gpu: nvgpu: fix vbios mem table parsing

bios tables are packed data structures. keeping
packed structrues inside union and assigning values
from it does not work.

bug 200287822

Change-Id: I1df9541495b96786412533570c51d779bfd0f43f
Signed-off-by: Vijayakumar <vsubbu@nvidia.com>
Reviewed-on: http://git-master/r/1326798
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Thomas Fleury <tfleury@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 32 insertions, 23 deletions

diff --git a/drivers/gpu/nvgpu/common/vbios/bios.c b/drivers/gpu/nvgpu/common/vbios/bios.c
index c31f9a29..b640a761 100644
--- a/drivers/gpu/nvgpu/common/vbios/bios.c
+++ b/drivers/gpu/nvgpu/common/vbios/bios.c
@@ -65,20 +65,21 @@ struct bit {
 #define TOKEN_ID_VIRT_PTRS 0x56
 #define TOKEN_ID_MEMORY_PTRS 0x4D
 
+#define MEMORY_PTRS_V1 1
+#define MEMORY_PTRS_V2 2
+
+struct memory_ptrs_v1 {
+        u8 rsvd0[2];
+        u8 mem_strap_data_count;
+        u16 mem_strap_xlat_tbl_ptr;
+        u8 rsvd1[8];
+} __packed;
 
-union memory_ptrs {
-        struct {
-                u8 rsvd0[2];
-                u8 mem_strap_data_count;
-                u16 mem_strap_xlat_tbl_ptr;
-                u8 rsvd1[8];
-        } v1 __packed;
-        struct {
-                u8 mem_strap_data_count;
-                u16 mem_strap_xlat_tbl_ptr;
-                u8 rsvd[14];
-        } v2 __packed;
-};
+struct memory_ptrs_v2 {
+        u8 mem_strap_data_count;
+        u16 mem_strap_xlat_tbl_ptr;
+        u8 rsvd[14];
+} __packed;
 
 struct biosdata {
         u32 version;
@@ -322,17 +323,25 @@ static void nvgpu_bios_parse_nvinit_ptrs(struct gk20a *g, int offset)
 
 static void nvgpu_bios_parse_memory_ptrs(struct gk20a *g, int offset, u8 version)
 {
-        union memory_ptrs memory_ptrs;
-
-        if ((version < 1) || (version > 2))
+        struct memory_ptrs_v1 v1;
+        struct memory_ptrs_v2 v2;
+
+        switch (version) {
+        case MEMORY_PTRS_V1:
+                memcpy(&v1, &g->bios.data[offset], sizeof(v1));
+                g->bios.mem_strap_data_count = v1.mem_strap_data_count;
+                g->bios.mem_strap_xlat_tbl_ptr = v1.mem_strap_xlat_tbl_ptr;
                 return;
-
-        memcpy(&memory_ptrs, &g->bios.data[offset], sizeof(memory_ptrs));
-
-        g->bios.mem_strap_data_count = (version > 1) ? memory_ptrs.v2.mem_strap_data_count :
-                memory_ptrs.v1.mem_strap_data_count;
-        g->bios.mem_strap_xlat_tbl_ptr = (version > 1) ? memory_ptrs.v2.mem_strap_xlat_tbl_ptr :
-                memory_ptrs.v1.mem_strap_xlat_tbl_ptr;
+        case MEMORY_PTRS_V2:
+                memcpy(&v2, &g->bios.data[offset], sizeof(v2));
+                g->bios.mem_strap_data_count = v2.mem_strap_data_count;
+                g->bios.mem_strap_xlat_tbl_ptr = v2.mem_strap_xlat_tbl_ptr;
+                return;
+        default:
+                gk20a_err(dev_from_gk20a(g),
+                        "unknown vbios memory table version %x", version);
+                return;
+        }
 }
 
 static void nvgpu_bios_parse_devinit_appinfo(struct gk20a *g, int dmem_offset)