On 8/3/23 11:26, Anshuman Khandual wrote:
ACPI TRBE does not have a HID for identification which could create and add a platform device into the platform bus. Also without a platform device, it cannot be probed and bound to a platform driver.
This creates a dummy platform device for TRBE after ascertaining that ACPI provides required interrupts uniformly across all cpus on the system. This device gets created inside drivers/perf/arm_pmu_acpi.c to accommodate TRBE being built as a module.
Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com
arch/arm64/include/asm/acpi.h | 3 +++ drivers/perf/arm_pmu_acpi.c | 37 ++++++++++++++++++++++++++++++++++- include/linux/perf/arm_pmu.h | 1 + 3 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index bd68e1b7f29f..4d537d56eb84 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -42,6 +42,9 @@ #define ACPI_MADT_GICC_SPE (offsetof(struct acpi_madt_generic_interrupt, \ spe_interrupt) + sizeof(u16)) +#define ACPI_MADT_GICC_TRBE (offsetof(struct acpi_madt_generic_interrupt, \
- trbe_interrupt) + sizeof(u16))
/* Basic configuration for ACPI */ #ifdef CONFIG_ACPI pgprot_t __acpi_get_mem_attribute(phys_addr_t addr); diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c index 235c14766a36..79feea548e6e 100644 --- a/drivers/perf/arm_pmu_acpi.c +++ b/drivers/perf/arm_pmu_acpi.c @@ -69,7 +69,7 @@ static void arm_pmu_acpi_unregister_irq(int cpu) acpi_unregister_gsi(gsi); } -#if IS_ENABLED(CONFIG_ARM_SPE_PMU) +#if IS_ENABLED(CONFIG_ARM_SPE_PMU) || IS_ENABLED(CONFIG_CORESIGHT_TRBE)
Rather than adding IS_ENABLED() checks for all applicable configs in future which will need to call arm_acpi_register_pmu_device() for a dummy platform device, could we instead just add __maybe_unused for the function to prevent build warning when there are no call sites ? Seems bit better and simpler.
static int arm_acpi_register_pmu_device(struct platform_device *pdev, u8 len, u16 (*parse_gsi)(struct acpi_madt_generic_interrupt *)) @@ -166,6 +166,40 @@ static inline void arm_spe_acpi_register_device(void) } #endif /* CONFIG_ARM_SPE_PMU */ +#ifdef CONFIG_CORESIGHT_TRBE +static struct resource trbe_resources[] = {
- {
/* irq */.flags = IORESOURCE_IRQ,- }
+};
+static struct platform_device trbe_dev = {
- .name = ARMV8_TRBE_PDEV_NAME,
- .id = -1,
- .resource = trbe_resources,
- .num_resources = ARRAY_SIZE(trbe_resources)
+};
+static u16 arm_trbe_parse_gsi(struct acpi_madt_generic_interrupt *gicc) +{
- return gicc->trbe_interrupt;
+}
+static void arm_trbe_acpi_register_device(void) +{
- int ret = arm_acpi_register_pmu_device(&trbe_dev, ACPI_MADT_GICC_TRBE,
arm_trbe_parse_gsi);- if (ret)
pr_warn("ACPI: TRBE: Unable to register device\n");+} +#else +static inline void arm_trbe_acpi_register_device(void) +{
+} +#endif /* CONFIG_CORESIGHT_TRBE */
static int arm_pmu_acpi_parse_irqs(void) { int irq, cpu, irq_cpu, err; @@ -401,6 +435,7 @@ static int arm_pmu_acpi_init(void) return 0; arm_spe_acpi_register_device();
- arm_trbe_acpi_register_device();
return 0; } diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index a0801f68762b..143fbc10ecfe 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -187,5 +187,6 @@ void armpmu_free_irq(int irq, int cpu); #endif /* CONFIG_ARM_PMU */ #define ARMV8_SPE_PDEV_NAME "arm,spe-v1" +#define ARMV8_TRBE_PDEV_NAME "arm,trbe" #endif /* __ARM_PMU_H__ */