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| author | Huang Ying <ying.huang@intel.com> | 2009-08-31 07:11:54 +0200 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-09-02 06:39:15 +0200 |
| commit | ae4b688db2432baad379f73fdcac13ec24f603d5 (patch) | |
| tree | e367ad761a6835fffeb25694f3308e9315d7ef3c /arch/x86/include/asm/i387.h | |
| parent | x86, msr: fix msr-reg.S compilation with gas 2.16.1 (diff) | |
| download | linux-ae4b688db2432baad379f73fdcac13ec24f603d5.tar.xz linux-ae4b688db2432baad379f73fdcac13ec24f603d5.zip | |
x86: Move kernel_fpu_using to irq_fpu_usable in asm/i387.h
This function measures whether the FPU/SSE state can be touched in
interrupt context. If the interrupted code is in user space or has no
valid FPU/SSE context (CR0.TS == 1), FPU/SSE state can be used in IRQ
or soft_irq context too.
This is used by AES-NI accelerated AES implementation and PCLMULQDQ
accelerated GHASH implementation.
v3:
- Renamed to irq_fpu_usable to reflect the purpose of the function.
v2:
- Renamed to irq_is_fpu_using to reflect the real situation.
Signed-off-by: Huang Ying <ying.huang@intel.com>
CC: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/i387.h')
| -rw-r--r-- | arch/x86/include/asm/i387.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index 175adf58dd4f..fb7f0d64e14f 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -301,6 +301,14 @@ static inline void kernel_fpu_end(void) preempt_enable(); } +static inline bool irq_fpu_usable(void) +{ + struct pt_regs *regs; + + return !in_interrupt() || !(regs = get_irq_regs()) || \ + user_mode(regs) || (read_cr0() & X86_CR0_TS); +} + /* * Some instructions like VIA's padlock instructions generate a spurious * DNA fault but don't modify SSE registers. And these instructions |