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author | Takao Indoh <indou.takao@jp.fujitsu.com> | 2009-11-19 16:39:22 -0500 |
---|---|---|
committer | Tony Luck <tony.luck@intel.com> | 2009-12-14 16:37:58 -0800 |
commit | 9ee27c76393394c7fb1ddeca3f1622d4537185a0 (patch) | |
tree | d211485178ade9358e830dc21506db21f6d91cf5 /arch/ia64 | |
parent | 09b366b78c9602f53344c269eac608fd6e24d670 (diff) | |
download | linux-9ee27c76393394c7fb1ddeca3f1622d4537185a0.tar.gz linux-9ee27c76393394c7fb1ddeca3f1622d4537185a0.tar.bz2 linux-9ee27c76393394c7fb1ddeca3f1622d4537185a0.zip |
[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 <indou.takao@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64')
-rw-r--r-- | arch/ia64/include/asm/mca.h | 5 | ||||
-rw-r--r-- | arch/ia64/kernel/mca.c | 11 |
2 files changed, 13 insertions, 3 deletions
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 { diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c index 496ac7a99488..32f2639e9b0a 100644 --- a/arch/ia64/kernel/mca.c +++ b/arch/ia64/kernel/mca.c @@ -888,9 +888,10 @@ ia64_mca_modify_comm(const struct task_struct *previous_current) } static void -finish_pt_regs(struct pt_regs *regs, const pal_min_state_area_t *ms, +finish_pt_regs(struct pt_regs *regs, struct ia64_sal_os_state *sos, unsigned long *nat) { + const pal_min_state_area_t *ms = sos->pal_min_state; const u64 *bank; /* If ipsr.ic then use pmsa_{iip,ipsr,ifs}, else use @@ -904,6 +905,10 @@ finish_pt_regs(struct pt_regs *regs, const pal_min_state_area_t *ms, regs->cr_iip = ms->pmsa_xip; regs->cr_ipsr = ms->pmsa_xpsr; regs->cr_ifs = ms->pmsa_xfs; + + sos->iip = ms->pmsa_iip; + sos->ipsr = ms->pmsa_ipsr; + sos->ifs = ms->pmsa_ifs; } regs->pr = ms->pmsa_pr; regs->b0 = ms->pmsa_br0; @@ -1079,7 +1084,7 @@ ia64_mca_modify_original_stack(struct pt_regs *regs, memcpy(old_regs, regs, sizeof(*regs)); old_regs->loadrs = loadrs; old_unat = old_regs->ar_unat; - finish_pt_regs(old_regs, ms, &old_unat); + finish_pt_regs(old_regs, sos, &old_unat); /* Next stack a struct switch_stack. mca_asm.S built a partial * switch_stack, copy it and fill in the blanks using pt_regs and @@ -1150,7 +1155,7 @@ no_mod: mprintk(KERN_INFO "cpu %d, %s %s, original stack not modified\n", smp_processor_id(), type, msg); old_unat = regs->ar_unat; - finish_pt_regs(regs, ms, &old_unat); + finish_pt_regs(regs, sos, &old_unat); return previous_current; } |