From 18461960cbf50bf345ef0667d45d5f64de8fb893 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Tue, 10 Sep 2013 20:21:10 +1000 Subject: powerpc: Provide for giveup_fpu/altivec to save state in alternate location This provides a facility which is intended for use by KVM, where the contents of the FP/VSX and VMX (Altivec) registers can be saved away to somewhere other than the thread_struct when kernel code wants to use floating point or VMX instructions. This is done by providing a pointer in the thread_struct to indicate where the state should be saved to. The giveup_fpu() and giveup_altivec() functions test these pointers and save state to the indicated location if they are non-NULL. Note that the MSR_FP/VEC bits in task->thread.regs->msr are still used to indicate whether the CPU register state is live, even when an alternate save location is being used. This also provides load_fp_state() and load_vr_state() functions, which load up FP/VSX and VMX state from memory into the CPU registers, and corresponding store_fp_state() and store_vr_state() functions, which store FP/VSX and VMX state into memory from the CPU registers. Signed-off-by: Paul Mackerras Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/asm-offsets.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/powerpc/kernel/asm-offsets.c') diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 8d27b61c95b9..6278edddc3f8 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -91,9 +91,11 @@ int main(void) #endif DEFINE(THREAD_FPEXC_MODE, offsetof(struct thread_struct, fpexc_mode)); DEFINE(THREAD_FPSTATE, offsetof(struct thread_struct, fp_state)); + DEFINE(THREAD_FPSAVEAREA, offsetof(struct thread_struct, fp_save_area)); DEFINE(FPSTATE_FPSCR, offsetof(struct thread_fp_state, fpscr)); #ifdef CONFIG_ALTIVEC DEFINE(THREAD_VRSTATE, offsetof(struct thread_struct, vr_state)); + DEFINE(THREAD_VRSAVEAREA, offsetof(struct thread_struct, vr_save_area)); DEFINE(THREAD_VRSAVE, offsetof(struct thread_struct, vrsave)); DEFINE(THREAD_USED_VR, offsetof(struct thread_struct, used_vr)); DEFINE(VRSTATE_VSCR, offsetof(struct thread_vr_state, vscr)); -- cgit v1.2.2