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/ppc_ksyms.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/powerpc/kernel/ppc_ksyms.c') diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c index 21646dbe1bb3..56a4bec1b11a 100644 --- a/arch/powerpc/kernel/ppc_ksyms.c +++ b/arch/powerpc/kernel/ppc_ksyms.c @@ -98,9 +98,13 @@ EXPORT_SYMBOL(start_thread); #ifdef CONFIG_PPC_FPU EXPORT_SYMBOL(giveup_fpu); +EXPORT_SYMBOL(load_fp_state); +EXPORT_SYMBOL(store_fp_state); #endif #ifdef CONFIG_ALTIVEC EXPORT_SYMBOL(giveup_altivec); +EXPORT_SYMBOL(load_vr_state); +EXPORT_SYMBOL(store_vr_state); #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSX EXPORT_SYMBOL(giveup_vsx); -- cgit v1.2.3