Add an HV variant of FIXUP_ENDIAN which uses HSRR[01] and does not
clear MSR[RI], which improves recoverability.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/include/asm/ppc_asm.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/arch/powerpc/include/asm/ppc_asm.h
b/arch/powerpc/include/asm/ppc_asm.h
index d6b56aebe602..ae94b3626b6c 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -774,6 +774,10 @@ END_FTR_SECTION_IFCLR(CPU_FTR_601)
#ifdef CONFIG_PPC_BOOK3E
#define FIXUP_ENDIAN
#else
+/*
+ * This version may be used in in HV or non-HV context.
+ * MSR[EE] must be disabled.
+ */
#define FIXUP_ENDIAN \
tdi 0,0,0x48; /* Reverse endian of b . + 8 */ \
b 191f; /* Skip trampoline if endian is good */ \
@@ -789,6 +793,24 @@ END_FTR_SECTION_IFCLR(CPU_FTR_601)
.long 0x2400004c; /* rfid */ \
191:
+/*
+ * This version that may only be used with MSR[HV]=1
+ * - Does not clear MSR[RI], so more robust.
+ * - Slightly smaller and faster.
+ */
+#define FIXUP_ENDIAN_HV \
+ tdi 0,0,0x48; /* Reverse endian of b . + 8 */ \
+ b 191f; /* Skip trampoline if endian is good */ \
+ .long 0xa600607d; /* mfmsr r11 */ \
+ .long 0x01006b69; /* xori r11,r11,1 */ \
+ .long 0x05009f42; /* bcl 20,31,$+4 */ \
+ .long 0xa602487d; /* mflr r10 */ \
+ .long 0x14004a39; /* addi r10,r10,20 */ \
+ .long 0xa64b5a7d; /* mthsrr0 r10 */ \
+ .long 0xa64b7b7d; /* mthsrr1 r11 */ \
+ .long 0x2402004c; /* hrfid */ \
+191:
+
#endif /* !CONFIG_PPC_BOOK3E */
#endif /* __ASSEMBLY__ */
--
2.13.3
