@@ -284,6 +284,16 @@ 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 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
@@ -99,6 +99,7 @@ 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
new file mode 100755
@@ -0,0 +1,391 @@
+// 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>
+
+/*
+ * 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_scrub_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 device *dev, struct ras2_scrub_ctx *ras2_ctx,
+ int pcc_subspace_id)
+{
+ struct acpi_pcct_hw_reduced *ras2_ss;
+ struct mbox_client *ras2_mbox_cl;
+ struct pcc_mbox_chan *pcc_chan;
+ struct ras2_pcc_subspace *pcc_subspace;
+
+ 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;
+ pcc_subspace->pcc_subspace_id = pcc_subspace_id;
+ ras2_mbox_cl = &pcc_subspace->mbox_client;
+ ras2_mbox_cl->dev = dev;
+ ras2_mbox_cl->knows_txdone = true;
+
+ pcc_chan = pcc_mbox_request_channel(ras2_mbox_cl, pcc_subspace_id);
+ if (IS_ERR(pcc_chan)) {
+ kfree(pcc_subspace);
+ return PTR_ERR(pcc_chan);
+ }
+ pcc_subspace->pcc_chan = pcc_chan;
+ ras2_ss = pcc_chan->mchan->con_priv;
+ pcc_subspace->comm_base_addr = ras2_ss->base_address;
+
+ /*
+ * ras2_ss->latency is just a Nominal value. In reality
+ * the remote processor could be much slower to reply.
+ * So add an arbitrary amount of wait on top of Nominal.
+ */
+ pcc_subspace->deadline = ns_to_ktime(RAS2_NUM_RETRIES * ras2_ss->latency *
+ NSEC_PER_USEC);
+ pcc_subspace->pcc_mrtt = ras2_ss->min_turnaround_time;
+ pcc_subspace->pcc_mpar = ras2_ss->max_access_rate;
+ pcc_subspace->pcc_comm_addr = acpi_os_ioremap(pcc_subspace->comm_base_addr,
+ ras2_ss->length);
+ /* Set flag so that we dont come here for each CPU. */
+ pcc_subspace->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;
+
+ return 0;
+}
+
+static void ras2_unregister_pcc_channel(void *ctx)
+{
+ struct ras2_scrub_ctx *ras2_ctx = ctx;
+ struct ras2_pcc_subspace *pcc_subspace = ras2_ctx->pcc_subspace;
+
+ if (!pcc_subspace || !pcc_subspace->pcc_chan)
+ return;
+
+ 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);
+ }
+}
+
+/**
+ * devm_ras2_register_pcc_channel() - Register RAS2 PCC channel
+ * @dev: pointer to the ras2 device
+ * @ras2_ctx: pointer to the ras2 context structure
+ * @pcc_subspace_id: identifier of the RAS2 PCC channel.
+ *
+ * Returns: 0 on success, an error otherwise
+ */
+int devm_ras2_register_pcc_channel(struct device *dev, struct ras2_scrub_ctx *ras2_ctx,
+ int pcc_subspace_id)
+{
+ int ret;
+
+ ret = ras2_register_pcc_channel(dev, ras2_ctx, pcc_subspace_id);
+ if (ret)
+ return ret;
+
+ return devm_add_action_or_reset(dev, ras2_unregister_pcc_channel, ras2_ctx);
+}
+EXPORT_SYMBOL_NS_GPL(devm_ras2_register_pcc_channel, ACPI_RAS2);
+
+static struct platform_device *ras2_add_platform_device(char *name, int channel)
+{
+ int ret;
+ struct platform_device *pdev __free(platform_device_put) =
+ platform_device_alloc(name, PLATFORM_DEVID_AUTO);
+ if (!pdev)
+ return ERR_PTR(-ENOMEM);
+
+ ret = platform_device_add_data(pdev, &channel, sizeof(channel));
+ if (ret)
+ return ERR_PTR(ret);
+
+ ret = platform_device_add(pdev);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return_ptr(pdev);
+}
+
+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 platform_device *pdev;
+ int pcc_subspace_id;
+ acpi_size ras2_size;
+ acpi_status status;
+ u8 count = 0, i;
+ int ret;
+
+ 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;
+ }
+
+ struct platform_device **pdev_list __free(kfree) =
+ kcalloc(pRas2Table->num_pcc_descs, sizeof(*pdev_list),
+ GFP_KERNEL);
+ if (!pdev_list) {
+ ret = -ENOMEM;
+ 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++;
+ }
+ if (count == 1) {
+ pdev = ras2_add_platform_device("acpi_ras2", pcc_subspace_id);
+ if (!pdev) {
+ ret = -ENODEV;
+ goto free_ras2_pdev;
+ }
+ pdev_list[0] = pdev;
+ return 0;
+ }
+
+ 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 the platform device and bind ACPI RAS2 memory driver */
+ pdev = ras2_add_platform_device("acpi_ras2", pcc_subspace_id);
+ if (!pdev)
+ goto free_ras2_pdev;
+ pdev_list[count++] = pdev;
+ }
+
+ acpi_put_table(pAcpiTable);
+ return 0;
+
+free_ras2_pdev:
+ for (i = count; i >= 0; i++)
+ platform_device_put(pdev_list[i]);
+
+free_ras2_table:
+ acpi_put_table(pAcpiTable);
+
+ return ret;
+}
+late_initcall(ras2_acpi_init)
new file mode 100644
@@ -0,0 +1,59 @@
+/* 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/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
+
+struct device;
+
+/* Data structures for PCC communication and RAS2 table */
+struct pcc_mbox_chan;
+
+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;
+ u64 comm_base_addr;
+ bool pcc_channel_acquired;
+ ktime_t deadline;
+ unsigned int pcc_mpar;
+ unsigned int pcc_mrtt;
+ struct list_head elem;
+ u16 ref_count;
+};
+
+struct ras2_scrub_ctx {
+ struct device *dev;
+ struct ras2_pcc_subspace *pcc_subspace;
+ int id;
+ struct device *scrub_dev;
+ bool bg;
+ u64 base, size;
+ u8 schrs, schrs_min, schrs_max; /* schrs - scrub cycle in hours */
+ /* Lock to provide mutually exclusive access to PCC channel */
+ struct mutex lock;
+};
+
+int ras2_send_pcc_cmd(struct ras2_scrub_ctx *ras2_ctx, u16 cmd);
+int devm_ras2_register_pcc_channel(struct device *dev, struct ras2_scrub_ctx *ras2_ctx,
+ int pcc_subspace_id);
+
+#endif /* _RAS2_ACPI_H */