Re: [PATCH 2/6] ACPI: Add CPPC v4 definitions

[Mario Limonciello]

On 4/26/26 22:55, Mario Limonciello (AMD) wrote:
> ACPI 6.6 introduced new optional package values for
> `OSPMNominalPerformanceRegister` and
> `ResourcePriorityRegisters`.
>
> Add these into the defines.  As they're not used right now they are not
> wired up to anything at this time.
>
> Link: https://uefi.org/specs/ACPI/6.6/08_Processor_Configuration_and_Control.html#cpc-continuous-performance-control
> Signed-off-by: Mario Limonciello (AMD) <superm1@xxxxxxxxxx>

This patch will be dropped in favor of Sumit's patches on the same subject.

https://lore.kernel.org/linux-acpi/20260427051823.280419-1-sumitg@xxxxxxxxxx/

I will rebase the next version of the series on this instead.

> ---
>   drivers/acpi/cppc_acpi.c | 16 ++++++++++++----
>   include/acpi/cppc_acpi.h | 13 +++++++++----
>   2 files changed, 21 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 2e91c5a977611..cbfebc50b6eab 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -755,14 +755,15 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
>   	 */
>   	if ((cpc_rev == CPPC_V2_REV && num_ent != CPPC_V2_NUM_ENT) ||
>   	    (cpc_rev == CPPC_V3_REV && num_ent != CPPC_V3_NUM_ENT) ||
> -	    (cpc_rev > CPPC_V3_REV && num_ent <= CPPC_V3_NUM_ENT)) {
> +	    (cpc_rev == CPPC_V4_REV && num_ent != CPPC_V4_NUM_ENT) ||
> +	    (cpc_rev > CPPC_V4_REV && num_ent <= CPPC_V4_NUM_ENT)) {
>   		pr_debug("Unexpected number of _CPC return package entries (%d) for CPU:%d\n",
>   			 num_ent, pr->id);
>   		goto out_free;
>   	}
> -	if (cpc_rev > CPPC_V3_REV) {
> -		num_ent = CPPC_V3_NUM_ENT;
> -		cpc_rev = CPPC_V3_REV;
> +	if (cpc_rev > CPPC_V4_REV) {
> +		num_ent = CPPC_V4_NUM_ENT;
> +		cpc_rev = CPPC_V4_REV;
>   	}
>   
>   	cpc_ptr->num_entries = num_ent;
> @@ -845,6 +846,13 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
>   
>   			cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER;
>   			memcpy(&cpc_ptr->cpc_regs[i-2].cpc_entry.reg, gas_t, sizeof(*gas_t));
> +		} else if (cpc_obj->type == ACPI_TYPE_PACKAGE) {
> +			/*
> +			 * CPPC v4 ResourcePriorityRegisters is a Package.
> +			 * Store NULL for now as it's not wired up to anything.
> +			 */
> +			cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_PACKAGE;
> +			cpc_ptr->cpc_regs[i-2].cpc_entry.pkg_data = NULL;
>   		} else {
>   			pr_debug("Invalid entry type (%d) in _CPC for CPU:%d\n",
>   				 i, pr->id);
> diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
> index d1f02ceec4f98..38bf9013c6e2e 100644
> --- a/include/acpi/cppc_acpi.h
> +++ b/include/acpi/cppc_acpi.h
> @@ -17,16 +17,18 @@
>   #include <acpi/pcc.h>
>   #include <acpi/processor.h>
>   
> -/* CPPCv2 and CPPCv3 support */
> +/* CPPC support */
>   #define CPPC_V2_REV	2
>   #define CPPC_V3_REV	3
> +#define CPPC_V4_REV	4
>   #define CPPC_V2_NUM_ENT	21
>   #define CPPC_V3_NUM_ENT	23
> +#define CPPC_V4_NUM_ENT	25
>   
>   #define PCC_CMD_COMPLETE_MASK	(1 << 0)
>   #define PCC_ERROR_MASK		(1 << 2)
>   
> -#define MAX_CPC_REG_ENT 21
> +#define MAX_CPC_REG_ENT 23
>   
>   /* CPPC specific PCC commands. */
>   #define	CMD_READ 0
> @@ -60,8 +62,8 @@ struct cpc_reg {
>   
>   /*
>    * Each entry in the CPC table is either
> - * of type ACPI_TYPE_BUFFER or
> - * ACPI_TYPE_INTEGER.
> + * of type ACPI_TYPE_BUFFER, ACPI_TYPE_INTEGER,
> + * or ACPI_TYPE_PACKAGE (for CPPC v4 ResourcePriorityRegisters).
>    */
>   struct cpc_register_resource {
>   	acpi_object_type type;
> @@ -69,6 +71,7 @@ struct cpc_register_resource {
>   	union {
>   		struct cpc_reg reg;
>   		u64 int_value;
> +		void *pkg_data;
>   	} cpc_entry;
>   };
>   
> @@ -109,6 +112,8 @@ enum cppc_regs {
>   	REFERENCE_PERF,
>   	LOWEST_FREQ,
>   	NOMINAL_FREQ,
> +	OSPM_NOMINAL_PERF,
> +	RESOURCE_PRIO,
>   };
>   
>   /*