From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave.Martin@arm.com (Dave Martin) Date: Thu, 12 Jan 2017 11:26:03 +0000 Subject: [RFC PATCH 04/10] arm64/sve: Factor out clearing of tasks' SVE regs In-Reply-To: <1484220369-23970-1-git-send-email-Dave.Martin@arm.com> References: <1484220369-23970-1-git-send-email-Dave.Martin@arm.com> Message-ID: <1484220369-23970-5-git-send-email-Dave.Martin@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The patch factors out the code that clears a task's SVE regs on exec(), so that we can reuse it in subsequent patches. Signed-off-by: Dave Martin --- arch/arm64/kernel/fpsimd.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index ab2bb62..54d7ed0 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -260,6 +260,19 @@ void fpsimd_thread_switch(struct task_struct *next) } } +static void clear_sve_regs(struct task_struct *task) +{ + BUG_ON(task == current && preemptible()); + + BUG_ON((char *)__task_sve_state(task) < (char *)task); + BUG_ON(arch_task_struct_size < + ((char *)__task_sve_state(task) - (char *)task)); + + memset(__task_sve_state(task), 0, + arch_task_struct_size - + ((char *)__task_sve_state(task) - (char *)task)); +} + void fpsimd_flush_thread(void) { if (!system_supports_fpsimd()) @@ -272,13 +285,7 @@ void fpsimd_flush_thread(void) memset(¤t->thread.fpsimd_state, 0, sizeof(struct fpsimd_state)); if (IS_ENABLED(CONFIG_ARM64_SVE) && (elf_hwcap & HWCAP_SVE)) { - BUG_ON((char *)__task_sve_state(current) < (char *)current); - BUG_ON(arch_task_struct_size < - ((char *)__task_sve_state(current) - (char *)current)); - - memset(__task_sve_state(current), 0, - arch_task_struct_size - - ((char *)__task_sve_state(current) - (char *)current)); + clear_sve_regs(current); /* * User tasks must have a valid vector length set, but tasks -- 2.1.4