Re: [PATCHv3 03/13] acpi/hmat: Parse and report heterogeneous memory
From: Rafael J. Wysocki
Date: Thu Jan 10 2019 - 10:43:02 EST
On Wed, Jan 9, 2019 at 6:47 PM Keith Busch <keith.busch@xxxxxxxxx> wrote:
>
> Systems may provide different memory types and export this information
> in the ACPI Heterogeneous Memory Attribute Table (HMAT). Parse these
> tables provided by the platform and report the memory access and caching
> attributes.
>
> Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
While this is generally fine by me, it's another piece of code going
under drivers/acpi/ just because it happens to use ACPI to extract
some information from the platform firmware.
Isn't there any better place for it?
> ---
> drivers/acpi/Kconfig | 8 +++
> drivers/acpi/Makefile | 1 +
> drivers/acpi/hmat.c | 180 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 189 insertions(+)
> create mode 100644 drivers/acpi/hmat.c
>
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index 7b65a807b3dd..b102d9f544ee 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -326,6 +326,14 @@ config ACPI_NUMA
> depends on (X86 || IA64 || ARM64)
> default y if IA64_GENERIC || IA64_SGI_SN2 || ARM64
>
> +config ACPI_HMAT
> + bool "ACPI Heterogeneous Memory Attribute Table Support"
> + depends on ACPI_NUMA
> + help
> + Parses representation of the ACPI Heterogeneous Memory Attributes
> + Table (HMAT) and set the memory node relationships and access
> + attributes.
> +
> config ACPI_CUSTOM_DSDT_FILE
> string "Custom DSDT Table file to include"
> default ""
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 7c6afc111d76..2a435dcfaa9c 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -55,6 +55,7 @@ acpi-$(CONFIG_X86) += x86/apple.o
> acpi-$(CONFIG_X86) += x86/utils.o
> acpi-$(CONFIG_DEBUG_FS) += debugfs.o
> acpi-$(CONFIG_ACPI_NUMA) += numa.o
> +acpi-$(CONFIG_ACPI_HMAT) += hmat.o
> acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
> acpi-y += acpi_lpat.o
> acpi-$(CONFIG_ACPI_LPIT) += acpi_lpit.o
> diff --git a/drivers/acpi/hmat.c b/drivers/acpi/hmat.c
> new file mode 100644
> index 000000000000..833a783868d5
> --- /dev/null
> +++ b/drivers/acpi/hmat.c
> @@ -0,0 +1,180 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Heterogeneous Memory Attributes Table (HMAT) representation
> + *
> + * Copyright (c) 2018, Intel Corporation.
> + */
> +
> +#include <acpi/acpi_numa.h>
> +#include <linux/acpi.h>
> +#include <linux/bitops.h>
> +#include <linux/cpu.h>
> +#include <linux/device.h>
> +#include <linux/init.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/node.h>
> +#include <linux/slab.h>
> +#include <linux/sysfs.h>
> +
> +static __init const char *hmat_data_type(u8 type)
> +{
> + switch (type) {
> + case ACPI_HMAT_ACCESS_LATENCY:
> + return "Access Latency";
> + case ACPI_HMAT_READ_LATENCY:
> + return "Read Latency";
> + case ACPI_HMAT_WRITE_LATENCY:
> + return "Write Latency";
> + case ACPI_HMAT_ACCESS_BANDWIDTH:
> + return "Access Bandwidth";
> + case ACPI_HMAT_READ_BANDWIDTH:
> + return "Read Bandwidth";
> + case ACPI_HMAT_WRITE_BANDWIDTH:
> + return "Write Bandwidth";
> + default:
> + return "Reserved";
> + };
> +}
> +
> +static __init const char *hmat_data_type_suffix(u8 type)
> +{
> + switch (type) {
> + case ACPI_HMAT_ACCESS_LATENCY:
> + case ACPI_HMAT_READ_LATENCY:
> + case ACPI_HMAT_WRITE_LATENCY:
> + return " nsec";
> + case ACPI_HMAT_ACCESS_BANDWIDTH:
> + case ACPI_HMAT_READ_BANDWIDTH:
> + case ACPI_HMAT_WRITE_BANDWIDTH:
> + return " MB/s";
> + default:
> + return "";
> + };
> +}
> +
> +static __init int hmat_parse_locality(union acpi_subtable_headers *header,
> + const unsigned long end)
> +{
> + struct acpi_hmat_locality *loc = (void *)header;
> + unsigned int init, targ, total_size, ipds, tpds;
> + u32 *inits, *targs, value;
> + u16 *entries;
> + u8 type;
> +
> + if (loc->header.length < sizeof(*loc)) {
> + pr_err("HMAT: Unexpected locality header length: %d\n",
> + loc->header.length);
> + return -EINVAL;
> + }
> +
> + type = loc->data_type;
> + ipds = loc->number_of_initiator_Pds;
> + tpds = loc->number_of_target_Pds;
> + total_size = sizeof(*loc) + sizeof(*entries) * ipds * tpds +
> + sizeof(*inits) * ipds + sizeof(*targs) * tpds;
> + if (loc->header.length < total_size) {
> + pr_err("HMAT: Unexpected locality header length:%d, minimum required:%d\n",
> + loc->header.length, total_size);
> + return -EINVAL;
> + }
> +
> + pr_info("HMAT: Locality: Flags:%02x Type:%s Initiator Domains:%d Target Domains:%d Base:%lld\n",
> + loc->flags, hmat_data_type(type), ipds, tpds,
> + loc->entry_base_unit);
> +
> + inits = (u32 *)(loc + 1);
> + targs = &inits[ipds];
> + entries = (u16 *)(&targs[tpds]);
> + for (targ = 0; targ < tpds; targ++) {
> + for (init = 0; init < ipds; init++) {
> + value = entries[init * tpds + targ];
> + value = (value * loc->entry_base_unit) / 10;
> + pr_info(" Initiator-Target[%d-%d]:%d%s\n",
> + inits[init], targs[targ], value,
> + hmat_data_type_suffix(type));
> + }
> + }
> + return 0;
> +}
> +
> +static __init int hmat_parse_cache(union acpi_subtable_headers *header,
> + const unsigned long end)
> +{
> + struct acpi_hmat_cache *cache = (void *)header;
> + u32 attrs;
> +
> + if (cache->header.length < sizeof(*cache)) {
> + pr_err("HMAT: Unexpected cache header length: %d\n",
> + cache->header.length);
> + return -EINVAL;
> + }
> +
> + attrs = cache->cache_attributes;
> + pr_info("HMAT: Cache: Domain:%d Size:%llu Attrs:%08x SMBIOS Handles:%d\n",
> + cache->memory_PD, cache->cache_size, attrs,
> + cache->number_of_SMBIOShandles);
> +
> + return 0;
> +}
> +
> +static int __init hmat_parse_address_range(union acpi_subtable_headers *header,
> + const unsigned long end)
> +{
> + struct acpi_hmat_address_range *spa = (void *)header;
> +
> + if (spa->header.length != sizeof(*spa)) {
> + pr_err("HMAT: Unexpected address range header length: %d\n",
> + spa->header.length);
> + return -EINVAL;
> + }
> + pr_info("HMAT: Memory (%#llx length %#llx) Flags:%04x Processor Domain:%d Memory Domain:%d\n",
> + spa->physical_address_base, spa->physical_address_length,
> + spa->flags, spa->processor_PD, spa->memory_PD);
> + return 0;
> +}
> +
> +static int __init hmat_parse_subtable(union acpi_subtable_headers *header,
> + const unsigned long end)
> +{
> + struct acpi_hmat_structure *hdr = (void *)header;
> +
> + if (!hdr)
> + return -EINVAL;
> +
> + switch (hdr->type) {
> + case ACPI_HMAT_TYPE_ADDRESS_RANGE:
> + return hmat_parse_address_range(header, end);
> + case ACPI_HMAT_TYPE_LOCALITY:
> + return hmat_parse_locality(header, end);
> + case ACPI_HMAT_TYPE_CACHE:
> + return hmat_parse_cache(header, end);
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static __init int hmat_init(void)
> +{
> + struct acpi_table_header *tbl;
> + enum acpi_hmat_type i;
> + acpi_status status;
> +
> + if (srat_disabled())
> + return 0;
> +
> + status = acpi_get_table(ACPI_SIG_HMAT, 0, &tbl);
> + if (ACPI_FAILURE(status))
> + return 0;
> +
> + for (i = ACPI_HMAT_TYPE_ADDRESS_RANGE; i < ACPI_HMAT_TYPE_RESERVED; i++) {
> + if (acpi_table_parse_entries(ACPI_SIG_HMAT,
> + sizeof(struct acpi_table_hmat), i,
> + hmat_parse_subtable, 0) < 0)
> + goto out_put;
> + }
> +out_put:
> + acpi_put_table(tbl);
> + return 0;
> +}
> +subsys_initcall(hmat_init);
> --
> 2.14.4
>