, for eg. HW-based memory scrubbing. + If your platform does not support RAS2 in firmware, leave this + option disabled. + 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 a984ccd4a2a0..b02ceb2837c6 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -31,6 +31,7 @@ #include #include #include +#include #include "internal.h" @@ -1474,6 +1475,8 @@ 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..9df94d8c953c --- /dev/null +++ b/drivers/acpi/ras2.c @@ -0,0 +1,398 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ACPI RAS2 feature table driver. + * + * Copyright (c) 2024-2025 HiSilicon Limited. + * + * Support for RAS2 table - ACPI 6.5 Specification, section 5.2.21, which + * provides interfaces for platform RAS features, for eg. HW-based memory + * scrubbing, and logical to PA translation service. RAS2 uses PCC channel + * subspace for communicating with the ACPI compliant HW platform. + */ + +#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 micro secs + * for PCC command complete + * @pcc_mpar: Maximum Periodic Access Rate (MPAR) for PCC channel + * @pcc_mrtt: Minimum Request Turnaround Time (MRTT) in micro secs + * OS must wait after completion of a PCC command before + * issue 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 + * @pcc_chnl_acq: Status of PCC channel acquired + */ +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; + unsigned int 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; + bool pcc_chnl_acq; +}; + +/* + * Arbitrary retries for PCC commands because the remote processor + * could be much slower to reply. Keeping it high enough to cover + * emulators where the processors run painfully slow. + */ +#define PCC_NUM_RETRIES 600ULL + +#define RAS2_FEAT_TYPE_MEMORY 0x00 + +static int decode_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: + return 0; + } +} + +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 + * platform and should have set the command completion bit when + * PCC can be used by OSPM. + * + * Poll PCC status register every 3us for maximum of 600ULL * 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, 3, + sspcc->deadline_us); + if (rc) { + pr_warn("PCC check channel timeout for pcc_id=%d rc=%d\n", + sspcc->pcc_id, rc); + return rc; + } + + if (status & PCC_STATUS_ERROR) { + pr_warn("Error in executing last command=%d for pcc_id=%d\n", + sspcc->last_cmd, sspcc->pcc_id); + status &= ~PCC_STATUS_ERROR; + writew_relaxed(status, &gen_comm_base->status); + return -EIO; + } + + cap_status = readw_relaxed(&gen_comm_base->set_caps_status); + writew_relaxed(0x0, &gen_comm_base->set_caps_status); + return decode_cap_error(cap_status); +} + +/** + * 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_sspcc *sspcc = ras2_ctx->sspcc; + struct acpi_ras2_shmem __iomem *gen_comm_base = sspcc->comm_addr; + struct mbox_chan *pcc_channel; + unsigned int time_delta; + int rc; + + 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) + udelay(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 == 0) { + time_delta = ktime_ms_delta(ktime_get(), + sspcc->last_mpar_reset); + if (time_delta < 60 * MSEC_PER_SEC) { + dev_dbg(ras2_ctx->dev, + "PCC cmd(%u) 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 */ + writew_relaxed(cmd, &gen_comm_base->command); + + /* Flip CMD COMPLETE bit */ + writew_relaxed(0, &gen_comm_base->status); + + /* Ring doorbell */ + rc = mbox_send_message(pcc_channel, &cmd); + if (rc < 0) { + dev_warn(ras2_ctx->dev, + "Err sending PCC mbox message. cmd:%d, rc:%d\n", + cmd, rc); + return rc; + } + + sspcc->last_cmd = cmd; + + /* + * If Minimum Request Turnaround Time is non-zero, need + * to record the completion time of both READ and WRITE + * command 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_chan_txdone(pcc_channel, rc); + else + mbox_client_txdone(pcc_channel, rc); + + return rc < 0 ? rc : 0; +} +EXPORT_SYMBOL_GPL(ras2_send_pcc_cmd); + +static int register_pcc_channel(struct ras2_mem_ctx *ras2_ctx, int pcc_id) +{ + struct ras2_sspcc *sspcc; + struct pcc_mbox_chan *pcc_chan; + struct mbox_client *mbox_cl; + + if (pcc_id < 0) + return -EINVAL; + + sspcc = kzalloc(sizeof(*sspcc), GFP_KERNEL); + if (!sspcc) + return -ENOMEM; + + mbox_cl = &sspcc->mbox_client; + mbox_cl->knows_txdone = true; + + pcc_chan = pcc_mbox_request_channel(mbox_cl, pcc_id); + if (IS_ERR(pcc_chan)) { + kfree(sspcc); + return PTR_ERR(pcc_chan); + } + + sspcc->pcc_id = pcc_id; + sspcc->pcc_chan = pcc_chan; + sspcc->comm_addr = pcc_chan->shmem; + sspcc->deadline_us = PCC_NUM_RETRIES * pcc_chan->latency; + sspcc->pcc_mrtt = pcc_chan->min_turnaround_time; + sspcc->pcc_mpar = pcc_chan->max_access_rate; + sspcc->mbox_client.knows_txdone = true; + sspcc->pcc_chnl_acq = true; + + ras2_ctx->sspcc = sspcc; + ras2_ctx->comm_addr = sspcc->comm_addr; + ras2_ctx->dev = pcc_chan->mchan->mbox->dev; + + mutex_init(&sspcc->pcc_lock); + 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_sspcc *sspcc; + struct ras2_mem_ctx *ras2_ctx = + container_of(auxdev, struct ras2_mem_ctx, adev); + + ida_free(&ras2_ida, auxdev->id); + sspcc = ras2_ctx->sspcc; + pcc_mbox_free_channel(sspcc->pcc_chan); + kfree(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; + struct ras2_sspcc *sspcc; + int id, rc; + + ras2_ctx = kzalloc(sizeof(*ras2_ctx), GFP_KERNEL); + if (!ras2_ctx) + return ERR_PTR(-ENOMEM); + + ras2_ctx->sys_comp_nid = pxm_to_node(pxm_inst); + + rc = register_pcc_channel(ras2_ctx, channel); + if (rc < 0) { + pr_debug("Failed to register pcc channel rc=%d\n", 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 = RAS2_MEM_DEV_ID_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: + sspcc = ras2_ctx->sspcc; + pcc_mbox_free_channel(sspcc->pcc_chan); + kfree(sspcc); +ctx_free: + kfree(ras2_ctx); + + return ERR_PTR(rc); +} + +static void acpi_ras2_parse(struct acpi_table_ras2 *ras2_tab) +{ + struct acpi_ras2_pcc_desc *pcc_desc_list; + struct ras2_mem_ctx *ras2_ctx; + u16 i, count; + + 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; + } + + if (!ras2_tab->num_pcc_descs) { + pr_warn(FW_WARN "No PCC descs in ACPI RAS2 table\n"); + return; + } + + struct ras2_mem_ctx **pctx_list __free(kfree) = + kzalloc(ras2_tab->num_pcc_descs * sizeof(*pctx_list), + GFP_KERNEL); + if (!pctx_list) + return; + + count = 0; + 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); + if (IS_ERR(ras2_ctx)) { + pr_warn("Failed to add RAS2 auxiliary device rc=%ld\n", + PTR_ERR(ras2_ctx)); + for (i = count; i > 0; i--) + auxiliary_device_uninit(&pctx_list[i - 1]->adev); + return; + } + pctx_list[count++] = ras2_ctx; + } +} + +/** + * 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_err("Failed to get table, %s\n", acpi_format_exception(status)); + return; + } + + acpi_ras2_parse(ras2_tab); + 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..10deab0b5541 --- /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) 2024-2025 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 */ -- 2.43.0