ACPI: CPPC: Add three functions related to autonomous selection

cppc_set_epp() - write energy performance preference register value,
based on ACPI 6.5, s8.4.6.1.7

cppc_get_auto_act_window() - read autonomous activity window register
value, based on ACPI 6.5, s8.4.6.1.6

cppc_set_auto_act_window() - write autonomous activity window register
value, based on ACPI 6.5, s8.4.6.1.6

Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20250411093855.982491-9-zhenglifeng1@huawei.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 6163831..a9ae2fd 100644 (file)
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1601,6 +1601,89 @@ int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable)
 }
 EXPORT_SYMBOL_GPL(cppc_set_epp_perf);
 
+/**
+ * cppc_set_epp() - Write the EPP register.
+ * @cpu: CPU on which to write register.
+ * @epp_val: Value to write to the EPP register.
+ */
+int cppc_set_epp(int cpu, u64 epp_val)
+{
+       if (epp_val > CPPC_ENERGY_PERF_MAX)
+               return -EINVAL;
+
+       return cppc_set_reg_val(cpu, ENERGY_PERF, epp_val);
+}
+EXPORT_SYMBOL_GPL(cppc_set_epp);
+
+/**
+ * cppc_get_auto_act_window() - Read autonomous activity window register.
+ * @cpu: CPU from which to read register.
+ * @auto_act_window: Return address.
+ *
+ * According to ACPI 6.5, s8.4.6.1.6, the value read from the autonomous
+ * activity window register consists of two parts: a 7 bits value indicate
+ * significand and a 3 bits value indicate exponent.
+ */
+int cppc_get_auto_act_window(int cpu, u64 *auto_act_window)
+{
+       unsigned int exp;
+       u64 val, sig;
+       int ret;
+
+       if (auto_act_window == NULL)
+               return -EINVAL;
+
+       ret = cppc_get_reg_val(cpu, AUTO_ACT_WINDOW, &val);
+       if (ret)
+               return ret;
+
+       sig = val & CPPC_AUTO_ACT_WINDOW_MAX_SIG;
+       exp = (val >> CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) & CPPC_AUTO_ACT_WINDOW_MAX_EXP;
+       *auto_act_window = sig * int_pow(10, exp);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(cppc_get_auto_act_window);
+
+/**
+ * cppc_set_auto_act_window() - Write autonomous activity window register.
+ * @cpu: CPU on which to write register.
+ * @auto_act_window: usec value to write to the autonomous activity window register.
+ *
+ * According to ACPI 6.5, s8.4.6.1.6, the value to write to the autonomous
+ * activity window register consists of two parts: a 7 bits value indicate
+ * significand and a 3 bits value indicate exponent.
+ */
+int cppc_set_auto_act_window(int cpu, u64 auto_act_window)
+{
+       /* The max value to store is 1270000000 */
+       u64 max_val = CPPC_AUTO_ACT_WINDOW_MAX_SIG * int_pow(10, CPPC_AUTO_ACT_WINDOW_MAX_EXP);
+       int exp = 0;
+       u64 val;
+
+       if (auto_act_window > max_val)
+               return -EINVAL;
+
+       /*
+        * The max significand is 127, when auto_act_window is larger than
+        * 129, discard the precision of the last digit and increase the
+        * exponent by 1.
+        */
+       while (auto_act_window > CPPC_AUTO_ACT_WINDOW_SIG_CARRY_THRESH) {
+               auto_act_window /= 10;
+               exp += 1;
+       }
+
+       /* For 128 and 129, cut it to 127. */
+       if (auto_act_window > CPPC_AUTO_ACT_WINDOW_MAX_SIG)
+               auto_act_window = CPPC_AUTO_ACT_WINDOW_MAX_SIG;
+
+       val = (exp << CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) + auto_act_window;
+
+       return cppc_set_reg_val(cpu, AUTO_ACT_WINDOW, val);
+}
+EXPORT_SYMBOL_GPL(cppc_set_auto_act_window);
+
 /**
  * cppc_get_auto_sel() - Read autonomous selection register.
  * @cpu: CPU from which to read register.

diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 31767c6..325e954 100644 (file)
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -32,6 +32,15 @@
 #define        CMD_READ 0
 #define        CMD_WRITE 1
 
+#define CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE      (7)
+#define CPPC_AUTO_ACT_WINDOW_EXP_BIT_SIZE      (3)
+#define CPPC_AUTO_ACT_WINDOW_MAX_SIG   ((1 << CPPC_AUTO_ACT_WINDOW_SIG_BIT_SIZE) - 1)
+#define CPPC_AUTO_ACT_WINDOW_MAX_EXP   ((1 << CPPC_AUTO_ACT_WINDOW_EXP_BIT_SIZE) - 1)
+/* CPPC_AUTO_ACT_WINDOW_MAX_SIG is 127, so 128 and 129 will decay to 127 when writing */
+#define CPPC_AUTO_ACT_WINDOW_SIG_CARRY_THRESH 129
+
+#define CPPC_ENERGY_PERF_MAX   (0xFF)
+
 /* Each register has the folowing format. */
 struct cpc_reg {
        u8 descriptor;
@@ -159,6 +168,9 @@ extern int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val);
 extern int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val);
 extern int cppc_get_epp_perf(int cpunum, u64 *epp_perf);
 extern int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable);
+extern int cppc_set_epp(int cpu, u64 epp_val);
+extern int cppc_get_auto_act_window(int cpu, u64 *auto_act_window);
+extern int cppc_set_auto_act_window(int cpu, u64 auto_act_window);
 extern int cppc_get_auto_sel(int cpu, bool *enable);
 extern int cppc_set_auto_sel(int cpu, bool enable);
 extern int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf);
@@ -229,6 +241,18 @@ static inline int cppc_get_epp_perf(int cpunum, u64 *epp_perf)
 {
        return -EOPNOTSUPP;
 }
+static inline int cppc_set_epp(int cpu, u64 epp_val)
+{
+       return -EOPNOTSUPP;
+}
+static inline int cppc_get_auto_act_window(int cpu, u64 *auto_act_window)
+{
+       return -EOPNOTSUPP;
+}
+static inline int cppc_set_auto_act_window(int cpu, u64 auto_act_window)
+{
+       return -EOPNOTSUPP;
+}
 static inline int cppc_get_auto_sel(int cpu, bool *enable)
 {
        return -EOPNOTSUPP;