[PATCH v2] ACPI / PPTT: Populate cache-id from rev3 of PPTT in ACPIv6.4

[PATCH v2] ACPI / PPTT: Populate cache-id from rev3 of PPTT in ACPIv6.4

[Joey Gouly]

From: James Morse <james.morse@arm.com>

ACPIv6.4 adds a 'cache id' to the PPTT Cache Type Structure.
Copy this property across into the cacheinfo leaf when it was
provided by firmware.

This value gets exposed to userspace as:
/sys/devices/system/cpu/cpu*/cache/index*/id.
See the "Cache IDs" section of Documentation/x86/resctrl.rst.

Co-authored-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
---

v2:
- Pass `revision` instead of the table to `update_cache_properties`.

v1: https://lore.kernel.org/linux-acpi/20210527143955.38591-1-joey.gouly@arm.com/

 drivers/acpi/pptt.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index 4ae93350b70d..fe69dc518f31 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -347,6 +347,7 @@ static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *ta
  * @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
+ * @revision: The revision of the PPTT table
  *
  * 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
@@ -356,8 +357,11 @@ static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *ta
  */
 static void update_cache_properties(struct cacheinfo *this_leaf,
 				    struct acpi_pptt_cache *found_cache,
-				    struct acpi_pptt_processor *cpu_node)
+				    struct acpi_pptt_processor *cpu_node,
+				    u8 revision)
 {
+	struct acpi_pptt_cache_v1* found_cache_v1;
+
 	this_leaf->fw_token = cpu_node;
 	if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID)
 		this_leaf->size = found_cache->size;
@@ -405,6 +409,13 @@ static void update_cache_properties(struct cacheinfo *this_leaf,
 	if (this_leaf->type == CACHE_TYPE_NOCACHE &&
 	    found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)
 		this_leaf->type = CACHE_TYPE_UNIFIED;
+
+	if (revision >= 3 && (found_cache->flags & ACPI_PPTT_CACHE_ID_VALID)) {
+		found_cache_v1 = ACPI_ADD_PTR(struct acpi_pptt_cache_v1,
+	                                      found_cache, sizeof(struct acpi_pptt_cache));
+		this_leaf->id = found_cache_v1->cache_id;
+		this_leaf->attributes |= CACHE_ID;
+	}
 }
 
 static void cache_setup_acpi_cpu(struct acpi_table_header *table,
@@ -425,9 +436,8 @@ static void cache_setup_acpi_cpu(struct acpi_table_header *table,
 						   &cpu_node);
 		pr_debug("found = %p %p\n", found_cache, cpu_node);
 		if (found_cache)
-			update_cache_properties(this_leaf,
-						found_cache,
-						cpu_node);
+			update_cache_properties(this_leaf, found_cache,
+			                        cpu_node, table->revision);
 
 		index++;
 	}
-- 
2.17.1

Re: [PATCH v2] ACPI / PPTT: Populate cache-id from rev3 of PPTT in ACPIv6.4

[Rafael J. Wysocki]

On Tue, Jun 1, 2021 at 2:17 PM Joey Gouly <joey.gouly@arm.com> wrote:
>
> From: James Morse <james.morse@arm.com>
>
> ACPIv6.4 adds a 'cache id' to the PPTT Cache Type Structure.
> Copy this property across into the cacheinfo leaf when it was
> provided by firmware.
>
> This value gets exposed to userspace as:
> /sys/devices/system/cpu/cpu*/cache/index*/id.
> See the "Cache IDs" section of Documentation/x86/resctrl.rst.
>
> Co-authored-by: Joey Gouly <joey.gouly@arm.com>
> Signed-off-by: James Morse <james.morse@arm.com>
> Signed-off-by: Joey Gouly <joey.gouly@arm.com>
> ---
>
> v2:
> - Pass `revision` instead of the table to `update_cache_properties`.
>
> v1: https://lore.kernel.org/linux-acpi/20210527143955.38591-1-joey.gouly@arm.com/
>
>  drivers/acpi/pptt.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
> index 4ae93350b70d..fe69dc518f31 100644
> --- a/drivers/acpi/pptt.c
> +++ b/drivers/acpi/pptt.c
> @@ -347,6 +347,7 @@ static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *ta
>   * @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
> + * @revision: The revision of the PPTT table
>   *
>   * 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
> @@ -356,8 +357,11 @@ static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *ta
>   */
>  static void update_cache_properties(struct cacheinfo *this_leaf,
>                                     struct acpi_pptt_cache *found_cache,
> -                                   struct acpi_pptt_processor *cpu_node)
> +                                   struct acpi_pptt_processor *cpu_node,
> +                                   u8 revision)
>  {
> +       struct acpi_pptt_cache_v1* found_cache_v1;
> +
>         this_leaf->fw_token = cpu_node;
>         if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID)
>                 this_leaf->size = found_cache->size;
> @@ -405,6 +409,13 @@ static void update_cache_properties(struct cacheinfo *this_leaf,
>         if (this_leaf->type == CACHE_TYPE_NOCACHE &&
>             found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)
>                 this_leaf->type = CACHE_TYPE_UNIFIED;
> +
> +       if (revision >= 3 && (found_cache->flags & ACPI_PPTT_CACHE_ID_VALID)) {
> +               found_cache_v1 = ACPI_ADD_PTR(struct acpi_pptt_cache_v1,
> +                                             found_cache, sizeof(struct acpi_pptt_cache));
> +               this_leaf->id = found_cache_v1->cache_id;
> +               this_leaf->attributes |= CACHE_ID;
> +       }
>  }
>
>  static void cache_setup_acpi_cpu(struct acpi_table_header *table,
> @@ -425,9 +436,8 @@ static void cache_setup_acpi_cpu(struct acpi_table_header *table,
>                                                    &cpu_node);
>                 pr_debug("found = %p %p\n", found_cache, cpu_node);
>                 if (found_cache)
> -                       update_cache_properties(this_leaf,
> -                                               found_cache,
> -                                               cpu_node);
> +                       update_cache_properties(this_leaf, found_cache,
> +                                               cpu_node, table->revision);
>
>                 index++;
>         }
> --

Applied as 5.14 material with some edits in the subject and changelog, thanks!