diff mbox

[-v2] ACPI, APEI: Fix BERT resources conflict with ACPI NVS area

Message ID 20170220011343.6736-1-ying.huang@intel.com (mailing list archive)
State Accepted, archived
Delegated to: Rafael Wysocki
Headers show

Commit Message

Huang, Ying Feb. 20, 2017, 1:12 a.m. UTC 
From: Huang Ying <ying.huang@intel.com>

It was reported that on some machines, there is overlap between ACPI
NVS area and BERT address range.  This appears reasonable because BERT
contents need to be non-volatile across reboot.  But this will cause
resources conflict in current Linux kernel implementation because the
ACPI NVS area is marked as busy.  The resource conflict is fixed via
excluding the ACPI NVS area when requesting IO resources for BERT.
When accessing the BERT contents, the whole BERT address range will be
ioremapped and accessed.

Reported-and-tested-by: Hans Kristian Rosbach <hansr@raskesider.no>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
---
 drivers/acpi/apei/bert.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

Comments

Borislav Petkov Feb. 20, 2017, 9:44 a.m. UTC | #1 
On Mon, Feb 20, 2017 at 09:12:58AM +0800, Huang, Ying wrote:
> From: Huang Ying <ying.huang@intel.com>
> 
> It was reported that on some machines, there is overlap between ACPI
> NVS area and BERT address range.  This appears reasonable because BERT
> contents need to be non-volatile across reboot.  But this will cause
> resources conflict in current Linux kernel implementation because the
> ACPI NVS area is marked as busy.  The resource conflict is fixed via
> excluding the ACPI NVS area when requesting IO resources for BERT.
> When accessing the BERT contents, the whole BERT address range will be
> ioremapped and accessed.
> 
> Reported-and-tested-by: Hans Kristian Rosbach <hansr@raskesider.no>
> Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
> ---
>  drivers/acpi/apei/bert.c | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)

Acked-by: Borislav Petkov <bp@suse.de>
diff mbox

Patch

diff --git a/drivers/acpi/apei/bert.c b/drivers/acpi/apei/bert.c
index a05b5c0cf181..12771fcf0417 100644
--- a/drivers/acpi/apei/bert.c
+++ b/drivers/acpi/apei/bert.c
@@ -97,6 +97,7 @@  static int __init bert_check_table(struct acpi_table_bert *bert_tab)
 
 static int __init bert_init(void)
 {
+	struct apei_resources bert_resources;
 	struct acpi_bert_region *boot_error_region;
 	struct acpi_table_bert *bert_tab;
 	unsigned int region_len;
@@ -127,13 +128,14 @@  static int __init bert_init(void)
 	}
 
 	region_len = bert_tab->region_length;
-	if (!request_mem_region(bert_tab->address, region_len, "APEI BERT")) {
-		pr_err("Can't request iomem region <%016llx-%016llx>.\n",
-		       (unsigned long long)bert_tab->address,
-		       (unsigned long long)bert_tab->address + region_len - 1);
-		return -EIO;
-	}
-
+	apei_resources_init(&bert_resources);
+	rc = apei_resources_add(&bert_resources, bert_tab->address,
+				region_len, true);
+	if (rc)
+		return rc;
+	rc = apei_resources_request(&bert_resources, "APEI BERT");
+	if (rc)
+		goto out_fini;
 	boot_error_region = ioremap_cache(bert_tab->address, region_len);
 	if (boot_error_region) {
 		bert_print_all(boot_error_region, region_len);
@@ -142,7 +144,9 @@  static int __init bert_init(void)
 		rc = -ENOMEM;
 	}
 
-	release_mem_region(bert_tab->address, region_len);
+	apei_resources_release(&bert_resources);
+out_fini:
+	apei_resources_fini(&bert_resources);
 
 	return rc;
 }