nfit: Adjust for different _FIT and NFIT headers
When support for _FIT was added, the code presumed that the data
returned by the _FIT method is identical to the NFIT table, which
starts with an acpi_table_header. However, the _FIT is defined
to return a data in the format of a series of NFIT type structure
entries and as a method, has an acpi_object header rather tahn
an acpi_table_header.
To address the differences, explicitly save the acpi_table_header
from the NFIT, since it is accessible through /sys, and change
the nfit pointer in the acpi_desc structure to point to the
table entries rather than the headers.
Reported-by: Jeff Moyer (jmoyer@redhat.com>
Signed-off-by: Linda Knippers <linda.knippers@hpe.com>
Acked-by: Vishal Verma <vishal.l.verma@intel.com>
[vishal: fix up unit test for new header assumptions]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index f92adb5..e7ed39b 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -661,7 +661,7 @@
struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
- return sprintf(buf, "%d\n", acpi_desc->nfit->header.revision);
+ return sprintf(buf, "%d\n", acpi_desc->acpi_header.revision);
}
static DEVICE_ATTR_RO(revision);
@@ -1658,7 +1658,6 @@
data = (u8 *) acpi_desc->nfit;
end = data + sz;
- data += sizeof(struct acpi_table_nfit);
while (!IS_ERR_OR_NULL(data))
data = add_table(acpi_desc, &prev, data, end);
@@ -1754,13 +1753,29 @@
return PTR_ERR(acpi_desc);
}
- acpi_desc->nfit = (struct acpi_table_nfit *) tbl;
+ /*
+ * Save the acpi header for later and then skip it,
+ * making nfit point to the first nfit table header.
+ */
+ acpi_desc->acpi_header = *tbl;
+ acpi_desc->nfit = (void *) tbl + sizeof(struct acpi_table_nfit);
+ sz -= sizeof(struct acpi_table_nfit);
/* Evaluate _FIT and override with that if present */
status = acpi_evaluate_object(adev->handle, "_FIT", NULL, &buf);
if (ACPI_SUCCESS(status) && buf.length > 0) {
- acpi_desc->nfit = (struct acpi_table_nfit *)buf.pointer;
- sz = buf.length;
+ union acpi_object *obj;
+ /*
+ * Adjust for the acpi_object header of the _FIT
+ */
+ obj = buf.pointer;
+ if (obj->type == ACPI_TYPE_BUFFER) {
+ acpi_desc->nfit =
+ (struct acpi_nfit_header *)obj->buffer.pointer;
+ sz = obj->buffer.length;
+ } else
+ dev_dbg(dev, "%s invalid type %d, ignoring _FIT\n",
+ __func__, (int) obj->type);
}
rc = acpi_nfit_init(acpi_desc, sz);
@@ -1783,7 +1798,8 @@
{
struct acpi_nfit_desc *acpi_desc = dev_get_drvdata(&adev->dev);
struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
- struct acpi_table_nfit *nfit_saved;
+ struct acpi_nfit_header *nfit_saved;
+ union acpi_object *obj;
struct device *dev = &adev->dev;
acpi_status status;
int ret;
@@ -1814,12 +1830,19 @@
}
nfit_saved = acpi_desc->nfit;
- acpi_desc->nfit = (struct acpi_table_nfit *)buf.pointer;
- ret = acpi_nfit_init(acpi_desc, buf.length);
- if (ret) {
- /* Merge failed, restore old nfit, and exit */
- acpi_desc->nfit = nfit_saved;
- dev_err(dev, "failed to merge updated NFIT\n");
+ obj = buf.pointer;
+ if (obj->type == ACPI_TYPE_BUFFER) {
+ acpi_desc->nfit =
+ (struct acpi_nfit_header *)obj->buffer.pointer;
+ ret = acpi_nfit_init(acpi_desc, obj->buffer.length);
+ if (ret) {
+ /* Merge failed, restore old nfit, and exit */
+ acpi_desc->nfit = nfit_saved;
+ dev_err(dev, "failed to merge updated NFIT\n");
+ }
+ } else {
+ /* Bad _FIT, restore old nfit */
+ dev_err(dev, "Invalid _FIT\n");
}
kfree(buf.pointer);