Commit b9020bdb authored by Tony Luck's avatar Tony Luck Committed by Rafael J. Wysocki
Browse files

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: default avatarTony Luck <tony.luck@intel.com>
Link: https://patch.msgid.link/20250505173819.419271-2-tony.luck@intel.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent fec2686d

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/acpi/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -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

drivers/acpi/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

drivers/acpi/acpi_mrrm.c

0 → 100644
+42 −0
Original line number Diff line number Diff line 
// 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 <linux/acpi.h>

#include <linux/init.h>



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);

include/linux/acpi.h

+9 −0
Original line number Diff line number Diff line
@@ -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