[PATCH v4 03/22] ACPI: CPPC: implement support for SystemIO registers
From: Huang Rui <ray.huang@amd.com>
Date: 2021-11-19 10:32:00
Also in:
lkml
Subsystem:
acpi, the rest · Maintainers:
"Rafael J. Wysocki", Linus Torvalds
From: Steven Noonan <redacted> According to the ACPI v6.2 (and later) specification, SystemIO can be used for _CPC registers. This teaches cppc_acpi how to handle such registers. This patch was tested using the amd_pstate driver on my Zephyrus G15 (model GA503QS) using the current version 410 BIOS, which uses a SystemIO register for the HighestPerformance element in _CPC. Signed-off-by: Steven Noonan <redacted> Signed-off-by: Huang Rui <ray.huang@amd.com> --- drivers/acpi/cppc_acpi.c | 46 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index a85c351589be..ca62c3dc9899 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c@@ -746,9 +746,24 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) goto out_free; cpc_ptr->cpc_regs[i-2].sys_mem_vaddr = addr; } + } else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { + if (gas_t->access_width < 1 || gas_t->access_width > 3) { + /* 1 = 8-bit, 2 = 16-bit, and 3 = 32-bit. SystemIO doesn't + * implement 64-bit registers. + */ + pr_debug("Invalid access width %d for SystemIO register\n", + gas_t->access_width); + goto out_free; + } + if (gas_t->address & ~0xFFFFULL) { + /* SystemIO registers use 16-bit integer addresses */ + pr_debug("Invalid IO port %llu for SystemIO register\n", + gas_t->address); + goto out_free; + } } else { if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) { - /* Support only PCC ,SYS MEM and FFH type regs */ + /* Support only PCC, SystemMemory, SystemIO, and FFH type regs. */ pr_debug("Unsupported register type: %d\n", gas_t->space_id); goto out_free; }
@@ -923,7 +938,20 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val) } *val = 0; - if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) + + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { + u32 width = 8 << (reg->access_width - 1); + acpi_status status; + + status = acpi_os_read_port((acpi_io_address)reg->address, (u32 *)val, width); + + if (status != AE_OK) { + pr_debug("Error: Failed to read SystemIO port %llx\n", reg->address); + return -EFAULT; + } + + return 0; + } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) vaddr = reg_res->sys_mem_vaddr;
@@ -962,7 +990,19 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); struct cpc_reg *reg = ®_res->cpc_entry.reg; - if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) + if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { + u32 width = 8 << (reg->access_width - 1); + acpi_status status; + + status = acpi_os_write_port((acpi_io_address)reg->address, (u32)val, width); + + if (status != AE_OK) { + pr_debug("Error: Failed to write SystemIO port %llx\n", reg->address); + return -EFAULT; + } + + return 0; + } else if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM && pcc_ss_id >= 0) vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) vaddr = reg_res->sys_mem_vaddr;
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2.25.1