powerpc: Rework pseries machine check handler
Rework pseries machine check handler:
- If MSR_RI isn't set, we cannot recover even if the machine check was fully
recovered
- Rename nonfatal to recovered
- Handle RTAS_DISP_LIMITED_RECOVERY
- Use BUS_MCEERR_AR instead of BUS_ADRERR
- Don't check all the RTAS error log fields when receiving a synchronous
machine check. Recent versions of the pseries firmware do not fill them
in during a machine check and instead send a follow up error log with
the detailed information. If we see a synchronous machine check, and we
came from userspace then kill the task.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 048e257..d194150 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -259,31 +259,43 @@
* Return 1 if corrected (or delivered a signal).
* Return 0 if there is nothing we can do.
*/
-static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err)
+static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err)
{
- int nonfatal = 0;
+ int recovered = 0;
- if (err->disposition == RTAS_DISP_FULLY_RECOVERED) {
+ if (!(regs->msr & MSR_RI)) {
+ /* If MSR_RI isn't set, we cannot recover */
+ recovered = 0;
+
+ } else if (err->disposition == RTAS_DISP_FULLY_RECOVERED) {
/* Platform corrected itself */
- nonfatal = 1;
- } else if ((regs->msr & MSR_RI) &&
- user_mode(regs) &&
- err->severity == RTAS_SEVERITY_ERROR_SYNC &&
- err->disposition == RTAS_DISP_NOT_RECOVERED &&
- err->target == RTAS_TARGET_MEMORY &&
- err->type == RTAS_TYPE_ECC_UNCORR &&
- !(current->pid == 0 || is_global_init(current))) {
- /* Kill off a user process with an ECC error */
- printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n",
- current->pid);
- /* XXX something better for ECC error? */
- _exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
- nonfatal = 1;
+ recovered = 1;
+
+ } else if (err->disposition == RTAS_DISP_LIMITED_RECOVERY) {
+ /* Platform corrected itself but could be degraded */
+ printk(KERN_ERR "MCE: limited recovery, system may "
+ "be degraded\n");
+ recovered = 1;
+
+ } else if (user_mode(regs) && !is_global_init(current) &&
+ err->severity == RTAS_SEVERITY_ERROR_SYNC) {
+
+ /*
+ * If we received a synchronous error when in userspace
+ * kill the task. Firmware may report details of the fail
+ * asynchronously, so we can't rely on the target and type
+ * fields being valid here.
+ */
+ printk(KERN_ERR "MCE: uncorrectable error, killing task "
+ "%s:%d\n", current->comm, current->pid);
+
+ _exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
+ recovered = 1;
}
log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
- return nonfatal;
+ return recovered;
}
/*