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Commit 31dc52b3 authored by Dave Martin's avatar Dave Martin Committed by Marc Zyngier
Browse files

arm64/sve: Move read_zcr_features() out of cpufeature.h 



Having read_zcr_features() inline in cpufeature.h results in that
header requiring #includes which make it hard to include
<asm/fpsimd.h> elsewhere without triggering header inclusion
cycles.

This is not a hot-path function and arguably should not be in
cpufeature.h in the first place, so this patch moves it to
fpsimd.c, compiled conditionally if CONFIG_ARM64_SVE=y.

This allows some SVE-related #includes to be dropped from
cpufeature.h, which will ease future maintenance.

A couple of missing #includes of <asm/fpsimd.h> are exposed by this
change under arch/arm64/.  This patch adds the missing #includes as
necessary.

No functional change.

Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
Reviewed-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent e6b673b7

arch/arm64/include/asm/cpufeature.h

+0 −29
Original line number Diff line number Diff line
@@ -11,9 +11,7 @@ 


#include <asm/cpucaps.h>

#include <asm/cputype.h>

#include <asm/fpsimd.h>

#include <asm/hwcap.h>

#include <asm/sigcontext.h>

#include <asm/sysreg.h>



/*
@@ -510,33 +508,6 @@ static inline bool system_supports_sve(void) 
		cpus_have_const_cap(ARM64_SVE);

}



/*

 * Read the pseudo-ZCR used by cpufeatures to identify the supported SVE

 * vector length.

 *

 * Use only if SVE is present.

 * This function clobbers the SVE vector length.

 */

static inline u64 read_zcr_features(void)

{

	u64 zcr;

	unsigned int vq_max;



	/*

	 * Set the maximum possible VL, and write zeroes to all other

	 * bits to see if they stick.

	 */

	sve_kernel_enable(NULL);

	write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL1);



	zcr = read_sysreg_s(SYS_ZCR_EL1);

	zcr &= ~(u64)ZCR_ELx_LEN_MASK; /* find sticky 1s outside LEN field */

	vq_max = sve_vq_from_vl(sve_get_vl());

	zcr |= vq_max - 1; /* set LEN field to maximum effective value */



	return zcr;

}



#endif /* __ASSEMBLY__ */



#endif

arch/arm64/include/asm/fpsimd.h

+2 −0
Original line number Diff line number Diff line
@@ -69,6 +69,8 @@ extern unsigned int sve_get_vl(void); 
struct arm64_cpu_capabilities;

extern void sve_kernel_enable(const struct arm64_cpu_capabilities *__unused);



extern u64 read_zcr_features(void);



extern int __ro_after_init sve_max_vl;



#ifdef CONFIG_ARM64_SVE

arch/arm64/include/asm/processor.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 


#include <asm/alternative.h>

#include <asm/cpufeature.h>

#include <asm/fpsimd.h>

#include <asm/hw_breakpoint.h>

#include <asm/lse.h>

#include <asm/pgtable-hwdef.h>

arch/arm64/kernel/fpsimd.c

+28 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#include <linux/sched/task_stack.h>

#include <linux/signal.h>

#include <linux/slab.h>

#include <linux/stddef.h>

#include <linux/sysctl.h>



#include <asm/esr.h>
@@ -755,6 +756,33 @@ void sve_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p) 
	isb();

}



/*

 * Read the pseudo-ZCR used by cpufeatures to identify the supported SVE

 * vector length.

 *

 * Use only if SVE is present.

 * This function clobbers the SVE vector length.

 */

u64 read_zcr_features(void)

{

	u64 zcr;

	unsigned int vq_max;



	/*

	 * Set the maximum possible VL, and write zeroes to all other

	 * bits to see if they stick.

	 */

	sve_kernel_enable(NULL);

	write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL1);



	zcr = read_sysreg_s(SYS_ZCR_EL1);

	zcr &= ~(u64)ZCR_ELx_LEN_MASK; /* find sticky 1s outside LEN field */

	vq_max = sve_vq_from_vl(sve_get_vl());

	zcr |= vq_max - 1; /* set LEN field to maximum effective value */



	return zcr;

}



void __init sve_setup(void)

{

	u64 zcr;

arch/arm64/kernel/ptrace.c

+1 −0
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 
#include <asm/compat.h>

#include <asm/cpufeature.h>

#include <asm/debug-monitors.h>

#include <asm/fpsimd.h>

#include <asm/pgtable.h>

#include <asm/stacktrace.h>

#include <asm/syscall.h>