powercap / RAPL: Floor frequency setting in Atom SoC

CPU Floor frequency is set in BIOS for newer Atom
SoCs. This patch handles configuration of floor
frequency for different variants of Atom SoCs
appropriately and ensures configuration of floor
frequency is not done from driver for these
newer Atom SoCs.

Since address of the register for configuring
floor frequency might change for different
Atom SoCs, this patch also prevents potential
overwriting of wrong registers.

Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/powercap/intel_rapl.c

@@ -187,6 +187,7 @@ struct rapl_package {
 };
 
 struct rapl_defaults {
+	u8 floor_freq_reg_addr;
 	int (*check_unit)(struct rapl_package *rp, int cpu);
 	void (*set_floor_freq)(struct rapl_domain *rd, bool mode);
 	u64 (*compute_time_window)(struct rapl_package *rp, u64 val,
@@ -196,7 +197,8 @@ struct rapl_defaults {
 static struct rapl_defaults *rapl_defaults;
 
 /* Sideband MBI registers */
-#define IOSF_CPU_POWER_BUDGET_CTL (0x2)
+#define IOSF_CPU_POWER_BUDGET_CTL_BYT (0x2)
+#define IOSF_CPU_POWER_BUDGET_CTL_TNG (0xdf)
 
 #define PACKAGE_PLN_INT_SAVED   BIT(0)
 #define MAX_PRIM_NAME (32)
@@ -358,7 +360,8 @@ static int set_domain_enable(struct powercap_zone *power_zone, bool mode)
 
 	get_online_cpus();
 	rapl_write_data_raw(rd, PL1_ENABLE, mode);
-	rapl_defaults->set_floor_freq(rd, mode);
+	if (rapl_defaults->set_floor_freq)
+		rapl_defaults->set_floor_freq(rd, mode);
 	put_online_cpus();
 
 	return 0;
@@ -979,16 +982,22 @@ static void set_floor_freq_atom(struct rapl_domain *rd, bool enable)
 	static u32 power_ctrl_orig_val;
 	u32 mdata;
 
+	if (!rapl_defaults->floor_freq_reg_addr) {
+		pr_err("Invalid floor frequency config register\n");
+		return;
+	}
+
 	if (!power_ctrl_orig_val)
 		iosf_mbi_read(BT_MBI_UNIT_PMC, BT_MBI_PMC_READ,
-			IOSF_CPU_POWER_BUDGET_CTL, &power_ctrl_orig_val);
+			rapl_defaults->floor_freq_reg_addr,
+				&power_ctrl_orig_val);
 	mdata = power_ctrl_orig_val;
 	if (enable) {
 		mdata &= ~(0x7f << 8);
 		mdata |= 1 << 8;
 	}
 	iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_PMC_WRITE,
-		IOSF_CPU_POWER_BUDGET_CTL, mdata);
+		rapl_defaults->floor_freq_reg_addr, mdata);
 }
 
 static u64 rapl_compute_time_window_core(struct rapl_package *rp, u64 value,
@@ -1029,6 +1038,7 @@ static u64 rapl_compute_time_window_atom(struct rapl_package *rp, u64 value,
 }
 
 static const struct rapl_defaults rapl_defaults_core = {
+	.floor_freq_reg_addr = 0,
 	.check_unit = rapl_check_unit_core,
 	.set_floor_freq = set_floor_freq_default,
 	.compute_time_window = rapl_compute_time_window_core,
@@ -1041,12 +1051,34 @@ static const struct rapl_defaults rapl_defaults_hsw_server = {
 	.dram_domain_energy_unit = 15300,
 };
 
-static const struct rapl_defaults rapl_defaults_atom = {
+static const struct rapl_defaults rapl_defaults_byt = {
+	.floor_freq_reg_addr = IOSF_CPU_POWER_BUDGET_CTL_BYT,
+	.check_unit = rapl_check_unit_atom,
+	.set_floor_freq = set_floor_freq_atom,
+	.compute_time_window = rapl_compute_time_window_atom,
+};
+
+static const struct rapl_defaults rapl_defaults_tng = {
+	.floor_freq_reg_addr = IOSF_CPU_POWER_BUDGET_CTL_TNG,
 	.check_unit = rapl_check_unit_atom,
 	.set_floor_freq = set_floor_freq_atom,
 	.compute_time_window = rapl_compute_time_window_atom,
 };
 
+static const struct rapl_defaults rapl_defaults_ann = {
+	.floor_freq_reg_addr = 0,
+	.check_unit = rapl_check_unit_atom,
+	.set_floor_freq = NULL,
+	.compute_time_window = rapl_compute_time_window_atom,
+};
+
+static const struct rapl_defaults rapl_defaults_cht = {
+	.floor_freq_reg_addr = 0,
+	.check_unit = rapl_check_unit_atom,
+	.set_floor_freq = NULL,
+	.compute_time_window = rapl_compute_time_window_atom,
+};
+
 #define RAPL_CPU(_model, _ops) {			\
 		.vendor = X86_VENDOR_INTEL,		\
 		.family = 6,				\
@@ -1057,7 +1089,7 @@ static const struct rapl_defaults rapl_defaults_atom = {
 static const struct x86_cpu_id rapl_ids[] __initconst = {
 	RAPL_CPU(0x2a, rapl_defaults_core),/* Sandy Bridge */
 	RAPL_CPU(0x2d, rapl_defaults_core),/* Sandy Bridge EP */
-	RAPL_CPU(0x37, rapl_defaults_atom),/* Valleyview */
+	RAPL_CPU(0x37, rapl_defaults_byt),/* Valleyview */
 	RAPL_CPU(0x3a, rapl_defaults_core),/* Ivy Bridge */
 	RAPL_CPU(0x3c, rapl_defaults_core),/* Haswell */
 	RAPL_CPU(0x3d, rapl_defaults_core),/* Broadwell */
@@ -1065,10 +1097,10 @@ static const struct x86_cpu_id rapl_ids[] __initconst = {
 	RAPL_CPU(0x4f, rapl_defaults_hsw_server),/* Broadwell servers */
 	RAPL_CPU(0x45, rapl_defaults_core),/* Haswell ULT */
 	RAPL_CPU(0x4E, rapl_defaults_core),/* Skylake */
-	RAPL_CPU(0x4C, rapl_defaults_atom),/* Braswell */
-	RAPL_CPU(0x4A, rapl_defaults_atom),/* Tangier */
+	RAPL_CPU(0x4C, rapl_defaults_cht),/* Braswell/Cherryview */
+	RAPL_CPU(0x4A, rapl_defaults_tng),/* Tangier */
 	RAPL_CPU(0x56, rapl_defaults_core),/* Future Xeon */
-	RAPL_CPU(0x5A, rapl_defaults_atom),/* Annidale */
+	RAPL_CPU(0x5A, rapl_defaults_ann),/* Annidale */
 	{}
 };
 MODULE_DEVICE_TABLE(x86cpu, rapl_ids);