FAILED: patch "[PATCH] x86/MCE/AMD: Clear DFR errors found in THR handler" failed to apply to 5.4-stable tree

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Possible dependencies:

bc1b705b0eee ("x86/MCE/AMD: Clear DFR errors found in THR handler") 8121b8f947be ("x86/mce: Get rid of msr_ops")
c9bf318f77b3 ("x86/mce/amd: Init thresholding machinery only on relevant vendors") 6e5cf31fbe65 ("x86/mce/amd: Publish the bank pointer only after setup has succeeded")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From bc1b705b0eee4c645ad8b3bbff3c8a66e9688362 Mon Sep 17 00:00:00 2001
From: Yazen Ghannam <[email protected]>
Date: Tue, 21 Jun 2022 15:59:43 +0000
Subject: [PATCH] x86/MCE/AMD: Clear DFR errors found in THR handler

AMD's MCA Thresholding feature counts errors of all severity levels, not just correctable errors. If a deferred error causes the threshold limit to be reached (it was the error that caused the overflow), then both a deferred error interrupt and a thresholding interrupt will be triggered.

The order of the interrupts is not guaranteed. If the threshold interrupt handler is executed first, then it will clear MCA_STATUS for the error. It will not check or clear MCA_DESTAT which also holds a copy of the deferred error. When the deferred error interrupt handler runs it will not find an error in MCA_STATUS, but it will find the error in MCA_DESTAT. This will cause two errors to be logged.

Check for deferred errors when handling a threshold interrupt. If a bank contains a deferred error, then clear the bank's MCA_DESTAT register.

Define a new helper function to do the deferred error check and clearing of MCA_DESTAT.

[ bp: Simplify, convert comment to passive voice. ]

index 1c87501e0fa3..10fb5b5c9efa 100644
@@ -788,6 +788,24 @@ _log_error_bank(unsigned int bank, u32 msr_stat, u32 msr_addr, u64 misc)
 	return status & MCI_STATUS_DEFERRED;
 }
 
+static bool _log_error_deferred(unsigned int bank, u32 misc)
+{
+	if (!_log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS),
+			     mca_msr_reg(bank, MCA_ADDR), misc))
+		return false;
+
+	/*
+	 * Non-SMCA systems don't have MCA_DESTAT/MCA_DEADDR registers.
+	 * Return true here to avoid accessing these registers.
+	 */
+	if (!mce_flags.smca)
+		return true;
+
+	/* Clear MCA_DESTAT if the deferred error was logged from MCA_STATUS. */
+	wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), 0);
+	return true;
+}
+
 /*
  * We have three scenarios for checking for Deferred errors:
  *

@@ -799,19 +817,8 @@ _log_error_bank(unsigned int bank, u32 msr_stat, u32 msr_addr, u64 misc)
  */
 static void log_error_deferred(unsigned int bank)
 {
-	bool defrd;
-
-	defrd = _log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS),
-				mca_msr_reg(bank, MCA_ADDR), 0);
-
-	if (!mce_flags.smca)
-		return;
-
-	/* Clear MCA_DESTAT if we logged the deferred error from MCA_STATUS. */
-	if (defrd) {
-		wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), 0);
+	if (_log_error_deferred(bank, 0))
 		return;
-	}
 
 	/*
 	 * Only deferred errors are logged in MCA_DE{STAT,ADDR} so just check

@@ -832,7 +839,7 @@ static void amd_deferred_error_interrupt(void)
 
 static void log_error_thresholding(unsigned int bank, u64 misc)
 {
-	_log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS), mca_msr_reg(bank, MCA_ADDR), misc);
+	_log_error_deferred(bank, misc);
 }
 
 static void log_and_reset_block(struct threshold_block *block)