From: Yazen Ghannam <yazen.ghan...@amd.com>

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.ghan...@amd.com>
[ carved out into a patch, cleaned up, productized ]
Signed-off-by: Janakarajan Natarajan <janakarajan.natara...@amd.com>
---
 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

Reply via email to