Commit e05c7507 authored by Lifeng Zheng's avatar Lifeng Zheng Committed by Rafael J. Wysocki
Browse files

ACPI: CPPC: Add cppc_set_reg_val() 



Add cppc_set_reg_val() as a generic function for setting CPPC register
values, with this features:

 1. Check register. If a register is writeable, it must be a buffer and
    can not be null.

 2. Extract the operations if register is in PCC out as
    cppc_set_reg_val_in_pcc().

This function can be used to reduce some existing code duplication.

Reviewed-by: default avatarPierre Gondois <pierre.gondois@arm.com>
Signed-off-by: default avatarLifeng Zheng <zhenglifeng1@huawei.com>
Reviewed-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20250411093855.982491-6-zhenglifeng1@huawei.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent b5ef45e6

drivers/acpi/cppc_acpi.c

+49 −0
Original line number Diff line number Diff line
@@ -1232,6 +1232,55 @@ static int cppc_get_reg_val(int cpu, enum cppc_regs reg_idx, u64 *val) 
	return cpc_read(cpu, reg, val);

}



static int cppc_set_reg_val_in_pcc(int cpu, struct cpc_register_resource *reg, u64 val)

{

	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);

	struct cppc_pcc_data *pcc_ss_data = NULL;

	int ret;



	if (pcc_ss_id < 0) {

		pr_debug("Invalid pcc_ss_id\n");

		return -ENODEV;

	}



	ret = cpc_write(cpu, reg, val);

	if (ret)

		return ret;



	pcc_ss_data = pcc_data[pcc_ss_id];



	down_write(&pcc_ss_data->pcc_lock);

	/* 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);



	return ret;

}



static int cppc_set_reg_val(int cpu, enum cppc_regs reg_idx, u64 val)

{

	struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);

	struct cpc_register_resource *reg;



	if (!cpc_desc) {

		pr_debug("No CPC descriptor for CPU:%d\n", cpu);

		return -ENODEV;

	}



	reg = &cpc_desc->cpc_regs[reg_idx];



	/* if a register is writeable, it must be a buffer and not null */

	if ((reg->type != ACPI_TYPE_BUFFER) || IS_NULL_REG(&reg->cpc_entry.reg)) {

		pr_debug("CPC register is not supported\n");

		return -EOPNOTSUPP;

	}



	if (CPC_IN_PCC(reg))

		return cppc_set_reg_val_in_pcc(cpu, reg, val);



	return cpc_write(cpu, reg, val);

}



/**

 * cppc_get_desired_perf - Get the desired performance register value.

 * @cpunum: CPU from which to get desired performance.