From 896a375623c3643a3f189353e7d4828c48a7fdf8 Mon Sep 17 00:00:00 2001 From: Grant Grundler Date: Fri, 21 Oct 2005 22:40:07 -0400 Subject: [PARISC] Make sure use of RFI conforms to PA 2.0 and 1.1 arch docs 2.6.12-rc4-pa3 : first pass at making sure use of RFI conforms to PA 2.0 arch pages F-4 and F-5, PA 1.1 Arch page 3-19 and 3-20. The discussion revolves around all the rules for clearing PSW Q-bit. The hard part is meeting all the rules for "relied upon translation". .align directive is used to guarantee the critical sequence ends more than 8 instructions (32 bytes) from the end of page. Signed-off-by: Grant Grundler Signed-off-by: Kyle McMartin --- include/asm-parisc/assembly.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'include/asm-parisc/assembly.h') 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 -- cgit v1.2.1