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Diffstat (limited to 'drivers/acpi/pptt.c')
| -rw-r--r-- | drivers/acpi/pptt.c | 706 |
1 files changed, 706 insertions, 0 deletions
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c new file mode 100644 index 000000000..9dbf86a0c --- /dev/null +++ b/drivers/acpi/pptt.c @@ -0,0 +1,706 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * pptt.c - parsing of Processor Properties Topology Table (PPTT) + * + * Copyright (C) 2018, ARM + * + * This file implements parsing of the Processor Properties Topology Table + * which is optionally used to describe the processor and cache topology. + * Due to the relative pointers used throughout the table, this doesn't + * leverage the existing subtable parsing in the kernel. + * + * The PPTT structure is an inverted tree, with each node potentially + * holding one or two inverted tree data structures describing + * the caches available at that level. Each cache structure optionally + * contains properties describing the cache at a given level which can be + * used to override hardware probed values. + */ +#define pr_fmt(fmt) "ACPI PPTT: " fmt + +#include <linux/acpi.h> +#include <linux/cacheinfo.h> +#include <acpi/processor.h> + +static struct acpi_subtable_header *fetch_pptt_subtable(struct acpi_table_header *table_hdr, + u32 pptt_ref) +{ + struct acpi_subtable_header *entry; + + /* there isn't a subtable at reference 0 */ + if (pptt_ref < sizeof(struct acpi_subtable_header)) + return NULL; + + if (pptt_ref + sizeof(struct acpi_subtable_header) > table_hdr->length) + return NULL; + + entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, pptt_ref); + + if (entry->length == 0) + return NULL; + + if (pptt_ref + entry->length > table_hdr->length) + return NULL; + + return entry; +} + +static struct acpi_pptt_processor *fetch_pptt_node(struct acpi_table_header *table_hdr, + u32 pptt_ref) +{ + return (struct acpi_pptt_processor *)fetch_pptt_subtable(table_hdr, pptt_ref); +} + +static struct acpi_pptt_cache *fetch_pptt_cache(struct acpi_table_header *table_hdr, + u32 pptt_ref) +{ + return (struct acpi_pptt_cache *)fetch_pptt_subtable(table_hdr, pptt_ref); +} + +static struct acpi_subtable_header *acpi_get_pptt_resource(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *node, + int resource) +{ + u32 *ref; + + if (resource >= node->number_of_priv_resources) + return NULL; + + ref = ACPI_ADD_PTR(u32, node, sizeof(struct acpi_pptt_processor)); + ref += resource; + + return fetch_pptt_subtable(table_hdr, *ref); +} + +static inline bool acpi_pptt_match_type(int table_type, int type) +{ + return ((table_type & ACPI_PPTT_MASK_CACHE_TYPE) == type || + table_type & ACPI_PPTT_CACHE_TYPE_UNIFIED & type); +} + +/** + * acpi_pptt_walk_cache() - Attempt to find the requested acpi_pptt_cache + * @table_hdr: Pointer to the head of the PPTT table + * @local_level: passed res reflects this cache level + * @res: cache resource in the PPTT we want to walk + * @found: returns a pointer to the requested level if found + * @level: the requested cache level + * @type: the requested cache type + * + * Attempt to find a given cache level, while counting the max number + * of cache levels for the cache node. + * + * Given a pptt resource, verify that it is a cache node, then walk + * down each level of caches, counting how many levels are found + * as well as checking the cache type (icache, dcache, unified). If a + * level & type match, then we set found, and continue the search. + * Once the entire cache branch has been walked return its max + * depth. + * + * Return: The cache structure and the level we terminated with. + */ +static int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr, + int local_level, + struct acpi_subtable_header *res, + struct acpi_pptt_cache **found, + int level, int type) +{ + struct acpi_pptt_cache *cache; + + if (res->type != ACPI_PPTT_TYPE_CACHE) + return 0; + + cache = (struct acpi_pptt_cache *) res; + while (cache) { + local_level++; + + if (local_level == level && + cache->flags & ACPI_PPTT_CACHE_TYPE_VALID && + acpi_pptt_match_type(cache->attributes, type)) { + if (*found != NULL && cache != *found) + pr_warn("Found duplicate cache level/type unable to determine uniqueness\n"); + + pr_debug("Found cache @ level %d\n", level); + *found = cache; + /* + * continue looking at this node's resource list + * to verify that we don't find a duplicate + * cache node. + */ + } + cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache); + } + return local_level; +} + +static struct acpi_pptt_cache *acpi_find_cache_level(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *cpu_node, + int *starting_level, int level, + int type) +{ + struct acpi_subtable_header *res; + int number_of_levels = *starting_level; + int resource = 0; + struct acpi_pptt_cache *ret = NULL; + int local_level; + + /* walk down from processor node */ + while ((res = acpi_get_pptt_resource(table_hdr, cpu_node, resource))) { + resource++; + + local_level = acpi_pptt_walk_cache(table_hdr, *starting_level, + res, &ret, level, type); + /* + * we are looking for the max depth. Since its potentially + * possible for a given node to have resources with differing + * depths verify that the depth we have found is the largest. + */ + if (number_of_levels < local_level) + number_of_levels = local_level; + } + if (number_of_levels > *starting_level) + *starting_level = number_of_levels; + + return ret; +} + +/** + * acpi_count_levels() - Given a PPTT table, and a cpu node, count the caches + * @table_hdr: Pointer to the head of the PPTT table + * @cpu_node: processor node we wish to count caches for + * + * Given a processor node containing a processing unit, walk into it and count + * how many levels exist solely for it, and then walk up each level until we hit + * the root node (ignore the package level because it may be possible to have + * caches that exist across packages). Count the number of cache levels that + * exist at each level on the way up. + * + * Return: Total number of levels found. + */ +static int acpi_count_levels(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *cpu_node) +{ + int total_levels = 0; + + do { + acpi_find_cache_level(table_hdr, cpu_node, &total_levels, 0, 0); + cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent); + } while (cpu_node); + + return total_levels; +} + +/** + * acpi_pptt_leaf_node() - Given a processor node, determine if its a leaf + * @table_hdr: Pointer to the head of the PPTT table + * @node: passed node is checked to see if its a leaf + * + * Determine if the *node parameter is a leaf node by iterating the + * PPTT table, looking for nodes which reference it. + * + * Return: 0 if we find a node referencing the passed node (or table error), + * or 1 if we don't. + */ +static int acpi_pptt_leaf_node(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *node) +{ + struct acpi_subtable_header *entry; + unsigned long table_end; + u32 node_entry; + struct acpi_pptt_processor *cpu_node; + u32 proc_sz; + + table_end = (unsigned long)table_hdr + table_hdr->length; + node_entry = ACPI_PTR_DIFF(node, table_hdr); + entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, + sizeof(struct acpi_table_pptt)); + proc_sz = sizeof(struct acpi_pptt_processor *); + + while ((unsigned long)entry + proc_sz < table_end) { + cpu_node = (struct acpi_pptt_processor *)entry; + if (entry->type == ACPI_PPTT_TYPE_PROCESSOR && + cpu_node->parent == node_entry) + return 0; + if (entry->length == 0) + return 0; + entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry, + entry->length); + + } + return 1; +} + +/** + * acpi_find_processor_node() - Given a PPTT table find the requested processor + * @table_hdr: Pointer to the head of the PPTT table + * @acpi_cpu_id: cpu we are searching for + * + * Find the subtable entry describing the provided processor. + * This is done by iterating the PPTT table looking for processor nodes + * which have an acpi_processor_id that matches the acpi_cpu_id parameter + * passed into the function. If we find a node that matches this criteria + * we verify that its a leaf node in the topology rather than depending + * on the valid flag, which doesn't need to be set for leaf nodes. + * + * Return: NULL, or the processors acpi_pptt_processor* + */ +static struct acpi_pptt_processor *acpi_find_processor_node(struct acpi_table_header *table_hdr, + u32 acpi_cpu_id) +{ + struct acpi_subtable_header *entry; + unsigned long table_end; + struct acpi_pptt_processor *cpu_node; + u32 proc_sz; + + table_end = (unsigned long)table_hdr + table_hdr->length; + entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, + sizeof(struct acpi_table_pptt)); + proc_sz = sizeof(struct acpi_pptt_processor *); + + /* find the processor structure associated with this cpuid */ + while ((unsigned long)entry + proc_sz < table_end) { + cpu_node = (struct acpi_pptt_processor *)entry; + + if (entry->length == 0) { + pr_warn("Invalid zero length subtable\n"); + break; + } + if (entry->type == ACPI_PPTT_TYPE_PROCESSOR && + acpi_cpu_id == cpu_node->acpi_processor_id && + acpi_pptt_leaf_node(table_hdr, cpu_node)) { + return (struct acpi_pptt_processor *)entry; + } + + entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry, + entry->length); + } + + return NULL; +} + +static int acpi_find_cache_levels(struct acpi_table_header *table_hdr, + u32 acpi_cpu_id) +{ + int number_of_levels = 0; + struct acpi_pptt_processor *cpu; + + cpu = acpi_find_processor_node(table_hdr, acpi_cpu_id); + if (cpu) + number_of_levels = acpi_count_levels(table_hdr, cpu); + + return number_of_levels; +} + +static u8 acpi_cache_type(enum cache_type type) +{ + switch (type) { + case CACHE_TYPE_DATA: + pr_debug("Looking for data cache\n"); + return ACPI_PPTT_CACHE_TYPE_DATA; + case CACHE_TYPE_INST: + pr_debug("Looking for instruction cache\n"); + return ACPI_PPTT_CACHE_TYPE_INSTR; + default: + case CACHE_TYPE_UNIFIED: + pr_debug("Looking for unified cache\n"); + /* + * It is important that ACPI_PPTT_CACHE_TYPE_UNIFIED + * contains the bit pattern that will match both + * ACPI unified bit patterns because we use it later + * to match both cases. + */ + return ACPI_PPTT_CACHE_TYPE_UNIFIED; + } +} + +static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *table_hdr, + u32 acpi_cpu_id, + enum cache_type type, + unsigned int level, + struct acpi_pptt_processor **node) +{ + int total_levels = 0; + struct acpi_pptt_cache *found = NULL; + struct acpi_pptt_processor *cpu_node; + u8 acpi_type = acpi_cache_type(type); + + pr_debug("Looking for CPU %d's level %d cache type %d\n", + acpi_cpu_id, level, acpi_type); + + cpu_node = acpi_find_processor_node(table_hdr, acpi_cpu_id); + + while (cpu_node && !found) { + found = acpi_find_cache_level(table_hdr, cpu_node, + &total_levels, level, acpi_type); + *node = cpu_node; + cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent); + } + + return found; +} + +/** + * update_cache_properties() - Update cacheinfo for the given processor + * @this_leaf: Kernel cache info structure being updated + * @found_cache: The PPTT node describing this cache instance + * @cpu_node: A unique reference to describe this cache instance + * + * The ACPI spec implies that the fields in the cache structures are used to + * extend and correct the information probed from the hardware. Lets only + * set fields that we determine are VALID. + * + * Return: nothing. Side effect of updating the global cacheinfo + */ +static void update_cache_properties(struct cacheinfo *this_leaf, + struct acpi_pptt_cache *found_cache, + struct acpi_pptt_processor *cpu_node) +{ + this_leaf->fw_token = cpu_node; + if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID) + this_leaf->size = found_cache->size; + if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID) + this_leaf->coherency_line_size = found_cache->line_size; + if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID) + this_leaf->number_of_sets = found_cache->number_of_sets; + if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID) + this_leaf->ways_of_associativity = found_cache->associativity; + if (found_cache->flags & ACPI_PPTT_WRITE_POLICY_VALID) { + switch (found_cache->attributes & ACPI_PPTT_MASK_WRITE_POLICY) { + case ACPI_PPTT_CACHE_POLICY_WT: + this_leaf->attributes = CACHE_WRITE_THROUGH; + break; + case ACPI_PPTT_CACHE_POLICY_WB: + this_leaf->attributes = CACHE_WRITE_BACK; + break; + } + } + if (found_cache->flags & ACPI_PPTT_ALLOCATION_TYPE_VALID) { + switch (found_cache->attributes & ACPI_PPTT_MASK_ALLOCATION_TYPE) { + case ACPI_PPTT_CACHE_READ_ALLOCATE: + this_leaf->attributes |= CACHE_READ_ALLOCATE; + break; + case ACPI_PPTT_CACHE_WRITE_ALLOCATE: + this_leaf->attributes |= CACHE_WRITE_ALLOCATE; + break; + case ACPI_PPTT_CACHE_RW_ALLOCATE: + case ACPI_PPTT_CACHE_RW_ALLOCATE_ALT: + this_leaf->attributes |= + CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE; + break; + } + } + /* + * If cache type is NOCACHE, then the cache hasn't been specified + * via other mechanisms. Update the type if a cache type has been + * provided. + * + * Note, we assume such caches are unified based on conventional system + * design and known examples. Significant work is required elsewhere to + * fully support data/instruction only type caches which are only + * specified in PPTT. + */ + if (this_leaf->type == CACHE_TYPE_NOCACHE && + found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID) + this_leaf->type = CACHE_TYPE_UNIFIED; +} + +static void cache_setup_acpi_cpu(struct acpi_table_header *table, + unsigned int cpu) +{ + struct acpi_pptt_cache *found_cache; + struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); + struct cacheinfo *this_leaf; + unsigned int index = 0; + struct acpi_pptt_processor *cpu_node = NULL; + + while (index < get_cpu_cacheinfo(cpu)->num_leaves) { + this_leaf = this_cpu_ci->info_list + index; + found_cache = acpi_find_cache_node(table, acpi_cpu_id, + this_leaf->type, + this_leaf->level, + &cpu_node); + pr_debug("found = %p %p\n", found_cache, cpu_node); + if (found_cache) + update_cache_properties(this_leaf, + found_cache, + cpu_node); + + index++; + } +} + +/* Passing level values greater than this will result in search termination */ +#define PPTT_ABORT_PACKAGE 0xFF + +static struct acpi_pptt_processor *acpi_find_processor_package_id(struct acpi_table_header *table_hdr, + struct acpi_pptt_processor *cpu, + int level, int flag) +{ + struct acpi_pptt_processor *prev_node; + + while (cpu && level) { + if (cpu->flags & flag) + break; + pr_debug("level %d\n", level); + prev_node = fetch_pptt_node(table_hdr, cpu->parent); + if (prev_node == NULL) + break; + cpu = prev_node; + level--; + } + return cpu; +} + +/** + * topology_get_acpi_cpu_tag() - Find a unique topology value for a feature + * @table: Pointer to the head of the PPTT table + * @cpu: Kernel logical cpu number + * @level: A level that terminates the search + * @flag: A flag which terminates the search + * + * Get a unique value given a cpu, and a topology level, that can be + * matched to determine which cpus share common topological features + * at that level. + * + * Return: Unique value, or -ENOENT if unable to locate cpu + */ +static int topology_get_acpi_cpu_tag(struct acpi_table_header *table, + unsigned int cpu, int level, int flag) +{ + struct acpi_pptt_processor *cpu_node; + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); + + cpu_node = acpi_find_processor_node(table, acpi_cpu_id); + if (cpu_node) { + cpu_node = acpi_find_processor_package_id(table, cpu_node, + level, flag); + /* + * As per specification if the processor structure represents + * an actual processor, then ACPI processor ID must be valid. + * For processor containers ACPI_PPTT_ACPI_PROCESSOR_ID_VALID + * should be set if the UID is valid + */ + if (level == 0 || + cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID) + return cpu_node->acpi_processor_id; + return ACPI_PTR_DIFF(cpu_node, table); + } + pr_warn_once("PPTT table found, but unable to locate core %d (%d)\n", + cpu, acpi_cpu_id); + return -ENOENT; +} + +static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag) +{ + struct acpi_table_header *table; + acpi_status status; + int retval; + + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + pr_warn_once("No PPTT table found, cpu topology may be inaccurate\n"); + return -ENOENT; + } + retval = topology_get_acpi_cpu_tag(table, cpu, level, flag); + pr_debug("Topology Setup ACPI cpu %d, level %d ret = %d\n", + cpu, level, retval); + acpi_put_table(table); + + return retval; +} + +/** + * check_acpi_cpu_flag() - Determine if CPU node has a flag set + * @cpu: Kernel logical CPU number + * @rev: The minimum PPTT revision defining the flag + * @flag: The flag itself + * + * Check the node representing a CPU for a given flag. + * + * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or + * the table revision isn't new enough. + * 1, any passed flag set + * 0, flag unset + */ +static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag) +{ + struct acpi_table_header *table; + acpi_status status; + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); + struct acpi_pptt_processor *cpu_node = NULL; + int ret = -ENOENT; + + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + pr_warn_once("No PPTT table found, cpu topology may be inaccurate\n"); + return ret; + } + + if (table->revision >= rev) + cpu_node = acpi_find_processor_node(table, acpi_cpu_id); + + if (cpu_node) + ret = (cpu_node->flags & flag) != 0; + + acpi_put_table(table); + + return ret; +} + +/** + * acpi_find_last_cache_level() - Determines the number of cache levels for a PE + * @cpu: Kernel logical cpu number + * + * Given a logical cpu number, returns the number of levels of cache represented + * in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0 + * indicating we didn't find any cache levels. + * + * Return: Cache levels visible to this core. + */ +int acpi_find_last_cache_level(unsigned int cpu) +{ + u32 acpi_cpu_id; + struct acpi_table_header *table; + int number_of_levels = 0; + acpi_status status; + + pr_debug("Cache Setup find last level cpu=%d\n", cpu); + + acpi_cpu_id = get_acpi_id_for_cpu(cpu); + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + pr_warn_once("No PPTT table found, cache topology may be inaccurate\n"); + } else { + number_of_levels = acpi_find_cache_levels(table, acpi_cpu_id); + acpi_put_table(table); + } + pr_debug("Cache Setup find last level level=%d\n", number_of_levels); + + return number_of_levels; +} + +/** + * cache_setup_acpi() - Override CPU cache topology with data from the PPTT + * @cpu: Kernel logical cpu number + * + * Updates the global cache info provided by cpu_get_cacheinfo() + * when there are valid properties in the acpi_pptt_cache nodes. A + * successful parse may not result in any updates if none of the + * cache levels have any valid flags set. Futher, a unique value is + * associated with each known CPU cache entry. This unique value + * can be used to determine whether caches are shared between cpus. + * + * Return: -ENOENT on failure to find table, or 0 on success + */ +int cache_setup_acpi(unsigned int cpu) +{ + struct acpi_table_header *table; + acpi_status status; + + pr_debug("Cache Setup ACPI cpu %d\n", cpu); + + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + pr_warn_once("No PPTT table found, cache topology may be inaccurate\n"); + return -ENOENT; + } + + cache_setup_acpi_cpu(table, cpu); + acpi_put_table(table); + + return status; +} + +/** + * acpi_pptt_cpu_is_thread() - Determine if CPU is a thread + * @cpu: Kernel logical CPU number + * + * Return: 1, a thread + * 0, not a thread + * -ENOENT ,if the PPTT doesn't exist, the CPU cannot be found or + * the table revision isn't new enough. + */ +int acpi_pptt_cpu_is_thread(unsigned int cpu) +{ + return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD); +} + +/** + * find_acpi_cpu_topology() - Determine a unique topology value for a given cpu + * @cpu: Kernel logical cpu number + * @level: The topological level for which we would like a unique ID + * + * Determine a topology unique ID for each thread/core/cluster/mc_grouping + * /socket/etc. This ID can then be used to group peers, which will have + * matching ids. + * + * The search terminates when either the requested level is found or + * we reach a root node. Levels beyond the termination point will return the + * same unique ID. The unique id for level 0 is the acpi processor id. All + * other levels beyond this use a generated value to uniquely identify + * a topological feature. + * + * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found. + * Otherwise returns a value which represents a unique topological feature. + */ +int find_acpi_cpu_topology(unsigned int cpu, int level) +{ + return find_acpi_cpu_topology_tag(cpu, level, 0); +} + +/** + * find_acpi_cpu_cache_topology() - Determine a unique cache topology value + * @cpu: Kernel logical cpu number + * @level: The cache level for which we would like a unique ID + * + * Determine a unique ID for each unified cache in the system + * + * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found. + * Otherwise returns a value which represents a unique topological feature. + */ +int find_acpi_cpu_cache_topology(unsigned int cpu, int level) +{ + struct acpi_table_header *table; + struct acpi_pptt_cache *found_cache; + acpi_status status; + u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); + struct acpi_pptt_processor *cpu_node = NULL; + int ret = -1; + + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + pr_warn_once("No PPTT table found, topology may be inaccurate\n"); + return -ENOENT; + } + + found_cache = acpi_find_cache_node(table, acpi_cpu_id, + CACHE_TYPE_UNIFIED, + level, + &cpu_node); + if (found_cache) + ret = ACPI_PTR_DIFF(cpu_node, table); + + acpi_put_table(table); + + return ret; +} + + +/** + * find_acpi_cpu_topology_package() - Determine a unique cpu package value + * @cpu: Kernel logical cpu number + * + * Determine a topology unique package ID for the given cpu. + * This ID can then be used to group peers, which will have matching ids. + * + * The search terminates when either a level is found with the PHYSICAL_PACKAGE + * flag set or we reach a root node. + * + * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found. + * Otherwise returns a value which represents the package for this cpu. + */ +int find_acpi_cpu_topology_package(unsigned int cpu) +{ + return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, + ACPI_PPTT_PHYSICAL_PACKAGE); +} |