From b9020bdb9f76b58117f9902db3047693fd12b11b Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Mon, 5 May 2025 10:38:17 -0700 Subject: [PATCH] ACPI: MRRM: Minimal parse of ACPI MRRM table The resctrl file system code needs to know how many region tags are supported. Parse the ACPI MRRM table and save the max_mem_region value. Provide a function for resctrl to collect that value. Signed-off-by: Tony Luck Link: https://patch.msgid.link/20250505173819.419271-2-tony.luck@intel.com Signed-off-by: Rafael J. Wysocki --- arch/x86/Kconfig | 1 + drivers/acpi/Kconfig | 3 +++ drivers/acpi/Makefile | 1 + drivers/acpi/acpi_mrrm.c | 42 ++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 9 +++++++++ 5 files changed, 56 insertions(+) create mode 100644 drivers/acpi/acpi_mrrm.c diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 4b9f378e05f6..0e43069082df 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -38,6 +38,7 @@ config X86_64 select ARCH_HAS_ELFCORE_COMPAT select ZONE_DMA32 select EXECMEM if DYNAMIC_FTRACE + select ACPI_MRRM if ACPI config FORCE_DYNAMIC_FTRACE def_bool y diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 7f10aa38269d..7bc40c2735ac 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -576,6 +576,9 @@ config ACPI_FFH Enable this feature if you want to set up and install the FFH Address Space handler to handle FFH OpRegion in the firmware. +config ACPI_MRRM + bool + source "drivers/acpi/pmic/Kconfig" config ACPI_VIOT diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 797070fc9a3f..d1b0affb844f 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -66,6 +66,7 @@ acpi-$(CONFIG_ACPI_WATCHDOG) += acpi_watchdog.o acpi-$(CONFIG_ACPI_PRMT) += prmt.o acpi-$(CONFIG_ACPI_PCC) += acpi_pcc.o acpi-$(CONFIG_ACPI_FFH) += acpi_ffh.o +acpi-$(CONFIG_ACPI_MRRM) += acpi_mrrm.o # Address translation acpi-$(CONFIG_ACPI_ADXL) += acpi_adxl.o diff --git a/drivers/acpi/acpi_mrrm.c b/drivers/acpi/acpi_mrrm.c new file mode 100644 index 000000000000..ab8022e58da5 --- /dev/null +++ b/drivers/acpi/acpi_mrrm.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2025, Intel Corporation. + * + * Memory Range and Region Mapping (MRRM) structure + */ + +#define pr_fmt(fmt) "acpi/mrrm: " fmt + +#include +#include + +static int max_mem_region = -ENOENT; + +/* Access for use by resctrl file system */ +int acpi_mrrm_max_mem_region(void) +{ + return max_mem_region; +} + +static __init int acpi_parse_mrrm(struct acpi_table_header *table) +{ + struct acpi_table_mrrm *mrrm; + + mrrm = (struct acpi_table_mrrm *)table; + if (!mrrm) + return -ENODEV; + + max_mem_region = mrrm->max_mem_region; + + return 0; +} + +static __init int mrrm_init(void) +{ + int ret; + + ret = acpi_table_parse(ACPI_SIG_MRRM, acpi_parse_mrrm); + + return ret; +} +device_initcall(mrrm_init); diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 3f2e93ed9730..c409f4cecb09 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -772,6 +772,10 @@ int acpi_get_local_u64_address(acpi_handle handle, u64 *addr); int acpi_get_local_address(acpi_handle handle, u32 *addr); const char *acpi_get_subsystem_id(acpi_handle handle); +#ifdef CONFIG_ACPI_MRRM +int acpi_mrrm_max_mem_region(void); +#endif + #else /* !CONFIG_ACPI */ #define acpi_disabled 1 @@ -1092,6 +1096,11 @@ static inline acpi_handle acpi_get_processor_handle(int cpu) return NULL; } +static inline int acpi_mrrm_max_mem_region(void) +{ + return -ENOENT; +} + #endif /* !CONFIG_ACPI */ #ifdef CONFIG_ACPI_HMAT -- 2.50.1