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Commit 359b7064 authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: Extract feature parsing code from cpu_errata.c 



As we detect more architectural features at runtime, it makes
sense to reuse the existing framework whilst avoiding to call
a feature an erratum...

This patch extract the core capability parsing, moves it into
a new file (cpufeature.c), and let the CPU errata detection code
use it.

Reviewed-by: default avatarAndre Przywara <andre.przywara@arm.com>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent fef7f2b2

arch/arm64/include/asm/cpufeature.h

+15 −0
Original line number Diff line number Diff line
@@ -28,6 +28,18 @@ 


#ifndef __ASSEMBLY__



struct arm64_cpu_capabilities {

	const char *desc;

	u16 capability;

	bool (*matches)(const struct arm64_cpu_capabilities *);

	union {

		struct {	/* To be used for erratum handling only */

			u32 midr_model;

			u32 midr_range_min, midr_range_max;

		};

	};

};



extern DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);



static inline bool cpu_have_feature(unsigned int num)
@@ -51,7 +63,10 @@ static inline void cpus_set_cap(unsigned int num) 
		__set_bit(num, cpu_hwcaps);

}



void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,

			    const char *info);

void check_local_cpu_errata(void);

void check_local_cpu_features(void);

bool cpu_supports_mixed_endian_el0(void);

bool system_supports_mixed_endian_el0(void);

arch/arm64/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -17,7 +17,7 @@ arm64-obj-y := debug-monitors.o entry.o irq.o fpsimd.o \ 
			   sys.o stacktrace.o time.o traps.o io.o vdso.o	\

			   hyp-stub.o psci.o psci-call.o cpu_ops.o insn.o	\

			   return_address.o cpuinfo.o cpu_errata.o		\

			   alternative.o cacheinfo.o

			   cpufeature.o alternative.o cacheinfo.o



arm64-obj-$(CONFIG_COMPAT)		+= sys32.o kuser32.o signal32.o 	\

					   sys_compat.o entry32.o		\

arch/arm64/kernel/cpu_errata.c

+4 −32
Original line number Diff line number Diff line
@@ -16,8 +16,6 @@ 
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#define pr_fmt(fmt) "alternatives: " fmt



#include <linux/types.h>

#include <asm/cpu.h>

#include <asm/cputype.h>
@@ -26,27 +24,11 @@ 
#define MIDR_CORTEX_A53 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)

#define MIDR_CORTEX_A57 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57)



/*

 * Add a struct or another datatype to the union below if you need

 * different means to detect an affected CPU.

 */

struct arm64_cpu_capabilities {

	const char *desc;

	u16 capability;

	bool (*is_affected)(struct arm64_cpu_capabilities *);

	union {

		struct {

			u32 midr_model;

			u32 midr_range_min, midr_range_max;

		};

	};

};



#define CPU_MODEL_MASK (MIDR_IMPLEMENTOR_MASK | MIDR_PARTNUM_MASK | \

			MIDR_ARCHITECTURE_MASK)



static bool __maybe_unused

is_affected_midr_range(struct arm64_cpu_capabilities *entry)

is_affected_midr_range(const struct arm64_cpu_capabilities *entry)

{

	u32 midr = read_cpuid_id();
@@ -59,12 +41,12 @@ is_affected_midr_range(struct arm64_cpu_capabilities *entry) 
}



#define MIDR_RANGE(model, min, max) \

	.is_affected = is_affected_midr_range, \

	.matches = is_affected_midr_range, \

	.midr_model = model, \

	.midr_range_min = min, \

	.midr_range_max = max



struct arm64_cpu_capabilities arm64_errata[] = {

const struct arm64_cpu_capabilities arm64_errata[] = {

#if	defined(CONFIG_ARM64_ERRATUM_826319) || \

	defined(CONFIG_ARM64_ERRATUM_827319) || \

	defined(CONFIG_ARM64_ERRATUM_824069)
@@ -97,15 +79,5 @@ struct arm64_cpu_capabilities arm64_errata[] = { 


void check_local_cpu_errata(void)

{

	struct arm64_cpu_capabilities *cpus = arm64_errata;

	int i;



	for (i = 0; cpus[i].desc; i++) {

		if (!cpus[i].is_affected(&cpus[i]))

			continue;



		if (!cpus_have_cap(cpus[i].capability))

			pr_info("enabling workaround for %s\n", cpus[i].desc);

		cpus_set_cap(cpus[i].capability);

	}

	check_cpu_capabilities(arm64_errata, "enabling workaround for");

}

arch/arm64/kernel/cpufeature.c

0 → 100644
+47 −0
Original line number Diff line number Diff line 
/*

 * Contains CPU feature definitions

 *

 * Copyright (C) 2015 ARM Ltd.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */



#define pr_fmt(fmt) "alternatives: " fmt



#include <linux/types.h>

#include <asm/cpu.h>

#include <asm/cpufeature.h>



static const struct arm64_cpu_capabilities arm64_features[] = {

	{},

};



void check_cpu_capabilities(const struct arm64_cpu_capabilities *caps,

			    const char *info)

{

	int i;



	for (i = 0; caps[i].desc; i++) {

		if (!caps[i].matches(&caps[i]))

			continue;



		if (!cpus_have_cap(caps[i].capability))

			pr_info("%s %s\n", info, caps[i].desc);

		cpus_set_cap(caps[i].capability);

	}

}



void check_local_cpu_features(void)

{

	check_cpu_capabilities(arm64_features, "detected feature");

}

arch/arm64/kernel/cpuinfo.c

+1 −0
Original line number Diff line number Diff line
@@ -236,6 +236,7 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info) 
	cpuinfo_detect_icache_policy(info);



	check_local_cpu_errata();

	check_local_cpu_features();

	update_cpu_features(info);

}