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path: root/drivers/acpi/arm64/mpam.c
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Diffstat (limited to 'drivers/acpi/arm64/mpam.c')
-rw-r--r--drivers/acpi/arm64/mpam.c411
1 files changed, 411 insertions, 0 deletions
diff --git a/drivers/acpi/arm64/mpam.c b/drivers/acpi/arm64/mpam.c
new file mode 100644
index 000000000000..84963a20c3e7
--- /dev/null
+++ b/drivers/acpi/arm64/mpam.c
@@ -0,0 +1,411 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2025 Arm Ltd.
+
+/* Parse the MPAM ACPI table feeding the discovered nodes into the driver */
+
+#define pr_fmt(fmt) "ACPI MPAM: " fmt
+
+#include <linux/acpi.h>
+#include <linux/arm_mpam.h>
+#include <linux/bits.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/platform_device.h>
+
+#include <acpi/processor.h>
+
+/*
+ * Flags for acpi_table_mpam_msc.*_interrupt_flags.
+ * See 2.1.1 Interrupt Flags, Table 5, of DEN0065B_MPAM_ACPI_3.0-bet.
+ */
+#define ACPI_MPAM_MSC_IRQ_MODE BIT(0)
+#define ACPI_MPAM_MSC_IRQ_TYPE_MASK GENMASK(2, 1)
+#define ACPI_MPAM_MSC_IRQ_TYPE_WIRED 0
+#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_MASK BIT(3)
+#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR 0
+#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR_CONTAINER 1
+#define ACPI_MPAM_MSC_IRQ_AFFINITY_VALID BIT(4)
+
+/*
+ * Encodings for the MSC node body interface type field.
+ * See 2.1 MPAM MSC node, Table 4 of DEN0065B_MPAM_ACPI_3.0-bet.
+ */
+#define ACPI_MPAM_MSC_IFACE_MMIO 0x00
+#define ACPI_MPAM_MSC_IFACE_PCC 0x0a
+
+static bool _is_ppi_partition(u32 flags)
+{
+ u32 aff_type, is_ppi;
+ bool ret;
+
+ is_ppi = FIELD_GET(ACPI_MPAM_MSC_IRQ_AFFINITY_VALID, flags);
+ if (!is_ppi)
+ return false;
+
+ aff_type = FIELD_GET(ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_MASK, flags);
+ ret = (aff_type == ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR_CONTAINER);
+ if (ret)
+ pr_err_once("Partitioned interrupts not supported\n");
+
+ return ret;
+}
+
+static int acpi_mpam_register_irq(struct platform_device *pdev,
+ u32 intid, u32 flags)
+{
+ int irq;
+ u32 int_type;
+ int trigger;
+
+ if (!intid)
+ return -EINVAL;
+
+ if (_is_ppi_partition(flags))
+ return -EINVAL;
+
+ trigger = FIELD_GET(ACPI_MPAM_MSC_IRQ_MODE, flags);
+ int_type = FIELD_GET(ACPI_MPAM_MSC_IRQ_TYPE_MASK, flags);
+ if (int_type != ACPI_MPAM_MSC_IRQ_TYPE_WIRED)
+ return -EINVAL;
+
+ irq = acpi_register_gsi(&pdev->dev, intid, trigger, ACPI_ACTIVE_HIGH);
+ if (irq < 0)
+ pr_err_once("Failed to register interrupt 0x%x with ACPI\n", intid);
+
+ return irq;
+}
+
+static void acpi_mpam_parse_irqs(struct platform_device *pdev,
+ struct acpi_mpam_msc_node *tbl_msc,
+ struct resource *res, int *res_idx)
+{
+ u32 flags, intid;
+ int irq;
+
+ intid = tbl_msc->overflow_interrupt;
+ flags = tbl_msc->overflow_interrupt_flags;
+ irq = acpi_mpam_register_irq(pdev, intid, flags);
+ if (irq > 0)
+ res[(*res_idx)++] = DEFINE_RES_IRQ_NAMED(irq, "overflow");
+
+ intid = tbl_msc->error_interrupt;
+ flags = tbl_msc->error_interrupt_flags;
+ irq = acpi_mpam_register_irq(pdev, intid, flags);
+ if (irq > 0)
+ res[(*res_idx)++] = DEFINE_RES_IRQ_NAMED(irq, "error");
+}
+
+static int acpi_mpam_parse_resource(struct mpam_msc *msc,
+ struct acpi_mpam_resource_node *res)
+{
+ int level, nid;
+ u32 cache_id;
+
+ switch (res->locator_type) {
+ case ACPI_MPAM_LOCATION_TYPE_PROCESSOR_CACHE:
+ cache_id = res->locator.cache_locator.cache_reference;
+ level = find_acpi_cache_level_from_id(cache_id);
+ if (level <= 0) {
+ pr_err_once("Bad level (%d) for cache with id %u\n", level, cache_id);
+ return -EINVAL;
+ }
+ return mpam_ris_create(msc, res->ris_index, MPAM_CLASS_CACHE,
+ level, cache_id);
+ case ACPI_MPAM_LOCATION_TYPE_MEMORY:
+ nid = pxm_to_node(res->locator.memory_locator.proximity_domain);
+ if (nid == NUMA_NO_NODE) {
+ pr_debug("Bad proximity domain %lld, using node 0 instead\n",
+ res->locator.memory_locator.proximity_domain);
+ nid = 0;
+ }
+ return mpam_ris_create(msc, res->ris_index, MPAM_CLASS_MEMORY,
+ MPAM_CLASS_ID_DEFAULT, nid);
+ default:
+ /* These get discovered later and are treated as unknown */
+ return 0;
+ }
+}
+
+int acpi_mpam_parse_resources(struct mpam_msc *msc,
+ struct acpi_mpam_msc_node *tbl_msc)
+{
+ int i, err;
+ char *ptr, *table_end;
+ struct acpi_mpam_resource_node *resource;
+
+ table_end = (char *)tbl_msc + tbl_msc->length;
+ ptr = (char *)(tbl_msc + 1);
+ for (i = 0; i < tbl_msc->num_resource_nodes; i++) {
+ u64 max_deps, remaining_table;
+
+ if (ptr + sizeof(*resource) > table_end)
+ return -EINVAL;
+
+ resource = (struct acpi_mpam_resource_node *)ptr;
+
+ remaining_table = table_end - ptr;
+ max_deps = remaining_table / sizeof(struct acpi_mpam_func_deps);
+ if (resource->num_functional_deps > max_deps) {
+ pr_debug("MSC has impossible number of functional dependencies\n");
+ return -EINVAL;
+ }
+
+ err = acpi_mpam_parse_resource(msc, resource);
+ if (err)
+ return err;
+
+ ptr += sizeof(*resource);
+ ptr += resource->num_functional_deps * sizeof(struct acpi_mpam_func_deps);
+ }
+
+ return 0;
+}
+
+/*
+ * Creates the device power management link and returns true if the
+ * acpi id is valid and usable for cpu affinity. This is the case
+ * when the linked device is a processor or a processor container.
+ */
+static bool __init parse_msc_pm_link(struct acpi_mpam_msc_node *tbl_msc,
+ struct platform_device *pdev,
+ u32 *acpi_id)
+{
+ char hid[sizeof(tbl_msc->hardware_id_linked_device) + 1] = { 0 };
+ bool acpi_id_valid = false;
+ struct acpi_device *buddy;
+ char uid[11];
+ int len;
+
+ memcpy(hid, &tbl_msc->hardware_id_linked_device,
+ sizeof(tbl_msc->hardware_id_linked_device));
+
+ if (!strcmp(hid, ACPI_PROCESSOR_CONTAINER_HID)) {
+ *acpi_id = tbl_msc->instance_id_linked_device;
+ acpi_id_valid = true;
+ }
+
+ len = snprintf(uid, sizeof(uid), "%u",
+ tbl_msc->instance_id_linked_device);
+ if (len >= sizeof(uid)) {
+ pr_debug("Failed to convert uid of device for power management.");
+ return acpi_id_valid;
+ }
+
+ buddy = acpi_dev_get_first_match_dev(hid, uid, -1);
+ if (buddy) {
+ device_link_add(&pdev->dev, &buddy->dev, DL_FLAG_STATELESS);
+ acpi_dev_put(buddy);
+ }
+
+ return acpi_id_valid;
+}
+
+static int decode_interface_type(struct acpi_mpam_msc_node *tbl_msc,
+ enum mpam_msc_iface *iface)
+{
+ switch (tbl_msc->interface_type) {
+ case ACPI_MPAM_MSC_IFACE_MMIO:
+ *iface = MPAM_IFACE_MMIO;
+ return 0;
+ case ACPI_MPAM_MSC_IFACE_PCC:
+ *iface = MPAM_IFACE_PCC;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static struct platform_device * __init acpi_mpam_parse_msc(struct acpi_mpam_msc_node *tbl_msc)
+{
+ struct platform_device *pdev __free(platform_device_put) =
+ platform_device_alloc("mpam_msc", tbl_msc->identifier);
+ int next_res = 0, next_prop = 0, err;
+ /* pcc, nrdy, affinity and a sentinel */
+ struct property_entry props[4] = { 0 };
+ /* mmio, 2xirq, no sentinel. */
+ struct resource res[3] = { 0 };
+ struct acpi_device *companion;
+ enum mpam_msc_iface iface;
+ char uid[16];
+ u32 acpi_id;
+
+ if (!pdev)
+ return ERR_PTR(-ENOMEM);
+
+ /* Some power management is described in the namespace: */
+ err = snprintf(uid, sizeof(uid), "%u", tbl_msc->identifier);
+ if (err > 0 && err < sizeof(uid)) {
+ companion = acpi_dev_get_first_match_dev("ARMHAA5C", uid, -1);
+ if (companion) {
+ ACPI_COMPANION_SET(&pdev->dev, companion);
+ acpi_dev_put(companion);
+ } else {
+ pr_debug("MSC.%u: missing namespace entry\n", tbl_msc->identifier);
+ }
+ }
+
+ if (decode_interface_type(tbl_msc, &iface)) {
+ pr_debug("MSC.%u: unknown interface type\n", tbl_msc->identifier);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (iface == MPAM_IFACE_MMIO) {
+ res[next_res++] = DEFINE_RES_MEM_NAMED(tbl_msc->base_address,
+ tbl_msc->mmio_size,
+ "MPAM:MSC");
+ } else if (iface == MPAM_IFACE_PCC) {
+ props[next_prop++] = PROPERTY_ENTRY_U32("pcc-channel",
+ tbl_msc->base_address);
+ }
+
+ acpi_mpam_parse_irqs(pdev, tbl_msc, res, &next_res);
+
+ WARN_ON_ONCE(next_res > ARRAY_SIZE(res));
+ err = platform_device_add_resources(pdev, res, next_res);
+ if (err)
+ return ERR_PTR(err);
+
+ props[next_prop++] = PROPERTY_ENTRY_U32("arm,not-ready-us",
+ tbl_msc->max_nrdy_usec);
+
+ /*
+ * The MSC's CPU affinity is described via its linked power
+ * management device, but only if it points at a Processor or
+ * Processor Container.
+ */
+ if (parse_msc_pm_link(tbl_msc, pdev, &acpi_id))
+ props[next_prop++] = PROPERTY_ENTRY_U32("cpu_affinity", acpi_id);
+
+ WARN_ON_ONCE(next_prop > ARRAY_SIZE(props) - 1);
+ err = device_create_managed_software_node(&pdev->dev, props, NULL);
+ if (err)
+ return ERR_PTR(err);
+
+ /*
+ * Stash the table entry for acpi_mpam_parse_resources() to discover
+ * what this MSC controls.
+ */
+ err = platform_device_add_data(pdev, tbl_msc, tbl_msc->length);
+ if (err)
+ return ERR_PTR(err);
+
+ err = platform_device_add(pdev);
+ if (err)
+ return ERR_PTR(err);
+
+ return_ptr(pdev);
+}
+
+static int __init acpi_mpam_parse(void)
+{
+ char *table_end, *table_offset;
+ struct acpi_mpam_msc_node *tbl_msc;
+ struct platform_device *pdev;
+
+ if (acpi_disabled || !system_supports_mpam())
+ return 0;
+
+ struct acpi_table_header *table __free(acpi_put_table) =
+ acpi_get_table_pointer(ACPI_SIG_MPAM, 0);
+
+ if (IS_ERR(table))
+ return 0;
+
+ if (table->revision < 1) {
+ pr_debug("MPAM ACPI table revision %d not supported\n", table->revision);
+ return 0;
+ }
+
+ table_offset = (char *)(table + 1);
+ table_end = (char *)table + table->length;
+
+ while (table_offset < table_end) {
+ tbl_msc = (struct acpi_mpam_msc_node *)table_offset;
+ if (table_offset + sizeof(*tbl_msc) > table_end ||
+ table_offset + tbl_msc->length > table_end) {
+ pr_err("MSC entry overlaps end of ACPI table\n");
+ return -EINVAL;
+ }
+ table_offset += tbl_msc->length;
+
+ /*
+ * If any of the reserved fields are set, make no attempt to
+ * parse the MSC structure. This MSC will still be counted by
+ * acpi_mpam_count_msc(), meaning the MPAM driver can't probe
+ * against all MSC, and will never be enabled. There is no way
+ * to enable it safely, because we cannot determine safe
+ * system-wide partid and pmg ranges in this situation.
+ */
+ if (tbl_msc->reserved || tbl_msc->reserved1 || tbl_msc->reserved2) {
+ pr_err_once("Unrecognised MSC, MPAM not usable\n");
+ pr_debug("MSC.%u: reserved field set\n", tbl_msc->identifier);
+ continue;
+ }
+
+ if (!tbl_msc->mmio_size) {
+ pr_debug("MSC.%u: marked as disabled\n", tbl_msc->identifier);
+ continue;
+ }
+
+ pdev = acpi_mpam_parse_msc(tbl_msc);
+ if (IS_ERR(pdev))
+ return PTR_ERR(pdev);
+ }
+
+ return 0;
+}
+
+/**
+ * acpi_mpam_count_msc() - Count the number of MSC described by firmware.
+ *
+ * Returns the number of MSCs, or zero for an error.
+ *
+ * This can be called before or in parallel with acpi_mpam_parse().
+ */
+int acpi_mpam_count_msc(void)
+{
+ char *table_end, *table_offset;
+ struct acpi_mpam_msc_node *tbl_msc;
+ int count = 0;
+
+ if (acpi_disabled || !system_supports_mpam())
+ return 0;
+
+ struct acpi_table_header *table __free(acpi_put_table) =
+ acpi_get_table_pointer(ACPI_SIG_MPAM, 0);
+
+ if (IS_ERR(table))
+ return 0;
+
+ if (table->revision < 1)
+ return 0;
+
+ table_offset = (char *)(table + 1);
+ table_end = (char *)table + table->length;
+
+ while (table_offset < table_end) {
+ tbl_msc = (struct acpi_mpam_msc_node *)table_offset;
+
+ if (table_offset + sizeof(*tbl_msc) > table_end)
+ return -EINVAL;
+ if (tbl_msc->length < sizeof(*tbl_msc))
+ return -EINVAL;
+ if (tbl_msc->length > table_end - table_offset)
+ return -EINVAL;
+ table_offset += tbl_msc->length;
+
+ if (!tbl_msc->mmio_size)
+ continue;
+
+ count++;
+ }
+
+ return count;
+}
+
+/*
+ * Call after ACPI devices have been created, which happens behind acpi_scan_init()
+ * called from subsys_initcall(). PCC requires the mailbox driver, which is
+ * initialised from postcore_initcall().
+ */
+subsys_initcall_sync(acpi_mpam_parse);
generated by cgit (git 2.34.1) at 2025-12-03 18:29:22 +0000