Messages in this thread | | | Subject | Re: [PATCH v6 13/14] arm64, acpi, numa: NUMA support based on SRAT and SLIT | From | Hanjun Guo <> | Date | Thu, 12 May 2016 09:03:28 +0800 |
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On 2016/5/12 8:06, David Daney wrote: > On 05/11/2016 03:39 AM, Catalin Marinas wrote: >> 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. >> > > I just tried that, and it doesn't work. > > The problem is that this code is being run very early in the boot, and > kmalloc cannot be used. acpi_get_phys_id() and its ilk can only be used > once we have working kmalloc. We need to extract the NUMA information > early like this precisely because it is needed to initializing the slab > system > > Notice that we are using early_acpi_os_unmap_memory() et al. in > get_mpidr_in_madt() explicitly for this reason.
I got the same conclusion when I was preparing this patch set.
Thanks Hanjun
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