[PATCH v2 1/5] perf: arm_cspmu: Support 32-bit accesses to 64-bit registers
From: Ilkka Koskinen <hidden>
Date: 2023-06-01 03:02:53
Also in:
linux-doc, lkml
Subsystem:
arm pmu profiling and debugging, the rest · Maintainers:
Will Deacon, Mark Rutland, Linus Torvalds
Split the 64-bit register accesses if 64-bit access is not supported by the PMU. Signed-off-by: Ilkka Koskinen <redacted> --- drivers/perf/arm_cspmu/arm_cspmu.c | 8 ++++++-- drivers/perf/arm_cspmu/arm_cspmu.h | 1 + 2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
index a3f1c410b417..88547a2b73e6 100644
--- a/drivers/perf/arm_cspmu/arm_cspmu.c
+++ b/drivers/perf/arm_cspmu/arm_cspmu.c@@ -701,8 +701,12 @@ static void arm_cspmu_write_counter(struct perf_event *event, u64 val) if (use_64b_counter_reg(cspmu)) { offset = counter_offset(sizeof(u64), event->hw.idx); - - writeq(val, cspmu->base1 + offset); + if (!cspmu->impl.split_64bit_access) { + writeq(val, cspmu->base1 + offset); + } else { + writel(lower_32_bits(val), cspmu->base1 + offset); + writel(upper_32_bits(val), cspmu->base1 + offset + 4); + } } else { offset = counter_offset(sizeof(u32), event->hw.idx);
diff --git a/drivers/perf/arm_cspmu/arm_cspmu.h b/drivers/perf/arm_cspmu/arm_cspmu.h
index 51323b175a4a..c0412cf2bd97 100644
--- a/drivers/perf/arm_cspmu/arm_cspmu.h
+++ b/drivers/perf/arm_cspmu/arm_cspmu.h@@ -110,6 +110,7 @@ struct arm_cspmu_impl_ops { /* Vendor/implementer descriptor. */ struct arm_cspmu_impl { u32 pmiidr; + bool split_64bit_access; struct arm_cspmu_impl_ops ops; void *ctx; };
--
2.40.1
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