| Message ID | 20190322071122.6677-2-Jason@zx2c4.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | WireGuard: Secure Network Tunnel | expand |
Jason, On Fri, 22 Mar 2019, Jason A. Donenfeld wrote: > index 000000000000..264ed84b41d8 > --- /dev/null > +++ b/arch/arm/include/asm/simd.h > @@ -0,0 +1,63 @@ > +/* SPDX-License-Identifier: GPL-2.0 The SPDX identifier has to be in a separate comment line. /* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2015-2018 Jason.... */ Yes, it looks odd, but it's defined that way. > +static __must_check inline bool simd_use(simd_context_t *ctx) > +{ > + if (!(*ctx & HAVE_FULL_SIMD)) > + return false; > + if (*ctx & HAVE_SIMD_IN_USE) > + return true; > + kernel_neon_begin(); > + *ctx |= HAVE_SIMD_IN_USE; > + return true; > +} > +static __must_check inline bool simd_use(simd_context_t *ctx) > +{ > + if (!(*ctx & HAVE_FULL_SIMD)) > + return false; > + if (*ctx & HAVE_SIMD_IN_USE) > + return true; > + kernel_neon_begin(); > + *ctx |= HAVE_SIMD_IN_USE; > + return true; > +} > +static __must_check inline bool simd_use(simd_context_t *ctx) > +{ > +#if !defined(CONFIG_UML) > + if (!(*ctx & HAVE_FULL_SIMD)) > + return false; > + if (*ctx & HAVE_SIMD_IN_USE) > + return true; > + kernel_fpu_begin(); > + *ctx |= HAVE_SIMD_IN_USE; > + return true; > +#else > + return false; > +#endif > +} So now we have 3 almost identical copies of the same thing and x86/UM handling it differently than the ARM(64) ones. That can be completely avoided. Untested patch below. Thanks, tglx 8<------------- --- /dev/null +++ b/arch/arm/include/asm/simd.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H + +#ifdef CONFIG_KERNEL_MODE_NEON +#include <asm/neon.h> + +static __must_check inline bool may_use_simd(void) +{ + return !in_nmi() && !in_irq() && !in_serving_softirq(); +} + +static inline void arch_simd_end(void) +{ + kernel_neon_end(); +} + +static inline void arch_simd_begin(void) +{ + kernel_neon_begin(); +} + +#else +#include <asm-generic/simd.h> +#endif + +#endif /* _ASM_SIMD_H */ --- a/arch/arm64/include/asm/simd.h +++ b/arch/arm64/include/asm/simd.h @@ -1,11 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published - * by the Free Software Foundation. + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */ +#include <linux/simd.h> #ifndef __ASM_SIMD_H #define __ASM_SIMD_H @@ -16,6 +15,8 @@ #include <linux/types.h> #ifdef CONFIG_KERNEL_MODE_NEON +#include <asm/neon.h> +#include <asm/simd.h> DECLARE_PER_CPU(bool, kernel_neon_busy); @@ -40,12 +41,18 @@ static __must_check inline bool may_use_ !this_cpu_read(kernel_neon_busy); } -#else /* ! CONFIG_KERNEL_MODE_NEON */ +static inline void arch_simd_end(void) +{ + kernel_neon_end(); +} -static __must_check inline bool may_use_simd(void) { - return false; +static inline void arch_simd_begin(void) +{ + kernel_neon_begin(); } -#endif /* ! CONFIG_KERNEL_MODE_NEON */ +#else +#include <asm-generic/simd.h> +#endif #endif --- a/arch/x86/include/asm/simd.h +++ b/arch/x86/include/asm/simd.h @@ -1,4 +1,12 @@ /* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H + +#ifndef CONFIG_UML #include <asm/fpu/api.h> @@ -10,3 +18,21 @@ static __must_check inline bool may_use_ { return irq_fpu_usable(); } + +static inline void arch_simd_begin(void) +{ + kernel_fpu_begin(); +} + +static inline void arch_simd_end(void) +{ + kernel_fpu_end(); +} + +#else +#include <asm-generic/simd.h> +#endif + +#include <linux/simd.h> + +#endif /* _ASM_SIMD_H */ --- a/include/asm-generic/simd.h +++ b/include/asm-generic/simd.h @@ -1,7 +1,12 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H + #include <linux/hardirq.h> +#define SIMD_GENERIC 1 + /* * may_use_simd - whether it is allowable at this time to issue SIMD * instructions or access the SIMD register file @@ -13,3 +18,10 @@ static __must_check inline bool may_use_ { return !in_interrupt(); } + +static inline void arch_simd_begin(void) { } +static inline void arch_simd_end(void) { } + +#include <linux/simd.h> + +#endif /* _ASM_SIMD_H */ --- /dev/null +++ b/include/linux/simd.h @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#ifndef _SIMD_H +#define _SIMD_H + +typedef enum { + HAVE_NO_SIMD = 1 << 0, + HAVE_FULL_SIMD = 1 << 1, + HAVE_SIMD_IN_USE = 1 << 31 +} simd_context_t; + +#define DONT_USE_SIMD ((simd_context_t []){ HAVE_NO_SIMD }) + +#include <asm/simd.h> + +#ifndef SIMD_GENERIC + +#include <linux/sched.h> + +static inline bool simd_relax(simd_context_t *ctx) +{ +#ifdef CONFIG_PREEMPT + if ((*ctx & HAVE_SIMD_IN_USE) && need_resched()) { + simd_put(ctx); + simd_get(ctx); + return true; + } +#endif + return false; +} + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = may_use_simd() ? HAVE_FULL_SIMD : HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ + if (*ctx & HAVE_SIMD_IN_USE) + arch_simd_end(); + + *ctx = HAVE_NO_SIMD; +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + if (!(*ctx & HAVE_FULL_SIMD)) + return false; + if (*ctx & HAVE_SIMD_IN_USE) + return true; + arch_simd_begin(); + *ctx |= HAVE_SIMD_IN_USE; + return true; +} + +#else /* !SIMD_GENERIC */ + +static inline bool simd_relax(simd_context_t *ctx) +{ + return false; +} + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + return false; +} + +#endif /* SIMD_GENERIC */ + +#endif /* _SIMD_H */
diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild index dc0ab28baca1..b385c2036290 100644 --- a/arch/alpha/include/asm/Kbuild +++ b/arch/alpha/include/asm/Kbuild @@ -13,3 +13,4 @@ generic-y += sections.h generic-y += trace_clock.h generic-y += current.h generic-y += kprobes.h +generic-y += simd.h diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild index b41f8881ecc8..3028a2246ab4 100644 --- a/arch/arc/include/asm/Kbuild +++ b/arch/arc/include/asm/Kbuild @@ -19,6 +19,7 @@ generic-y += msi.h generic-y += parport.h generic-y += percpu.h generic-y += preempt.h +generic-y += simd.h generic-y += topology.h generic-y += trace_clock.h generic-y += user.h diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild index 1d66db9c9db5..ebdc9eeb8d39 100644 --- a/arch/arm/include/asm/Kbuild +++ b/arch/arm/include/asm/Kbuild @@ -16,7 +16,6 @@ generic-y += rwsem.h generic-y += seccomp.h generic-y += segment.h generic-y += serial.h -generic-y += simd.h generic-y += sizes.h generic-y += timex.h generic-y += trace_clock.h diff --git a/arch/arm/include/asm/simd.h b/arch/arm/include/asm/simd.h new file mode 100644 index 000000000000..264ed84b41d8 --- /dev/null +++ b/arch/arm/include/asm/simd.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#include <linux/simd.h> +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H + +#ifdef CONFIG_KERNEL_MODE_NEON +#include <asm/neon.h> + +static __must_check inline bool may_use_simd(void) +{ + return !in_nmi() && !in_irq() && !in_serving_softirq(); +} + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = may_use_simd() ? HAVE_FULL_SIMD : HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ + if (*ctx & HAVE_SIMD_IN_USE) + kernel_neon_end(); + *ctx = HAVE_NO_SIMD; +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + if (!(*ctx & HAVE_FULL_SIMD)) + return false; + if (*ctx & HAVE_SIMD_IN_USE) + return true; + kernel_neon_begin(); + *ctx |= HAVE_SIMD_IN_USE; + return true; +} + +#else + +static __must_check inline bool may_use_simd(void) +{ + return false; +} + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + return false; +} +#endif + +#endif /* _ASM_SIMD_H */ diff --git a/arch/arm64/include/asm/simd.h b/arch/arm64/include/asm/simd.h index 6495cc51246f..a45ff1600040 100644 --- a/arch/arm64/include/asm/simd.h +++ b/arch/arm64/include/asm/simd.h @@ -1,11 +1,10 @@ -/* - * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> +/* SPDX-License-Identifier: GPL-2.0 * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published - * by the Free Software Foundation. + * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */ +#include <linux/simd.h> #ifndef __ASM_SIMD_H #define __ASM_SIMD_H @@ -16,6 +15,8 @@ #include <linux/types.h> #ifdef CONFIG_KERNEL_MODE_NEON +#include <asm/neon.h> +#include <asm/simd.h> DECLARE_PER_CPU(bool, kernel_neon_busy); @@ -40,9 +41,47 @@ static __must_check inline bool may_use_simd(void) !this_cpu_read(kernel_neon_busy); } +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = may_use_simd() ? HAVE_FULL_SIMD : HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ + if (*ctx & HAVE_SIMD_IN_USE) + kernel_neon_end(); + *ctx = HAVE_NO_SIMD; +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + if (!(*ctx & HAVE_FULL_SIMD)) + return false; + if (*ctx & HAVE_SIMD_IN_USE) + return true; + kernel_neon_begin(); + *ctx |= HAVE_SIMD_IN_USE; + return true; +} + #else /* ! CONFIG_KERNEL_MODE_NEON */ -static __must_check inline bool may_use_simd(void) { +static __must_check inline bool may_use_simd(void) +{ + return false; +} + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ return false; } diff --git a/arch/c6x/include/asm/Kbuild b/arch/c6x/include/asm/Kbuild index 63b4a1705182..b0aa9d783d2b 100644 --- a/arch/c6x/include/asm/Kbuild +++ b/arch/c6x/include/asm/Kbuild @@ -31,6 +31,7 @@ generic-y += preempt.h generic-y += segment.h generic-y += serial.h generic-y += shmparam.h +generic-y += simd.h generic-y += tlbflush.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/h8300/include/asm/Kbuild b/arch/h8300/include/asm/Kbuild index 961c1dc064e1..3de740b33f6e 100644 --- a/arch/h8300/include/asm/Kbuild +++ b/arch/h8300/include/asm/Kbuild @@ -41,6 +41,7 @@ generic-y += scatterlist.h generic-y += sections.h generic-y += serial.h generic-y += shmparam.h +generic-y += simd.h generic-y += sizes.h generic-y += spinlock.h generic-y += timex.h diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild index b25fd42aa0f4..843ae8d5c4d9 100644 --- a/arch/hexagon/include/asm/Kbuild +++ b/arch/hexagon/include/asm/Kbuild @@ -31,6 +31,7 @@ generic-y += sections.h generic-y += segment.h generic-y += serial.h generic-y += shmparam.h +generic-y += simd.h generic-y += sizes.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/ia64/include/asm/Kbuild b/arch/ia64/include/asm/Kbuild index 43e21fe3499c..4f4a969c4611 100644 --- a/arch/ia64/include/asm/Kbuild +++ b/arch/ia64/include/asm/Kbuild @@ -5,6 +5,7 @@ generic-y += irq_work.h generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h generic-y += preempt.h +generic-y += simd.h generic-y += trace_clock.h generic-y += vtime.h generic-y += word-at-a-time.h diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild index 95f8f631c4df..d60a481e6f73 100644 --- a/arch/m68k/include/asm/Kbuild +++ b/arch/m68k/include/asm/Kbuild @@ -21,6 +21,7 @@ generic-y += percpu.h generic-y += preempt.h generic-y += sections.h generic-y += shmparam.h +generic-y += simd.h generic-y += spinlock.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild index 791cc8d54d0a..103ed3592214 100644 --- a/arch/microblaze/include/asm/Kbuild +++ b/arch/microblaze/include/asm/Kbuild @@ -27,6 +27,7 @@ generic-y += percpu.h generic-y += preempt.h generic-y += serial.h generic-y += shmparam.h +generic-y += simd.h generic-y += syscalls.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/mips/include/asm/Kbuild b/arch/mips/include/asm/Kbuild index 87b86cdf126a..fb3345c870c6 100644 --- a/arch/mips/include/asm/Kbuild +++ b/arch/mips/include/asm/Kbuild @@ -20,6 +20,7 @@ generic-y += qrwlock.h generic-y += qspinlock.h generic-y += sections.h generic-y += segment.h +generic-y += simd.h generic-y += trace_clock.h generic-y += unaligned.h generic-y += user.h diff --git a/arch/nds32/include/asm/Kbuild b/arch/nds32/include/asm/Kbuild index 64ceff7ab99b..887923fdbb65 100644 --- a/arch/nds32/include/asm/Kbuild +++ b/arch/nds32/include/asm/Kbuild @@ -38,6 +38,7 @@ generic-y += preempt.h generic-y += sections.h generic-y += segment.h generic-y += serial.h +generic-y += simd.h generic-y += sizes.h generic-y += switch_to.h generic-y += timex.h diff --git a/arch/nios2/include/asm/Kbuild b/arch/nios2/include/asm/Kbuild index 8fde4fa2c34f..571a9d9ad107 100644 --- a/arch/nios2/include/asm/Kbuild +++ b/arch/nios2/include/asm/Kbuild @@ -33,6 +33,7 @@ generic-y += preempt.h generic-y += sections.h generic-y += segment.h generic-y += serial.h +generic-y += simd.h generic-y += spinlock.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild index 1f04844b6b82..82c06dd1519d 100644 --- a/arch/openrisc/include/asm/Kbuild +++ b/arch/openrisc/include/asm/Kbuild @@ -35,6 +35,7 @@ generic-y += qrwlock.h generic-y += sections.h generic-y += segment.h generic-y += shmparam.h +generic-y += simd.h generic-y += string.h generic-y += switch_to.h generic-y += topology.h diff --git a/arch/parisc/include/asm/Kbuild b/arch/parisc/include/asm/Kbuild index 0b1e354c8c24..087fb8b05e5e 100644 --- a/arch/parisc/include/asm/Kbuild +++ b/arch/parisc/include/asm/Kbuild @@ -20,6 +20,7 @@ generic-y += percpu.h generic-y += preempt.h generic-y += seccomp.h generic-y += segment.h +generic-y += simd.h generic-y += topology.h generic-y += trace_clock.h generic-y += user.h diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild index 77ff7fb24823..96269741bfb9 100644 --- a/arch/powerpc/include/asm/Kbuild +++ b/arch/powerpc/include/asm/Kbuild @@ -12,3 +12,4 @@ generic-y += preempt.h generic-y += rwsem.h generic-y += vtime.h generic-y += msi.h +generic-y += simd.h diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild index cccd12cf27d4..525bd8707c7d 100644 --- a/arch/riscv/include/asm/Kbuild +++ b/arch/riscv/include/asm/Kbuild @@ -28,6 +28,7 @@ generic-y += scatterlist.h generic-y += sections.h generic-y += serial.h generic-y += shmparam.h +generic-y += simd.h generic-y += topology.h generic-y += trace_clock.h generic-y += unaligned.h diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild index e3239772887a..3744c4c61fb5 100644 --- a/arch/s390/include/asm/Kbuild +++ b/arch/s390/include/asm/Kbuild @@ -22,6 +22,7 @@ generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h generic-y += preempt.h generic-y += rwsem.h +generic-y += simd.h generic-y += trace_clock.h generic-y += unaligned.h generic-y += word-at-a-time.h diff --git a/arch/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild index a6ef3fee5f85..74b7bb3ba96a 100644 --- a/arch/sh/include/asm/Kbuild +++ b/arch/sh/include/asm/Kbuild @@ -18,6 +18,7 @@ generic-y += percpu.h generic-y += preempt.h generic-y += rwsem.h generic-y += serial.h +generic-y += simd.h generic-y += sizes.h generic-y += trace_clock.h generic-y += xor.h diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild index b82f64e28f55..d053d5bad630 100644 --- a/arch/sparc/include/asm/Kbuild +++ b/arch/sparc/include/asm/Kbuild @@ -19,5 +19,6 @@ generic-y += msi.h generic-y += preempt.h generic-y += rwsem.h generic-y += serial.h +generic-y += simd.h generic-y += trace_clock.h generic-y += word-at-a-time.h diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index 00bcbe2326d9..a4dfffb2c22b 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -20,6 +20,7 @@ generic-y += param.h generic-y += pci.h generic-y += percpu.h generic-y += preempt.h +generic-y += simd.h generic-y += switch_to.h generic-y += topology.h generic-y += trace_clock.h diff --git a/arch/unicore32/include/asm/Kbuild b/arch/unicore32/include/asm/Kbuild index 1d1544b6ca74..c428158a3a19 100644 --- a/arch/unicore32/include/asm/Kbuild +++ b/arch/unicore32/include/asm/Kbuild @@ -29,6 +29,7 @@ generic-y += sections.h generic-y += segment.h generic-y += serial.h generic-y += shmparam.h +generic-y += simd.h generic-y += sizes.h generic-y += syscalls.h generic-y += topology.h diff --git a/arch/x86/include/asm/simd.h b/arch/x86/include/asm/simd.h index a341c878e977..4aad7f158dcb 100644 --- a/arch/x86/include/asm/simd.h +++ b/arch/x86/include/asm/simd.h @@ -1,4 +1,11 @@ -/* SPDX-License-Identifier: GPL-2.0 */ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#include <linux/simd.h> +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H #include <asm/fpu/api.h> @@ -10,3 +17,38 @@ static __must_check inline bool may_use_simd(void) { return irq_fpu_usable(); } + +static inline void simd_get(simd_context_t *ctx) +{ +#if !defined(CONFIG_UML) + *ctx = may_use_simd() ? HAVE_FULL_SIMD : HAVE_NO_SIMD; +#else + *ctx = HAVE_NO_SIMD; +#endif +} + +static inline void simd_put(simd_context_t *ctx) +{ +#if !defined(CONFIG_UML) + if (*ctx & HAVE_SIMD_IN_USE) + kernel_fpu_end(); +#endif + *ctx = HAVE_NO_SIMD; +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ +#if !defined(CONFIG_UML) + if (!(*ctx & HAVE_FULL_SIMD)) + return false; + if (*ctx & HAVE_SIMD_IN_USE) + return true; + kernel_fpu_begin(); + *ctx |= HAVE_SIMD_IN_USE; + return true; +#else + return false; +#endif +} + +#endif /* _ASM_SIMD_H */ diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild index d939e13e8d84..dce09e76b71e 100644 --- a/arch/xtensa/include/asm/Kbuild +++ b/arch/xtensa/include/asm/Kbuild @@ -27,6 +27,7 @@ generic-y += qrwlock.h generic-y += qspinlock.h generic-y += rwsem.h generic-y += sections.h +generic-y += simd.h generic-y += socket.h generic-y += topology.h generic-y += trace_clock.h diff --git a/include/asm-generic/simd.h b/include/asm-generic/simd.h index d0343d58a74a..b3dd61ac010e 100644 --- a/include/asm-generic/simd.h +++ b/include/asm-generic/simd.h @@ -1,5 +1,9 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/simd.h> +#ifndef _ASM_SIMD_H +#define _ASM_SIMD_H + #include <linux/hardirq.h> /* @@ -13,3 +17,19 @@ static __must_check inline bool may_use_simd(void) { return !in_interrupt(); } + +static inline void simd_get(simd_context_t *ctx) +{ + *ctx = HAVE_NO_SIMD; +} + +static inline void simd_put(simd_context_t *ctx) +{ +} + +static __must_check inline bool simd_use(simd_context_t *ctx) +{ + return false; +} + +#endif /* _ASM_SIMD_H */ diff --git a/include/linux/simd.h b/include/linux/simd.h new file mode 100644 index 000000000000..4e0b8a9bdc14 --- /dev/null +++ b/include/linux/simd.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + */ + +#ifndef _SIMD_H +#define _SIMD_H + +typedef enum { + HAVE_NO_SIMD = 1 << 0, + HAVE_FULL_SIMD = 1 << 1, + HAVE_SIMD_IN_USE = 1 << 31 +} simd_context_t; + +#define DONT_USE_SIMD ((simd_context_t []){ HAVE_NO_SIMD }) + +#include <linux/sched.h> +#include <asm/simd.h> + +static inline bool simd_relax(simd_context_t *ctx) +{ +#ifdef CONFIG_PREEMPT + if ((*ctx & HAVE_SIMD_IN_USE) && need_resched()) { + simd_put(ctx); + simd_get(ctx); + return true; + } +#endif + return false; +} + +#endif /* _SIMD_H */
Sometimes it's useful to amortize calls to XSAVE/XRSTOR and the related FPU/SIMD functions over a number of calls, because FPU restoration is quite expensive. This adds a simple header for carrying out this pattern: simd_context_t simd_context; simd_get(&simd_context); while ((item = get_item_from_queue()) != NULL) { encrypt_item(item, &simd_context); simd_relax(&simd_context); } simd_put(&simd_context); The relaxation step ensures that we don't trample over preemption, and the get/put API should be a familiar paradigm in the kernel. On the other end, code that actually wants to use SIMD instructions can accept this as a parameter and check it via: void encrypt_item(struct item *item, simd_context_t *simd_context) { if (item->len > LARGE_FOR_SIMD && simd_use(simd_context)) wild_simd_code(item); else boring_scalar_code(item); } The actual XSAVE happens during simd_use (and only on the first time), so that if the context is never actually used, no performance penalty is hit. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Samuel Neves <sneves@dei.uc.pt> Cc: Andy Lutomirski <luto@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: linux-arch@vger.kernel.org --- arch/alpha/include/asm/Kbuild | 1 + arch/arc/include/asm/Kbuild | 1 + arch/arm/include/asm/Kbuild | 1 - arch/arm/include/asm/simd.h | 63 ++++++++++++++++++++++++++++++ arch/arm64/include/asm/simd.h | 51 +++++++++++++++++++++--- arch/c6x/include/asm/Kbuild | 1 + arch/h8300/include/asm/Kbuild | 1 + arch/hexagon/include/asm/Kbuild | 1 + arch/ia64/include/asm/Kbuild | 1 + arch/m68k/include/asm/Kbuild | 1 + arch/microblaze/include/asm/Kbuild | 1 + arch/mips/include/asm/Kbuild | 1 + arch/nds32/include/asm/Kbuild | 1 + arch/nios2/include/asm/Kbuild | 1 + arch/openrisc/include/asm/Kbuild | 1 + arch/parisc/include/asm/Kbuild | 1 + arch/powerpc/include/asm/Kbuild | 1 + arch/riscv/include/asm/Kbuild | 1 + arch/s390/include/asm/Kbuild | 1 + arch/sh/include/asm/Kbuild | 1 + arch/sparc/include/asm/Kbuild | 1 + arch/um/include/asm/Kbuild | 1 + arch/unicore32/include/asm/Kbuild | 1 + arch/x86/include/asm/simd.h | 44 ++++++++++++++++++++- arch/xtensa/include/asm/Kbuild | 1 + include/asm-generic/simd.h | 20 ++++++++++ include/linux/simd.h | 32 +++++++++++++++ 27 files changed, 224 insertions(+), 8 deletions(-) create mode 100644 arch/arm/include/asm/simd.h create mode 100644 include/linux/simd.h