linux-kernel - [PATCH v2] x86/mce: Always save severity in machine_check

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Date:   Wed, 21 Jun 2017 14:46:42 -0500
From:   Yazen Ghannam <Yazen.Ghannam@....com>
To:     linux-edac@...r.kernel.org
Cc:     Borislav Petkov <bp@...e.de>, Tony Luck <tony.luck@...el.com>,
        x86@...nel.org, linux-kernel@...r.kernel.org,
        Yazen Ghannam <yazen.ghannam@....com>
Subject: [PATCH v2] x86/mce: Always save severity in machine_check_poll

From: Yazen Ghannam <yazen.ghannam@....com>

The severity gives a hint as to how to handle the error. The notifier
blocks can then use the severity to decide on an action. It's not necessary
for machine_check_poll() to filter errors for the notifier chain, since
each block will check its own set of conditions before handling an error.
Also, there isn't any urgency for machine_check_poll() to make decisions
based on severity like in do_machine_check().

If we can assume that a severity is set then we can use them in more
notifier blocks. For example, the CEC block can check for a "KEEP" severity
rather than checking bits in the status. This isn't possible now since the
severity is not set except for "DEFFRRED/UCNA" errors with a valid address.

Save the severity since we have it, and let the notifier blocks decide if
they want to do anything.

Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
---
Link:
https://lkml.kernel.org/r/1497286446-59533-1-git-send-email-Yazen.Ghannam@amd.com

v1->v2:
* Expand commit message.

 arch/x86/kernel/cpu/mcheck/mce.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index b58b77808ce4..6dde0497efc7 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -673,7 +673,6 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
 {
 	bool error_seen = false;
 	struct mce m;
-	int severity;
 	int i;

 	this_cpu_inc(mce_poll_count);
@@ -710,11 +709,7 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)

 		mce_read_aux(&m, i);

-		severity = mce_severity(&m, mca_cfg.tolerant, NULL, false);
-
-		if (severity == MCE_DEFERRED_SEVERITY && mce_is_memory_error(&m))
-			if (m.status & MCI_STATUS_ADDRV)
-				m.severity = severity;
+		m.severity = mce_severity(&m, mca_cfg.tolerant, NULL, false);

 		/*
 		 * Don't get the IP here because it's unlikely to
-- 
2.7.4