diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-19 21:00:51 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-19 21:00:51 +0000 |
commit | 6d03a247468059b0e59c821ef39e6762d4d6fc30 (patch) | |
tree | 17b9c00de2c62e68c965c742cdbc206f77a375da /arch/s390/include/asm/fpu.h | |
parent | Releasing progress-linux version 6.8.12-1~progress7.99u1. (diff) | |
download | linux-6d03a247468059b0e59c821ef39e6762d4d6fc30.tar.xz linux-6d03a247468059b0e59c821ef39e6762d4d6fc30.zip |
Merging upstream version 6.9.2.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/include/asm/fpu.h')
-rw-r--r-- | arch/s390/include/asm/fpu.h | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/arch/s390/include/asm/fpu.h b/arch/s390/include/asm/fpu.h new file mode 100644 index 0000000000..c84cb33913 --- /dev/null +++ b/arch/s390/include/asm/fpu.h @@ -0,0 +1,295 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * In-kernel FPU support functions + * + * + * Consider these guidelines before using in-kernel FPU functions: + * + * 1. Use kernel_fpu_begin() and kernel_fpu_end() to enclose all in-kernel + * use of floating-point or vector registers and instructions. + * + * 2. For kernel_fpu_begin(), specify the vector register range you want to + * use with the KERNEL_VXR_* constants. Consider these usage guidelines: + * + * a) If your function typically runs in process-context, use the lower + * half of the vector registers, for example, specify KERNEL_VXR_LOW. + * b) If your function typically runs in soft-irq or hard-irq context, + * prefer using the upper half of the vector registers, for example, + * specify KERNEL_VXR_HIGH. + * + * If you adhere to these guidelines, an interrupted process context + * does not require to save and restore vector registers because of + * disjoint register ranges. + * + * Also note that the __kernel_fpu_begin()/__kernel_fpu_end() functions + * includes logic to save and restore up to 16 vector registers at once. + * + * 3. You can nest kernel_fpu_begin()/kernel_fpu_end() by using different + * struct kernel_fpu states. Vector registers that are in use by outer + * levels are saved and restored. You can minimize the save and restore + * effort by choosing disjoint vector register ranges. + * + * 5. To use vector floating-point instructions, specify the KERNEL_FPC + * flag to save and restore floating-point controls in addition to any + * vector register range. + * + * 6. To use floating-point registers and instructions only, specify the + * KERNEL_FPR flag. This flag triggers a save and restore of vector + * registers V0 to V15 and floating-point controls. + * + * Copyright IBM Corp. 2015 + * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> + */ + +#ifndef _ASM_S390_FPU_H +#define _ASM_S390_FPU_H + +#include <linux/processor.h> +#include <linux/preempt.h> +#include <linux/string.h> +#include <linux/sched.h> +#include <asm/sigcontext.h> +#include <asm/fpu-types.h> +#include <asm/fpu-insn.h> +#include <asm/facility.h> + +static inline bool cpu_has_vx(void) +{ + return likely(test_facility(129)); +} + +enum { + KERNEL_FPC_BIT = 0, + KERNEL_VXR_V0V7_BIT, + KERNEL_VXR_V8V15_BIT, + KERNEL_VXR_V16V23_BIT, + KERNEL_VXR_V24V31_BIT, +}; + +#define KERNEL_FPC BIT(KERNEL_FPC_BIT) +#define KERNEL_VXR_V0V7 BIT(KERNEL_VXR_V0V7_BIT) +#define KERNEL_VXR_V8V15 BIT(KERNEL_VXR_V8V15_BIT) +#define KERNEL_VXR_V16V23 BIT(KERNEL_VXR_V16V23_BIT) +#define KERNEL_VXR_V24V31 BIT(KERNEL_VXR_V24V31_BIT) + +#define KERNEL_VXR_LOW (KERNEL_VXR_V0V7 | KERNEL_VXR_V8V15) +#define KERNEL_VXR_MID (KERNEL_VXR_V8V15 | KERNEL_VXR_V16V23) +#define KERNEL_VXR_HIGH (KERNEL_VXR_V16V23 | KERNEL_VXR_V24V31) + +#define KERNEL_VXR (KERNEL_VXR_LOW | KERNEL_VXR_HIGH) +#define KERNEL_FPR (KERNEL_FPC | KERNEL_VXR_LOW) + +void load_fpu_state(struct fpu *state, int flags); +void save_fpu_state(struct fpu *state, int flags); +void __kernel_fpu_begin(struct kernel_fpu *state, int flags); +void __kernel_fpu_end(struct kernel_fpu *state, int flags); + +static __always_inline void save_vx_regs(__vector128 *vxrs) +{ + fpu_vstm(0, 15, &vxrs[0]); + fpu_vstm(16, 31, &vxrs[16]); +} + +static __always_inline void load_vx_regs(__vector128 *vxrs) +{ + fpu_vlm(0, 15, &vxrs[0]); + fpu_vlm(16, 31, &vxrs[16]); +} + +static __always_inline void __save_fp_regs(freg_t *fprs, unsigned int offset) +{ + fpu_std(0, &fprs[0 * offset]); + fpu_std(1, &fprs[1 * offset]); + fpu_std(2, &fprs[2 * offset]); + fpu_std(3, &fprs[3 * offset]); + fpu_std(4, &fprs[4 * offset]); + fpu_std(5, &fprs[5 * offset]); + fpu_std(6, &fprs[6 * offset]); + fpu_std(7, &fprs[7 * offset]); + fpu_std(8, &fprs[8 * offset]); + fpu_std(9, &fprs[9 * offset]); + fpu_std(10, &fprs[10 * offset]); + fpu_std(11, &fprs[11 * offset]); + fpu_std(12, &fprs[12 * offset]); + fpu_std(13, &fprs[13 * offset]); + fpu_std(14, &fprs[14 * offset]); + fpu_std(15, &fprs[15 * offset]); +} + +static __always_inline void __load_fp_regs(freg_t *fprs, unsigned int offset) +{ + fpu_ld(0, &fprs[0 * offset]); + fpu_ld(1, &fprs[1 * offset]); + fpu_ld(2, &fprs[2 * offset]); + fpu_ld(3, &fprs[3 * offset]); + fpu_ld(4, &fprs[4 * offset]); + fpu_ld(5, &fprs[5 * offset]); + fpu_ld(6, &fprs[6 * offset]); + fpu_ld(7, &fprs[7 * offset]); + fpu_ld(8, &fprs[8 * offset]); + fpu_ld(9, &fprs[9 * offset]); + fpu_ld(10, &fprs[10 * offset]); + fpu_ld(11, &fprs[11 * offset]); + fpu_ld(12, &fprs[12 * offset]); + fpu_ld(13, &fprs[13 * offset]); + fpu_ld(14, &fprs[14 * offset]); + fpu_ld(15, &fprs[15 * offset]); +} + +static __always_inline void save_fp_regs(freg_t *fprs) +{ + __save_fp_regs(fprs, sizeof(freg_t) / sizeof(freg_t)); +} + +static __always_inline void load_fp_regs(freg_t *fprs) +{ + __load_fp_regs(fprs, sizeof(freg_t) / sizeof(freg_t)); +} + +static __always_inline void save_fp_regs_vx(__vector128 *vxrs) +{ + freg_t *fprs = (freg_t *)&vxrs[0].high; + + __save_fp_regs(fprs, sizeof(__vector128) / sizeof(freg_t)); +} + +static __always_inline void load_fp_regs_vx(__vector128 *vxrs) +{ + freg_t *fprs = (freg_t *)&vxrs[0].high; + + __load_fp_regs(fprs, sizeof(__vector128) / sizeof(freg_t)); +} + +static inline void load_user_fpu_regs(void) +{ + struct thread_struct *thread = ¤t->thread; + + if (!thread->ufpu_flags) + return; + load_fpu_state(&thread->ufpu, thread->ufpu_flags); + thread->ufpu_flags = 0; +} + +static __always_inline void __save_user_fpu_regs(struct thread_struct *thread, int flags) +{ + save_fpu_state(&thread->ufpu, flags); + __atomic_or(flags, &thread->ufpu_flags); +} + +static inline void save_user_fpu_regs(void) +{ + struct thread_struct *thread = ¤t->thread; + int mask, flags; + + mask = __atomic_or(KERNEL_FPC | KERNEL_VXR, &thread->kfpu_flags); + flags = ~READ_ONCE(thread->ufpu_flags) & (KERNEL_FPC | KERNEL_VXR); + if (flags) + __save_user_fpu_regs(thread, flags); + barrier(); + WRITE_ONCE(thread->kfpu_flags, mask); +} + +static __always_inline void _kernel_fpu_begin(struct kernel_fpu *state, int flags) +{ + struct thread_struct *thread = ¤t->thread; + int mask, uflags; + + mask = __atomic_or(flags, &thread->kfpu_flags); + state->hdr.mask = mask; + uflags = READ_ONCE(thread->ufpu_flags); + if ((uflags & flags) != flags) + __save_user_fpu_regs(thread, ~uflags & flags); + if (mask & flags) + __kernel_fpu_begin(state, flags); +} + +static __always_inline void _kernel_fpu_end(struct kernel_fpu *state, int flags) +{ + int mask = state->hdr.mask; + + if (mask & flags) + __kernel_fpu_end(state, flags); + barrier(); + WRITE_ONCE(current->thread.kfpu_flags, mask); +} + +void __kernel_fpu_invalid_size(void); + +static __always_inline void kernel_fpu_check_size(int flags, unsigned int size) +{ + unsigned int cnt = 0; + + if (flags & KERNEL_VXR_V0V7) + cnt += 8; + if (flags & KERNEL_VXR_V8V15) + cnt += 8; + if (flags & KERNEL_VXR_V16V23) + cnt += 8; + if (flags & KERNEL_VXR_V24V31) + cnt += 8; + if (cnt != size) + __kernel_fpu_invalid_size(); +} + +#define kernel_fpu_begin(state, flags) \ +{ \ + typeof(state) s = (state); \ + int _flags = (flags); \ + \ + kernel_fpu_check_size(_flags, ARRAY_SIZE(s->vxrs)); \ + _kernel_fpu_begin((struct kernel_fpu *)s, _flags); \ +} + +#define kernel_fpu_end(state, flags) \ +{ \ + typeof(state) s = (state); \ + int _flags = (flags); \ + \ + kernel_fpu_check_size(_flags, ARRAY_SIZE(s->vxrs)); \ + _kernel_fpu_end((struct kernel_fpu *)s, _flags); \ +} + +static inline void save_kernel_fpu_regs(struct thread_struct *thread) +{ + if (!thread->kfpu_flags) + return; + save_fpu_state(&thread->kfpu, thread->kfpu_flags); +} + +static inline void restore_kernel_fpu_regs(struct thread_struct *thread) +{ + if (!thread->kfpu_flags) + return; + load_fpu_state(&thread->kfpu, thread->kfpu_flags); +} + +static inline void convert_vx_to_fp(freg_t *fprs, __vector128 *vxrs) +{ + int i; + + for (i = 0; i < __NUM_FPRS; i++) + fprs[i].ui = vxrs[i].high; +} + +static inline void convert_fp_to_vx(__vector128 *vxrs, freg_t *fprs) +{ + int i; + + for (i = 0; i < __NUM_FPRS; i++) + vxrs[i].high = fprs[i].ui; +} + +static inline void fpregs_store(_s390_fp_regs *fpregs, struct fpu *fpu) +{ + fpregs->pad = 0; + fpregs->fpc = fpu->fpc; + convert_vx_to_fp((freg_t *)&fpregs->fprs, fpu->vxrs); +} + +static inline void fpregs_load(_s390_fp_regs *fpregs, struct fpu *fpu) +{ + fpu->fpc = fpregs->fpc; + convert_fp_to_vx(fpu->vxrs, (freg_t *)&fpregs->fprs); +} + +#endif /* _ASM_S390_FPU_H */ |