4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mark Rutland mark.rutland@arm.com
[ Upstream commit 7654137071fa706e5c91f4f27bc2a5cd7e435a9b ]
In armpmu_dispatch_irq() we look at arm_pmu::plat_device to acquire platdata, so that we can defer to platform-specific IRQ handling, required on some 32-bit parts. With the advent of ACPI we won't always have a platform_device, and so we must avoid trying to dereference fields from it.
This patch fixes up armpmu_dispatch_irq() to avoid doing so, introducing a new armpmu_get_platdata() helper.
Signed-off-by: Mark Rutland mark.rutland@arm.com Tested-by: Jeremy Linton jeremy.linton@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/perf/arm_pmu.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
--- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -322,10 +322,16 @@ validate_group(struct perf_event *event) return 0; }
+static struct arm_pmu_platdata *armpmu_get_platdata(struct arm_pmu *armpmu) +{ + struct platform_device *pdev = armpmu->plat_device; + + return pdev ? dev_get_platdata(&pdev->dev) : NULL; +} + static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) { struct arm_pmu *armpmu; - struct platform_device *plat_device; struct arm_pmu_platdata *plat; int ret; u64 start_clock, finish_clock; @@ -337,8 +343,8 @@ static irqreturn_t armpmu_dispatch_irq(i * dereference. */ armpmu = *(void **)dev; - plat_device = armpmu->plat_device; - plat = dev_get_platdata(&plat_device->dev); + + plat = armpmu_get_platdata(armpmu);
start_clock = sched_clock(); if (plat && plat->handle_irq)