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author | Paul Mackerras <paulus@samba.org> | 2013-09-10 20:21:10 +1000 |
---|---|---|
committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-10-11 17:26:50 +1100 |
commit | 18461960cbf50bf345ef0667d45d5f64de8fb893 (patch) | |
tree | 58947fe30598814684f7e33424675e204316e8ef /arch/powerpc/include/asm/processor.h | |
parent | de79f7b9f6f92ec1bd6f61fa1f20de60728a5b5e (diff) | |
download | linux-stable-18461960cbf50bf345ef0667d45d5f64de8fb893.tar.gz linux-stable-18461960cbf50bf345ef0667d45d5f64de8fb893.tar.bz2 linux-stable-18461960cbf50bf345ef0667d45d5f64de8fb893.zip |
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 <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm/processor.h')
-rw-r--r-- | arch/powerpc/include/asm/processor.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index afe695e9feb8..ea88e7bd4a34 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -211,6 +211,7 @@ struct thread_struct { #endif #endif struct thread_fp_state fp_state; + struct thread_fp_state *fp_save_area; int fpexc_mode; /* floating-point exception mode */ unsigned int align_ctl; /* alignment handling control */ #ifdef CONFIG_PPC64 @@ -229,6 +230,7 @@ struct thread_struct { unsigned long trap_nr; /* last trap # on this thread */ #ifdef CONFIG_ALTIVEC struct thread_vr_state vr_state; + struct thread_vr_state *vr_save_area; unsigned long vrsave; int used_vr; /* set if process has used altivec */ #endif /* CONFIG_ALTIVEC */ @@ -357,6 +359,11 @@ extern int set_endian(struct task_struct *tsk, unsigned int val); extern int get_unalign_ctl(struct task_struct *tsk, unsigned long adr); extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val); +extern void load_fp_state(struct thread_fp_state *fp); +extern void store_fp_state(struct thread_fp_state *fp); +extern void load_vr_state(struct thread_vr_state *vr); +extern void store_vr_state(struct thread_vr_state *vr); + static inline unsigned int __unpack_fe01(unsigned long msr_bits) { return ((msr_bits & MSR_FE0) >> 10) | ((msr_bits & MSR_FE1) >> 8); |