From: Dave Martin <Dave.Martin@arm.com> To: linux-arm-kernel@lists.infradead.org Cc: "Catalin Marinas" <catalin.marinas@arm.com>, "Will Deacon" <will.deacon@arm.com>, "Ard Biesheuvel" <ard.biesheuvel@linaro.org>, "Alex Bennée" <alex.bennee@linaro.org>, "Szabolcs Nagy" <szabolcs.nagy@arm.com>, "Richard Sandiford" <richard.sandiford@arm.com>, kvmarm@lists.cs.columbia.edu, libc-alpha@sourceware.org, linux-arch@vger.kernel.org Subject: [PATCH v2 12/28] arm64/sve: Support vector length resetting for new processes Date: Thu, 31 Aug 2017 18:00:44 +0100 [thread overview] Message-ID: <1504198860-12951-13-git-send-email-Dave.Martin@arm.com> (raw) In-Reply-To: <1504198860-12951-1-git-send-email-Dave.Martin@arm.com> 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 processes 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 <Dave.Martin@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> --- Changes since v1 ---------------- Requested by Alex Bennée: * Make sve_vl_onexec an unsigned int: that's the type used virtually everywhere else, and the memory saving is too minor to be interesting. --- arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/thread_info.h | 1 + arch/arm64/kernel/fpsimd.c | 16 ++++++++++++---- 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 4831d28..3faceac 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -87,6 +87,7 @@ 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 f0880fc..d3568ab 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -92,6 +92,7 @@ void arch_setup_new_exec(void); #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) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 9b1ebd7..e20b44d 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -106,6 +106,9 @@ */ static DEFINE_PER_CPU(struct fpsimd_state *, fpsimd_last_state); +/* Default VL for tasks that don't set it explicitly: */ +static int sve_default_vl = SVE_VL_MIN; + static void sve_free(struct task_struct *task) { kfree(task->thread.sve_state); @@ -380,15 +383,20 @@ void fpsimd_flush_thread(void) * If a bug causes this to go wrong, we make some noise and * try to fudge thread.sve_vl to a safe value here. */ - vl = current->thread.sve_vl; - - if (vl == 0) - vl = SVE_VL_MIN; + vl = current->thread.sve_vl_onexec ? + current->thread.sve_vl_onexec : sve_default_vl; if (WARN_ON(!sve_vl_valid(vl))) vl = SVE_VL_MIN; current->thread.sve_vl = vl; + + /* + * If the task is not set to inherit, ensure that the vector + * length will be reset by a subsequent exec: + */ + if (!test_thread_flag(TIF_SVE_VL_INHERIT)) + current->thread.sve_vl_onexec = 0; } set_thread_flag(TIF_FOREIGN_FPSTATE); -- 2.1.4
WARNING: multiple messages have this Message-ID (diff)
From: Dave.Martin@arm.com (Dave Martin) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 12/28] arm64/sve: Support vector length resetting for new processes Date: Thu, 31 Aug 2017 18:00:44 +0100 [thread overview] Message-ID: <1504198860-12951-13-git-send-email-Dave.Martin@arm.com> (raw) In-Reply-To: <1504198860-12951-1-git-send-email-Dave.Martin@arm.com> 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 processes 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 <Dave.Martin@arm.com> Cc: Alex Benn?e <alex.bennee@linaro.org> --- Changes since v1 ---------------- Requested by Alex Benn?e: * Make sve_vl_onexec an unsigned int: that's the type used virtually everywhere else, and the memory saving is too minor to be interesting. --- arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/thread_info.h | 1 + arch/arm64/kernel/fpsimd.c | 16 ++++++++++++---- 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 4831d28..3faceac 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -87,6 +87,7 @@ 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 f0880fc..d3568ab 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -92,6 +92,7 @@ void arch_setup_new_exec(void); #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) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 9b1ebd7..e20b44d 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -106,6 +106,9 @@ */ static DEFINE_PER_CPU(struct fpsimd_state *, fpsimd_last_state); +/* Default VL for tasks that don't set it explicitly: */ +static int sve_default_vl = SVE_VL_MIN; + static void sve_free(struct task_struct *task) { kfree(task->thread.sve_state); @@ -380,15 +383,20 @@ void fpsimd_flush_thread(void) * If a bug causes this to go wrong, we make some noise and * try to fudge thread.sve_vl to a safe value here. */ - vl = current->thread.sve_vl; - - if (vl == 0) - vl = SVE_VL_MIN; + vl = current->thread.sve_vl_onexec ? + current->thread.sve_vl_onexec : sve_default_vl; if (WARN_ON(!sve_vl_valid(vl))) vl = SVE_VL_MIN; current->thread.sve_vl = vl; + + /* + * If the task is not set to inherit, ensure that the vector + * length will be reset by a subsequent exec: + */ + if (!test_thread_flag(TIF_SVE_VL_INHERIT)) + current->thread.sve_vl_onexec = 0; } set_thread_flag(TIF_FOREIGN_FPSTATE); -- 2.1.4
next prev parent reply other threads:[~2017-08-31 17:01 UTC|newest] Thread overview: 224+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-08-31 17:00 [PATCH v2 00/28] ARM Scalable Vector Extension (SVE) Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 01/28] regset: Add support for dynamically sized regsets Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 02/28] arm64: KVM: Hide unsupported AArch64 CPU features from guests Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-13 14:37 ` Alex Bennée 2017-09-13 14:37 ` Alex Bennée 2017-09-13 14:37 ` Alex Bennée 2017-09-15 0:04 ` Dave Martin 2017-09-15 0:04 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 03/28] arm64: efi: Add missing Kconfig dependency on KERNEL_MODE_NEON Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 04/28] arm64: Port deprecated instruction emulation to new sysctl interface Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 05/28] arm64: fpsimd: Simplify uses of {set,clear}_ti_thread_flag() Dave Martin 2017-08-31 17:00 ` [PATCH v2 05/28] arm64: fpsimd: Simplify uses of {set, clear}_ti_thread_flag() Dave Martin 2017-08-31 17:00 ` [PATCH v2 06/28] arm64/sve: System register and exception syndrome definitions Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-13 14:48 ` Alex Bennée 2017-09-13 14:48 ` Alex Bennée 2017-09-13 14:48 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 07/28] arm64/sve: Low-level SVE architectural state manipulation functions Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-13 15:39 ` Alex Bennée 2017-09-13 15:39 ` Alex Bennée 2017-09-13 15:39 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 08/28] arm64/sve: Kconfig update and conditional compilation support Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 09/28] arm64/sve: Signal frame and context structure definition Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-13 13:36 ` Catalin Marinas 2017-09-13 13:36 ` Catalin Marinas 2017-09-13 21:33 ` Dave Martin 2017-09-13 21:33 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 10/28] arm64/sve: Low-level CPU setup Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-13 13:32 ` Catalin Marinas 2017-09-13 13:32 ` Catalin Marinas 2017-09-13 19:21 ` Dave Martin 2017-09-13 19:21 ` Dave Martin 2017-09-13 19:21 ` Dave Martin 2017-10-05 10:47 ` Dave Martin 2017-10-05 10:47 ` Dave Martin 2017-10-05 11:04 ` Suzuki K Poulose 2017-10-05 11:04 ` Suzuki K Poulose 2017-10-05 11:22 ` Dave Martin 2017-10-05 11:22 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 11/28] arm64/sve: Core task context handling Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-13 14:33 ` Catalin Marinas 2017-09-13 14:33 ` Catalin Marinas 2017-09-14 19:55 ` Dave Martin 2017-09-14 19:55 ` Dave Martin 2017-09-20 13:58 ` Catalin Marinas 2017-09-20 13:58 ` Catalin Marinas 2017-10-03 11:11 ` Dave Martin 2017-10-03 11:11 ` Dave Martin 2017-10-04 17:29 ` Catalin Marinas 2017-10-04 17:29 ` Catalin Marinas 2017-10-03 11:33 ` Dave Martin 2017-10-03 11:33 ` Dave Martin 2017-10-05 11:28 ` Catalin Marinas 2017-10-05 11:28 ` Catalin Marinas 2017-10-06 13:10 ` Dave Martin 2017-10-06 13:10 ` Dave Martin 2017-10-06 13:36 ` Catalin Marinas 2017-10-06 13:36 ` Catalin Marinas 2017-10-06 15:15 ` Dave Martin 2017-10-06 15:15 ` Dave Martin 2017-10-06 15:33 ` Catalin Marinas 2017-10-06 15:33 ` Catalin Marinas 2017-09-13 17:26 ` Catalin Marinas 2017-09-13 17:26 ` Catalin Marinas 2017-09-13 19:17 ` Dave Martin 2017-09-13 19:17 ` Dave Martin 2017-09-13 22:21 ` Catalin Marinas 2017-09-13 22:21 ` Catalin Marinas 2017-09-14 19:40 ` Dave Martin 2017-09-14 19:40 ` Dave Martin 2017-09-19 17:13 ` Catalin Marinas 2017-09-19 17:13 ` Catalin Marinas 2017-08-31 17:00 ` Dave Martin [this message] 2017-08-31 17:00 ` [PATCH v2 12/28] arm64/sve: Support vector length resetting for new processes Dave Martin 2017-09-14 8:47 ` Alex Bennée 2017-09-14 8:47 ` Alex Bennée 2017-09-14 8:47 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 13/28] arm64/sve: Signal handling support Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 9:30 ` Alex Bennée 2017-09-14 9:30 ` Alex Bennée 2017-09-14 9:30 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 14/28] arm64/sve: Backend logic for setting the vector length Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-13 17:29 ` Catalin Marinas 2017-09-13 17:29 ` Catalin Marinas 2017-09-13 19:06 ` Dave Martin 2017-09-13 19:06 ` Dave Martin 2017-09-13 22:11 ` Catalin Marinas 2017-09-13 22:11 ` Catalin Marinas 2017-10-05 16:42 ` Dave Martin 2017-10-05 16:42 ` Dave Martin 2017-10-05 16:53 ` Catalin Marinas 2017-10-05 16:53 ` Catalin Marinas 2017-10-05 17:04 ` Dave Martin 2017-10-05 17:04 ` Dave Martin 2017-09-20 10:57 ` Alan Hayward 2017-09-20 10:57 ` Alan Hayward 2017-09-20 10:59 ` Alan Hayward 2017-09-20 10:59 ` Alan Hayward 2017-09-20 11:09 ` Dave Martin 2017-09-20 11:09 ` Dave Martin 2017-09-20 18:08 ` Alan Hayward 2017-09-20 18:08 ` Alan Hayward 2017-09-21 11:19 ` Dave Martin 2017-09-21 11:19 ` Dave Martin 2017-09-21 11:57 ` Alan Hayward 2017-09-21 11:57 ` Alan Hayward 2017-08-31 17:00 ` [PATCH v2 15/28] arm64: cpufeature: Move sys_caps_initialised declarations Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 9:33 ` Alex Bennée 2017-09-14 9:33 ` Alex Bennée 2017-09-14 9:33 ` Alex Bennée 2017-09-14 9:35 ` Suzuki K Poulose 2017-09-14 9:35 ` Suzuki K Poulose 2017-08-31 17:00 ` [PATCH v2 16/28] arm64/sve: Probe SVE capabilities and usable vector lengths Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 9:45 ` Alex Bennée 2017-09-14 9:45 ` Alex Bennée 2017-09-14 9:45 ` Alex Bennée 2017-09-28 14:22 ` Dave Martin 2017-09-28 14:22 ` Dave Martin 2017-09-28 17:32 ` Alex Bennée 2017-09-28 17:32 ` Alex Bennée 2017-09-28 17:32 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 17/28] arm64/sve: Preserve SVE registers around kernel-mode NEON use Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 10:52 ` Alex Bennée 2017-09-14 10:52 ` Alex Bennée 2017-09-14 10:52 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 18/28] arm64/sve: Preserve SVE registers around EFI runtime service calls Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 11:01 ` Alex Bennée 2017-09-14 11:01 ` Alex Bennée 2017-09-14 11:01 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 19/28] arm64/sve: ptrace and ELF coredump support Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-06 16:21 ` Okamoto, Takayuki 2017-09-06 16:21 ` Okamoto, Takayuki 2017-09-06 18:16 ` Dave Martin 2017-09-06 18:16 ` Dave Martin 2017-09-07 5:11 ` Okamoto, Takayuki 2017-09-07 5:11 ` Okamoto, Takayuki 2017-09-07 5:11 ` Okamoto, Takayuki 2017-09-08 13:11 ` Dave Martin 2017-09-08 13:11 ` Dave Martin 2017-09-14 12:57 ` Alex Bennée 2017-09-14 12:57 ` Alex Bennée 2017-09-14 12:57 ` Alex Bennée 2017-09-28 14:57 ` Dave Martin 2017-09-28 14:57 ` Dave Martin 2017-09-29 12:46 ` Dave Martin 2017-09-29 12:46 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 20/28] arm64/sve: Add prctl controls for userspace vector length management Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 13:02 ` Alex Bennée 2017-09-14 13:02 ` Alex Bennée 2017-09-14 13:02 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 21/28] arm64/sve: Add sysctl to set the default vector length for new processes Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 13:05 ` Alex Bennée 2017-09-14 13:05 ` Alex Bennée 2017-09-14 13:05 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 22/28] arm64/sve: KVM: Prevent guests from using SVE Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 13:28 ` Alex Bennée 2017-09-14 13:28 ` Alex Bennée 2017-09-14 13:28 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 23/28] arm64/sve: KVM: Treat guest SVE use as undefined instruction execution Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 13:30 ` Alex Bennée 2017-09-14 13:30 ` Alex Bennée 2017-09-14 13:30 ` Alex Bennée 2017-09-14 13:31 ` Alex Bennée 2017-09-14 13:31 ` Alex Bennée 2017-09-14 13:31 ` Alex Bennée 2017-09-29 13:00 ` Dave Martin 2017-09-29 13:00 ` Dave Martin 2017-09-29 14:43 ` Alex Bennée 2017-09-29 14:43 ` Alex Bennée 2017-09-29 14:43 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 24/28] arm64/sve: KVM: Hide SVE from CPU features exposed to guests Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-09-14 13:32 ` Alex Bennée 2017-09-14 13:32 ` Alex Bennée 2017-09-14 13:32 ` Alex Bennée 2017-08-31 17:00 ` [PATCH v2 25/28] arm64/sve: Detect SVE and activate runtime support Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:00 ` [PATCH v2 26/28] arm64/sve: Add documentation Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-10-05 16:39 ` Szabolcs Nagy 2017-10-05 16:39 ` Szabolcs Nagy 2017-10-05 17:02 ` Dave Martin 2017-10-05 17:02 ` Dave Martin 2017-10-06 15:43 ` Szabolcs Nagy 2017-10-06 15:43 ` Szabolcs Nagy 2017-10-06 17:37 ` Dave Martin 2017-10-06 17:37 ` Dave Martin 2017-10-09 9:34 ` Alex Bennée 2017-10-09 9:34 ` Alex Bennée 2017-10-09 9:34 ` Alex Bennée 2017-10-09 9:49 ` Dave Martin 2017-10-09 9:49 ` Dave Martin 2017-10-09 14:07 ` Alex Bennée 2017-10-09 14:07 ` Alex Bennée 2017-10-09 14:07 ` Alex Bennée 2017-10-09 16:20 ` Dave Martin 2017-10-09 16:20 ` Dave Martin 2017-08-31 17:00 ` [RFC PATCH v2 27/28] arm64: signal: Report signal frame size to userspace via auxv Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:00 ` Dave Martin 2017-08-31 17:01 ` [RFC PATCH v2 28/28] arm64/sve: signal: Include SVE when computing AT_MINSIGSTKSZ Dave Martin 2017-08-31 17:01 ` Dave Martin
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