[PATCH -v3 4/4] ACPI, APEI, Report GHES error information via printk

[Huang Ying <ying.huang@intel.com>]

printk is one of the methods to report hardware errors to user space.
This patch implements hardware error reporting for GHES via printk.

Signed-off-by: Huang Ying <ying.huang@intel.com>
---
 drivers/acpi/apei/ghes.c |   25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -43,6 +43,7 @@
 #include <linux/kdebug.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>
+#include <linux/ratelimit.h>
 #include <acpi/apei.h>
 #include <acpi/atomicio.h>
 #include <acpi/hed.h>
@@ -255,11 +256,26 @@ static void ghes_do_proc(struct ghes *gh
 		}
 #endif
 	}
+}
+
+static void ghes_print_estatus(const char *pfx, struct ghes *ghes)
+{
+	/* Not more than 2 messages every 5 seconds */
+	static DEFINE_RATELIMIT_STATE(ratelimit, 5*HZ, 2);
 
-	if (!processed && printk_ratelimit())
-		pr_warning(GHES_PFX
-		"Unknown error record from generic hardware error source: %d\n",
-			   ghes->generic->header.source_id);
+	if (pfx == NULL) {
+		if (ghes_severity(ghes->estatus->error_severity) <=
+		    GHES_SEV_CORRECTED)
+			pfx = KERN_WARNING HW_ERR;
+		else
+			pfx = KERN_ERR HW_ERR;
+	}
+	if (__ratelimit(&ratelimit)) {
+		printk(
+	"%s""Hardware error from APEI Generic Hardware Error Source: %d\n",
+	pfx, ghes->generic->header.source_id);
+		apei_estatus_print(pfx, ghes->estatus);
+	}
 }
 
 static int ghes_proc(struct ghes *ghes)
@@ -269,6 +285,7 @@ static int ghes_proc(struct ghes *ghes)
 	rc = ghes_read_estatus(ghes, 0);
 	if (rc)
 		goto out;
+	ghes_print_estatus(NULL, ghes);
 	ghes_do_proc(ghes);
 
 out: