Re: [PATCH v6 13/14] arm64, acpi, numa: NUMA support based on SRAT and SLIT

[Catalin Marinas]

On Wed, Apr 27, 2016 at 11:07:15AM -0700, David Daney wrote:
> +static int __init get_mpidr_in_madt(int acpi_id, u64 *mpidr)
> +{
> +	unsigned long madt_end, entry;
> +	struct acpi_table_madt *madt;
> +	acpi_size tbl_size;
> +
> +	if (ACPI_FAILURE(acpi_get_table_with_size(ACPI_SIG_MADT, 0,
> +			(struct acpi_table_header **)&madt, &tbl_size)))
> +		return -ENODEV;
> +
> +	entry = (unsigned long)madt;
> +	madt_end = entry + madt->header.length;
> +
> +	/* Parse all entries looking for a match. */
> +	entry += sizeof(struct acpi_table_madt);
> +	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
> +		struct acpi_subtable_header *header =
> +			(struct acpi_subtable_header *)entry;
> +
> +		if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT) {
> +			struct acpi_madt_generic_interrupt *gicc =
> +				container_of(header,
> +				struct acpi_madt_generic_interrupt, header);
> +
> +			if ((gicc->flags & ACPI_MADT_ENABLED) &&
> +			    (gicc->uid == acpi_id)) {
> +				*mpidr = gicc->arm_mpidr;
> +				early_acpi_os_unmap_memory(madt, tbl_size);
> +				return 0;
> +			}
> +		}
> +		entry += header->length;
> +	}
> +
> +	early_acpi_os_unmap_memory(madt, tbl_size);
> +	return -ENODEV;
> +}
> +
> +/* Callback for Proximity Domain -> ACPI processor UID mapping */
> +void __init acpi_numa_gicc_affinity_init(struct acpi_srat_gicc_affinity *pa)
> +{
> +	int pxm, node;
> +	u64 mpidr;
> +
> +	if (srat_disabled())
> +		return;
> +
> +	if (pa->header.length < sizeof(struct acpi_srat_gicc_affinity)) {
> +		pr_err("SRAT: Invalid SRAT header length: %d\n",
> +			pa->header.length);
> +		bad_srat();
> +		return;
> +	}
> +
> +	if (!(pa->flags & ACPI_SRAT_GICC_ENABLED))
> +		return;
> +
> +	if (cpus_in_srat >= NR_CPUS) {
> +		pr_warn_once("SRAT: cpu_to_node_map[%d] is too small, may not be able to use all cpus\n",
> +			     NR_CPUS);
> +		return;
> +	}
> +
> +	pxm = pa->proximity_domain;
> +	node = acpi_map_pxm_to_node(pxm);
> +
> +	if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
> +		pr_err("SRAT: Too many proximity domains %d\n", pxm);
> +		bad_srat();
> +		return;
> +	}
> +
> +	if (get_mpidr_in_madt(pa->acpi_processor_uid, &mpidr)) {
> +		pr_err("SRAT: PXM %d with ACPI ID %d has no valid MPIDR in MADT\n",
> +			pxm, pa->acpi_processor_uid);
> +		bad_srat();
> +		return;
> +	}

I wonder whether you could replace the get_mpidr_in_madt() function with
something like acpi_get_phys_id(). It looks like get_mpidr_in_madt()
duplicates functionality already available elsewhere.

-- 
Catalin