This patch uniform data type of component_id/domid/id/cache_id to
u32 to avoid type confusion. According to ACPI for mpam, cache id
is used as locator for cache MSC. Reference to RD_PPTT_CACHE_ID
definition from edk2-platforms, u32 is enough for cache_id.

	(                                                              \
	  (((PackageId) & 0xF) << 20) | (((ClusterId) & 0xFF) << 12) | \
	  (((CoreId) & 0xFF) << 4) | ((CacheType) & 0xF)               \
	)

refs:
1. ACPI for mpam: https://developer.arm.com/documentation/den0065/latest/
2. RD_PPTT_CACHE_ID from edk2-platforms: https://github.com/tianocore/edk2-platforms/blob/master/Platform/ARM/SgiPkg/Include/SgiAcpiHeader.h#L202

Signed-off-by: Rex Nie <rex.nie@jaguarmicro.com>
---
 drivers/platform/mpam/mpam_devices.c | 8 ++++----
 include/linux/arm_mpam.h             | 2 +-
 include/linux/resctrl.h              | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/mpam/mpam_devices.c b/drivers/platform/mpam/mpam_devices.c
index c2457c36ab12..335ca9e441da 100644
--- a/drivers/platform/mpam/mpam_devices.c
+++ b/drivers/platform/mpam/mpam_devices.c
@@ -205,7 +205,7 @@ int mpam_register_requestor(u16 partid_max, u8 pmg_max)
 EXPORT_SYMBOL(mpam_register_requestor);
 
 static struct mpam_component *
-mpam_component_alloc(struct mpam_class *class, int id, gfp_t gfp)
+mpam_component_alloc(struct mpam_class *class, u32 id, gfp_t gfp)
 {
 	struct mpam_component *comp;
 
@@ -227,7 +227,7 @@ mpam_component_alloc(struct mpam_class *class, int id, gfp_t gfp)
 }
 
 static struct mpam_component *
-mpam_component_get(struct mpam_class *class, int id, bool alloc, gfp_t gfp)
+mpam_component_get(struct mpam_class *class, u32 id, bool alloc, gfp_t gfp)
 {
 	struct mpam_component *comp;
 
@@ -476,7 +476,7 @@ static int mpam_ris_get_affinity(struct mpam_msc *msc, cpumask_t *affinity,
 
 static int mpam_ris_create_locked(struct mpam_msc *msc, u8 ris_idx,
 				  enum mpam_class_types type, u8 class_id,
-				  int component_id, gfp_t gfp)
+				  u32 component_id, gfp_t gfp)
 {
 	int err;
 	struct mpam_msc_ris *ris;
@@ -525,7 +525,7 @@ static int mpam_ris_create_locked(struct mpam_msc *msc, u8 ris_idx,
 }
 
 int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx,
-		    enum mpam_class_types type, u8 class_id, int component_id)
+		    enum mpam_class_types type, u8 class_id, u32 component_id)
 {
 	int err;
 
diff --git a/include/linux/arm_mpam.h b/include/linux/arm_mpam.h
index d70e4e726fe6..0a4ac76682b5 100644
--- a/include/linux/arm_mpam.h
+++ b/include/linux/arm_mpam.h
@@ -48,7 +48,7 @@ static inline int acpi_mpam_count_msc(void) { return -EINVAL; }
 int mpam_register_requestor(u16 partid_max, u8 pmg_max);
 
 int mpam_ris_create(struct mpam_msc *msc, u8 ris_idx,
-		    enum mpam_class_types type, u8 class_id, int component_id);
+		    enum mpam_class_types type, u8 class_id, u32 component_id);
 
 static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
 {
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index dd34523469a5..b00a89addf91 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -108,7 +108,7 @@ struct resctrl_staged_config {
  */
 struct rdt_domain {
 	struct list_head		list;
-	int				id;
+	u32						id;
 	struct cpumask			cpu_mask;
 	unsigned long			*rmid_busy_llc;
 	struct mbm_state		*mbm_total;
-- 
2.34.1

Hi Rex Nie,

(for those following along at home - this is a patch against the MPAM tree, not mainline)

On 11/03/2024 08:18, Rex Nie wrote:
> This patch uniform data type of component_id/domid/id/cache_id to
> u32 to avoid type confusion. According to ACPI for mpam, cache id
> is used as locator for cache MSC. Reference to RD_PPTT_CACHE_ID
> definition from edk2-platforms, u32 is enough for cache_id.
> 
> 	(                                                              \
> 	  (((PackageId) & 0xF) << 20) | (((ClusterId) & 0xFF) << 12) | \
> 	  (((CoreId) & 0xFF) << 4) | ((CacheType) & 0xF)               \
> 	)

Aha, this is where those numbers are coming from! Thanks for digging that out.


> refs:
> 1. ACPI for mpam: https://developer.arm.com/documentation/den0065/latest/
> 2. RD_PPTT_CACHE_ID from edk2-platforms: https://github.com/tianocore/edk2-platforms/blob/master/Platform/ARM/SgiPkg/Include/SgiAcpiHeader.h#L202

Just to check - you don't see any side effects from doing this, its just cleaner.
I agree - today this is only an int because that's what it is in struct rdt_domain.


> diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
> index dd34523469a5..b00a89addf91 100644
> --- a/include/linux/resctrl.h
> +++ b/include/linux/resctrl.h
> @@ -108,7 +108,7 @@ struct resctrl_staged_config {
>   */
>  struct rdt_domain {
>  	struct list_head		list;
> -	int				id;
> +	u32						id;
>  	struct cpumask			cpu_mask;
>  	unsigned long			*rmid_busy_llc;
>  	struct mbm_state		*mbm_total;


We should probably only make this change if we clean this up in restrl, not just the MPAM
driver.


I'll pick the MPAM bits of this up for the MPAM tree. This will eventually get merged with
the patch that adds the original code as there is no point preserving the history of code
that isn't merged yet. I'll add you to 'CC' of those patches. (The joke is 'CC' also
stands for Celebrate Contribution!)


Thanks!

James