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Make ia64_mca_save_state MP safe. Protect access to the info block,

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updating the sysctl tree and clearing the SAL state by a spin lock.
This commit is contained in:
Marcel Moolenaar 2002-05-01 22:10:03 +00:00
parent f77e6d9569
commit 0e09ff93a3
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=95892
1 changed files with 57 additions and 9 deletions
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66
sys/ia64/ia64/mca.c
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@ -29,7 +29,9 @@
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
@ -41,6 +43,7 @@ MALLOC_DEFINE(M_MCA, "MCA", "Machine Check Architecture");
int64_t mca_info_size[SAL_INFO_TYPES];
vm_offset_t mca_info_block;
struct mtx mca_info_block_lock;
SYSCTL_NODE(_hw, OID_AUTO, mca, CTLFLAG_RW, 0, "MCA container");
@ -78,6 +81,7 @@ ia64_mca_save_state(int type)
struct mca_record_header *hdr;
struct sysctl_oid *oidp;
char *name, *state;
uint64_t seqnr;
size_t recsz, totsz;
/*
@ -88,20 +92,48 @@ ia64_mca_save_state(int type)
return;
while (1) {
mtx_lock_spin(&mca_info_block_lock);
result = ia64_sal_entry(SAL_GET_STATE_INFO, type, 0,
mca_info_block, 0, 0, 0, 0);
if (result.sal_status < 0) /* any error records? */
if (result.sal_status < 0) {
mtx_unlock_spin(&mca_info_block_lock);
return;
}
hdr = (struct mca_record_header *)mca_info_block;
recsz = hdr->rh_length;
totsz = sizeof(struct sysctl_oid) + recsz + 16;
seqnr = hdr->rh_seqnr;
mtx_unlock_spin(&mca_info_block_lock);
totsz = sizeof(struct sysctl_oid) + recsz + 32;
oidp = malloc(totsz, M_MCA, M_WAITOK|M_ZERO);
state = (char*)(oidp + 1);
name = state + recsz;
sprintf(name, "%lld", (long long)seqnr);
mtx_lock_spin(&mca_info_block_lock);
/*
* If the info block doesn't have our record anymore because
* we temporarily unlocked it, get it again from SAL. I assume
* that it's possible that we could get a different record.
* I expect this to happen in a SMP configuration where the
* record has been cleared by a different processor. So, if
* we get a different record we simply abort with this record
* and start over.
*/
if (seqnr != hdr->rh_seqnr) {
result = ia64_sal_entry(SAL_GET_STATE_INFO, type, 0,
mca_info_block, 0, 0, 0, 0);
if (seqnr != hdr->rh_seqnr) {
mtx_unlock_spin(&mca_info_block_lock);
free(oidp, M_MCA);
continue;
}
}
sprintf(name, "%d", hdr->rh_seqnr);
bcopy((char*)mca_info_block, state, recsz);
oidp->oid_parent = &sysctl__hw_mca_children;
@ -113,21 +145,27 @@ ia64_mca_save_state(int type)
oidp->oid_handler = mca_sysctl_handler;
oidp->oid_fmt = "S,MCA";
oidp->descr = "Error record";
sysctl_register_oid(oidp);
if (mca_count > 0) {
if (hdr->rh_seqnr < mca_first)
mca_first = hdr->rh_seqnr;
else if (hdr->rh_seqnr > mca_last)
mca_last = hdr->rh_seqnr;
if (seqnr < mca_first)
mca_first = seqnr;
else if (seqnr > mca_last)
mca_last = seqnr;
} else
mca_first = mca_last = hdr->rh_seqnr;
mca_first = mca_last = seqnr;
mca_count++;
/* Clear the record */
/*
* Clear the state so that we get any other records when
* they exist.
*/
result = ia64_sal_entry(SAL_CLEAR_STATE_INFO, type, 0, 0, 0,
0, 0, 0);
mtx_unlock_spin(&mca_info_block_lock);
}
}
@ -168,6 +206,16 @@ ia64_mca_init(void)
printf("MCA: allocated %d bytes for state information\n",
max_size);
/*
* Initialize the spin lock used to protect the info block. When APs
* get launched, there's a short moment of contention, but in all other
* cases it's not a hot spot. I think it's possible to have the MCA
* handler be called on multiple processors at the same time, but that
* should be rare. On top of that, performance is not an issue when
* dealing with machine checks...
*/
mtx_init(&mca_info_block_lock, "MCA spin lock", NULL, MTX_SPIN);
/*
* Get and save any processor and platfom error records. Note that in
* a SMP configuration the processor records are for the BSP only. We