arm: perf: Use GENMASK for PMMIR fields

This is so that FIELD_GET and FIELD_PREP can be used and that the fields
are in a consistent format to arm64/tools/sysreg
Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20231211161331.1277825-4-james.clark@arm.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_pmuv3.c

@@ -332,7 +332,7 @@ static ssize_t slots_show(struct device *dev, struct device_attribute *attr,
 {
 	struct pmu *pmu = dev_get_drvdata(dev);
 	struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
-	u32 slots = cpu_pmu->reg_pmmir & ARMV8_PMU_SLOTS_MASK;
+	u32 slots = FIELD_GET(ARMV8_PMU_SLOTS, cpu_pmu->reg_pmmir);
 
 	return sysfs_emit(page, "0x%08x\n", slots);
 }
@@ -344,8 +344,7 @@ static ssize_t bus_slots_show(struct device *dev, struct device_attribute *attr,
 {
 	struct pmu *pmu = dev_get_drvdata(dev);
 	struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
-	u32 bus_slots = (cpu_pmu->reg_pmmir >> ARMV8_PMU_BUS_SLOTS_SHIFT)
-			& ARMV8_PMU_BUS_SLOTS_MASK;
+	u32 bus_slots = FIELD_GET(ARMV8_PMU_BUS_SLOTS, cpu_pmu->reg_pmmir);
 
 	return sysfs_emit(page, "0x%08x\n", bus_slots);
 }
@@ -357,8 +356,7 @@ static ssize_t bus_width_show(struct device *dev, struct device_attribute *attr,
 {
 	struct pmu *pmu = dev_get_drvdata(dev);
 	struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
-	u32 bus_width = (cpu_pmu->reg_pmmir >> ARMV8_PMU_BUS_WIDTH_SHIFT)
-			& ARMV8_PMU_BUS_WIDTH_MASK;
+	u32 bus_width = FIELD_GET(ARMV8_PMU_BUS_WIDTH, cpu_pmu->reg_pmmir);
 	u32 val = 0;
 
 	/* Encoded as Log2(number of bytes), plus one */

include/linux/perf/arm_pmuv3.h

@@ -250,12 +250,9 @@
 #define ARMV8_PMU_USERENR_ER	(1 << 3) /* Event counter can be read at EL0 */
 
 /* PMMIR_EL1.SLOTS mask */
-#define ARMV8_PMU_SLOTS_MASK	0xff
-
-#define ARMV8_PMU_BUS_SLOTS_SHIFT 8
-#define ARMV8_PMU_BUS_SLOTS_MASK 0xff
-#define ARMV8_PMU_BUS_WIDTH_SHIFT 16
-#define ARMV8_PMU_BUS_WIDTH_MASK 0xf
+#define ARMV8_PMU_SLOTS		GENMASK(7, 0)
+#define ARMV8_PMU_BUS_SLOTS	GENMASK(15, 8)
+#define ARMV8_PMU_BUS_WIDTH	GENMASK(19, 16)
 
 /*
  * This code is really good