Commit f9209e26 authored by Mark Rutland's avatar Mark Rutland Committed by Will Deacon
Browse files

arm64: move sve_user_{enable,disable} to <asm/fpsimd.h> 



In subsequent patches, we'll want to make use of sve_user_enable() and
sve_user_disable() outside of kernel/fpsimd.c. Let's move these to
<asm/fpsimd.h> where we can make use of them.

To avoid ifdeffery in sequences like:

if (system_supports_sve() && some_condition)
	sve_user_disable();

... empty stubs are provided when support for SVE is not enabled. Note
that system_supports_sve() contains as IS_ENABLED(CONFIG_ARM64_SVE), so
the sve_user_disable() call should be optimized away entirely when
CONFIG_ARM64_SVE is not selected.

To ensure that this is the case, the stub definitions contain a
BUILD_BUG(), as we do for other stubs for which calls should always be
optimized away when the relevant config option is not selected.

At the same time, the include list of <asm/fpsimd.h> is sorted while
adding <asm/sysreg.h>.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarDave Martin <dave.martin@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 8d370933

arch/arm64/include/asm/fpsimd.h

+16 −1
Original line number Diff line number Diff line
@@ -16,13 +16,15 @@ 
#ifndef __ASM_FP_H

#define __ASM_FP_H



#include <asm/ptrace.h>

#include <asm/errno.h>

#include <asm/ptrace.h>

#include <asm/processor.h>

#include <asm/sigcontext.h>

#include <asm/sysreg.h>



#ifndef __ASSEMBLY__



#include <linux/build_bug.h>

#include <linux/cache.h>

#include <linux/init.h>

#include <linux/stddef.h>
@@ -102,6 +104,16 @@ extern int sve_set_vector_length(struct task_struct *task, 
extern int sve_set_current_vl(unsigned long arg);

extern int sve_get_current_vl(void);



static inline void sve_user_disable(void)

{

	sysreg_clear_set(cpacr_el1, CPACR_EL1_ZEN_EL0EN, 0);

}



static inline void sve_user_enable(void)

{

	sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_ZEN_EL0EN);

}



/*

 * Probing and setup functions.

 * Calls to these functions must be serialised with one another.
@@ -128,6 +140,9 @@ static inline int sve_get_current_vl(void) 
	return -EINVAL;

}



static inline void sve_user_disable(void) { BUILD_BUG(); }

static inline void sve_user_enable(void) { BUILD_BUG(); }



static inline void sve_init_vq_map(void) { }

static inline void sve_update_vq_map(void) { }

static inline int sve_verify_vq_map(void) { return 0; }

arch/arm64/kernel/fpsimd.c

+0 −10
Original line number Diff line number Diff line
@@ -159,16 +159,6 @@ static void sve_free(struct task_struct *task) 
	__sve_free(task);

}



static void sve_user_disable(void)

{

	sysreg_clear_set(cpacr_el1, CPACR_EL1_ZEN_EL0EN, 0);

}



static void sve_user_enable(void)

{

	sysreg_clear_set(cpacr_el1, 0, CPACR_EL1_ZEN_EL0EN);

}



/*

 * TIF_SVE controls whether a task can use SVE without trapping while

 * in userspace, and also the way a task's FPSIMD/SVE state is stored

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