[PATCHv3 5/6] acpi/cppc: Add support for CPPC Enable register

From: Natarajan, Janakarajan
Date: Wed Jul 10 2019 - 14:37:38 EST


From: Yazen Ghannam <Yazen.Ghannam@xxxxxxx>

To enable CPPC on a processor, the OS should write a value "1" to the
CPPC Enable register. Add support for this register.

Since we have a new variable "enable" in cppc_perf_ctrls, rename it
and the associated functions i.e. cppc_perf_ctrls->cppc_ctrls and
cppc_get_perf()->cppc_get_ctrls().

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@xxxxxxx>
[ carved out into a patch, cleaned up, productized ]
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@xxxxxxx>
---
drivers/acpi/cppc_acpi.c | 44 ++++++++++++++++++++++++----------------
include/acpi/cppc_acpi.h | 10 +++++----
2 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index b24e54263efb..3199433e3f71 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1343,12 +1343,12 @@ EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);
/**
* cppc_set_reg - Set the CPUs control register.
* @cpu: CPU for which to set the register.
- * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h
+ * @ctrls: ptr to cppc_ctrls. See cppc_acpi.h
* @reg_idx: Index of the register being accessed
*
* Return: 0 for success, -ERRNO otherwise.
*/
-int cppc_set_reg(int cpu, struct cppc_perf_ctrls *perf_ctrls,
+int cppc_set_reg(int cpu, struct cppc_ctrls *ctrls,
enum cppc_regs reg_idx)
{
struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
@@ -1364,20 +1364,23 @@ int cppc_set_reg(int cpu, struct cppc_perf_ctrls *perf_ctrls,
}

switch (reg_idx) {
+ case ENABLE:
+ value = ctrls->enable;
+ break;
case DESIRED_PERF:
- value = perf_ctrls->desired_perf;
+ value = ctrls->desired_perf;
break;
case MAX_PERF:
- value = perf_ctrls->max_perf;
+ value = ctrls->max_perf;
break;
case MIN_PERF:
- value = perf_ctrls->min_perf;
+ value = ctrls->min_perf;
break;
case ENERGY_PERF:
- value = perf_ctrls->energy_perf;
+ value = ctrls->energy_perf;
break;
case AUTO_SEL_ENABLE:
- value = perf_ctrls->auto_sel_enable;
+ value = ctrls->auto_sel_enable;
break;
default:
pr_debug("CPC register index #%d not writeable\n", reg_idx);
@@ -1485,13 +1488,14 @@ int cppc_set_reg(int cpu, struct cppc_perf_ctrls *perf_ctrls,
}
EXPORT_SYMBOL_GPL(cppc_set_reg);

-int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
+int cppc_get_ctrls(int cpu, struct cppc_ctrls *ctrls)
{
struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
struct cpc_register_resource *desired_reg, *max_reg, *min_reg;
struct cpc_register_resource *energy_reg, *auto_sel_enable_reg;
+ struct cpc_register_resource *enable_reg;
int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
- u64 desired, max, min, energy, auto_sel_enable;
+ u64 desired, max, min, energy, auto_sel_enable, enable;
struct cppc_pcc_data *pcc_ss_data = NULL;
int ret = 0, regs_in_pcc = 0;

@@ -1500,6 +1504,7 @@ int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
return -ENODEV;
}

+ enable_reg = &cpc_desc->cpc_regs[ENABLE];
desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
max_reg = &cpc_desc->cpc_regs[MAX_PERF];
min_reg = &cpc_desc->cpc_regs[MIN_PERF];
@@ -1509,7 +1514,7 @@ int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
/* Check if any of the perf registers are in PCC */
if (CPC_IN_PCC(desired_reg) || CPC_IN_PCC(max_reg) ||
CPC_IN_PCC(min_reg) || CPC_IN_PCC(energy_reg) ||
- CPC_IN_PCC(auto_sel_enable_reg)) {
+ CPC_IN_PCC(auto_sel_enable_reg) || CPC_IN_PCC(enable_reg)) {
pcc_ss_data = pcc_data[pcc_ss_id];
down_write(&pcc_ss_data->pcc_lock);
regs_in_pcc = 1;
@@ -1521,10 +1526,14 @@ int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
}
}

- /* desired_perf is the only mandatory value in perf_ctrls */
+ /* desired_perf is the only mandatory value in ctrls */
if (cpc_read(cpu, desired_reg, &desired))
ret = -EFAULT;

+ if (CPC_SUP_BUFFER_ONLY(enable_reg) &&
+ cpc_read(cpu, enable_reg, &enable))
+ ret = -EFAULT;
+
if (CPC_SUP_BUFFER_ONLY(max_reg) && cpc_read(cpu, max_reg, &max))
ret = -EFAULT;

@@ -1540,11 +1549,12 @@ int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
ret = -EFAULT;

if (!ret) {
- perf_ctrls->desired_perf = desired;
- perf_ctrls->max_perf = max;
- perf_ctrls->min_perf = min;
- perf_ctrls->energy_perf = energy;
- perf_ctrls->auto_sel_enable = auto_sel_enable;
+ ctrls->enable = enable;
+ ctrls->desired_perf = desired;
+ ctrls->max_perf = max;
+ ctrls->min_perf = min;
+ ctrls->energy_perf = energy;
+ ctrls->auto_sel_enable = auto_sel_enable;
}

out_err:
@@ -1552,7 +1562,7 @@ int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
up_write(&pcc_ss_data->pcc_lock);
return ret;
}
-EXPORT_SYMBOL_GPL(cppc_get_perf);
+EXPORT_SYMBOL_GPL(cppc_get_ctrls);

/**
* cppc_get_transition_latency - returns frequency transition latency in ns
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 80720b246c51..e6cd2a487874 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -109,7 +109,8 @@ struct cppc_perf_caps {
u32 nominal_freq;
};

-struct cppc_perf_ctrls {
+struct cppc_ctrls {
+ bool enable;
u32 max_perf;
u32 min_perf;
u32 desired_perf;
@@ -128,17 +129,18 @@ struct cppc_perf_fb_ctrs {
struct cppc_cpudata {
int cpu;
struct cppc_perf_caps perf_caps;
- struct cppc_perf_ctrls perf_ctrls;
+ struct cppc_ctrls ctrls;
struct cppc_perf_fb_ctrs perf_fb_ctrs;
struct cpufreq_policy *cur_policy;
unsigned int shared_type;
cpumask_var_t shared_cpu_map;
};

+extern int cppc_get_enable(int cpu);
extern int cppc_get_desired_perf(int cpunum, u64 *desired_perf);
extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
-extern int cppc_set_reg(int cpu, struct cppc_perf_ctrls *perf_ctrls, enum cppc_regs reg_idx);
-extern int cppc_get_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
+extern int cppc_set_reg(int cpu, struct cppc_ctrls *ctrls, enum cppc_regs reg_idx);
+extern int cppc_get_ctrls(int cpu, struct cppc_ctrls *ctrls);
extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
extern int acpi_get_psd_map(struct cppc_cpudata **);
extern unsigned int cppc_get_transition_latency(int cpu);
--
2.17.1