On Fri, Aug 01, 2008 at 06:43:08PM -0500, James Bottomley wrote: > On Fri, 2008-08-01 at 16:24 -0700, Luck, Tony wrote: > > Recent kernels are not booting on some HP systems (though > > it does boot on others). James spent time and tracked it > > to this patch in the pvops series: > > > > commit 498c5170472ff0c03a29d22dbd33225a0be038f4 > > Author: Isaku Yamahata <yamahata@xxxxxxxxxxxxx> > > Date: Mon May 19 22:13:38 2008 +0900 > > > > [IA64] pvops: paravirtualize ivt.S > > > > I did a quick compile with and without this patch applied and > > compared the diassembled ivt.o file and spotted two places > > where an _FROM_ macro had been used where _TO_ was intended. > > See the <<<<< OOPS below: > > > > > > @@ -1360,26 +1357,26 @@ ENTRY(speculation_vector) > > * > > * cr.imm contains zero_ext(imm21) > > */ > > - mov r18=cr.iim > > + MOV_FROM_IIM(r18) > > ;; > > - mov r17=cr.iip > > + MOV_FROM_IIP(r17) > > shl r18=r18,43 // put sign bit in position (43=64-21) > > ;; > > > > - mov r16=cr.ipsr > > + MOV_FROM_IPSR(p0, r16) > > shr r18=r18,39 // sign extend (39=43-4) > > ;; > > > > add r17=r17,r18 // now add the offset > > ;; > > - mov cr.iip=r17 > > + MOV_FROM_IIP(r17) <<<<<<< OOPS! > > dep r16=0,r16,41,2 // clear EI > > ;; > > > > - mov cr.ipsr=r16 > > + MOV_FROM_IPSR(p0, r16) <<<<<<<< OOPS! > > ;; > > > > - rfi // and go back > > + RFI > > END(speculation_vector) > > > > > > I don't know whether these are the cause of the problems on James' > > and Willy's machines (could you try swapping these round please?) > > Actually tony traced this to errors in the statements by comparing > disassembled output. There's two register moves that are now the wrong > way around. Applying this patch gets my system booting again. > > James > > --- > > diff --git a/arch/ia64/kernel/ivt.S b/arch/ia64/kernel/ivt.S > index c39627d..b8750a0 100644 > --- a/arch/ia64/kernel/ivt.S > +++ b/arch/ia64/kernel/ivt.S > @@ -1243,11 +1243,11 @@ ENTRY(speculation_vector) > > add r17=r17,r18 // now add the offset > ;; > - MOV_FROM_IIP(r17) > + MOV_TO_IIP(r17, p0) > dep r16=0,r16,41,2 // clear EI > ;; > > - MOV_FROM_IPSR(p0, r16) > + MOV_TO_IPSR(p0, r16, p0) > ;; > > RFI Ouch. Sorry for those. The last argument for those macro should be regular register. Here is the patch. >From cc61356b6cb83aad5e798c402fe2a323953bb3de Mon Sep 17 00:00:00 2001 From: Isaku Yamahata <yamahata@xxxxxxxxxxxxx> Date: Mon, 4 Aug 2008 12:02:28 +0900 Subject: [PATCH] [IA64] pv_ops: fix ivt.S paravirtualization Recent kernels are not booting on some HP systems (though it does boot on others). Two instructions were wrongly paravirtualized such that an _FROM_ macro had been used where _TO_ was intended by c/s 498c5170472ff0c03a29d22dbd33225a0be038f4. This patch fixes them. Cc: "Luck, Tony" <tony.luck@xxxxxxxxx> Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Cc: "Wilcox, Matthew R" <matthew.r.wilcox@xxxxxxxxx> Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx> --- arch/ia64/kernel/ivt.S | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/ia64/kernel/ivt.S b/arch/ia64/kernel/ivt.S index c39627d..416a952 100644 --- a/arch/ia64/kernel/ivt.S +++ b/arch/ia64/kernel/ivt.S @@ -1243,11 +1243,11 @@ ENTRY(speculation_vector) add r17=r17,r18 // now add the offset ;; - MOV_FROM_IIP(r17) + MOV_TO_IIP(r17, r19) dep r16=0,r16,41,2 // clear EI ;; - MOV_FROM_IPSR(p0, r16) + MOV_TO_IPSR(p0, r16, r19) ;; RFI -- 1.6.0.rc0.42.g186458 -- yamahata -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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