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

[Anshuman Khandual]

On 8/8/23 13:52, Anshuman Khandual wrote:
> +	/*
> +	 * 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;
> +		}
> +	}

As discussed on the previous version i.e V3 thread, will move the
'this_gsi' check after parse_gsi(), inside if (!gsi) conditional
block. This will treat subsequent cpu parse_gsi()'s failure as a
mismatch thus triggering the pr_warn() message.

diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index 845683ca7c64..6eae772d6298 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -98,11 +98,11 @@ arm_acpi_register_pmu_device(struct platform_device *pdev, u8 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) {
+                       if (!this_gsi)
+                               return 0;
+
                        hetid = this_hetid;
                        gsi = this_gsi;
                } else if (hetid != this_hetid || gsi != this_gsi) {