linux-kernel - [PATCH 2/7] platform/x86/intel-uncore-freq: Get rid of magic values

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Date: Mon, 17 Jun 2024 09:04:35 +0300
From: Tero Kristo <tero.kristo@...ux.intel.com>
To: hdegoede@...hat.com,
	srinivas.pandruvada@...ux.intel.com,
	ilpo.jarvinen@...ux.intel.com
Cc: linux-kernel@...r.kernel.org,
	platform-driver-x86@...r.kernel.org
Subject: [PATCH 2/7] platform/x86/intel-uncore-freq: Get rid of magic values

Get rid of any magic bitmasks from the code. Define proper macros for
these, and use the bitfield operations to access them.

No functional change intended.

Signed-off-by: Tero Kristo <tero.kristo@...ux.intel.com>
---
 .../intel/uncore-frequency/uncore-frequency.c | 22 ++++++++++++-------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c
index b89c0dda9e5d..d3fdae695bbd 100644
--- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c
+++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c
@@ -14,6 +14,7 @@
  * Author: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/cpu.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -36,6 +37,11 @@ static enum cpuhp_state uncore_hp_state __read_mostly;
 #define MSR_UNCORE_PERF_STATUS	0x621
 #define UNCORE_FREQ_KHZ_MULTIPLIER	100000
 
+#define UNCORE_MAX_RATIO_MASK	GENMASK_ULL(6, 0)
+#define UNCORE_MIN_RATIO_MASK	GENMASK_ULL(14, 8)
+
+#define UNCORE_CURRENT_RATIO_MASK	GENMASK_ULL(6, 0)
+
 static int uncore_read_control_freq(struct uncore_data *data, unsigned int *min,
 				    unsigned int *max)
 {
@@ -49,8 +55,8 @@ static int uncore_read_control_freq(struct uncore_data *data, unsigned int *min,
 	if (ret)
 		return ret;
 
-	*max = (cap & 0x7F) * UNCORE_FREQ_KHZ_MULTIPLIER;
-	*min = ((cap & GENMASK(14, 8)) >> 8) * UNCORE_FREQ_KHZ_MULTIPLIER;
+	*max = FIELD_GET(UNCORE_MAX_RATIO_MASK, cap) * UNCORE_FREQ_KHZ_MULTIPLIER;
+	*min = FIELD_GET(UNCORE_MIN_RATIO_MASK, cap) * UNCORE_FREQ_KHZ_MULTIPLIER;
 
 	return 0;
 }
@@ -62,7 +68,7 @@ static int uncore_write_control_freq(struct uncore_data *data, unsigned int inpu
 	u64 cap;
 
 	input /= UNCORE_FREQ_KHZ_MULTIPLIER;
-	if (!input || input > 0x7F)
+	if (!input || input > FIELD_MAX(UNCORE_MAX_RATIO_MASK))
 		return -EINVAL;
 
 	if (data->control_cpu < 0)
@@ -73,11 +79,11 @@ static int uncore_write_control_freq(struct uncore_data *data, unsigned int inpu
 		return ret;
 
 	if (min_max) {
-		cap &= ~0x7F;
-		cap |= input;
+		cap &= ~UNCORE_MAX_RATIO_MASK;
+		cap |= FIELD_PREP(UNCORE_MAX_RATIO_MASK, input);
 	} else  {
-		cap &= ~GENMASK(14, 8);
-		cap |= (input << 8);
+		cap &= ~UNCORE_MIN_RATIO_MASK;
+		cap |= FIELD_PREP(UNCORE_MIN_RATIO_MASK, input);
 	}
 
 	ret = wrmsrl_on_cpu(data->control_cpu, MSR_UNCORE_RATIO_LIMIT, cap);
@@ -101,7 +107,7 @@ static int uncore_read_freq(struct uncore_data *data, unsigned int *freq)
 	if (ret)
 		return ret;
 
-	*freq = (ratio & 0x7F) * UNCORE_FREQ_KHZ_MULTIPLIER;
+	*freq = FIELD_GET(UNCORE_CURRENT_RATIO_MASK, ratio) * UNCORE_FREQ_KHZ_MULTIPLIER;
 
 	return 0;
 }
-- 
2.43.0