Commit 7bc1fcd3 authored by Perry Yuan's avatar Perry Yuan Committed by Rafael J. Wysocki
Browse files

ACPI: CPPC: Add AMD pstate energy performance preference cppc control 



Add support for setting and querying EPP preferences to the generic
CPPC driver.  This enables downstream drivers such as amd-pstate to discover
and use these values.

Downstream drivers that want to use the new symbols cppc_get_epp_caps
and cppc_set_epp_perf for querying and setting EPP preferences will need
to call cppc_set_epp_perf to enable the EPP function firstly.

Acked-by: default avatarHuang Rui <ray.huang@amd.com>
Reviewed-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Reviewed-by: default avatarWyes Karny <wyes.karny@amd.com>
Tested-by: default avatarWyes Karny <wyes.karny@amd.com>
Signed-off-by: default avatarPerry Yuan <Perry.Yuan@amd.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 38a29e58

drivers/acpi/cppc_acpi.c

+67 −0
Original line number Diff line number Diff line
@@ -1153,6 +1153,19 @@ int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf) 
	return cppc_get_perf(cpunum, NOMINAL_PERF, nominal_perf);

}



/**

 * cppc_get_epp_perf - Get the epp register value.

 * @cpunum: CPU from which to get epp preference value.

 * @epp_perf: Return address.

 *

 * Return: 0 for success, -EIO otherwise.

 */

int cppc_get_epp_perf(int cpunum, u64 *epp_perf)

{

	return cppc_get_perf(cpunum, ENERGY_PERF, epp_perf);

}

EXPORT_SYMBOL_GPL(cppc_get_epp_perf);



/**

 * cppc_get_perf_caps - Get a CPU's performance capabilities.

 * @cpunum: CPU from which to get capabilities info.
@@ -1365,6 +1378,60 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) 
}

EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);



/*

 * Set Energy Performance Preference Register value through

 * Performance Controls Interface

 */

int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable)

{

	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);

	struct cpc_register_resource *epp_set_reg;

	struct cpc_register_resource *auto_sel_reg;

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

	struct cppc_pcc_data *pcc_ss_data = NULL;

	int ret;



	if (!cpc_desc) {

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

		return -ENODEV;

	}



	auto_sel_reg = &cpc_desc->cpc_regs[AUTO_SEL_ENABLE];

	epp_set_reg = &cpc_desc->cpc_regs[ENERGY_PERF];



	if (CPC_IN_PCC(epp_set_reg) || CPC_IN_PCC(auto_sel_reg)) {

		if (pcc_ss_id < 0) {

			pr_debug("Invalid pcc_ss_id for CPU:%d\n", cpu);

			return -ENODEV;

		}



		if (CPC_SUPPORTED(auto_sel_reg)) {

			ret = cpc_write(cpu, auto_sel_reg, enable);

			if (ret)

				return ret;

		}



		if (CPC_SUPPORTED(epp_set_reg)) {

			ret = cpc_write(cpu, epp_set_reg, perf_ctrls->energy_perf);

			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);

	} else {

		ret = -ENOTSUPP;

		pr_debug("_CPC in PCC is not supported\n");

	}



	return ret;

}

EXPORT_SYMBOL_GPL(cppc_set_epp_perf);



/**

 * cppc_set_enable - Set to enable CPPC on the processor by writing the

 * Continuous Performance Control package EnableRegister field.

include/acpi/cppc_acpi.h

+12 −0
Original line number Diff line number Diff line
@@ -108,12 +108,14 @@ struct cppc_perf_caps { 
	u32 lowest_nonlinear_perf;

	u32 lowest_freq;

	u32 nominal_freq;

	u32 energy_perf;

};



struct cppc_perf_ctrls {

	u32 max_perf;

	u32 min_perf;

	u32 desired_perf;

	u32 energy_perf;

};



struct cppc_perf_fb_ctrs {
@@ -149,6 +151,8 @@ extern bool cpc_ffh_supported(void); 
extern bool cpc_supported_by_cpu(void);

extern int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val);

extern int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val);

extern int cppc_get_epp_perf(int cpunum, u64 *epp_perf);

extern int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable);

#else /* !CONFIG_ACPI_CPPC_LIB */

static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf)

{
@@ -202,6 +206,14 @@ static inline int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) 
{

	return -ENOTSUPP;

}

static inline int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable)

{

	return -ENOTSUPP;

}

static inline int cppc_get_epp_perf(int cpunum, u64 *epp_perf)

{

	return -ENOTSUPP;

}

#endif /* !CONFIG_ACPI_CPPC_LIB */



#endif /* _CPPC_ACPI_H*/