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-rw-r--r--arch/powerpc/kernel/kvm_emul.S30
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/kvm_emul.S b/arch/powerpc/kernel/kvm_emul.S
index 5cfa2aeeecb0..1dac72dd6f6e 100644
--- a/arch/powerpc/kernel/kvm_emul.S
+++ b/arch/powerpc/kernel/kvm_emul.S
@@ -34,3 +34,33 @@ kvm_hypercall_start:
blr
#define KVM_MAGIC_PAGE (-4096)
+
+#ifdef CONFIG_64BIT
+#define LL64(reg, offs, reg2) ld reg, (offs)(reg2)
+#define STL64(reg, offs, reg2) std reg, (offs)(reg2)
+#else
+#define LL64(reg, offs, reg2) lwz reg, (offs + 4)(reg2)
+#define STL64(reg, offs, reg2) stw reg, (offs + 4)(reg2)
+#endif
+
+#define SCRATCH_SAVE \
+ /* Enable critical section. We are critical if \
+ shared->critical == r1 */ \
+ STL64(r1, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0); \
+ \
+ /* Save state */ \
+ PPC_STL r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0); \
+ PPC_STL r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0); \
+ mfcr r31; \
+ stw r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);
+
+#define SCRATCH_RESTORE \
+ /* Restore state */ \
+ PPC_LL r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0); \
+ lwz r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0); \
+ mtcr r30; \
+ PPC_LL r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0); \
+ \
+ /* Disable critical section. We are critical if \
+ shared->critical == r1 and r2 is always != r1 */ \
+ STL64(r2, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);