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path: root/drivers/firmware/broadcom/bcm47xx_nvram.c
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Diffstat (limited to 'drivers/firmware/broadcom/bcm47xx_nvram.c')
-rw-r--r--drivers/firmware/broadcom/bcm47xx_nvram.c92
1 files changed, 47 insertions, 45 deletions
diff --git a/drivers/firmware/broadcom/bcm47xx_nvram.c b/drivers/firmware/broadcom/bcm47xx_nvram.c
index 835ece9c00f1..bd235833b687 100644
--- a/drivers/firmware/broadcom/bcm47xx_nvram.c
+++ b/drivers/firmware/broadcom/bcm47xx_nvram.c
@@ -34,26 +34,46 @@ static char nvram_buf[NVRAM_SPACE];
static size_t nvram_len;
static const u32 nvram_sizes[] = {0x6000, 0x8000, 0xF000, 0x10000};
-static u32 find_nvram_size(void __iomem *end)
+/**
+ * bcm47xx_nvram_is_valid - check for a valid NVRAM at specified memory
+ */
+static bool bcm47xx_nvram_is_valid(void __iomem *nvram)
{
- struct nvram_header __iomem *header;
- int i;
+ return ((struct nvram_header *)nvram)->magic == NVRAM_MAGIC;
+}
+
+/**
+ * bcm47xx_nvram_copy - copy NVRAM to internal buffer
+ */
+static void bcm47xx_nvram_copy(void __iomem *nvram_start, size_t res_size)
+{
+ struct nvram_header __iomem *header = nvram_start;
+ size_t copy_size;
- for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
- header = (struct nvram_header *)(end - nvram_sizes[i]);
- if (header->magic == NVRAM_MAGIC)
- return nvram_sizes[i];
+ copy_size = header->len;
+ if (copy_size > res_size) {
+ pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n");
+ copy_size = res_size;
+ }
+ if (copy_size >= NVRAM_SPACE) {
+ pr_err("nvram on flash (%zu bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
+ copy_size, NVRAM_SPACE - 1);
+ copy_size = NVRAM_SPACE - 1;
}
- return 0;
+ __ioread32_copy(nvram_buf, nvram_start, DIV_ROUND_UP(copy_size, 4));
+ nvram_buf[NVRAM_SPACE - 1] = '\0';
+ nvram_len = copy_size;
}
-/* Probe for NVRAM header */
-static int nvram_find_and_copy(void __iomem *iobase, u32 lim)
+/**
+ * bcm47xx_nvram_find_and_copy - find NVRAM on flash mapping & copy it
+ */
+static int bcm47xx_nvram_find_and_copy(void __iomem *flash_start, size_t res_size)
{
- struct nvram_header __iomem *header;
- u32 off;
- u32 size;
+ size_t flash_size;
+ size_t offset;
+ int i;
if (nvram_len) {
pr_warn("nvram already initialized\n");
@@ -61,49 +81,31 @@ static int nvram_find_and_copy(void __iomem *iobase, u32 lim)
}
/* TODO: when nvram is on nand flash check for bad blocks first. */
- off = FLASH_MIN;
- while (off <= lim) {
- /* Windowed flash access */
- size = find_nvram_size(iobase + off);
- if (size) {
- header = (struct nvram_header *)(iobase + off - size);
- goto found;
+
+ /* Try every possible flash size and check for NVRAM at its end */
+ for (flash_size = FLASH_MIN; flash_size <= res_size; flash_size <<= 1) {
+ for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
+ offset = flash_size - nvram_sizes[i];
+ if (bcm47xx_nvram_is_valid(flash_start + offset))
+ goto found;
}
- off <<= 1;
}
/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
- header = (struct nvram_header *)(iobase + 4096);
- if (header->magic == NVRAM_MAGIC) {
- size = NVRAM_SPACE;
+
+ offset = 4096;
+ if (bcm47xx_nvram_is_valid(flash_start + offset))
goto found;
- }
- header = (struct nvram_header *)(iobase + 1024);
- if (header->magic == NVRAM_MAGIC) {
- size = NVRAM_SPACE;
+ offset = 1024;
+ if (bcm47xx_nvram_is_valid(flash_start + offset))
goto found;
- }
pr_err("no nvram found\n");
return -ENXIO;
found:
- __ioread32_copy(nvram_buf, header, sizeof(*header) / 4);
- nvram_len = ((struct nvram_header *)(nvram_buf))->len;
- if (nvram_len > size) {
- pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n");
- nvram_len = size;
- }
- if (nvram_len >= NVRAM_SPACE) {
- pr_err("nvram on flash (%zu bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
- nvram_len, NVRAM_SPACE - 1);
- nvram_len = NVRAM_SPACE - 1;
- }
- /* proceed reading data after header */
- __ioread32_copy(nvram_buf + sizeof(*header), header + 1,
- DIV_ROUND_UP(nvram_len, 4));
- nvram_buf[NVRAM_SPACE - 1] = '\0';
+ bcm47xx_nvram_copy(flash_start + offset, res_size - offset);
return 0;
}
@@ -124,7 +126,7 @@ int bcm47xx_nvram_init_from_mem(u32 base, u32 lim)
if (!iobase)
return -ENOMEM;
- err = nvram_find_and_copy(iobase, lim);
+ err = bcm47xx_nvram_find_and_copy(iobase, lim);
iounmap(iobase);