diff options
Diffstat (limited to 'drivers/acpi/acpi_mrrm.c')
| -rw-r--r-- | drivers/acpi/acpi_mrrm.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_mrrm.c b/drivers/acpi/acpi_mrrm.c new file mode 100644 index 000000000000..26c1a4e6b6ec --- /dev/null +++ b/drivers/acpi/acpi_mrrm.c @@ -0,0 +1,183 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2025, Intel Corporation. + * + * Memory Range and Region Mapping (MRRM) structure + * + * Parse and report the platform's MRRM table in /sys. + */ + +#define pr_fmt(fmt) "acpi/mrrm: " fmt + +#include <linux/acpi.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/sysfs.h> + +/* Default assume one memory region covering all system memory, per the spec */ +static int max_mem_region = 1; + +/* Access for use by resctrl file system */ +int acpi_mrrm_max_mem_region(void) +{ + return max_mem_region; +} + +struct mrrm_mem_range_entry { + u64 base; + u64 length; + int node; + u8 local_region_id; + u8 remote_region_id; +}; + +static struct mrrm_mem_range_entry *mrrm_mem_range_entry; +static u32 mrrm_mem_entry_num; + +static int get_node_num(struct mrrm_mem_range_entry *e) +{ + unsigned int nid; + + for_each_online_node(nid) { + for (int z = 0; z < MAX_NR_ZONES; z++) { + struct zone *zone = NODE_DATA(nid)->node_zones + z; + + if (!populated_zone(zone)) + continue; + if (zone_intersects(zone, PHYS_PFN(e->base), PHYS_PFN(e->length))) + return zone_to_nid(zone); + } + } + + return -ENOENT; +} + +static __init int acpi_parse_mrrm(struct acpi_table_header *table) +{ + struct acpi_mrrm_mem_range_entry *mre_entry; + struct acpi_table_mrrm *mrrm; + void *mre, *mrrm_end; + int mre_count = 0; + + mrrm = (struct acpi_table_mrrm *)table; + if (!mrrm) + return -ENODEV; + + if (mrrm->flags & ACPI_MRRM_FLAGS_REGION_ASSIGNMENT_OS) + return -EOPNOTSUPP; + + mrrm_end = (void *)mrrm + mrrm->header.length - 1; + mre = (void *)mrrm + sizeof(struct acpi_table_mrrm); + while (mre < mrrm_end) { + mre_entry = mre; + mre_count++; + mre += mre_entry->header.length; + } + if (!mre_count) { + pr_info(FW_BUG "No ranges listed in MRRM table\n"); + return -EINVAL; + } + + mrrm_mem_range_entry = kmalloc_array(mre_count, sizeof(*mrrm_mem_range_entry), + GFP_KERNEL | __GFP_ZERO); + if (!mrrm_mem_range_entry) + return -ENOMEM; + + mre = (void *)mrrm + sizeof(struct acpi_table_mrrm); + while (mre < mrrm_end) { + struct mrrm_mem_range_entry *e; + + mre_entry = mre; + e = mrrm_mem_range_entry + mrrm_mem_entry_num; + + e->base = mre_entry->addr_base; + e->length = mre_entry->addr_len; + e->node = get_node_num(e); + + if (mre_entry->region_id_flags & ACPI_MRRM_VALID_REGION_ID_FLAGS_LOCAL) + e->local_region_id = mre_entry->local_region_id; + else + e->local_region_id = -1; + if (mre_entry->region_id_flags & ACPI_MRRM_VALID_REGION_ID_FLAGS_REMOTE) + e->remote_region_id = mre_entry->remote_region_id; + else + e->remote_region_id = -1; + + mrrm_mem_entry_num++; + mre += mre_entry->header.length; + } + + max_mem_region = mrrm->max_mem_region; + + return 0; +} + +#define RANGE_ATTR(name, fmt) \ +static ssize_t name##_show(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf) \ +{ \ + struct mrrm_mem_range_entry *mre; \ + const char *kname = kobject_name(kobj); \ + int n, ret; \ + \ + ret = kstrtoint(kname + 5, 10, &n); \ + if (ret) \ + return ret; \ + \ + mre = mrrm_mem_range_entry + n; \ + \ + return sysfs_emit(buf, fmt, mre->name); \ +} \ +static struct kobj_attribute name##_attr = __ATTR_RO(name) + +RANGE_ATTR(base, "0x%llx\n"); +RANGE_ATTR(length, "0x%llx\n"); +RANGE_ATTR(node, "%d\n"); +RANGE_ATTR(local_region_id, "%d\n"); +RANGE_ATTR(remote_region_id, "%d\n"); + +static struct attribute *memory_range_attrs[] = { + &base_attr.attr, + &length_attr.attr, + &node_attr.attr, + &local_region_id_attr.attr, + &remote_region_id_attr.attr, + NULL +}; + +ATTRIBUTE_GROUPS(memory_range); + +static __init int add_boot_memory_ranges(void) +{ + struct kobject *pkobj, *kobj; + int ret = -EINVAL; + char *name; + + pkobj = kobject_create_and_add("memory_ranges", acpi_kobj); + + for (int i = 0; i < mrrm_mem_entry_num; i++) { + name = kasprintf(GFP_KERNEL, "range%d", i); + if (!name) + break; + + kobj = kobject_create_and_add(name, pkobj); + + ret = sysfs_create_groups(kobj, memory_range_groups); + if (ret) + return ret; + } + + return ret; +} + +static __init int mrrm_init(void) +{ + int ret; + + ret = acpi_table_parse(ACPI_SIG_MRRM, acpi_parse_mrrm); + if (ret < 0) + return ret; + + return add_boot_memory_ranges(); +} +device_initcall(mrrm_init); |