summaryrefslogtreecommitdiff
path: root/drivers/base/cacheinfo.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/base/cacheinfo.c')
-rw-r--r--drivers/base/cacheinfo.c436
1 files changed, 382 insertions, 54 deletions
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 950b22cdb5f7..613410705a47 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -8,13 +8,14 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/acpi.h>
+#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/cacheinfo.h>
#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/init.h>
-#include <linux/of_device.h>
+#include <linux/of.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/smp.h>
@@ -28,6 +29,9 @@ static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
#define per_cpu_cacheinfo_idx(cpu, idx) \
(per_cpu_cacheinfo(cpu) + (idx))
+/* Set if no cache information is found in DT/ACPI. */
+static bool use_arch_info;
+
struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
{
return ci_cacheinfo(cpu);
@@ -38,11 +42,11 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
{
/*
* For non DT/ACPI systems, assume unique level 1 caches,
- * system-wide shared caches for all other levels. This will be used
- * only if arch specific code has not populated shared_cpu_map
+ * system-wide shared caches for all other levels.
*/
- if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)))
- return !(this_leaf->level == 1);
+ if (!(IS_ENABLED(CONFIG_OF) || IS_ENABLED(CONFIG_ACPI)) ||
+ use_arch_info)
+ return (this_leaf->level != 1) && (sib_leaf->level != 1);
if ((sib_leaf->attributes & CACHE_ID) &&
(this_leaf->attributes & CACHE_ID))
@@ -55,7 +59,7 @@ bool last_level_cache_is_valid(unsigned int cpu)
{
struct cacheinfo *llc;
- if (!cache_leaves(cpu))
+ if (!cache_leaves(cpu) || !per_cpu_cacheinfo(cpu))
return false;
llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
@@ -79,6 +83,9 @@ bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y)
}
#ifdef CONFIG_OF
+
+static bool of_check_cache_nodes(struct device_node *np);
+
/* OF properties to query for a given cache type */
struct cache_type_info {
const char *size_prop;
@@ -177,6 +184,54 @@ static bool cache_node_is_unified(struct cacheinfo *this_leaf,
return of_property_read_bool(np, "cache-unified");
}
+static bool match_cache_node(struct device_node *cpu,
+ const struct device_node *cache_node)
+{
+ struct device_node *prev, *cache = of_find_next_cache_node(cpu);
+
+ while (cache) {
+ if (cache == cache_node) {
+ of_node_put(cache);
+ return true;
+ }
+
+ prev = cache;
+ cache = of_find_next_cache_node(cache);
+ of_node_put(prev);
+ }
+
+ return false;
+}
+
+#ifndef arch_compact_of_hwid
+#define arch_compact_of_hwid(_x) (_x)
+#endif
+
+static void cache_of_set_id(struct cacheinfo *this_leaf,
+ struct device_node *cache_node)
+{
+ struct device_node *cpu;
+ u32 min_id = ~0;
+
+ for_each_of_cpu_node(cpu) {
+ u64 id = of_get_cpu_hwid(cpu, 0);
+
+ id = arch_compact_of_hwid(id);
+ if (FIELD_GET(GENMASK_ULL(63, 32), id)) {
+ of_node_put(cpu);
+ return;
+ }
+
+ if (match_cache_node(cpu, cache_node))
+ min_id = min(min_id, id);
+ }
+
+ if (min_id != ~0) {
+ this_leaf->id = min_id;
+ this_leaf->attributes |= CACHE_ID;
+ }
+}
+
static void cache_of_set_props(struct cacheinfo *this_leaf,
struct device_node *np)
{
@@ -192,28 +247,29 @@ static void cache_of_set_props(struct cacheinfo *this_leaf,
cache_get_line_size(this_leaf, np);
cache_nr_sets(this_leaf, np);
cache_associativity(this_leaf);
+ cache_of_set_id(this_leaf, np);
}
static int cache_setup_of_node(unsigned int cpu)
{
- struct device_node *np, *prev;
struct cacheinfo *this_leaf;
unsigned int index = 0;
- np = of_cpu_device_node_get(cpu);
+ struct device_node *np __free(device_node) = of_cpu_device_node_get(cpu);
if (!np) {
pr_err("Failed to find cpu%d device node\n", cpu);
return -ENOENT;
}
- prev = np;
+ if (!of_check_cache_nodes(np)) {
+ return -ENOENT;
+ }
while (index < cache_leaves(cpu)) {
this_leaf = per_cpu_cacheinfo_idx(cpu, index);
if (this_leaf->level != 1) {
+ struct device_node *prev __free(device_node) = np;
np = of_find_next_cache_node(np);
- of_node_put(prev);
- prev = np;
if (!np)
break;
}
@@ -222,15 +278,92 @@ static int cache_setup_of_node(unsigned int cpu)
index++;
}
- of_node_put(np);
-
if (index != cache_leaves(cpu)) /* not all OF nodes populated */
return -ENOENT;
return 0;
}
+
+static bool of_check_cache_nodes(struct device_node *np)
+{
+ if (of_property_present(np, "cache-size") ||
+ of_property_present(np, "i-cache-size") ||
+ of_property_present(np, "d-cache-size") ||
+ of_property_present(np, "cache-unified"))
+ return true;
+
+ struct device_node *next __free(device_node) = of_find_next_cache_node(np);
+ if (next) {
+ return true;
+ }
+
+ return false;
+}
+
+static int of_count_cache_leaves(struct device_node *np)
+{
+ unsigned int leaves = 0;
+
+ if (of_property_present(np, "cache-size"))
+ ++leaves;
+ if (of_property_present(np, "i-cache-size"))
+ ++leaves;
+ if (of_property_present(np, "d-cache-size"))
+ ++leaves;
+
+ if (!leaves) {
+ /* The '[i-|d-|]cache-size' property is required, but
+ * if absent, fallback on the 'cache-unified' property.
+ */
+ if (of_property_read_bool(np, "cache-unified"))
+ return 1;
+ else
+ return 2;
+ }
+
+ return leaves;
+}
+
+int init_of_cache_level(unsigned int cpu)
+{
+ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+ struct device_node *np __free(device_node) = of_cpu_device_node_get(cpu);
+ unsigned int levels = 0, leaves, level;
+
+ if (!of_check_cache_nodes(np)) {
+ return -ENOENT;
+ }
+
+ leaves = of_count_cache_leaves(np);
+ if (leaves > 0)
+ levels = 1;
+
+ while (1) {
+ struct device_node *prev __free(device_node) = np;
+ np = of_find_next_cache_node(np);
+ if (!np)
+ break;
+
+ if (!of_device_is_compatible(np, "cache"))
+ return -EINVAL;
+ if (of_property_read_u32(np, "cache-level", &level))
+ return -EINVAL;
+ if (level <= levels)
+ return -EINVAL;
+
+ leaves += of_count_cache_leaves(np);
+ levels = level;
+ }
+
+ this_cpu_ci->num_levels = levels;
+ this_cpu_ci->num_leaves = leaves;
+
+ return 0;
+}
+
#else
static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
+int init_of_cache_level(unsigned int cpu) { return 0; }
#endif
int __weak cache_setup_acpi(unsigned int cpu)
@@ -249,6 +382,10 @@ static int cache_setup_properties(unsigned int cpu)
else if (!acpi_disabled)
ret = cache_setup_acpi(cpu);
+ // Assume there is no cache information available in DT/ACPI from now.
+ if (ret && use_arch_cache_info())
+ use_arch_info = true;
+
return ret;
}
@@ -256,7 +393,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
{
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
struct cacheinfo *this_leaf, *sib_leaf;
- unsigned int index;
+ unsigned int index, sib_index;
int ret = 0;
if (this_cpu_ci->cpu_map_populated)
@@ -267,7 +404,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
* to update the shared cpu_map if the cache attributes were
* populated early before all the cpus are brought online
*/
- if (!last_level_cache_is_valid(cpu)) {
+ if (!last_level_cache_is_valid(cpu) && !use_arch_info) {
ret = cache_setup_properties(cpu);
if (ret)
return ret;
@@ -280,15 +417,25 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
for_each_online_cpu(i) {
- struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
-
- if (i == cpu || !sib_cpu_ci->info_list)
+ if (i == cpu || !per_cpu_cacheinfo(i))
continue;/* skip if itself or no cacheinfo */
-
- sib_leaf = per_cpu_cacheinfo_idx(i, index);
- if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
- cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
- cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
+ for (sib_index = 0; sib_index < cache_leaves(i); sib_index++) {
+ sib_leaf = per_cpu_cacheinfo_idx(i, sib_index);
+
+ /*
+ * Comparing cache IDs only makes sense if the leaves
+ * belong to the same cache level of same type. Skip
+ * the check if level and type do not match.
+ */
+ if (sib_leaf->level != this_leaf->level ||
+ sib_leaf->type != this_leaf->type)
+ continue;
+
+ if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
+ cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
+ cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
+ break;
+ }
}
}
/* record the maximum cache line size */
@@ -296,28 +443,46 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
coherency_max_size = this_leaf->coherency_line_size;
}
+ /* shared_cpu_map is now populated for the cpu */
+ this_cpu_ci->cpu_map_populated = true;
return 0;
}
static void cache_shared_cpu_map_remove(unsigned int cpu)
{
+ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
struct cacheinfo *this_leaf, *sib_leaf;
- unsigned int sibling, index;
+ unsigned int sibling, index, sib_index;
for (index = 0; index < cache_leaves(cpu); index++) {
this_leaf = per_cpu_cacheinfo_idx(cpu, index);
for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
- struct cpu_cacheinfo *sib_cpu_ci =
- get_cpu_cacheinfo(sibling);
-
- if (sibling == cpu || !sib_cpu_ci->info_list)
+ if (sibling == cpu || !per_cpu_cacheinfo(sibling))
continue;/* skip if itself or no cacheinfo */
- sib_leaf = per_cpu_cacheinfo_idx(sibling, index);
- cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
- cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
+ for (sib_index = 0; sib_index < cache_leaves(sibling); sib_index++) {
+ sib_leaf = per_cpu_cacheinfo_idx(sibling, sib_index);
+
+ /*
+ * Comparing cache IDs only makes sense if the leaves
+ * belong to the same cache level of same type. Skip
+ * the check if level and type do not match.
+ */
+ if (sib_leaf->level != this_leaf->level ||
+ sib_leaf->type != this_leaf->type)
+ continue;
+
+ if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
+ cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
+ cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
+ break;
+ }
+ }
}
}
+
+ /* cpu is no longer populated in the shared map */
+ this_cpu_ci->cpu_map_populated = false;
}
static void free_cache_attributes(unsigned int cpu)
@@ -326,10 +491,11 @@ static void free_cache_attributes(unsigned int cpu)
return;
cache_shared_cpu_map_remove(cpu);
+}
- kfree(per_cpu_cacheinfo(cpu));
- per_cpu_cacheinfo(cpu) = NULL;
- cache_leaves(cpu) = 0;
+int __weak early_cache_level(unsigned int cpu)
+{
+ return -ENOENT;
}
int __weak init_cache_level(unsigned int cpu)
@@ -342,38 +508,113 @@ int __weak populate_cache_leaves(unsigned int cpu)
return -ENOENT;
}
-int detect_cache_attributes(unsigned int cpu)
+static inline int allocate_cache_info(int cpu)
{
+ per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), sizeof(struct cacheinfo), GFP_ATOMIC);
+ if (!per_cpu_cacheinfo(cpu)) {
+ cache_leaves(cpu) = 0;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+int fetch_cache_info(unsigned int cpu)
+{
+ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+ unsigned int levels = 0, split_levels = 0;
int ret;
- /* Since early detection of the cacheinfo is allowed via this
- * function and this also gets called as CPU hotplug callbacks via
- * cacheinfo_cpu_online, the initialisation can be skipped and only
- * CPU maps can be updated as the CPU online status would be update
- * if called via cacheinfo_cpu_online path.
+ if (acpi_disabled) {
+ ret = init_of_cache_level(cpu);
+ } else {
+ ret = acpi_get_cache_info(cpu, &levels, &split_levels);
+ if (!ret) {
+ this_cpu_ci->num_levels = levels;
+ /*
+ * This assumes that:
+ * - there cannot be any split caches (data/instruction)
+ * above a unified cache
+ * - data/instruction caches come by pair
+ */
+ this_cpu_ci->num_leaves = levels + split_levels;
+ }
+ }
+
+ if (ret || !cache_leaves(cpu)) {
+ ret = early_cache_level(cpu);
+ if (ret)
+ return ret;
+
+ if (!cache_leaves(cpu))
+ return -ENOENT;
+
+ this_cpu_ci->early_ci_levels = true;
+ }
+
+ return allocate_cache_info(cpu);
+}
+
+static inline int init_level_allocate_ci(unsigned int cpu)
+{
+ unsigned int early_leaves = cache_leaves(cpu);
+
+ /* Since early initialization/allocation of the cacheinfo is allowed
+ * via fetch_cache_info() and this also gets called as CPU hotplug
+ * callbacks via cacheinfo_cpu_online, the init/alloc can be skipped
+ * as it will happen only once (the cacheinfo memory is never freed).
+ * Just populate the cacheinfo. However, if the cacheinfo has been
+ * allocated early through the arch-specific early_cache_level() call,
+ * there is a chance the info is wrong (this can happen on arm64). In
+ * that case, call init_cache_level() anyway to give the arch-specific
+ * code a chance to make things right.
*/
- if (per_cpu_cacheinfo(cpu))
- goto update_cpu_map;
+ if (per_cpu_cacheinfo(cpu) && !ci_cacheinfo(cpu)->early_ci_levels)
+ return 0;
if (init_cache_level(cpu) || !cache_leaves(cpu))
return -ENOENT;
- per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
- sizeof(struct cacheinfo), GFP_ATOMIC);
- if (per_cpu_cacheinfo(cpu) == NULL) {
- cache_leaves(cpu) = 0;
- return -ENOMEM;
- }
+ /*
+ * Now that we have properly initialized the cache level info, make
+ * sure we don't try to do that again the next time we are called
+ * (e.g. as CPU hotplug callbacks).
+ */
+ ci_cacheinfo(cpu)->early_ci_levels = false;
/*
- * populate_cache_leaves() may completely setup the cache leaves and
- * shared_cpu_map or it may leave it partially setup.
+ * Some architectures (e.g., x86) do not use early initialization.
+ * Allocate memory now in such case.
*/
- ret = populate_cache_leaves(cpu);
+ if (cache_leaves(cpu) <= early_leaves && per_cpu_cacheinfo(cpu))
+ return 0;
+
+ kfree(per_cpu_cacheinfo(cpu));
+ return allocate_cache_info(cpu);
+}
+
+int detect_cache_attributes(unsigned int cpu)
+{
+ int ret;
+
+ ret = init_level_allocate_ci(cpu);
if (ret)
- goto free_ci;
+ return ret;
+
+ /*
+ * If LLC is valid the cache leaves were already populated so just go to
+ * update the cpu map.
+ */
+ if (!last_level_cache_is_valid(cpu)) {
+ /*
+ * populate_cache_leaves() may completely setup the cache leaves and
+ * shared_cpu_map or it may leave it partially setup.
+ */
+ ret = populate_cache_leaves(cpu);
+ if (ret)
+ goto free_ci;
+ }
-update_cpu_map:
/*
* For systems using DT for cache hierarchy, fw_token
* and shared_cpu_map will be set up here only if they are
@@ -689,24 +930,111 @@ err:
return rc;
}
+static unsigned int cpu_map_shared_cache(bool online, unsigned int cpu,
+ cpumask_t **map)
+{
+ struct cacheinfo *llc, *sib_llc;
+ unsigned int sibling;
+
+ if (!last_level_cache_is_valid(cpu))
+ return 0;
+
+ llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
+
+ if (llc->type != CACHE_TYPE_DATA && llc->type != CACHE_TYPE_UNIFIED)
+ return 0;
+
+ if (online) {
+ *map = &llc->shared_cpu_map;
+ return cpumask_weight(*map);
+ }
+
+ /* shared_cpu_map of offlined CPU will be cleared, so use sibling map */
+ for_each_cpu(sibling, &llc->shared_cpu_map) {
+ if (sibling == cpu || !last_level_cache_is_valid(sibling))
+ continue;
+ sib_llc = per_cpu_cacheinfo_idx(sibling, cache_leaves(sibling) - 1);
+ *map = &sib_llc->shared_cpu_map;
+ return cpumask_weight(*map);
+ }
+
+ return 0;
+}
+
+/*
+ * Calculate the size of the per-CPU data cache slice. This can be
+ * used to estimate the size of the data cache slice that can be used
+ * by one CPU under ideal circumstances. UNIFIED caches are counted
+ * in addition to DATA caches. So, please consider code cache usage
+ * when use the result.
+ *
+ * Because the cache inclusive/non-inclusive information isn't
+ * available, we just use the size of the per-CPU slice of LLC to make
+ * the result more predictable across architectures.
+ */
+static void update_per_cpu_data_slice_size_cpu(unsigned int cpu)
+{
+ struct cpu_cacheinfo *ci;
+ struct cacheinfo *llc;
+ unsigned int nr_shared;
+
+ if (!last_level_cache_is_valid(cpu))
+ return;
+
+ ci = ci_cacheinfo(cpu);
+ llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
+
+ if (llc->type != CACHE_TYPE_DATA && llc->type != CACHE_TYPE_UNIFIED)
+ return;
+
+ nr_shared = cpumask_weight(&llc->shared_cpu_map);
+ if (nr_shared)
+ ci->per_cpu_data_slice_size = llc->size / nr_shared;
+}
+
+static void update_per_cpu_data_slice_size(bool cpu_online, unsigned int cpu,
+ cpumask_t *cpu_map)
+{
+ unsigned int icpu;
+
+ for_each_cpu(icpu, cpu_map) {
+ if (!cpu_online && icpu == cpu)
+ continue;
+ update_per_cpu_data_slice_size_cpu(icpu);
+ setup_pcp_cacheinfo(icpu);
+ }
+}
+
static int cacheinfo_cpu_online(unsigned int cpu)
{
int rc = detect_cache_attributes(cpu);
+ cpumask_t *cpu_map;
if (rc)
return rc;
rc = cache_add_dev(cpu);
if (rc)
- free_cache_attributes(cpu);
+ goto err;
+ if (cpu_map_shared_cache(true, cpu, &cpu_map))
+ update_per_cpu_data_slice_size(true, cpu, cpu_map);
+ return 0;
+err:
+ free_cache_attributes(cpu);
return rc;
}
static int cacheinfo_cpu_pre_down(unsigned int cpu)
{
+ cpumask_t *cpu_map;
+ unsigned int nr_shared;
+
+ nr_shared = cpu_map_shared_cache(false, cpu, &cpu_map);
if (cpumask_test_and_clear_cpu(cpu, &cache_dev_map))
cpu_cache_sysfs_exit(cpu);
free_cache_attributes(cpu);
+ if (nr_shared > 1)
+ update_per_cpu_data_slice_size(false, cpu, cpu_map);
return 0;
}