From: Mario Limonciello mario.limonciello@amd.com
[ Upstream commit aaf21ac93909e08a12931173336bdb52ac8499f1 ]
Some Asus AMD systems are reported to not be able to change EPP values because the BIOS doesn't advertise support for the CPPC MSR and the PCC region is not configured.
However the ACPI 6.2 specification allows CPC registers to be declared in FFH: ``` Starting with ACPI Specification 6.2, all _CPC registers can be in PCC, System Memory, System IO, or Functional Fixed Hardware address spaces. OSPM support for this more flexible register space scheme is indicated by the “Flexible Address Space for CPPC Registers” _OSC bit. ```
If this _OSC has been set allow using FFH to configure EPP.
Reported-by: al0uette@outlook.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218686 Suggested-by: al0uette@outlook.com Tested-by: vderp@icloud.com Tested-by: al0uette@outlook.com Signed-off-by: Mario Limonciello mario.limonciello@amd.com Link: https://patch.msgid.link/20240910031524.106387-1-superm1@kernel.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/cppc_acpi.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 1d857978f5f40..9777369084d80 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -103,6 +103,11 @@ static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); (cpc)->cpc_entry.reg.space_id == \ ACPI_ADR_SPACE_PLATFORM_COMM)
+/* Check if a CPC register is in FFH */ +#define CPC_IN_FFH(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ + (cpc)->cpc_entry.reg.space_id == \ + ACPI_ADR_SPACE_FIXED_HARDWARE) + /* Check if a CPC register is in SystemMemory */ #define CPC_IN_SYSTEM_MEMORY(cpc) ((cpc)->type == ACPI_TYPE_BUFFER && \ (cpc)->cpc_entry.reg.space_id == \ @@ -1484,9 +1489,12 @@ int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable) /* after writing CPC, transfer the ownership of PCC to platform */ ret = send_pcc_cmd(pcc_ss_id, CMD_WRITE); up_write(&pcc_ss_data->pcc_lock); + } else if (osc_cpc_flexible_adr_space_confirmed && + CPC_SUPPORTED(epp_set_reg) && CPC_IN_FFH(epp_set_reg)) { + ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf); } else { ret = -ENOTSUPP; - pr_debug("_CPC in PCC is not supported\n"); + pr_debug("_CPC in PCC and _CPC in FFH are not supported\n"); }
return ret;