bcm47xx: make WGT634U NVRAM patch apply again

Fixes: 1c48eee5b2 ("kernel: backport Broadcom NVRAM driver cleanups")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit 9530b9bb78)

target/linux/bcm47xx/patches-5.4/820-wgt634u-nvram-fix.patch

@@ -250,28 +250,18 @@ out the configuration than the in kernel cfe config reader.
 +static int cfe_env;
 +extern char *cfe_env_get(char *nv_buf, const char *name);
  
- static u32 find_nvram_size(void __iomem *end)
- {
-@@ -52,7 +54,9 @@ static u32 find_nvram_size(void __iomem
- static int nvram_find_and_copy(void __iomem *iobase, u32 lim)
- {
- 	struct nvram_header __iomem *header;
-+	int i;
- 	u32 off;
-+	u32 *src, *dst;
- 	u32 size;
- 
- 	if (nvram_len) {
-@@ -60,6 +64,26 @@ static int nvram_find_and_copy(void __io
+ /**
+  * bcm47xx_nvram_is_valid - check for a valid NVRAM at specified memory
+@@ -80,6 +82,26 @@ static int bcm47xx_nvram_find_and_copy(v
  		return -EEXIST;
  	}
  
 +	cfe_env = 0;
 +
 +	/* XXX: hack for supporting the CFE environment stuff on WGT634U */
-+	if (lim >= 8 * 1024 * 1024) {
-+		src = (u32 *)(iobase + 8 * 1024 * 1024 - 0x2000);
-+		dst = (u32 *)nvram_buf;
++	if (res_size >= 8 * 1024 * 1024) {
++		u32 *src = (u32 *)(flash_start + 8 * 1024 * 1024 - 0x2000);
++		u32 *dst = (u32 *)nvram_buf;
 +
 +		if ((*src & 0xff00ff) == 0x000001) {
 +			printk("early_nvram_init: WGT634U NVRAM found.\n");
@@ -287,9 +277,9 @@ out the configuration than the in kernel cfe config reader.
 +	}
 +
  	/* TODO: when nvram is on nand flash check for bad blocks first. */
- 	off = FLASH_MIN;
- 	while (off <= lim) {
-@@ -170,6 +194,13 @@ int bcm47xx_nvram_getenv(const char *nam
+ 
+ 	/* Try every possible flash size and check for NVRAM at its end */
+@@ -172,6 +194,13 @@ int bcm47xx_nvram_getenv(const char *nam
  	if (!name)
  		return -EINVAL;