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authorMichael Neuling <mikey@neuling.org>2008-06-25 14:07:18 +1000
committerPaul Mackerras <paulus@samba.org>2008-07-01 11:28:50 +1000
commitce48b2100785e5ca629fb3aa8e3b50aca808f692 (patch)
tree63532ff7cc68b18ca4902bd10e03fcbaaf01cade /arch/powerpc/kernel/misc_64.S
parent72ffff5b1792b0fa4d40a8e2f3276fff999820ec (diff)
powerpc: Add VSX context save/restore, ptrace and signal support
This patch extends the floating point save and restore code to use the VSX load/stores when VSX is available. This will make FP context save/restore marginally slower on FP only code, when VSX is available, as it has to load/store 128bits rather than just 64bits. Mixing FP, VMX and VSX code will get constant architected state. The signals interface is extended to enable access to VSR 0-31 doubleword 1 after discussions with tool chain maintainers. Backward compatibility is maintained. The ptrace interface is also extended to allow access to VSR 0-31 full registers. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/misc_64.S')
-rw-r--r--arch/powerpc/kernel/misc_64.S33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 942951e76586..31b9026cf1e3 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -506,6 +506,39 @@ _GLOBAL(giveup_altivec)
#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_VSX
+/*
+ * giveup_vsx(tsk)
+ * Disable VSX for the task given as the argument,
+ * and save the vector registers in its thread_struct.
+ * Enables the VSX for use in the kernel on return.
+ */
+_GLOBAL(giveup_vsx)
+ mfmsr r5
+ oris r5,r5,MSR_VSX@h
+ mtmsrd r5 /* enable use of VSX now */
+ isync
+
+ cmpdi 0,r3,0
+ beqlr- /* if no previous owner, done */
+ addi r3,r3,THREAD /* want THREAD of task */
+ ld r5,PT_REGS(r3)
+ cmpdi 0,r5,0
+ beq 1f
+ ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ lis r3,MSR_VSX@h
+ andc r4,r4,r3 /* disable VSX for previous task */
+ std r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#ifndef CONFIG_SMP
+ li r5,0
+ ld r4,last_task_used_vsx@got(r2)
+ std r5,0(r4)
+#endif /* CONFIG_SMP */
+ blr
+
+#endif /* CONFIG_VSX */
+
/* kexec_wait(phys_cpu)
*
* wait for the flag to change, indicating this kernel is going away but