Messages in this thread | | | Date | Mon, 7 Aug 2023 11:03:40 +0530 | Subject | Re: [PATCH V3 1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device() | From | Anshuman Khandual <> |
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On 8/4/23 22:09, Will Deacon wrote: > On Thu, Aug 03, 2023 at 11:43:27AM +0530, Anshuman Khandual wrote: >> >> >> On 8/3/23 11:26, 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; >> >> Hello Will, >> >> Moved parse_gsi() return code checking to its original place just to >> make it similar in semantics to existing 'gicc->header.length check'. >> If 'gsi' is valid i.e atleast a single cpu has been probed, return >> -ENXIO indicating mismatch, otherwise just return 0. > > Wouldn't that still be the case without the check in this hunk? We'd run > into the homogeneous check and return -ENXIO from there, no? Although the return code will be the same i.e -ENXIO, but not for the same reason.
this_gsi = parse_gsi(gicc); if (!this_gsi) return gsi ? -ENXIO : 0;
This returns 0 when IRQ could not be parsed for the first cpu, but returns -ENXIO for subsequent cpus. Although return code -ENXIO here still indicates IRQ parsing to have failed.
} else if (hetid != this_hetid || gsi != this_gsi) { pr_warn("ACPI: %s: must be homogeneous\n", pdev->name); return -ENXIO; }
This returns -ENXIO when there is a IRQ mismatch. But if the above check is not there, -ENXIO return code here could not be classified into IRQ parse problem or mismatch without looking into the IRQ value.
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