From patchwork Thu Jan 12 11:26:00 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Martin X-Patchwork-Id: 18864 Received: (qmail 71334 invoked by alias); 12 Jan 2017 11:26:29 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 71265 invoked by uid 89); 12 Jan 2017 11:26:28 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-5.1 required=5.0 tests=BAYES_00, RP_MATCHES_RCVD, SPF_PASS autolearn=ham version=3.3.2 spammy=GID, 1978, 1974, sk:config_ X-Spam-User: qpsmtpd, 2 recipients X-HELO: foss.arm.com From: Dave Martin To: linux-arm-kernel@lists.infradead.org Cc: Ard Biesheuvel , Marc Zyngier , Alan Hayward , Christoffer Dall , linux-arch@vger.kernel.org, libc-alpha@sourceware.org, Florian Weimer , Joseph Myers , Szabolcs Nagy , Torvald Riegel , gdb@sourceware.org, Yao Qi Subject: [RFC PATCH 01/10] prctl: Add skeleton for PR_SVE_{SET, GET}_VL controls Date: Thu, 12 Jan 2017 11:26:00 +0000 Message-Id: <1484220369-23970-2-git-send-email-Dave.Martin@arm.com> In-Reply-To: <1484220369-23970-1-git-send-email-Dave.Martin@arm.com> References: <1484220369-23970-1-git-send-email-Dave.Martin@arm.com> This patch adds a do-nothing skeleton for the arm64 Scalable Vector Extension control prctls. These prctls are only avilable with CONFIG_ARM64=y CONFIG_ARM64_SVE=y Otherwise they will compile out and return -EINVAL if attempted from userspace. The backend functions sve_{set,get}_task_vl() will be fleshed out with actual functionality in subsequent patches. Signed-off-by: Dave Martin --- There will probably also be a call to discover the signal frame size (MINSIGSTKSZ equivalent) for the current configuration, something like * PR_GET_MINSIGSTKSZ This series doesn't add this yet: only the PR_SVE_{SET,GET}_VL prctls are provided. arch/arm64/include/asm/fpsimd.h | 19 +++++++++++++++++++ arch/arm64/include/asm/processor.h | 4 ++++ arch/arm64/kernel/fpsimd.c | 13 +++++++++++++ include/uapi/linux/prctl.h | 4 ++++ kernel/sys.c | 12 ++++++++++++ 5 files changed, 52 insertions(+) diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index 88bcf69..e13259e 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -17,6 +17,7 @@ #define __ASM_FP_H #include +#include #ifndef __ASSEMBLY__ @@ -110,12 +111,30 @@ extern unsigned int sve_get_vl(void); extern void fpsimd_sync_to_sve(struct task_struct *task); #ifdef CONFIG_ARM64_SVE + extern void fpsimd_sync_to_fpsimd(struct task_struct *task); extern void fpsimd_sync_from_fpsimd_zeropad(struct task_struct *task); +extern int sve_set_task_vl(struct task_struct *task, + unsigned long vector_length, unsigned long flags); +extern int sve_get_task_vl(struct task_struct *task); + #else /* !CONFIG_ARM64_SVE */ + static void __maybe_unused fpsimd_sync_to_fpsimd(struct task_struct *task) { } static void __maybe_unused fpsimd_sync_from_fpsimd_zeropad( struct task_struct *task) { } + +static int __maybe_unused sve_set_task_vl(struct task_struct *task, + unsigned long vector_length, unsigned long flags) +{ + return -EINVAL; +} + +static int __maybe_unused sve_get_task_vl(struct task_struct *task) +{ + return -EINVAL; +} + #endif /* !CONFIG_ARM64_SVE */ #endif diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 747c65a..6f0f300 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -190,4 +190,8 @@ int cpu_enable_pan(void *__unused); int cpu_enable_uao(void *__unused); int cpu_enable_cache_maint_trap(void *__unused); +#define SVE_SET_VL(task, vector_length, flags) \ + sve_set_task_vl(task, vector_length, flags) +#define SVE_GET_VL(task) sve_get_task_vl(task) + #endif /* __ASM_PROCESSOR_H */ diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 2c113e4..bdacfcd 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -468,6 +468,19 @@ void fpsimd_sync_from_fpsimd_zeropad(struct task_struct *task) __fpsimd_sync_from_fpsimd_zeropad(task, sve_vq_from_vl(vl)); } +/* PR_SVE_SET_VL */ +int sve_set_task_vl(struct task_struct *task, + unsigned long vector_length, unsigned long flags) +{ + return -EINVAL; +} + +/* PR_SVE_GET_VL */ +int sve_get_task_vl(struct task_struct *task) +{ + return -EINVAL; +} + #endif /* CONFIG_ARM64_SVE */ #ifdef CONFIG_KERNEL_MODE_NEON diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index a8d0759..e32e2da 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -197,4 +197,8 @@ struct prctl_mm_map { # define PR_CAP_AMBIENT_LOWER 3 # define PR_CAP_AMBIENT_CLEAR_ALL 4 +/* arm64 Scalable Vector Extension controls */ +#define PR_SVE_SET_VL 48 /* set task vector length */ +#define PR_SVE_GET_VL 49 /* get task vector length */ + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/sys.c b/kernel/sys.c index 842914e..5f50385 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -103,6 +103,12 @@ #ifndef SET_FP_MODE # define SET_FP_MODE(a,b) (-EINVAL) #endif +#ifndef SVE_SET_VL +# define SVE_SET_VL(a,b,c) (-EINVAL) +#endif +#ifndef SVE_GET_VL +# define SVE_GET_VL(a) (-EINVAL) +#endif /* * this is where the system-wide overflow UID and GID are defined, for @@ -2261,6 +2267,12 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, case PR_GET_FP_MODE: error = GET_FP_MODE(me); break; + case PR_SVE_SET_VL: + error = SVE_SET_VL(me, arg2, arg3); + break; + case PR_SVE_GET_VL: + error = SVE_GET_VL(me); + break; default: error = -EINVAL; break;