diff options
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 19:37:58 -0500 |
commit | 9ee27c76393394c7fb1ddeca3f1622d4537185a0 (patch) | |
tree | d211485178ade9358e830dc21506db21f6d91cf5 /arch/ia64/kernel/mca.c | |
parent | 09b366b78c9602f53344c269eac608fd6e24d670 (diff) |
[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/kernel/mca.c')
-rw-r--r-- | arch/ia64/kernel/mca.c | 11 |
1 files changed, 8 insertions, 3 deletions
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) | |||
888 | } | 888 | } |
889 | 889 | ||
890 | static void | 890 | static void |
891 | finish_pt_regs(struct pt_regs *regs, const pal_min_state_area_t *ms, | 891 | finish_pt_regs(struct pt_regs *regs, struct ia64_sal_os_state *sos, |
892 | unsigned long *nat) | 892 | unsigned long *nat) |
893 | { | 893 | { |
894 | const pal_min_state_area_t *ms = sos->pal_min_state; | ||
894 | const u64 *bank; | 895 | const u64 *bank; |
895 | 896 | ||
896 | /* If ipsr.ic then use pmsa_{iip,ipsr,ifs}, else use | 897 | /* 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, | |||
904 | regs->cr_iip = ms->pmsa_xip; | 905 | regs->cr_iip = ms->pmsa_xip; |
905 | regs->cr_ipsr = ms->pmsa_xpsr; | 906 | regs->cr_ipsr = ms->pmsa_xpsr; |
906 | regs->cr_ifs = ms->pmsa_xfs; | 907 | regs->cr_ifs = ms->pmsa_xfs; |
908 | |||
909 | sos->iip = ms->pmsa_iip; | ||
910 | sos->ipsr = ms->pmsa_ipsr; | ||
911 | sos->ifs = ms->pmsa_ifs; | ||
907 | } | 912 | } |
908 | regs->pr = ms->pmsa_pr; | 913 | regs->pr = ms->pmsa_pr; |
909 | regs->b0 = ms->pmsa_br0; | 914 | regs->b0 = ms->pmsa_br0; |
@@ -1079,7 +1084,7 @@ ia64_mca_modify_original_stack(struct pt_regs *regs, | |||
1079 | memcpy(old_regs, regs, sizeof(*regs)); | 1084 | memcpy(old_regs, regs, sizeof(*regs)); |
1080 | old_regs->loadrs = loadrs; | 1085 | old_regs->loadrs = loadrs; |
1081 | old_unat = old_regs->ar_unat; | 1086 | old_unat = old_regs->ar_unat; |
1082 | finish_pt_regs(old_regs, ms, &old_unat); | 1087 | finish_pt_regs(old_regs, sos, &old_unat); |
1083 | 1088 | ||
1084 | /* Next stack a struct switch_stack. mca_asm.S built a partial | 1089 | /* Next stack a struct switch_stack. mca_asm.S built a partial |
1085 | * switch_stack, copy it and fill in the blanks using pt_regs and | 1090 | * switch_stack, copy it and fill in the blanks using pt_regs and |
@@ -1150,7 +1155,7 @@ no_mod: | |||
1150 | mprintk(KERN_INFO "cpu %d, %s %s, original stack not modified\n", | 1155 | mprintk(KERN_INFO "cpu %d, %s %s, original stack not modified\n", |
1151 | smp_processor_id(), type, msg); | 1156 | smp_processor_id(), type, msg); |
1152 | old_unat = regs->ar_unat; | 1157 | old_unat = regs->ar_unat; |
1153 | finish_pt_regs(regs, ms, &old_unat); | 1158 | finish_pt_regs(regs, sos, &old_unat); |
1154 | return previous_current; | 1159 | return previous_current; |
1155 | } | 1160 | } |
1156 | 1161 | ||