Some firmware will access memory in ACPI NVS region via APEI. That
is, instructions in APEI ERST/EINJ table will read/write ACPI NVS
region. The original resource conflict checking in APEI code will
check memory/ioport accessed by APEI via general resource management
mech. But ACPI NVS region is marked as busy already, so that the
false resource conflict will prevent APEI ERST/EINJ to work.
To fix this, this patch excludes ACPI NVS regions when APEI components
request resources. So that they will not conflict with ACPI NVS
regions.
Reported-and-tested-by: Pavel Ivanov <paivanof@xxxxxxxxx>
Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
---
drivers/acpi/apei/apei-base.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)
--- a/drivers/acpi/apei/apei-base.c
+++ b/drivers/acpi/apei/apei-base.c
@@ -438,8 +438,19 @@ int apei_resources_sub(struct apei_resou
}
EXPORT_SYMBOL_GPL(apei_resources_sub);
+static int apei_get_nvs_callback(__u64 start, __u64 size, void *data)
+{
+ struct apei_resources *resources = data;
+ return apei_res_add(&resources->iomem, start, size);
+}
+
+static int apei_get_nvs_resources(struct apei_resources *resources)
+{
+ return acpi_nvs_for_each_region(apei_get_nvs_callback, resources);
+}
+
/*
- * IO memory/port rersource management mechanism is used to check
+ * IO memory/port resource management mechanism is used to check
* whether memory/port area used by GARs conflicts with normal memory
* or IO memory/port of devices.
*/
@@ -448,12 +459,26 @@ int apei_resources_request(struct apei_r
{
struct apei_res *res, *res_bak = NULL;
struct resource *r;
+ struct apei_resources nvs_resources;
int rc;
rc = apei_resources_sub(resources, &apei_resources_all);
if (rc)
return rc;
+ /*
+ * Some firmware uses ACPI NVS region, that has been marked as
+ * busy, so exclude it from APEI resources to avoid false
+ * conflict.
+ */
+ apei_resources_init(&nvs_resources);
+ rc = apei_get_nvs_resources(&nvs_resources);
+ if (rc)
+ goto res_fini;
+ rc = apei_resources_sub(resources, &nvs_resources);
+ if (rc)
+ goto res_fini;
+
rc = -EINVAL;
list_for_each_entry(res, &resources->iomem, list) {
r = request_mem_region(res->start, res->end - res->start,
@@ -500,6 +525,8 @@ err_unmap_iomem:
break;
release_mem_region(res->start, res->end - res->start);
}
+res_fini:
+ apei_resources_fini(&nvs_resources);
return rc;
}
EXPORT_SYMBOL_GPL(apei_resources_request);
--
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