There are a number of generic and vendor-specific status checks in
machine_check_poll(). These are used to determine if an error should be
skipped.
Move these into helper functions. Future vendor-specific checks will be
added to the helpers.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---
arch/x86/kernel/cpu/mce/core.c | 79 +++++++++++++++++-----------------
1 file changed, 39 insertions(+), 40 deletions(-)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 70c8df1a766a..704e651203b4 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -662,6 +662,44 @@ static noinstr void mce_read_aux(struct mce *m, int i)
DEFINE_PER_CPU(unsigned, mce_poll_count);
+static bool ser_log_poll_error(struct mce *m)
+{
+ /* Log "not enabled" (speculative) errors */
+ if (!(m->status & MCI_STATUS_EN))
+ return true;
+
+ /*
+ * Log UCNA (SDM: 15.6.3 "UCR Error Classification")
+ * UC == 1 && PCC == 0 && S == 0
+ */
+ if (!(m->status & MCI_STATUS_PCC) && !(m->status & MCI_STATUS_S))
+ return true;
+
+ return false;
+}
+
+static bool log_poll_error(enum mcp_flags flags, struct mce *m)
+{
+ /* If this entry is not valid, ignore it. */
+ if (!(m->status & MCI_STATUS_VAL))
+ return false;
+
+ /*
+ * If we are logging everything (at CPU online) or this
+ * is a corrected error, then we must log it.
+ */
+ if ((flags & MCP_UC) || !(m->status & MCI_STATUS_UC))
+ return true;
+
+ if (mca_cfg.ser)
+ return ser_log_poll_error(m);
+
+ if (m->status & MCI_STATUS_UC)
+ return false;
+
+ return true;
+}
+
/*
* Poll for corrected events or events that happened before reset.
* Those are just logged through /dev/mcelog.
@@ -709,48 +747,9 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
if (!mca_cfg.cmci_disabled)
mce_track_storm(&m);
- /* If this entry is not valid, ignore it */
- if (!(m.status & MCI_STATUS_VAL))
+ if (!log_poll_error(flags, &m))
continue;
- /*
- * If we are logging everything (at CPU online) or this
- * is a corrected error, then we must log it.
- */
- if ((flags & MCP_UC) || !(m.status & MCI_STATUS_UC))
- goto log_it;
-
- /*
- * Newer Intel systems that support software error
- * recovery need to make additional checks. Other
- * CPUs should skip over uncorrected errors, but log
- * everything else.
- */
- if (!mca_cfg.ser) {
- if (m.status & MCI_STATUS_UC)
- continue;
- goto log_it;
- }
-
- /* Log "not enabled" (speculative) errors */
- if (!(m.status & MCI_STATUS_EN))
- goto log_it;
-
- /*
- * Log UCNA (SDM: 15.6.3 "UCR Error Classification")
- * UC == 1 && PCC == 0 && S == 0
- */
- if (!(m.status & MCI_STATUS_PCC) && !(m.status & MCI_STATUS_S))
- goto log_it;
-
- /*
- * Skip anything else. Presumption is that our read of this
- * bank is racing with a machine check. Leave the log alone
- * for do_machine_check() to deal with it.
- */
- continue;
-
-log_it:
if (flags & MCP_DONTLOG)
goto clear_it;
--
2.34.1On Thu, May 23, 2024 at 10:56:36AM -0500, Yazen Ghannam wrote:
> @@ -709,48 +747,9 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
> if (!mca_cfg.cmci_disabled)
> mce_track_storm(&m);
>
> - /* If this entry is not valid, ignore it */
> - if (!(m.status & MCI_STATUS_VAL))
> + if (!log_poll_error(flags, &m))
> continue;
>
> - /*
> - * If we are logging everything (at CPU online) or this
> - * is a corrected error, then we must log it.
> - */
> - if ((flags & MCP_UC) || !(m.status & MCI_STATUS_UC))
> - goto log_it;
> -
> - /*
> - * Newer Intel systems that support software error
> - * recovery need to make additional checks. Other
> - * CPUs should skip over uncorrected errors, but log
> - * everything else.
> - */
You lost that comment.
> - if (!mca_cfg.ser) {
> - if (m.status & MCI_STATUS_UC)
> - continue;
> - goto log_it;
> - }
> -
> - /* Log "not enabled" (speculative) errors */
> - if (!(m.status & MCI_STATUS_EN))
> - goto log_it;
> -
> - /*
> - * Log UCNA (SDM: 15.6.3 "UCR Error Classification")
> - * UC == 1 && PCC == 0 && S == 0
> - */
> - if (!(m.status & MCI_STATUS_PCC) && !(m.status & MCI_STATUS_S))
> - goto log_it;
> -
> - /*
> - * Skip anything else. Presumption is that our read of this
> - * bank is racing with a machine check. Leave the log alone
> - * for do_machine_check() to deal with it.
> - */
> - continue;
> -
> -log_it:
> if (flags & MCP_DONTLOG)
> goto clear_it;
Btw, the code looks really weird now:
if (!log_poll_error(flags, &m))
continue;
if (flags & MCP_DONTLOG)
goto clear_it;
i.e.,
1. Should I log it?
2. Should I not log it?
Oh well, it was like that before logically so...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
On Mon, Jun 03, 2024 at 07:37:27PM +0200, Borislav Petkov wrote:
> On Thu, May 23, 2024 at 10:56:36AM -0500, Yazen Ghannam wrote:
> > @@ -709,48 +747,9 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
> > if (!mca_cfg.cmci_disabled)
> > mce_track_storm(&m);
> >
> > - /* If this entry is not valid, ignore it */
> > - if (!(m.status & MCI_STATUS_VAL))
> > + if (!log_poll_error(flags, &m))
> > continue;
> >
> > - /*
> > - * If we are logging everything (at CPU online) or this
> > - * is a corrected error, then we must log it.
> > - */
> > - if ((flags & MCP_UC) || !(m.status & MCI_STATUS_UC))
> > - goto log_it;
> > -
> > - /*
> > - * Newer Intel systems that support software error
> > - * recovery need to make additional checks. Other
> > - * CPUs should skip over uncorrected errors, but log
> > - * everything else.
> > - */
>
> You lost that comment.
>
Sorry, will keep it.
> > - if (!mca_cfg.ser) {
> > - if (m.status & MCI_STATUS_UC)
> > - continue;
> > - goto log_it;
> > - }
> > -
> > - /* Log "not enabled" (speculative) errors */
> > - if (!(m.status & MCI_STATUS_EN))
> > - goto log_it;
> > -
> > - /*
> > - * Log UCNA (SDM: 15.6.3 "UCR Error Classification")
> > - * UC == 1 && PCC == 0 && S == 0
> > - */
> > - if (!(m.status & MCI_STATUS_PCC) && !(m.status & MCI_STATUS_S))
> > - goto log_it;
> > -
> > - /*
> > - * Skip anything else. Presumption is that our read of this
> > - * bank is racing with a machine check. Leave the log alone
> > - * for do_machine_check() to deal with it.
> > - */
> > - continue;
> > -
> > -log_it:
> > if (flags & MCP_DONTLOG)
> > goto clear_it;
>
> Btw, the code looks really weird now:
>
> if (!log_poll_error(flags, &m))
> continue;
>
> if (flags & MCP_DONTLOG)
> goto clear_it;
>
> i.e.,
>
> 1. Should I log it?
>
> 2. Should I not log it?
>
> Oh well, it was like that before logically so...
>
We can rename the new function and add comments. What do you think of
the change below?
Thanks,
Yazen
@@ -797,9 +797,11 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
if (!mca_cfg.cmci_disabled)
mce_track_storm(&m);
- if (!log_poll_error(flags, &m, &status_reg))
+ /* Verify that the error should be logged based on hardware conditions. */
+ if (!loggable_poll_error(flags, &m, &status_reg))
continue;
+ /* Clear a loggable error, e.g., one leftover from boot time. */
if (flags & MCP_DONTLOG)
goto clear_it;
On Fri, Jul 26, 2024 at 10:00:30AM -0400, Yazen Ghannam wrote:
> @@ -797,9 +797,11 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
> if (!mca_cfg.cmci_disabled)
> mce_track_storm(&m);
>
> - if (!log_poll_error(flags, &m, &status_reg))
> + /* Verify that the error should be logged based on hardware conditions. */
> + if (!loggable_poll_error(flags, &m, &status_reg))
Right, or do
if (!should_log_poll_error(...)
as it becomes maximally readable then - like a plain English sentence.
> continue;
>
> + /* Clear a loggable error, e.g., one leftover from boot time. */
> if (flags & MCP_DONTLOG)
> goto clear_it;
So yeah, I guess.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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