ACPI: PPTT: Update acpi_find_last_cache_level() to acpi_get_cache_info()

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>
Acked-by: Rafael J. Wysocki  <rafael.j.wysocki@intel.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230104183033.755668-6-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c
index 97c42be71338..36c3b07cdf2d 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++) {
@@ -59,10 +59,13 @@ int init_cache_level(unsigned int cpu)
 		leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
 	}
 
-	if (acpi_disabled)
+	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;