Re: [PATCH v5 12/14] arm64, acpi, numa: NUMA support based on SRAT and SLIT

From: Ganapatrao Kulkarni
Date: Wed Apr 20 2016 - 04:31:16 EST


On Wed, Apr 20, 2016 at 1:11 PM, Dennis Chen <dennis.chen@xxxxxxxxxx> wrote:
> On 20 April 2016 at 09:40, David Daney <ddaney.cavm@xxxxxxxxx> wrote:
>> From: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
>>
>> Introduce a new file to hold ACPI based NUMA information parsing from
>> SRAT and SLIT.
>>
>> SRAT includes the CPU ACPI ID to Proximity Domain mappings and memory
>> ranges to Proximity Domain mapping. SLIT has the information of inter
>> node distances(relative number for access latency).
>>
>> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
>> Signed-off-by: Ganapatrao Kulkarni <gkulkarni@xxxxxxxxxxxxxxxxxx>
>> [rrichter@xxxxxxxxxx Reworked for numa v10 series ]
>> Signed-off-by: Robert Richter <rrichter@xxxxxxxxxx>
>> [david.daney@xxxxxxxxxx reorderd and combinded with other patches in Hanjun Guo's original set]
>> Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
>> ---
>> arch/arm64/include/asm/acpi.h | 8 +++
>> arch/arm64/include/asm/numa.h | 2 +
>> arch/arm64/kernel/Makefile | 1 +
>> arch/arm64/kernel/acpi_numa.c | 149 ++++++++++++++++++++++++++++++++++++++++++
>> arch/arm64/kernel/smp.c | 2 +
>> arch/arm64/mm/numa.c | 5 +-
>> 6 files changed, 166 insertions(+), 1 deletion(-)
>> create mode 100644 arch/arm64/kernel/acpi_numa.c
>>
>> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
>> index aee323b..4b13ecd 100644
>> --- a/arch/arm64/include/asm/acpi.h
>> +++ b/arch/arm64/include/asm/acpi.h
>> @@ -113,4 +113,12 @@ static inline const char *acpi_get_enable_method(int cpu)
>> pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);
>> #endif
>>
>> +#ifdef CONFIG_ACPI_NUMA
>> +int arm64_acpi_numa_init(void);
>> +int acpi_numa_get_nid(unsigned int cpu, u64 hwid);
>> +#else
>> +static inline int arm64_acpi_numa_init(void) { return -ENOSYS; }
>> +static inline int acpi_numa_get_nid(unsigned int cpu, u64 hwid) { return NUMA_NO_NODE; }
>> +#endif /* CONFIG_ACPI_NUMA */
>> +
>> #endif /*_ASM_ACPI_H*/
>> diff --git a/arch/arm64/include/asm/numa.h b/arch/arm64/include/asm/numa.h
>> index e9b4f29..600887e 100644
>> --- a/arch/arm64/include/asm/numa.h
>> +++ b/arch/arm64/include/asm/numa.h
>> @@ -5,6 +5,8 @@
>>
>> #ifdef CONFIG_NUMA
>>
>> +#define NR_NODE_MEMBLKS (MAX_NUMNODES * 2)
>> +
>> /* currently, arm64 implements flat NUMA topology */
>> #define parent_node(node) (node)
>>
>> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
>> index 3793003..69569c6 100644
>> --- a/arch/arm64/kernel/Makefile
>> +++ b/arch/arm64/kernel/Makefile
>> @@ -42,6 +42,7 @@ arm64-obj-$(CONFIG_EFI) += efi.o efi-entry.stub.o
>> arm64-obj-$(CONFIG_PCI) += pci.o
>> arm64-obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o
>> arm64-obj-$(CONFIG_ACPI) += acpi.o
>> +arm64-obj-$(CONFIG_ACPI_NUMA) += acpi_numa.o
>> arm64-obj-$(CONFIG_ARM64_ACPI_PARKING_PROTOCOL) += acpi_parking_protocol.o
>> arm64-obj-$(CONFIG_PARAVIRT) += paravirt.o
>> arm64-obj-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
>> diff --git a/arch/arm64/kernel/acpi_numa.c b/arch/arm64/kernel/acpi_numa.c
>> new file mode 100644
>> index 0000000..fd72070
>> --- /dev/null
>> +++ b/arch/arm64/kernel/acpi_numa.c
>> @@ -0,0 +1,149 @@
>> +/*
>> + * 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) 2013-2016, 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>
>> +
>> +static int cpus_in_srat;
>> +
>> +struct __node_cpu_hwid {
>> + u32 node_id; /* logical node containing this CPU */
>> + u64 cpu_hwid; /* MPIDR for this CPU */
>> +};
>> +
>> +static struct __node_cpu_hwid early_node_cpu_hwid[NR_CPUS] = {
>> +[0 ... NR_CPUS - 1] = {NUMA_NO_NODE, PHYS_CPUID_INVALID} };
>> +
>> +int acpi_numa_get_nid(unsigned int cpu, u64 hwid)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < cpus_in_srat; i++) {
>> + if (hwid == early_node_cpu_hwid[i].cpu_hwid)
>> + return early_node_cpu_hwid[i].node_id;
>> + }
>> +
>> + return NUMA_NO_NODE;
>> +}
>> +
>> +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;
>> + }
>> +
>> + early_node_cpu_hwid[cpus_in_srat].node_id = node;
>> + early_node_cpu_hwid[cpus_in_srat].cpu_hwid = mpidr;
>> + node_set(node, numa_nodes_parsed);
>> + cpus_in_srat++;
>> + pr_info("SRAT: PXM %d -> MPIDR 0x%Lx -> Node %d cpu %d\n",
>> + pxm, mpidr, node, cpus_in_srat);
>> +}
>> +
>> +int __init arm64_acpi_numa_init(void)
>> +{
>> + int ret;
>> +
>> + ret = acpi_numa_init();
>> + if (ret)
>> + return ret;
>> +
>> + return srat_disabled() ? -EINVAL : 0;
>> +}
>> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
>> index bebc4c6..6c7ef8f 100644
>> --- a/arch/arm64/kernel/smp.c
>> +++ b/arch/arm64/kernel/smp.c
>> @@ -524,6 +524,8 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
>> */
>> acpi_set_mailbox_entry(cpu_count, processor);
>>
>> + early_map_cpu_to_node(cpu_count, acpi_numa_get_nid(cpu_count, hwid));
>> +
>> cpu_count++;
>> }
>>
>> diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
>> index 6cb03f9..fc15186 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/memblock.h>
>> #include <linux/module.h>
>> @@ -388,7 +389,9 @@ static int __init dummy_numa_init(void)
>> void __init arm64_numa_init(void)
>> {
>> if (!numa_off) {
>> - if (!numa_init(of_numa_init))
>> + if (!acpi_disabled && !numa_init(arm64_acpi_numa_init))
>> + return;
>> + if (acpi_disabled && !numa_init(of_numa_init))
>> return;
>> }
>>
> On top of the latest version of the dt-based numa patch, if 'numa=off'
> specified in the command line,
> this function will fallback to invoke dummy_numa_init(), which give
> rise the question here is, do we need to
> touch any ACPI related stuff in the case? If not, then the output

no, ACPI is not fallback configuration for DT and vice versa.

> message "No NUMA configuration found" followed
> seems is not necessary since it's a little bit confusing in case of
> numa has already been turned off explicitly.

thanks, this print can be moved out.
from function dummy_numa_init and it can be added in function arm64_numa_init
as a last line of if (!numa_off) to indicate, ACPI/DT based NUMA
configuration failed.

more appropriate would be,
pr_info("%s\n", "NUMA configuration failed or not found");

thanks
Ganapat

>
> Thanks,
> Dennis
>
>> --
>> 1.7.11.7
>>
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