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Message-Id: <20230728112733.359620-2-anshuman.khandual@arm.com>
Date: Fri, 28 Jul 2023 16:57:31 +0530
From: Anshuman Khandual <anshuman.khandual@....com>
To: linux-arm-kernel@...ts.infradead.org, suzuki.poulose@....com
Cc: Anshuman Khandual <anshuman.khandual@....com>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>,
Mark Rutland <mark.rutland@....com>,
linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] arm_pmu: acpi: Add a representative platform device for TRBE
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@....com>
Cc: Will Deacon <will@...nel.org>
Cc: Mark Rutland <mark.rutland@....com>
Cc: linux-arm-kernel@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
---
arch/arm64/include/asm/acpi.h | 3 ++
drivers/perf/arm_pmu_acpi.c | 63 +++++++++++++++++++++++++++++++++++
include/linux/perf/arm_pmu.h | 1 +
3 files changed, 67 insertions(+)
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 90815ad762eb..dd3df6729808 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -139,6 +139,68 @@ static inline void arm_spe_acpi_register_device(void)
}
#endif /* CONFIG_ARM_SPE_PMU */
+#ifdef CONFIG_CORESIGHT_TRBE
+static struct resource trbe_acpi_resources[] = {
+ {
+ /* irq */
+ .flags = IORESOURCE_IRQ,
+ }
+};
+
+static struct platform_device trbe_acpi_dev = {
+ .name = ARMV8_TRBE_PDEV_NAME,
+ .id = -1,
+ .resource = trbe_acpi_resources,
+ .num_resources = ARRAY_SIZE(trbe_acpi_resources)
+};
+
+static void arm_trbe_acpi_register_device(void)
+{
+ int cpu, hetid, irq, ret;
+ bool first = true;
+ u16 gsi = 0;
+
+ for_each_possible_cpu(cpu) {
+ struct acpi_madt_generic_interrupt *gicc;
+
+ gicc = acpi_cpu_get_madt_gicc(cpu);
+ if (gicc->header.length < ACPI_MADT_GICC_TRBE)
+ return;
+
+ if (first) {
+ gsi = gicc->trbe_interrupt;
+ if (!gsi)
+ return;
+
+ hetid = find_acpi_cpu_topology_hetero_id(cpu);
+ first = false;
+ } else if ((gsi != gicc->trbe_interrupt) ||
+ (hetid != find_acpi_cpu_topology_hetero_id(cpu))) {
+ pr_warn("ACPI: TRBE must be homogeneous\n");
+ return;
+ }
+ }
+
+ irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_HIGH);
+ if (irq < 0) {
+ pr_warn("ACPI: TRBE Unable to register interrupt: %d\n", gsi);
+ return;
+ }
+ trbe_acpi_resources[0].start = irq;
+
+ ret = platform_device_register(&trbe_acpi_dev);
+ if (ret < 0) {
+ pr_warn("ACPI: TRBE: Unable to register device\n");
+ acpi_unregister_gsi(gsi);
+ }
+}
+#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;
@@ -374,6 +436,7 @@ 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..7ec26d21303d 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-acpi"
#endif /* __ARM_PMU_H__ */
--
2.25.1
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