| Message ID | 20190521172139.21277-3-julien.grall@arm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 54b8c7cbc57c1ce21f4e35101f2609092c4af49a |
| Headers | show |
| Series | arm64/fpsimd: Don't disable softirq when touching FPSIMD/SVE state | expand |
On Tue, May 21, 2019 at 06:21:38PM +0100, Julien Grall wrote: > The only external user of fpsimd_save() and fpsimd_flush_cpu_state() is > the KVM FPSIMD code. > > A following patch will introduce a mechanism to acquire owernship of the > FPSIMD/SVE context for performing context management operations. Rather > than having to export the new helpers to get/put the context, we can just > introduce a new function to combine fpsimd_save() and > fpsimd_flush_cpu_state(). > > This has also the advantage to remove any external call of fpsimd_save() > and fpsimd_flush_cpu_state(), so they can be turned static. > > Lastly, the new function can also be used in the PM notifier. > > Signed-off-by: Julien Grall <julien.grall@arm.com> > Reviewed-by: Dave Martin <Dave.Martin@arm.com> [...] > --- > arch/arm64/include/asm/fpsimd.h | 4 +--- > arch/arm64/kernel/fpsimd.c | 17 +++++++++++++---- > arch/arm64/kvm/fpsimd.c | 4 +--- > 3 files changed, 15 insertions(+), 10 deletions(-) Marc, since this touches KVM, can I get an ack on this patch? I plan to queue the series. Thanks.
On 04/06/2019 12:12, Catalin Marinas wrote: > On Tue, May 21, 2019 at 06:21:38PM +0100, Julien Grall wrote: >> The only external user of fpsimd_save() and fpsimd_flush_cpu_state() is >> the KVM FPSIMD code. >> >> A following patch will introduce a mechanism to acquire owernship of the >> FPSIMD/SVE context for performing context management operations. Rather >> than having to export the new helpers to get/put the context, we can just >> introduce a new function to combine fpsimd_save() and >> fpsimd_flush_cpu_state(). >> >> This has also the advantage to remove any external call of fpsimd_save() >> and fpsimd_flush_cpu_state(), so they can be turned static. >> >> Lastly, the new function can also be used in the PM notifier. >> >> Signed-off-by: Julien Grall <julien.grall@arm.com> >> Reviewed-by: Dave Martin <Dave.Martin@arm.com> > [...] >> --- >> arch/arm64/include/asm/fpsimd.h | 4 +--- >> arch/arm64/kernel/fpsimd.c | 17 +++++++++++++---- >> arch/arm64/kvm/fpsimd.c | 4 +--- >> 3 files changed, 15 insertions(+), 10 deletions(-) > > Marc, since this touches KVM, can I get an ack on this patch? I plan to > queue the series. Sure. Please add my Acked-by: Marc Zyngier <marc.zyngier@arm.com> to the whole series. Thanks, M.
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h index b73d12fcc7f9..4154851c21ab 100644 --- a/arch/arm64/include/asm/fpsimd.h +++ b/arch/arm64/include/asm/fpsimd.h @@ -48,8 +48,6 @@ struct task_struct; extern void fpsimd_save_state(struct user_fpsimd_state *state); extern void fpsimd_load_state(struct user_fpsimd_state *state); -extern void fpsimd_save(void); - extern void fpsimd_thread_switch(struct task_struct *next); extern void fpsimd_flush_thread(void); @@ -63,7 +61,7 @@ extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state, void *sve_state, unsigned int sve_vl); extern void fpsimd_flush_task_state(struct task_struct *target); -extern void fpsimd_flush_cpu_state(void); +extern void fpsimd_save_and_flush_cpu_state(void); /* Maximum VL that SVE VL-agnostic software can transparently support */ #define SVE_VL_ARCH_MAX 0x100 diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index a38bf74bcca8..6448921a2f59 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -246,7 +246,7 @@ static void task_fpsimd_load(void) * * Softirqs (and preemption) must be disabled. */ -void fpsimd_save(void) +static void fpsimd_save(void) { struct fpsimd_last_state_struct const *last = this_cpu_ptr(&fpsimd_last_state); @@ -1122,12 +1122,22 @@ void fpsimd_flush_task_state(struct task_struct *t) * Invalidate any task's FPSIMD state that is present on this cpu. * This function must be called with softirqs disabled. */ -void fpsimd_flush_cpu_state(void) +static void fpsimd_flush_cpu_state(void) { __this_cpu_write(fpsimd_last_state.st, NULL); set_thread_flag(TIF_FOREIGN_FPSTATE); } +/* + * Save the FPSIMD state to memory and invalidate cpu view. + * This function must be called with softirqs (and preemption) disabled. + */ +void fpsimd_save_and_flush_cpu_state(void) +{ + fpsimd_save(); + fpsimd_flush_cpu_state(); +} + #ifdef CONFIG_KERNEL_MODE_NEON DEFINE_PER_CPU(bool, kernel_neon_busy); @@ -1284,8 +1294,7 @@ static int fpsimd_cpu_pm_notifier(struct notifier_block *self, { switch (cmd) { case CPU_PM_ENTER: - fpsimd_save(); - fpsimd_flush_cpu_state(); + fpsimd_save_and_flush_cpu_state(); break; case CPU_PM_EXIT: break; diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 6e3c9c8b2df9..525010504f9d 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -112,9 +112,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { u64 *guest_zcr = &vcpu->arch.ctxt.sys_regs[ZCR_EL1]; - /* Clean guest FP state to memory and invalidate cpu view */ - fpsimd_save(); - fpsimd_flush_cpu_state(); + fpsimd_save_and_flush_cpu_state(); if (guest_has_sve) *guest_zcr = read_sysreg_s(SYS_ZCR_EL12);