diff options
| -rw-r--r-- | sys/arch/sparc64/sparc64/locore.s | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/sys/arch/sparc64/sparc64/locore.s b/sys/arch/sparc64/sparc64/locore.s index 4eafbf2f531..7d457609bcc 100644 --- a/sys/arch/sparc64/sparc64/locore.s +++ b/sys/arch/sparc64/sparc64/locore.s @@ -1,4 +1,4 @@ -/* $OpenBSD: locore.s,v 1.157 2009/01/23 19:16:39 kettenis Exp $ */ +/* $OpenBSD: locore.s,v 1.158 2009/04/30 11:36:57 kettenis Exp $ */ /* $NetBSD: locore.s,v 1.137 2001/08/13 06:10:10 jdolecek Exp $ */ /* @@ -108,7 +108,14 @@ _C_LABEL(sun4v_mp_patch): .previous #endif +/* + * The UltraSPARC T1 has a "feature" where a LDXA/STXA to ASI_SCRATCHPAD + * registers may corrupt an unrelated integer register file register. + * To prevent this, it is required to have a non-store or NOP instruction + * before any LDXA/STXA to this register. + */ #define GET_CPUINFO_VA(ci) \ + nop ;\ 999: set CPUINFO_VA, ci ;\ .section .sun4v_mp_patch, "ax" ;\ .word 999b ;\ |