From 9ee27c76393394c7fb1ddeca3f1622d4537185a0 Mon Sep 17 00:00:00 2001 From: Takao Indoh Date: Thu, 19 Nov 2009 16:39:22 -0500 Subject: [IA64] Save I-resources to ia64_sal_os_state This is a patch related to this discussion. http://www.spinics.net/lists/linux-ia64/msg07605.html When INIT is sent, ip/psr/pfs register is stored to the I-resources (iip/ipsr/ifs registers), and they are copied in the min-state save area(pmsa_{iip,ipsr,ifs}). Therefore, in creating pt_regs at ia64_mca_modify_original_stack(), cr_{iip,ipsr,ifs} should be derived from pmsa_{iip,ipsr,ifs}. But current code copies pmsa_{xip,xpsr,xfs} to cr_{iip,ipsr,ifs} when PSR.ic is 0. finish_pt_regs(struct pt_regs *regs, const pal_min_state_area_t *ms, unsigned long *nat) { (snip) if (ia64_psr(regs)->ic) { regs->cr_iip = ms->pmsa_iip; regs->cr_ipsr = ms->pmsa_ipsr; regs->cr_ifs = ms->pmsa_ifs; } else { regs->cr_iip = ms->pmsa_xip; regs->cr_ipsr = ms->pmsa_xpsr; regs->cr_ifs = ms->pmsa_xfs; } It's ok when PSR.ic is not 0. But when PSR.ic is 0, this could be a problem when we investigate kernel as the value of regs->cr_iip does not point to where INIT really interrupted. At first I tried to change finish_pt_regs() so that it uses always pmsa_{iip,ipsr,ifs} for cr_{iip,ipsr,ifs}, but Keith Owens pointed out it could cause another problem if I change it. >The only problem I can think of is an MCA/INIT >arriving while code like SAVE_MIN or SAVE_REST is executing. Back >tracing at that point using pmsa_iip is going to be a problem, you have >no idea what state the registers or stack are in. I confirmed he was right, so I decided to keep it as-is and to save pmsa_{iip,ipsr,ifs} to ia64_sal_os_state for debugging. An attached patch is just adding new members into ia64_sal_os_state to save pmsa_{iip,ipsr,ifs}. Signed-off-by: Takao Indoh Signed-off-by: Tony Luck --- arch/ia64/include/asm/mca.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/ia64/include') diff --git a/arch/ia64/include/asm/mca.h b/arch/ia64/include/asm/mca.h index c171cdf0a789..43f96ab18fa0 100644 --- a/arch/ia64/include/asm/mca.h +++ b/arch/ia64/include/asm/mca.h @@ -106,6 +106,11 @@ struct ia64_sal_os_state { unsigned long os_status; /* OS status to SAL, enum below */ unsigned long context; /* 0 if return to same context 1 if return to new context */ + + /* I-resources */ + unsigned long iip; + unsigned long ipsr; + unsigned long ifs; }; enum { -- cgit v1.2.2