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path: root/drivers/nvdimm/bus.c
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Diffstat (limited to 'drivers/nvdimm/bus.c')
-rw-r--r--drivers/nvdimm/bus.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index a8b6949a8778..23d4a1728cdf 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -715,7 +715,7 @@ EXPORT_SYMBOL_GPL(nd_cmd_in_size);
u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
- const u32 *out_field)
+ const u32 *out_field, unsigned long remainder)
{
if (idx >= desc->out_num)
return UINT_MAX;
@@ -727,9 +727,24 @@ u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
return in_field[1];
else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
return out_field[1];
- else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2)
- return out_field[1] - 8;
- else if (cmd == ND_CMD_CALL) {
+ else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 2) {
+ /*
+ * Per table 9-276 ARS Data in ACPI 6.1, out_field[1] is
+ * "Size of Output Buffer in bytes, including this
+ * field."
+ */
+ if (out_field[1] < 4)
+ return 0;
+ /*
+ * ACPI 6.1 is ambiguous if 'status' is included in the
+ * output size. If we encounter an output size that
+ * overshoots the remainder by 4 bytes, assume it was
+ * including 'status'.
+ */
+ if (out_field[1] - 8 == remainder)
+ return remainder;
+ return out_field[1] - 4;
+ } else if (cmd == ND_CMD_CALL) {
struct nd_cmd_pkg *pkg = (struct nd_cmd_pkg *) in_field;
return pkg->nd_size_out;
@@ -876,7 +891,7 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
/* process an output envelope */
for (i = 0; i < desc->out_num; i++) {
u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
- (u32 *) in_env, (u32 *) out_env);
+ (u32 *) in_env, (u32 *) out_env, 0);
u32 copy;
if (out_size == UINT_MAX) {