diff options
| author | Cyril Bur <cyrilbur@gmail.com> | 2016-02-29 07:53:51 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2016-03-02 13:34:50 +0100 |
| commit | bf6a4d5b75d1ea87897fe68d0e45d35a2996c678 (patch) | |
| tree | 8e967bdd1fe1dcd8bda0b38baa212c945c40cab1 /arch/powerpc/kernel/process.c | |
| parent | powerpc: Add the ability to save Altivec without giving it up (diff) | |
| download | linux-bf6a4d5b75d1ea87897fe68d0e45d35a2996c678.tar.xz linux-bf6a4d5b75d1ea87897fe68d0e45d35a2996c678.zip | |
powerpc: Add the ability to save VSX without giving it up
This patch adds the ability to be able to save the VSX registers to the
thread struct without giving up (disabling the facility) next time the
process returns to userspace.
This patch builds on a previous optimisation for the FPU and VEC registers
in the thread copy path to avoid a possibly pointless reload of VSX state.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 42 |
1 files changed, 30 insertions, 12 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 14c09d25de98..d7a9df51b974 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -280,19 +280,31 @@ static inline int restore_altivec(struct task_struct *tsk) { return 0; } #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSX -void giveup_vsx(struct task_struct *tsk) +static void __giveup_vsx(struct task_struct *tsk) { - check_if_tm_restore_required(tsk); - - msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); if (tsk->thread.regs->msr & MSR_FP) __giveup_fpu(tsk); if (tsk->thread.regs->msr & MSR_VEC) __giveup_altivec(tsk); + tsk->thread.regs->msr &= ~MSR_VSX; +} + +static void giveup_vsx(struct task_struct *tsk) +{ + check_if_tm_restore_required(tsk); + + msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); __giveup_vsx(tsk); msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX); } -EXPORT_SYMBOL(giveup_vsx); + +static void save_vsx(struct task_struct *tsk) +{ + if (tsk->thread.regs->msr & MSR_FP) + save_fpu(tsk); + if (tsk->thread.regs->msr & MSR_VEC) + save_altivec(tsk); +} void enable_kernel_vsx(void) { @@ -335,6 +347,7 @@ static int restore_vsx(struct task_struct *tsk) } #else static inline int restore_vsx(struct task_struct *tsk) { return 0; } +static inline void save_vsx(struct task_struct *tsk) { } #endif /* CONFIG_VSX */ #ifdef CONFIG_SPE @@ -478,14 +491,19 @@ void save_all(struct task_struct *tsk) msr_check_and_set(msr_all_available); - if (usermsr & MSR_FP) - save_fpu(tsk); - - if (usermsr & MSR_VEC) - save_altivec(tsk); + /* + * Saving the way the register space is in hardware, save_vsx boils + * down to a save_fpu() and save_altivec() + */ + if (usermsr & MSR_VSX) { + save_vsx(tsk); + } else { + if (usermsr & MSR_FP) + save_fpu(tsk); - if (usermsr & MSR_VSX) - __giveup_vsx(tsk); + if (usermsr & MSR_VEC) + save_altivec(tsk); + } if (usermsr & MSR_SPE) __giveup_spe(tsk); |