On Tue, Nov 17, 2015 at 11:55:32PM +0530, Ganapatrao Kulkarni wrote:
[...]
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index 7987763..555c4a5 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -42,6 +42,7 @@ arm64-obj-$(CONFIG_PCI) += pci.o
> arm64-obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o
> arm64-obj-$(CONFIG_ACPI) += acpi.o
> arm64-obj-$(CONFIG_OF_NUMA) += of_numa.o
> +arm64-obj-$(CONFIG_ACPI_NUMA) += acpi_numa.o
Isn't it better to merge ACPI and DT support in one file (a bit like
what we did for smp.c) to remove some of this iffdeffery ?
>
> obj-y += $(arm64-obj-y) vdso/
> obj-m += $(arm64-obj-m)
> diff --git a/arch/arm64/kernel/acpi_numa.c b/arch/arm64/kernel/acpi_numa.c
> new file mode 100644
> index 0000000..8aee205
> --- /dev/null
> +++ b/arch/arm64/kernel/acpi_numa.c
> @@ -0,0 +1,215 @@
> +/*
> + * ACPI 5.1 based NUMA setup for ARM64
> + * Lots of code was borrowed from arch/x86/mm/srat.c
> + *
> + * Copyright 2004 Andi Kleen, SuSE Labs.
> + * Copyright (C) 2013-2014, Linaro Ltd.
> + * Author: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> + *
> + * Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
> + *
> + * Called from acpi_numa_init while reading the SRAT and SLIT tables.
> + * Assumes all memory regions belonging to a single proximity domain
> + * are in one chunk. Holes between them will be included in the node.
> + */
> +
> +#define pr_fmt(fmt) "ACPI: NUMA: " fmt
> +
> +#include <linux/acpi.h>
> +#include <linux/bitmap.h>
> +#include <linux/bootmem.h>
> +#include <linux/kernel.h>
> +#include <linux/mm.h>
> +#include <linux/memblock.h>
> +#include <linux/mmzone.h>
> +#include <linux/module.h>
> +#include <linux/topology.h>
> +
> +#include <acpi/processor.h>
> +#include <asm/numa.h>
> +
> +int acpi_numa __initdata;
> +
> +static __init int setup_node(int pxm)
> +{
> + return acpi_map_pxm_to_node(pxm);
> +}
This function is not that useful given how it is used in the patch.
> +
> +static __init void bad_srat(void)
> +{
> + pr_err("SRAT not used.\n");
> + acpi_numa = -1;
> +}
> +
> +static __init inline int srat_disabled(void)
> +{
> + return acpi_numa < 0;
> +}
> +
> +/*
> + * Callback for SLIT parsing.
> + * It will get the distance information presented by SLIT
> + * and init the distance matrix of numa nodes
> + */
> +void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
> +{
> + int i, j;
> +
> + for (i = 0; i < slit->locality_count; i++) {
> + const int from_node = pxm_to_node(i);
> +
> + if (from_node == NUMA_NO_NODE)
> + continue;
> +
> + for (j = 0; j < slit->locality_count; j++) {
> + const int to_node = pxm_to_node(j);
> +
> + if (to_node == NUMA_NO_NODE)
> + continue;
> +
> + pr_info("SLIT: Distance[%d][%d] = %d\n",
> + from_node, to_node,
> + slit->entry[
> + slit->locality_count * i + j]);
> + numa_set_distance(from_node, to_node,
> + slit->entry[slit->locality_count * i + j]);
> + }
> + }
> +}
This function is an x86 copy'n'paste. ia64 just requires this callback
to save a slit table pointer (that can be moved to generic code and it is
initdata anyway), so my question is, do we really need to duplicate it ?
> +static int __init get_mpidr_in_madt(int acpi_id, u64 *mpidr)
> +{
Looks familiar. I guess you can't reuse the code in drivers/acpi
(acpi_map_cpuid()) only because that implies permanent table mappings to be
in place and you need to call this function before acpi_gbl_permanent_mmap
is set ?
> + 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;
> + static int cpus_in_srat;
> +
> + if (srat_disabled())
> + return;
> +
> + if (pa->header.length < sizeof(struct acpi_srat_gicc_affinity)) {
> + 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[%ld] is too small, may not be able to use all cpus\n",
> + NR_CPUS);
> + return;
> + }
> +
> + pxm = pa->proximity_domain;
> + node = setup_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_warn("SRAT: PXM %d with ACPI ID %d has no valid MPIDR in MADT\n",
> + pxm, pa->acpi_processor_uid);
> + bad_srat();
> + return;
> + }
> +
> + cpu_to_node_map[cpus_in_srat] = node;
This looks wrong. cpus_in_srat is a logical index, but I do not see why
it has to be sequential. You retrieve the mpidr for a given SRAT entry
and with that value you should retrieve the cpu_logical index that
corresponds to it (get_logical_index()), or maybe I am missing something
from the ACPI specs that enforce a SRAT entries ordering, on which we
should not rely upon anyway.
> + node_set(node, numa_nodes_parsed);
> + acpi_numa = 1;
What's the point if you are checking for < 0 in srat_disabled() ?
> + cpus_in_srat++;
> + pr_info("SRAT: PXM %d -> MPIDR 0x%Lx -> Node %d cpu %d\n",
> + pxm, mpidr, node, cpus_in_srat);
> +}
> +
> +/* Callback for parsing of the Proximity Domain <-> Memory Area mappings */
> +int __init acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
> +{
> + u64 start, end;
> + int node, pxm;
> +
> + if (srat_disabled())
> + return -EINVAL;
> +
> + if (ma->header.length != sizeof(struct acpi_srat_mem_affinity)) {
> + bad_srat();
> + return -EINVAL;
> + }
> +
> + start = ma->base_address;
> + end = start + ma->length;
> + pxm = ma->proximity_domain;
> +
> + node = setup_node(pxm);
> +
> + if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
> + pr_err("SRAT: Too many proximity domains.\n");
> + bad_srat();
> + return -EINVAL;
> + }
> +
> + pr_info("SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]\n",
> + node, pxm,
> + (unsigned long long) start, (unsigned long long) end - 1);
> +
> + if (numa_add_memblk(node, start, (end - start)) < 0) {
> + bad_srat();
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
I do not see again any major changes compared to x86, numa_add_memblk()
has a different interface (size vs end) but apart from that it would
be nice to avoid rewriting the same code time and again.
> +
> +void __init acpi_numa_arch_fixup(void) { }
Sigh. How many of these useless callbacks are we forced to define ?
> +
> +int __init arm64_acpi_numa_init(void)
> +{
> + int ret;
> +
> + ret = acpi_numa_init();
> + if (ret < 0)
> + return ret;
> +
> + return srat_disabled() ? -EINVAL : 0;
> +}
> diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
> index 209c7a9..c2950fc 100644
> --- a/arch/arm64/mm/numa.c
> +++ b/arch/arm64/mm/numa.c
> @@ -17,6 +17,7 @@
> * along with this program. If not, see <http://www.gnu.org/licenses/>.
> */
>
> +#include <linux/acpi.h>
> #include <linux/bootmem.h>
> #include <linux/ctype.h>
> #include <linux/init.h>
> @@ -383,9 +384,13 @@ void __init arm64_numa_init(void)
> int ret = -ENODEV;
>
> #ifdef CONFIG_OF_NUMA
> - if (!numa_off)
> + if (!numa_off && acpi_disabled)
> ret = numa_init(arm64_of_numa_init);
> #endif
> +#ifdef CONFIG_ACPI_NUMA
> + if (!numa_off && !acpi_disabled)
> + ret = numa_init(arm64_acpi_numa_init);
> +#endif
See my comment above on DT/ACPI, this ifdeffery does not look great.
Thanks,
Lorenzo
>
> if (ret)
> numa_init(dummy_numa_init);
> --
> 1.8.1.4
>
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