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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-06-19 21:00:51 +0000 |
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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/api.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/api.h')
-rw-r--r-- | arch/s390/include/asm/fpu/api.h | 126 |
1 files changed, 0 insertions, 126 deletions
diff --git a/arch/s390/include/asm/fpu/api.h b/arch/s390/include/asm/fpu/api.h deleted file mode 100644 index d6ca8bc6ca..0000000000 --- a/arch/s390/include/asm/fpu/api.h +++ /dev/null @@ -1,126 +0,0 @@ -/* 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_API_H -#define _ASM_S390_FPU_API_H - -#include <linux/preempt.h> -#include <asm/asm-extable.h> -#include <asm/fpu/internal.h> - -void save_fpu_regs(void); -void load_fpu_regs(void); -void __load_fpu_regs(void); - -/** - * sfpc_safe - Set floating point control register safely. - * @fpc: new value for floating point control register - * - * Set floating point control register. This may lead to an exception, - * since a saved value may have been modified by user space (ptrace, - * signal return, kvm registers) to an invalid value. In such a case - * set the floating point control register to zero. - */ -static inline void sfpc_safe(u32 fpc) -{ - asm volatile("\n" - "0: sfpc %[fpc]\n" - "1: nopr %%r7\n" - ".pushsection .fixup, \"ax\"\n" - "2: lghi %[fpc],0\n" - " jg 0b\n" - ".popsection\n" - EX_TABLE(1b, 2b) - : [fpc] "+d" (fpc) - : : "memory"); -} - -#define KERNEL_FPC 1 -#define KERNEL_VXR_V0V7 2 -#define KERNEL_VXR_V8V15 4 -#define KERNEL_VXR_V16V23 8 -#define KERNEL_VXR_V24V31 16 - -#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) - -struct kernel_fpu; - -/* - * Note the functions below must be called with preemption disabled. - * Do not enable preemption before calling __kernel_fpu_end() to prevent - * an corruption of an existing kernel FPU state. - * - * Prefer using the kernel_fpu_begin()/kernel_fpu_end() pair of functions. - */ -void __kernel_fpu_begin(struct kernel_fpu *state, u32 flags); -void __kernel_fpu_end(struct kernel_fpu *state, u32 flags); - - -static inline void kernel_fpu_begin(struct kernel_fpu *state, u32 flags) -{ - preempt_disable(); - state->mask = S390_lowcore.fpu_flags; - if (!test_cpu_flag(CIF_FPU)) - /* Save user space FPU state and register contents */ - save_fpu_regs(); - else if (state->mask & flags) - /* Save FPU/vector register in-use by the kernel */ - __kernel_fpu_begin(state, flags); - S390_lowcore.fpu_flags |= flags; -} - -static inline void kernel_fpu_end(struct kernel_fpu *state, u32 flags) -{ - S390_lowcore.fpu_flags = state->mask; - if (state->mask & flags) - /* Restore FPU/vector register in-use by the kernel */ - __kernel_fpu_end(state, flags); - preempt_enable(); -} - -#endif /* _ASM_S390_FPU_API_H */ |