ACPI, APEI, GHES: Cleanup ghes memory error handling

Cleanup the logic in ghes_handle_memory_failure(). While at it, add
proper PFN validity check for UC error and cleanup the code logic to
make it simpler and cleaner.
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1385363701-12387-2-git-send-email-gong.chen@linux.intel.com
[ Boris: massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>

drivers/acpi/apei/ghes.c

@@ -413,27 +413,31 @@ static void ghes_handle_memory_failure(struct acpi_generic_data *gdata, int sev)
 {
 #ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
 	unsigned long pfn;
+	int flags = -1;
 	int sec_sev = ghes_severity(gdata->error_severity);
 	struct cper_sec_mem_err *mem_err;
 	mem_err = (struct cper_sec_mem_err *)(gdata + 1);
 
-	if (sec_sev == GHES_SEV_CORRECTED &&
-	    (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED) &&
-	    (mem_err->validation_bits & CPER_MEM_VALID_PA)) {
-		pfn = mem_err->physical_addr >> PAGE_SHIFT;
-		if (pfn_valid(pfn))
-			memory_failure_queue(pfn, 0, MF_SOFT_OFFLINE);
-		else if (printk_ratelimit())
-			pr_warn(FW_WARN GHES_PFX
-			"Invalid address in generic error data: %#llx\n",
-			mem_err->physical_addr);
-	}
-	if (sev == GHES_SEV_RECOVERABLE &&
-	    sec_sev == GHES_SEV_RECOVERABLE &&
-	    mem_err->validation_bits & CPER_MEM_VALID_PA) {
-		pfn = mem_err->physical_addr >> PAGE_SHIFT;
-		memory_failure_queue(pfn, 0, 0);
+	if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
+		return;
+
+	pfn = mem_err->physical_addr >> PAGE_SHIFT;
+	if (!pfn_valid(pfn)) {
+		pr_warn_ratelimited(FW_WARN GHES_PFX
+		"Invalid address in generic error data: %#llx\n",
+		mem_err->physical_addr);
+		return;
 	}
+
+	/* iff following two events can be handled properly by now */
+	if (sec_sev == GHES_SEV_CORRECTED &&
+	    (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED))
+		flags = MF_SOFT_OFFLINE;
+	if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
+		flags = 0;
+
+	if (flags != -1)
+		memory_failure_queue(pfn, 0, flags);
 #endif
 }