ACPI / CPPC: Read lowest nonlinear perf in cppc_get_perf_caps()

Read lowest non linear perf in cppc_get_perf_caps so that it can be exposed
via sysfs to the usespace. Lowest non linear perf is the lowest performance
level at which nonlinear power savings are achieved.

Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 11 insertions, 8 deletions

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 3ca0729f7e0e..ee00a1c94ff6 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -972,9 +972,9 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 {
         struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
-        struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf,
-                                                                 *nom_perf;
-        u64 high, low, nom;
+        struct cpc_register_resource *highest_reg, *lowest_reg,
+                *lowest_non_linear_reg, *nominal_reg;
+        u64 high, low, nom, min_nonlinear;
         int ret = 0, regs_in_pcc = 0;
 
         if (!cpc_desc) {
@@ -984,12 +984,12 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 
         highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF];
         lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF];
-        ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF];
-        nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF];
+        lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF];
+        nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
 
         /* Are any of the regs PCC ?*/
         if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) ||
-                CPC_IN_PCC(ref_perf) || CPC_IN_PCC(nom_perf)) {
+                CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg)) {
                 regs_in_pcc = 1;
                 down_write(&pcc_data.pcc_lock);
                 /* Ring doorbell once to update PCC subspace */
@@ -1005,10 +1005,13 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
         cpc_read(cpunum, lowest_reg, &low);
         perf_caps->lowest_perf = low;
 
-        cpc_read(cpunum, nom_perf, &nom);
+        cpc_read(cpunum, nominal_reg, &nom);
         perf_caps->nominal_perf = nom;
 
-        if (!high || !low || !nom)
+        cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear);
+        perf_caps->lowest_nonlinear_perf = min_nonlinear;
+
+        if (!high || !low || !nom || !min_nonlinear)
                 ret = -EFAULT;
 
 out_err: