On Mon, Nov 21, 2022 at 06:12:12PM +0100, Pierre Gondois wrote:
> acpi_find_last_cache_level() allows to find the last level of cache
> for a given CPU. The function is only called on arm64 ACPI based
> platforms to check for cache information that would be missing in
> the CLIDR_EL1 register.
> To allow populating (struct cpu_cacheinfo).num_leaves by only parsing
> a PPTT, update acpi_find_last_cache_level() to get the 'split_levels',
> i.e. the number of cache levels being split in data/instruction
> caches.
>
> It is assumed that there will not be data/instruction caches above a
> unified cache.
> If a split level consist of one data cache and no instruction cache
> (or opposite), then the missing cache will still be populated
> by default with minimal cache information, and maximal cpumask
> (all non-existing caches have the same fw_token).
>
> Suggested-by: Jeremy Linton <jeremy.linton@arm.com>
> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
> arch/arm64/kernel/cacheinfo.c | 9 +++--
> drivers/acpi/pptt.c | 76 +++++++++++++++++++++++------------
> include/linux/cacheinfo.h | 8 ++--
> 3 files changed, 61 insertions(+), 32 deletions(-)
>
> diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c
> index 97c42be71338..164255651d64 100644
> --- a/arch/arm64/kernel/cacheinfo.c
> +++ b/arch/arm64/kernel/cacheinfo.c
> @@ -46,7 +46,7 @@ static void ci_leaf_init(struct cacheinfo *this_leaf,
> int init_cache_level(unsigned int cpu)
> {
> unsigned int ctype, level, leaves;
> - int fw_level;
> + int fw_level, ret;
> struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
>
> for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
> @@ -61,8 +61,11 @@ int init_cache_level(unsigned int cpu)
>
> if (acpi_disabled)
> fw_level = of_find_last_cache_level(cpu);
> - else
> - fw_level = acpi_find_last_cache_level(cpu);
> + else {
You need to add braces to if as well in such cases. I think checkpatch
might tell you that. Just found this by chance.
Anyways, this looks good to me.
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
@@ -46,7 +46,7 @@ static void ci_leaf_init(struct cacheinfo *this_leaf,
int init_cache_level(unsigned int cpu)
{
unsigned int ctype, level, leaves;
- int fw_level;
+ int fw_level, ret;
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
@@ -61,8 +61,11 @@ int init_cache_level(unsigned int cpu)
if (acpi_disabled)
fw_level = of_find_last_cache_level(cpu);
- else
- fw_level = acpi_find_last_cache_level(cpu);
+ else {
+ ret = acpi_get_cache_info(cpu, &fw_level, NULL);
+ if (ret < 0)
+ return ret;
+ }
if (fw_level < 0)
return fw_level;
@@ -81,6 +81,7 @@ static inline bool acpi_pptt_match_type(int table_type, int 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
+ * @split_levels: Number of split cache levels (data/instruction).
* @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
@@ -100,6 +101,7 @@ static inline bool acpi_pptt_match_type(int table_type, int type)
*/
static unsigned int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr,
unsigned int local_level,
+ unsigned int *split_levels,
struct acpi_subtable_header *res,
struct acpi_pptt_cache **found,
unsigned int level, int type)
@@ -113,8 +115,17 @@ static unsigned int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr,
while (cache) {
local_level++;
+ if (!(cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)) {
+ cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache);
+ continue;
+ }
+
+ if (split_levels &&
+ (acpi_pptt_match_type(cache->attributes, ACPI_PPTT_CACHE_TYPE_DATA) ||
+ acpi_pptt_match_type(cache->attributes, ACPI_PPTT_CACHE_TYPE_INSTR)))
+ *split_levels = 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");
@@ -135,8 +146,8 @@ static unsigned int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr,
static struct acpi_pptt_cache *
acpi_find_cache_level(struct acpi_table_header *table_hdr,
struct acpi_pptt_processor *cpu_node,
- unsigned int *starting_level, unsigned int level,
- int type)
+ unsigned int *starting_level, unsigned int *split_levels,
+ unsigned int level, int type)
{
struct acpi_subtable_header *res;
unsigned int number_of_levels = *starting_level;
@@ -149,7 +160,8 @@ acpi_find_cache_level(struct acpi_table_header *table_hdr,
resource++;
local_level = acpi_pptt_walk_cache(table_hdr, *starting_level,
- res, &ret, level, type);
+ split_levels, res, &ret,
+ level, type);
/*
* we are looking for the max depth. Since its potentially
* possible for a given node to have resources with differing
@@ -165,29 +177,29 @@ acpi_find_cache_level(struct acpi_table_header *table_hdr,
}
/**
- * acpi_count_levels() - Given a PPTT table, and a CPU node, count the caches
+ * acpi_count_levels() - Given a PPTT table, and a CPU node, count the cache
+ * levels and split cache levels (data/instruction).
* @table_hdr: Pointer to the head of the PPTT table
* @cpu_node: processor node we wish to count caches for
+ * @levels: Number of levels if success.
+ * @split_levels: Number of split cache levels (data/instruction) if
+ * success. Can by NULL.
*
* 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.
+ * caches that exist across packages). Count the number of cache levels and
+ * split cache levels (data/instruction) that exist at each level on the way
+ * up.
*/
-static int acpi_count_levels(struct acpi_table_header *table_hdr,
- struct acpi_pptt_processor *cpu_node)
+static void acpi_count_levels(struct acpi_table_header *table_hdr,
+ struct acpi_pptt_processor *cpu_node,
+ unsigned int *levels, unsigned int *split_levels)
{
- int total_levels = 0;
-
do {
- acpi_find_cache_level(table_hdr, cpu_node, &total_levels, 0, 0);
+ acpi_find_cache_level(table_hdr, cpu_node, levels, split_levels, 0, 0);
cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
} while (cpu_node);
-
- return total_levels;
}
/**
@@ -321,7 +333,7 @@ static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *ta
while (cpu_node && !found) {
found = acpi_find_cache_level(table_hdr, cpu_node,
- &total_levels, level, acpi_type);
+ &total_levels, NULL, level, acpi_type);
*node = cpu_node;
cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
}
@@ -589,36 +601,48 @@ static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag)
}
/**
- * acpi_find_last_cache_level() - Determines the number of cache levels for a PE
+ * acpi_get_cache_info() - Determine the number of cache levels and
+ * split cache levels (data/instruction) and for a PE.
* @cpu: Kernel logical CPU number
+ * @levels: Number of levels if success.
+ * @split_levels: Number of levels being split (i.e. data/instruction)
+ * if success. Can by NULL.
*
* 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.
+ * Return: -ENOENT if no PPTT table or no PPTT processor struct found.
+ * 0 on success.
*/
-int acpi_find_last_cache_level(unsigned int cpu)
+int acpi_get_cache_info(unsigned int cpu, unsigned int *levels,
+ unsigned int *split_levels)
{
struct acpi_pptt_processor *cpu_node;
struct acpi_table_header *table;
- int number_of_levels = 0;
u32 acpi_cpu_id;
+ *levels = 0;
+ if (split_levels)
+ *split_levels = 0;
+
table = acpi_get_pptt();
if (!table)
return -ENOENT;
- pr_debug("Cache Setup find last level CPU=%d\n", cpu);
+ pr_debug("Cache Setup: find cache levels for CPU=%d\n", cpu);
acpi_cpu_id = get_acpi_id_for_cpu(cpu);
cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
- if (cpu_node)
- number_of_levels = acpi_count_levels(table, cpu_node);
+ if (!cpu_node)
+ return -ENOENT;
- pr_debug("Cache Setup find last level level=%d\n", number_of_levels);
+ acpi_count_levels(table, cpu_node, levels, split_levels);
- return number_of_levels;
+ pr_debug("Cache Setup: last_level=%d split_levels=%d\n",
+ *levels, split_levels ? *split_levels : -1);
+
+ return 0;
}
/**
@@ -88,19 +88,21 @@ bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y);
int detect_cache_attributes(unsigned int cpu);
#ifndef CONFIG_ACPI_PPTT
/*
- * acpi_find_last_cache_level is only called on ACPI enabled
+ * acpi_get_cache_info() is only called on ACPI enabled
* platforms using the PPTT for topology. This means that if
* the platform supports other firmware configuration methods
* we need to stub out the call when ACPI is disabled.
* ACPI enabled platforms not using PPTT won't be making calls
* to this function so we need not worry about them.
*/
-static inline int acpi_find_last_cache_level(unsigned int cpu)
+static inline int acpi_get_cache_info(unsigned int cpu,
+ unsigned int *levels, unsigned int *split_levels)
{
return 0;
}
#else
-int acpi_find_last_cache_level(unsigned int cpu);
+int acpi_get_cache_info(unsigned int cpu,
+ unsigned int *levels, unsigned int *split_levels);
#endif
const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);