On Wed, May 11, 2016 at 05:06:13PM -0700, 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.
>
> In summary: I don't think we need another revision of this patch, it is like
> this for a good reason.
Slightly confusing, in another reply you said you are going to address
my comment. So, is it doable?
--
Catalin
