From 79ab047c75d6a9f95d8840d94f405e20cbacac4b Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Tue, 31 Oct 2017 15:51:06 +0000 Subject: arm64/sve: Support vector length resetting for new processes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It's desirable to be able to reset the vector length to some sane default for new processes, since the new binary and its libraries may or may not be SVE-aware. This patch tracks the desired post-exec vector length (if any) in a new thread member sve_vl_onexec, and adds a new thread flag TIF_SVE_VL_INHERIT to control whether to inherit or reset the vector length. Currently these are inactive. Subsequent patches will provide the capability to configure them. Signed-off-by: Dave Martin Reviewed-by: Alex Bennée Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/thread_info.h | 1 + 2 files changed, 2 insertions(+) (limited to 'arch/arm64/include/asm') diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index e2f575dbdddd..c6fddb005dc2 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -107,6 +107,7 @@ struct thread_struct { struct fpsimd_state fpsimd_state; void *sve_state; /* SVE registers, if any */ unsigned int sve_vl; /* SVE vector length */ + unsigned int sve_vl_onexec; /* SVE vl after next exec */ unsigned long fault_address; /* fault info */ unsigned long fault_code; /* ESR_EL1 value */ struct debug_info debug; /* debugging */ diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 92b7b48576c8..eb431286bacd 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -95,6 +95,7 @@ void arch_release_task_struct(struct task_struct *tsk); #define TIF_SINGLESTEP 21 #define TIF_32BIT 22 /* 32bit process */ #define TIF_SVE 23 /* Scalable Vector Extension in use */ +#define TIF_SVE_VL_INHERIT 24 /* Inherit sve_vl_onexec across exec */ #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) -- cgit v1.2.1