ACPI: extlog: Handle multiple records

If there is no user space consumer of extlog_mem trace records, then
Linux properly handles multiple error records in an ELOG block

extlog_print()
print_extlog_rcd()
__print_extlog_rcd()
cper_estatus_print()
apei_estatus_for_each_section()

But the other code path hard codes looking for a single record to
output a trace record.

Fix by using the same apei_estatus_for_each_section() iterator
to step over all records.

Fixes: 2dfb7d51a61d ("trace, RAS: Add eMCA trace event interface")
Signed-off-by: Tony Luck <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/acpi/acpi_extlog.c

···
 #include <linux/ratelimit.h>
 #include <linux/edac.h>
 #include <linux/ras.h>
+#include <acpi/ghes.h>
 #include <asm/cpu.h>
 #include <asm/mce.h>
 
···
 	int	cpu = mce->extcpu;
 	struct acpi_hest_generic_status *estatus, *tmp;
 	struct acpi_hest_generic_data *gdata;
-	const guid_t *fru_id = &guid_null;
-	char *fru_text = "";
+	const guid_t *fru_id;
+	char *fru_text;
 	guid_t *sec_type;
 	static u32 err_seq;
 
···
 
 	/* log event via trace */
 	err_seq++;
-	gdata = (struct acpi_hest_generic_data *)(tmp + 1);
-	if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
-		fru_id = (guid_t *)gdata->fru_id;
-	if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
-		fru_text = gdata->fru_text;
-	sec_type = (guid_t *)gdata->section_type;
-	if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
-		struct cper_sec_mem_err *mem = (void *)(gdata + 1);
-		if (gdata->error_data_length >= sizeof(*mem))
-			trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
-					       (u8)gdata->error_severity);
+	apei_estatus_for_each_section(tmp, gdata) {
+		if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
+			fru_id = (guid_t *)gdata->fru_id;
+		else
+			fru_id = &guid_null;
+		if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
+			fru_text = gdata->fru_text;
+		else
+			fru_text = "";
+		sec_type = (guid_t *)gdata->section_type;
+		if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
+			struct cper_sec_mem_err *mem = (void *)(gdata + 1);
+
+			if (gdata->error_data_length >= sizeof(*mem))
+				trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
+						       (u8)gdata->error_severity);
+		}
 	}
 
 out: