Commit c28a280b authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI: CPPC: Do not use CPUFREQ_ETERNAL as an error value 



Instead of using CPUFREQ_ETERNAL for signaling an error condition
in cppc_get_transition_latency(), change the return value type of
that function to int and make it return a proper negative error
code on failures.

No intentional functional impact.

Reviewed-by: default avatarMario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: default avatarJie Zhan <zhanjie9@hisilicon.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: default avatarQais Yousef <qyousef@layalina.io>
parent f965d111

drivers/acpi/cppc_acpi.c

+7 −9
Original line number Diff line number Diff line
@@ -1876,7 +1876,7 @@ EXPORT_SYMBOL_GPL(cppc_set_perf); 
 * If desired_reg is in the SystemMemory or SystemIo ACPI address space,

 * then assume there is no latency.

 */

unsigned int cppc_get_transition_latency(int cpu_num)

int cppc_get_transition_latency(int cpu_num)

{

	/*

	 * Expected transition latency is based on the PCCT timing values
@@ -1889,31 +1889,29 @@ unsigned int cppc_get_transition_latency(int cpu_num) 
	 *              completion of a command before issuing the next command,

	 *              in microseconds.

	 */

	unsigned int latency_ns = 0;

	struct cpc_desc *cpc_desc;

	struct cpc_register_resource *desired_reg;

	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu_num);

	struct cppc_pcc_data *pcc_ss_data;

	int latency_ns = 0;



	cpc_desc = per_cpu(cpc_desc_ptr, cpu_num);

	if (!cpc_desc)

		return CPUFREQ_ETERNAL;

		return -ENODATA;



	desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];

	if (CPC_IN_SYSTEM_MEMORY(desired_reg) || CPC_IN_SYSTEM_IO(desired_reg))

		return 0;

	else if (!CPC_IN_PCC(desired_reg))

		return CPUFREQ_ETERNAL;



	if (pcc_ss_id < 0)

		return CPUFREQ_ETERNAL;

	if (!CPC_IN_PCC(desired_reg) || pcc_ss_id < 0)

		return -ENODATA;



	pcc_ss_data = pcc_data[pcc_ss_id];

	if (pcc_ss_data->pcc_mpar)

		latency_ns = 60 * (1000 * 1000 * 1000 / pcc_ss_data->pcc_mpar);



	latency_ns = max(latency_ns, pcc_ss_data->pcc_nominal * 1000);

	latency_ns = max(latency_ns, pcc_ss_data->pcc_mrtt * 1000);

	latency_ns = max_t(int, latency_ns, pcc_ss_data->pcc_nominal * 1000);

	latency_ns = max_t(int, latency_ns, pcc_ss_data->pcc_mrtt * 1000);



	return latency_ns;

}

drivers/cpufreq/amd-pstate.c

+4 −4
Original line number Diff line number Diff line
@@ -872,10 +872,10 @@ static void amd_pstate_update_limits(struct cpufreq_policy *policy) 
 */

static u32 amd_pstate_get_transition_delay_us(unsigned int cpu)

{

	u32 transition_delay_ns;

	int transition_delay_ns;



	transition_delay_ns = cppc_get_transition_latency(cpu);

	if (transition_delay_ns == CPUFREQ_ETERNAL) {

	if (transition_delay_ns < 0) {

		if (cpu_feature_enabled(X86_FEATURE_AMD_FAST_CPPC))

			return AMD_PSTATE_FAST_CPPC_TRANSITION_DELAY;

		else
@@ -891,10 +891,10 @@ static u32 amd_pstate_get_transition_delay_us(unsigned int cpu) 
 */

static u32 amd_pstate_get_transition_latency(unsigned int cpu)

{

	u32 transition_latency;

	int transition_latency;



	transition_latency = cppc_get_transition_latency(cpu);

	if (transition_latency  == CPUFREQ_ETERNAL)

	if (transition_latency < 0)

		return AMD_PSTATE_TRANSITION_LATENCY;



	return transition_latency;

drivers/cpufreq/cppc_cpufreq.c

+2 −2
Original line number Diff line number Diff line
@@ -310,9 +310,9 @@ static int cppc_verify_policy(struct cpufreq_policy_data *policy) 


static unsigned int __cppc_cpufreq_get_transition_delay_us(unsigned int cpu)

{

	unsigned int transition_latency_ns = cppc_get_transition_latency(cpu);

	int transition_latency_ns = cppc_get_transition_latency(cpu);



	if (transition_latency_ns == CPUFREQ_ETERNAL)

	if (transition_latency_ns < 0)

		return CPUFREQ_DEFAULT_TRANSITION_LATENCY_NS / NSEC_PER_USEC;



	return transition_latency_ns / NSEC_PER_USEC;

include/acpi/cppc_acpi.h

+3 −3
Original line number Diff line number Diff line
@@ -160,7 +160,7 @@ extern unsigned int cppc_khz_to_perf(struct cppc_perf_caps *caps, unsigned int f 
extern bool acpi_cpc_valid(void);

extern bool cppc_allow_fast_switch(void);

extern int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data);

extern unsigned int cppc_get_transition_latency(int cpu);

extern int cppc_get_transition_latency(int cpu);

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);
@@ -216,9 +216,9 @@ static inline bool cppc_allow_fast_switch(void) 
{

	return false;

}

static inline unsigned int cppc_get_transition_latency(int cpu)

static inline int cppc_get_transition_latency(int cpu)

{

	return CPUFREQ_ETERNAL;

	return -ENODATA;

}

static inline bool cpc_ffh_supported(void)

{