diff options
Diffstat (limited to 'drivers/acpi/cppc_acpi.c')
-rw-r--r-- | drivers/acpi/cppc_acpi.c | 80 |
1 files changed, 46 insertions, 34 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 903528f7e187..1e15a9f25ae9 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -578,6 +578,19 @@ bool __weak cpc_ffh_supported(void) } /** + * cpc_supported_by_cpu() - check if CPPC is supported by CPU + * + * Check if the architectural support for CPPC is present even + * if the _OSC hasn't prescribed it + * + * Return: true for supported, false for not supported + */ +bool __weak cpc_supported_by_cpu(void) +{ + return false; +} + +/** * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace * * Check and allocate the cppc_pcc_data memory. @@ -605,33 +618,6 @@ static int pcc_data_alloc(int pcc_ss_id) return 0; } -/* Check if CPPC revision + num_ent combination is supported */ -static bool is_cppc_supported(int revision, int num_ent) -{ - int expected_num_ent; - - switch (revision) { - case CPPC_V2_REV: - expected_num_ent = CPPC_V2_NUM_ENT; - break; - case CPPC_V3_REV: - expected_num_ent = CPPC_V3_NUM_ENT; - break; - default: - pr_debug("Firmware exports unsupported CPPC revision: %d\n", - revision); - return false; - } - - if (expected_num_ent != num_ent) { - pr_debug("Firmware exports %d entries. Expected: %d for CPPC rev:%d\n", - num_ent, expected_num_ent, revision); - return false; - } - - return true; -} - /* * An example CPC table looks like the following. * @@ -684,8 +670,11 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) acpi_status status; int ret = -ENODATA; - if (osc_sb_cppc_not_supported) - return -ENODEV; + if (!osc_sb_cppc2_support_acked) { + pr_debug("CPPC v2 _OSC not acked\n"); + if (!cpc_supported_by_cpu()) + return -ENODEV; + } /* Parse the ACPI _CPC table for this CPU. */ status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output, @@ -717,7 +706,6 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) cpc_obj->type, pr->id); goto out_free; } - cpc_ptr->num_entries = num_ent; /* Second entry should be revision. */ cpc_obj = &out_obj->package.elements[1]; @@ -728,10 +716,32 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) cpc_obj->type, pr->id); goto out_free; } - cpc_ptr->version = cpc_rev; - if (!is_cppc_supported(cpc_rev, num_ent)) + if (cpc_rev < CPPC_V2_REV) { + pr_debug("Unsupported _CPC Revision (%d) for CPU:%d\n", cpc_rev, + pr->id); goto out_free; + } + + /* + * Disregard _CPC if the number of entries in the return pachage is not + * as expected, but support future revisions being proper supersets of + * the v3 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)) { + 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; + } + + cpc_ptr->num_entries = num_ent; + cpc_ptr->version = cpc_rev; /* Iterate through remaining entries in _CPC */ for (i = 2; i < num_ent; i++) { @@ -766,7 +776,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) if (!osc_cpc_flexible_adr_space_confirmed) { pr_debug("Flexible address space capability not supported\n"); - goto out_free; + if (!cpc_supported_by_cpu()) + goto out_free; } addr = ioremap(gas_t->address, gas_t->bit_width/8); @@ -793,7 +804,8 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) } if (!osc_cpc_flexible_adr_space_confirmed) { pr_debug("Flexible address space capability not supported\n"); - goto out_free; + if (!cpc_supported_by_cpu()) + goto out_free; } } else { if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) { |