i7core_edac: Use a lockless ringbuffer

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Mauro Carvalho Chehab 2009-10-04 10:15:40 -03:00
parent b968759ee7
commit ca9c90ba09

View File

@ -28,7 +28,6 @@
#include <linux/edac.h>
#include <linux/mmzone.h>
#include <linux/edac_mce.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <asm/processor.h>
@ -239,9 +238,16 @@ struct i7core_pvt {
/* mcelog glue */
struct edac_mce edac_mce;
/* Fifo double buffers */
struct mce mce_entry[MCE_LOG_LEN];
unsigned mce_count;
spinlock_t mce_lock;
struct mce mce_outentry[MCE_LOG_LEN];
/* Fifo in/out counters */
unsigned mce_in, mce_out;
/* Count indicator to show errors not got */
unsigned mce_overrun;
};
/* Static vars */
@ -1617,30 +1623,50 @@ static void i7core_check_error(struct mem_ctl_info *mci)
struct i7core_pvt *pvt = mci->pvt_info;
int i;
unsigned count = 0;
struct mce *m = NULL;
unsigned long flags;
struct mce *m;
/* Copy all mce errors into a temporary buffer */
spin_lock_irqsave(&pvt->mce_lock, flags);
if (pvt->mce_count) {
m = kmalloc(sizeof(*m) * pvt->mce_count, GFP_ATOMIC);
/*
* MCE first step: Copy all mce errors into a temporary buffer
* We use a double buffering here, to reduce the risk of
* loosing an error.
*/
smp_rmb();
count = (pvt->mce_out + sizeof(mce_entry) - pvt->mce_in)
% sizeof(mce_entry);
if (!count)
return;
if (m) {
count = pvt->mce_count;
memcpy(m, &pvt->mce_entry, sizeof(*m) * count);
}
pvt->mce_count = 0;
m = pvt->mce_outentry;
if (pvt->mce_in + count > sizeof(mce_entry)) {
unsigned l = sizeof(mce_entry) - pvt->mce_in;
memcpy(m, &pvt->mce_entry[pvt->mce_in], sizeof(*m) * l);
smp_wmb();
pvt->mce_in = 0;
count -= l;
m += l;
}
memcpy(m, &pvt->mce_entry[pvt->mce_in], sizeof(*m) * count);
smp_wmb();
pvt->mce_in += count;
smp_rmb();
if (pvt->mce_overrun) {
i7core_printk(KERN_ERR, "Lost %d memory errors\n",
pvt->mce_overrun);
smp_wmb();
pvt->mce_overrun = 0;
}
spin_unlock_irqrestore(&pvt->mce_lock, flags);
/* proccess mcelog errors */
/*
* MCE second step: parse errors and display
*/
for (i = 0; i < count; i++)
i7core_mce_output_error(mci, &m[i]);
i7core_mce_output_error(mci, &pvt->mce_outentry[i]);
kfree(m);
/* check memory count errors */
/*
* Now, let's increment CE error counts
*/
if (!pvt->is_registered)
i7core_udimm_check_mc_ecc_err(mci);
else
@ -1657,7 +1683,6 @@ static int i7core_mce_check_error(void *priv, struct mce *mce)
{
struct mem_ctl_info *mci = priv;
struct i7core_pvt *pvt = mci->pvt_info;
unsigned long flags;
/*
* Just let mcelog handle it if the error is
@ -1679,12 +1704,15 @@ static int i7core_mce_check_error(void *priv, struct mce *mce)
return 0;
}
spin_lock_irqsave(&pvt->mce_lock, flags);
if (pvt->mce_count < MCE_LOG_LEN) {
memcpy(&pvt->mce_entry[pvt->mce_count], mce, sizeof(*mce));
pvt->mce_count++;
smp_rmb();
if ((pvt->mce_out + 1) % sizeof(mce_entry) == pvt->mce_in) {
smp_wmb();
pvt->mce_overrun++;
return 0;
}
spin_unlock_irqrestore(&pvt->mce_lock, flags);
smp_wmb();
pvt->mce_out = (pvt->mce_out + 1) % sizeof(mce_entry);
memcpy(&pvt->mce_entry[pvt->mce_out], mce, sizeof(*mce));
/* Handle fatal errors immediately */
if (mce->mcgstatus & 1)
@ -1777,7 +1805,6 @@ static int i7core_register_mci(struct i7core_dev *i7core_dev,
/* Registers on edac_mce in order to receive memory errors */
pvt->edac_mce.priv = mci;
pvt->edac_mce.check_error = i7core_mce_check_error;
spin_lock_init(&pvt->mce_lock);
rc = edac_mce_register(&pvt->edac_mce);
if (unlikely(rc < 0)) {