bnx2: Refine VPD logic.

- Replace magic values with constants
- Simplify length calculation and fix a bug

Based on valuable feedback from Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index cf4322d..4bfc808 100644 (file)
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -7730,24 +7730,27 @@ bnx2_read_vpd_fw_ver(struct bnx2 *bp)
        u8 *v0_str = NULL;
        bool mn_match = false;
 
+#define BNX2_VPD_NVRAM_OFFSET  0x300
+#define BNX2_VPD_LEN           128
 #define BNX2_MAX_VER_SLEN      30
 
        data = kmalloc(256, GFP_KERNEL);
        if (!data)
                return;
 
-       rc = bnx2_nvram_read(bp, 0x300, data + 128, 128);
+       rc = bnx2_nvram_read(bp, BNX2_VPD_NVRAM_OFFSET, data + BNX2_VPD_LEN,
+                            BNX2_VPD_LEN);
        if (rc)
                goto vpd_done;
 
-       for (i = 0; i < 128; i += 4) {
-               data[i] = data[i + 131];
-               data[i + 1] = data[i + 130];
-               data[i + 2] = data[i + 129];
-               data[i + 3] = data[i + 128];
+       for (i = 0; i < BNX2_VPD_LEN; i += 4) {
+               data[i] = data[i + BNX2_VPD_LEN + 3];
+               data[i + 1] = data[i + BNX2_VPD_LEN + 2];
+               data[i + 2] = data[i + BNX2_VPD_LEN + 1];
+               data[i + 3] = data[i + BNX2_VPD_LEN];
        }
 
-       for (i = 0; i < 128; ) {
+       for (i = 0; i <= BNX2_VPD_LEN - 3; ) {
                unsigned char val = data[i];
                unsigned int block_end;
 
@@ -7762,39 +7765,29 @@ bnx2_read_vpd_fw_ver(struct bnx2 *bp)
                block_end = (i + 3 + (data[i + 1] + (data[i + 2] << 8)));
                i += 3;
 
-               if (block_end > 128)
+               if (block_end > BNX2_VPD_LEN)
                        goto vpd_done;
 
                while (i < (block_end - 2)) {
-                       if (data[i] == 'M' && data[i + 1] == 'N') {
-                               int mn_len = data[i + 2];
+                       int len = data[i + 2];
 
-                               if (mn_len != 4)
-                                       goto vpd_done;
+                       if (i + 3 + len > block_end)
+                               goto vpd_done;
 
-                               i += 3;
-                               if (memcmp(&data[i], "1028", 4))
+                       if (data[i] == 'M' && data[i + 1] == 'N') {
+                               if (len != 4 ||
+                                   memcmp(&data[i + 3], "1028", 4))
                                        goto vpd_done;
                                mn_match = true;
-                               i += 4;
 
                        } else if (data[i] == 'V' && data[i + 1] == '0') {
-                               v0_len = data[i + 2];
-
-                               i += 3;
-                               if (v0_len > BNX2_MAX_VER_SLEN ||
-                                   (v0_len + i) > 128)
+                               if (len > BNX2_MAX_VER_SLEN)
                                        goto vpd_done;
 
-                               if (v0_len > BNX2_MAX_VER_SLEN)
-                                       v0_len = BNX2_MAX_VER_SLEN;
-
-                               v0_str = &data[i];
-                               i += data[i + 2];
-
-                       } else {
-                               i += 3 + data[i + 2];
+                               v0_len = len;
+                               v0_str = &data[i + 3];
                        }
+                       i += 3 + len;
 
                        if (mn_match && v0_str) {
                                memcpy(bp->fw_version, v0_str, v0_len);