soc/amd/picasso: introduce and use pstate_msr bitfield struct

Add the pstate_msr union of a bitfield struct and a raw uint64_t to
allow easier access of the bitfields of the P state MSRs and use this
bitfield struct in get_pstate_core_freq and get_pstate_core_power. The
signature of those two function will be changed in a follow-up commit.

TEST=The coreboot-generated SSDT containing the P state packages stays
identical on Mandolin.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I8dc293351f9941cfb8a9c84d9fb9a4fd76361d5d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73643
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>

2 files changed, 24 insertions, 19 deletions

diff --git a/src/soc/amd/picasso/acpi.c b/src/soc/amd/picasso/acpi.c
index 25ea87ca52..ce8caa4e51 100644
--- a/src/soc/amd/picasso/acpi.c
+++ b/src/soc/amd/picasso/acpi.c
@@ -103,13 +103,15 @@ uint32_t get_pstate_core_freq(msr_t pstate_def)
 {
 	uint32_t core_freq, core_freq_mul, core_freq_div;
 	bool valid_freq_divisor;
+	union pstate_msr pstate_reg;
+
+	pstate_reg.raw = pstate_def.raw;
 
 	/* Core frequency multiplier */
-	core_freq_mul = pstate_def.lo & PSTATE_DEF_LO_FREQ_MUL_MASK;
+	core_freq_mul = pstate_reg.cpu_fid_0_7;
 
 	/* Core frequency divisor ID */
-	core_freq_div =
-		(pstate_def.lo & PSTATE_DEF_LO_FREQ_DIV_MASK) >> PSTATE_DEF_LO_FREQ_DIV_SHIFT;
+	core_freq_div = pstate_reg.cpu_dfs_id;
 
 	if (core_freq_div == 0) {
 		return 0;
@@ -140,18 +142,18 @@ uint32_t get_pstate_core_freq(msr_t pstate_def)
 uint32_t get_pstate_core_power(msr_t pstate_def)
 {
 	uint32_t voltage_in_uvolts, core_vid, current_value_amps, current_divisor, power_in_mw;
+	union pstate_msr pstate_reg;
+
+	pstate_reg.raw = pstate_def.raw;
 
 	/* Core voltage ID */
-	core_vid =
-		(pstate_def.lo & PSTATE_DEF_LO_CORE_VID_MASK) >> PSTATE_DEF_LO_CORE_VID_SHIFT;
+	core_vid = pstate_reg.cpu_vid_0_7;
 
 	/* Current value in amps */
-	current_value_amps =
-		(pstate_def.lo & PSTATE_DEF_LO_CUR_VAL_MASK) >> PSTATE_DEF_LO_CUR_VAL_SHIFT;
+	current_value_amps = pstate_reg.idd_value;
 
 	/* Current divisor */
-	current_divisor =
-		(pstate_def.lo & PSTATE_DEF_LO_CUR_DIV_MASK) >> PSTATE_DEF_LO_CUR_DIV_SHIFT;
+	current_divisor = pstate_reg.idd_div;
 
 	/* Voltage */
 	if ((core_vid >= 0xF8) && (core_vid <= 0xFF)) {
diff --git a/src/soc/amd/picasso/include/soc/msr.h b/src/soc/amd/picasso/include/soc/msr.h
index 23926144c2..05cda1ca89 100644
--- a/src/soc/amd/picasso/include/soc/msr.h
+++ b/src/soc/amd/picasso/include/soc/msr.h
@@ -8,19 +8,22 @@
 #define AMD_PICASSO_MSR_H
 
 /* MSRC001_00[6B:64] P-state [7:0] bit definitions */
-#define PSTATE_DEF_LO_CUR_DIV_SHIFT	30
-#define PSTATE_DEF_LO_CUR_DIV_MASK	(0x3 << PSTATE_DEF_LO_CUR_DIV_SHIFT)
-#define PSTATE_DEF_LO_CUR_VAL_SHIFT	22
-#define PSTATE_DEF_LO_CUR_VAL_MASK	(0xFF << PSTATE_DEF_LO_CUR_VAL_SHIFT)
-#define PSTATE_DEF_LO_CORE_VID_SHIFT	14
-#define PSTATE_DEF_LO_CORE_VID_MASK	(0xFF << PSTATE_DEF_LO_CORE_VID_SHIFT)
-#define PSTATE_DEF_LO_FREQ_DIV_SHIFT	8
-#define PSTATE_DEF_LO_FREQ_DIV_MASK	(0x3F << PSTATE_DEF_LO_FREQ_DIV_SHIFT)
+union pstate_msr {
+	struct {
+		uint64_t cpu_fid_0_7	:  8; /* [ 0.. 7] */
+		uint64_t cpu_dfs_id	:  6; /* [ 8..13] */
+		uint64_t cpu_vid_0_7	:  8; /* [14..21] */
+		uint64_t idd_value	:  8; /* [22..29] */
+		uint64_t idd_div	:  2; /* [30..31] */
+		uint64_t		: 31; /* [32..62] */
+		uint64_t pstate_en	:  1; /* [63..63] */
+	};
+	uint64_t raw;
+};
+
 #define PSTATE_DEF_LO_FREQ_DIV_MIN	0x8
 #define PSTATE_DEF_LO_EIGHTH_STEP_MAX	0x1A
 #define PSTATE_DEF_LO_FREQ_DIV_MAX	0x3E
-#define PSTATE_DEF_LO_FREQ_MUL_SHIFT	0
-#define PSTATE_DEF_LO_FREQ_MUL_MASK	(0xFF << PSTATE_DEF_LO_FREQ_MUL_SHIFT)
 #define PSTATE_DEF_LO_CORE_FREQ_BASE	25
 
 /* Value defined in Serial VID Interface 2.0 spec (#48022, NDA only) */