diff options
Diffstat (limited to 'include/asm-parisc/assembly.h')
| -rw-r--r-- | include/asm-parisc/assembly.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/include/asm-parisc/assembly.h b/include/asm-parisc/assembly.h index 30b023411fef..b24a99e3ef9c 100644 --- a/include/asm-parisc/assembly.h +++ b/include/asm-parisc/assembly.h @@ -450,5 +450,30 @@ REST_CR (%cr22, PT_PSW (\regs)) .endm + + /* First step to create a "relied upon translation" + * See PA 2.0 Arch. page F-4 and F-5. + * + * The ssm was originally necessary due to a "PCxT bug". + * But someone decided it needed to be added to the architecture + * and this "feature" went into rev3 of PA-RISC 1.1 Arch Manual. + * It's been carried forward into PA 2.0 Arch as well. :^( + * + * "ssm 0,%r0" is a NOP with side effects (prefetch barrier). + * rsm/ssm prevents the ifetch unit from speculatively fetching + * instructions past this line in the code stream. + * PA 2.0 processor will single step all insn in the same QUAD (4 insn). + */ + .macro pcxt_ssm_bug + rsm PSW_SM_I,%r0 + nop /* 1 */ + nop /* 2 */ + nop /* 3 */ + nop /* 4 */ + nop /* 5 */ + nop /* 6 */ + nop /* 7 */ + .endm + #endif /* __ASSEMBLY__ */ #endif |