ACPI / CPPC: Add support for guaranteed performance

The Continuous Performance Control package may contain an optional
guaranteed performance field.

Add support to read guaranteed performance from _CPC.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

2 files changed, 7 insertions, 2 deletions

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index d9ce4b162e2c..217a782c3e55 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1061,9 +1061,9 @@ 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,
-                *lowest_non_linear_reg, *nominal_reg,
+                *lowest_non_linear_reg, *nominal_reg, *guaranteed_reg,
                 *low_freq_reg = NULL, *nom_freq_reg = NULL;
-        u64 high, low, nom, min_nonlinear, low_f = 0, nom_f = 0;
+        u64 high, low, guaranteed, nom, min_nonlinear, low_f = 0, nom_f = 0;
         int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);
         struct cppc_pcc_data *pcc_ss_data = NULL;
         int ret = 0, regs_in_pcc = 0;
@@ -1079,6 +1079,7 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
         nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF];
         low_freq_reg = &cpc_desc->cpc_regs[LOWEST_FREQ];
         nom_freq_reg = &cpc_desc->cpc_regs[NOMINAL_FREQ];
+        guaranteed_reg = &cpc_desc->cpc_regs[GUARANTEED_PERF];
 
         /* Are any of the regs PCC ?*/
         if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) ||
@@ -1107,6 +1108,9 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
         cpc_read(cpunum, nominal_reg, &nom);
         perf_caps->nominal_perf = nom;
 
+        cpc_read(cpunum, guaranteed_reg, &guaranteed);
+        perf_caps->guaranteed_perf = guaranteed;
+
         cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear);
         perf_caps->lowest_nonlinear_perf = min_nonlinear;
 
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 8e0b8250a139..cf59e6210d27 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -104,6 +104,7 @@ enum cppc_regs {
  * today.
  */
 struct cppc_perf_caps {
+        u32 guaranteed_perf;
         u32 highest_perf;
         u32 nominal_perf;
         u32 lowest_perf;