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authorHuang Ying <ying.huang@intel.com>2009-08-31 13:11:54 +0800
committerH. Peter Anvin <hpa@zytor.com>2009-09-01 21:39:15 -0700
commitae4b688db2432baad379f73fdcac13ec24f603d5 (patch)
treee367ad761a6835fffeb25694f3308e9315d7ef3c /arch/x86/include/asm
parentf6909f394c2d4a0a71320797df72d54c49c5927e (diff)
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')
-rw-r--r--arch/x86/include/asm/i387.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 175adf58dd4..fb7f0d64e14 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