From: Sumit Gupta Date: Wed, 27 May 2026 19:46:25 +0000 (+0530) Subject: ACPI: CPPC: Add support for CPPC v4 X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=71e1815113f7e37e7e39ed69526cd7d399e5a0c9;p=thirdparty%2Fkernel%2Flinux.git ACPI: CPPC: Add support for CPPC v4 CPPC v4 (ACPI 6.6, Section 8.4.6) adds two optional entries to the _CPC package: 1. OSPM Nominal Performance (8.4.6.1.2.6): A write-only register that lets OSPM inform the platform what it considers nominal performance. The platform classifies performance above this level as boost and below as throttle for its power/thermal decisions. 2. Resource Priority (8.4.6.1.2.7): A Package of Resource Priority Register Descriptor sub-packages that allow OSPM to set relative priority among processors for shared resources (boost, throttle, L2/L3 cache, memory bandwidth). Parsing the full structure is not yet supported; such entries are marked as unsupported. Add v4 _CPC table parsing (25 entries) and update REG_OPTIONAL to mark the two new registers as optional. Signed-off-by: Sumit Gupta Reviewed-by: Mario Limonciello (AMD) Reviewed-by: Pierre Gondois Link: https://patch.msgid.link/20260527194626.185286-2-sumitg@nvidia.com Signed-off-by: Rafael J. Wysocki --- diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index f370be8715ae..c76cfafa3589 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -134,7 +134,7 @@ static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); * cpc_regs[] with the corresponding index. 0 means mandatory and 1 * means optional. */ -#define REG_OPTIONAL (0x1FC7D0) +#define REG_OPTIONAL (0x7FC7D0) /* * Use the index of the register in per-cpu cpc_regs[] to check if @@ -751,18 +751,19 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) /* * Disregard _CPC if the number of entries in the return package is not * as expected, but support future revisions being proper supersets of - * the v3 and only causing more entries to be returned by _CPC. + * the v4 and only causing more entries to be returned by _CPC. */ 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 +846,16 @@ 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 && (i - 2) == RESOURCE_PRIORITY) { + /* + * ACPI 6.6, s8.4.6.1.2.7 defines Resource Priority as a + * Package of Resource Priority Register Descriptor sub-packages. + * Parsing the full structure is not yet supported. + * Mark the register as unsupported for now. + */ + pr_debug("CPU:%d Resource Priority not supported\n", pr->id); + cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER; + cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = 0; } 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 d1f02ceec4f9..8693890a7275 100644 --- a/include/acpi/cppc_acpi.h +++ b/include/acpi/cppc_acpi.h @@ -17,16 +17,18 @@ #include #include -/* CPPCv2 and CPPCv3 support */ +/* CPPCv2, CPPCv3 and CPPCv4 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 @@ -109,6 +111,8 @@ enum cppc_regs { REFERENCE_PERF, LOWEST_FREQ, NOMINAL_FREQ, + OSPM_NOMINAL_PERF, + RESOURCE_PRIORITY, }; /*