Commit a2c8f92b authored by Steven Noonan's avatar Steven Noonan Committed by Rafael J. Wysocki
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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: default avatarSteven Noonan <steven@valvesoftware.com>
Signed-off-by: default avatarHuang Rui <ray.huang@amd.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 89aa94b4

drivers/acpi/cppc_acpi.c

+49 −3
Original line number Diff line number Diff line
@@ -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 = &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;