From ea3b8f094eaf46a8862d845a626c23c0ed3a80ec Mon Sep 17 00:00:00 2001 From: Steven Noonan Date: Fri, 24 Dec 2021 09:04:57 +0800 Subject: [PATCH] ACPI: CPPC: Implement support for SystemIO registers 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 Signed-off-by: Huang Rui --- drivers/acpi/cppc_acpi.c | 52 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 49 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index b62c87b8ce4a9..69e0746470033 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -118,6 +118,8 @@ static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); */ #define NUM_RETRIES 500ULL +#define OVER_16BTS_MASK ~0xFFFFULL + #define define_one_cppc_ro(_name) \ static struct kobj_attribute _name = \ __ATTR(_name, 0444, show_##_name, NULL) @@ -746,9 +748,26 @@ 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 & OVER_16BTS_MASK) { + /* 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 +942,21 @@ 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 (ACPI_FAILURE(status)) { + 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 +995,20 @@ 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 (ACPI_FAILURE(status)) { + 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;