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| author | Vineet Gupta <vgupta@synopsys.com> | 2020-01-17 15:04:03 -0800 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2020-01-17 16:53:44 -0800 |
| commit | f45ba2bd6da0dc8000aa7ea7a3858fb51608f766 (patch) | |
| tree | 3be8113cb45459531bc5ffee5bbbb1de38d5d234 /arch/arc/kernel/fpu.c | |
| parent | f05523aa7a1e63bfada5e222c0a57e02dbd4fcfa (diff) | |
| download | linux-f45ba2bd6da0dc8000aa7ea7a3858fb51608f766.tar.bz2 | |
ARCv2: fpu: preserve userspace fpu state
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel/fpu.c')
| -rw-r--r-- | arch/arc/kernel/fpu.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/arc/kernel/fpu.c b/arch/arc/kernel/fpu.c index 7a3b56ce56bb..c67c0f0f5f77 100644 --- a/arch/arc/kernel/fpu.c +++ b/arch/arc/kernel/fpu.c @@ -8,6 +8,8 @@ #include <linux/sched.h> #include <asm/fpu.h> +#ifdef CONFIG_ISA_ARCOMPACT + /* * To save/restore FPU regs, simplest scheme would use LR/SR insns. * However since SR serializes the pipeline, an alternate "hack" can be used @@ -50,3 +52,28 @@ void fpu_save_restore(struct task_struct *prev, struct task_struct *next) : "r" (zero), "r" (*(readfrom + 3)), "r" (*(readfrom + 2)) ); } + +#else + +void fpu_init_task(struct pt_regs *regs) +{ + /* default rounding mode */ + write_aux_reg(ARC_REG_FPU_CTRL, 0x100); + + /* set "Write enable" to allow explicit write to exception flags */ + write_aux_reg(ARC_REG_FPU_STATUS, 0x80000000); +} + +void fpu_save_restore(struct task_struct *prev, struct task_struct *next) +{ + struct arc_fpu *save = &prev->thread.fpu; + struct arc_fpu *restore = &next->thread.fpu; + + save->ctrl = read_aux_reg(ARC_REG_FPU_CTRL); + save->status = read_aux_reg(ARC_REG_FPU_STATUS); + + write_aux_reg(ARC_REG_FPU_CTRL, restore->ctrl); + write_aux_reg(ARC_REG_FPU_STATUS, restore->status); +} + +#endif |