[PATCH V4 1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()

Anshuman Khandual
2023-08-08T08:23:33Z

Sanity checking all the GICC tables for same interrupt number, and ensuring
a homogeneous ACPI based machine, could be used for other platform devices
as well. Hence this refactors arm_spe_acpi_register_device() into a common
helper arm_acpi_register_pmu_device().

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
Co-developed-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
drivers/perf/arm_pmu_acpi.c | 105 ++++++++++++++++++++++--------------
1 file changed, 65 insertions(+), 40 deletions(-)

diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index 90815ad762eb..72454bef2a70 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -69,6 +69,63 @@ static void arm_pmu_acpi_unregister_irq(int cpu)
acpi_unregister_gsi(gsi);
}

+static int __maybe_unused
+arm_acpi_register_pmu_device(struct platform_device *pdev, u8 len,
+ u16 (*parse_gsi)(struct acpi_madt_generic_interrupt *))
+{
+ int cpu, this_hetid, hetid, irq, ret;
+ u16 this_gsi, gsi = 0;
+
+ /*
+ * Ensure that platform device must have IORESOURCE_IRQ
+ * resource to hold gsi interrupt.
+ */
+ if (pdev->num_resources != 1)
+ return -ENXIO;
+
+ if (pdev->resource[0].flags != IORESOURCE_IRQ)
+ return -ENXIO;
+
+ /*
+ * Sanity check all the GICC tables for the same interrupt
+ * number. For now, only support homogeneous ACPI machines.
+ */
+ for_each_possible_cpu(cpu) {
+ struct acpi_madt_generic_interrupt *gicc;
+
+ gicc = acpi_cpu_get_madt_gicc(cpu);
+ if (gicc->header.length < len)
+ return gsi ? -ENXIO : 0;
+
+ this_gsi = parse_gsi(gicc);
+ if (!this_gsi)
+ return gsi ? -ENXIO : 0;
+
+ this_hetid = find_acpi_cpu_topology_hetero_id(cpu);
+ if (!gsi) {
+ hetid = this_hetid;
+ gsi = this_gsi;
+ } else if (hetid != this_hetid || gsi != this_gsi) {
+ pr_warn("ACPI: %s: must be homogeneous\n", pdev->name);
+ return -ENXIO;
+ }
+ }
+
+ irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_HIGH);
+ if (irq < 0) {
+ pr_warn("ACPI: %s Unable to register interrupt: %d\n", pdev->name, gsi);
+ return -ENXIO;
+ }
+
+ pdev->resource[0].start = irq;
+ ret = platform_device_register(pdev);
+ if (ret < 0) {
+ pr_warn("ACPI: %s: Unable to register device\n", pdev->name);
+ acpi_unregister_gsi(gsi);
+ }
+ return ret;
+}
+
#if IS_ENABLED(CONFIG_ARM_SPE_PMU)
static struct resource spe_resources[] = {
{
@@ -84,6 +141,11 @@ static struct platform_device spe_dev = {
.num_resources = ARRAY_SIZE(spe_resources)
};

+static u16 arm_spe_parse_gsi(struct acpi_madt_generic_interrupt *gicc)
+{
+ return gicc->spe_interrupt;
+}
+
/*
* For lack of a better place, hook the normal PMU MADT walk
* and create a SPE device if we detect a recent MADT with
@@ -91,47 +153,10 @@ static struct platform_device spe_dev = {
*/
static void arm_spe_acpi_register_device(void)
{
- int cpu, hetid, irq, ret;
- bool first = true;
- u16 gsi = 0;
-
- /*
- * Sanity check all the GICC tables for the same interrupt number.
- * For now, we only support homogeneous ACPI/SPE machines.
- */
- 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_SPE)
- return;
-
- if (first) {
- gsi = gicc->spe_interrupt;
- if (!gsi)
- return;
- hetid = find_acpi_cpu_topology_hetero_id(cpu);
- first = false;
- } else if ((gsi != gicc->spe_interrupt) ||
- (hetid != find_acpi_cpu_topology_hetero_id(cpu))) {
- pr_warn("ACPI: SPE must be homogeneous\n");
- return;
- }
- }
-
- irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE,
- ACPI_ACTIVE_HIGH);
- if (irq < 0) {
- pr_warn("ACPI: SPE Unable to register interrupt: %d\n", gsi);
- return;
- }
-
- spe_resources[0].start = irq;
- ret = platform_device_register(&spe_dev);
- if (ret < 0) {
+ int ret = arm_acpi_register_pmu_device(&spe_dev, ACPI_MADT_GICC_SPE,
+ arm_spe_parse_gsi);
+ if (ret)
pr_warn("ACPI: SPE: Unable to register device\n");
- acpi_unregister_gsi(gsi);
- }
}
#else
static inline void arm_spe_acpi_register_device(void)
--
2.25.1