@@ -17,9 +17,20 @@
#define NVRAM_MAGIC "FLSH"
+/**
+ * struct brcm_nvram - driver state internal struct
+ *
+ * @nvmem_size: Size of the whole space available for NVRAM
+ * @data: NVRAM data copy stored to avoid poking underlaying flash controller
+ * @data_len: NVRAM data size
+ * @padding_byte: Padding value used to fill remaining space
+ */
struct brcm_nvram {
struct device *dev;
- void __iomem *base;
+ size_t nvmem_size;
+ uint8_t *data;
+ size_t data_len;
+ uint8_t padding_byte;
struct nvmem_cell_info *cells;
int ncells;
};
@@ -36,10 +47,47 @@ static int brcm_nvram_read(void *context, unsigned int offset, void *val,
size_t bytes)
{
struct brcm_nvram *priv = context;
- u8 *dst = val;
+ size_t to_copy;
+
+ if (offset + bytes > priv->data_len)
+ to_copy = max_t(ssize_t, (ssize_t)priv->data_len - offset, 0);
+ else
+ to_copy = bytes;
+
+ memcpy(val, priv->data + offset, to_copy);
+
+ memset((uint8_t *)val + to_copy, priv->padding_byte, bytes - to_copy);
+
+ return 0;
+}
+
+static int brcm_nvram_copy_data(struct brcm_nvram *priv, struct platform_device *pdev)
+{
+ struct resource *res;
+ void __iomem *base;
+
+ base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ priv->nvmem_size = resource_size(res);
+
+ priv->padding_byte = readb(base + priv->nvmem_size - 1);
+ for (priv->data_len = priv->nvmem_size;
+ priv->data_len;
+ priv->data_len--) {
+ if (readb(base + priv->data_len - 1) != priv->padding_byte)
+ break;
+ }
+ WARN(priv->data_len > SZ_128K, "Unexpected (big) NVRAM size: %zu B\n", priv->data_len);
+
+ priv->data = devm_kzalloc(priv->dev, priv->data_len, GFP_KERNEL);
+ if (!priv->data)
+ return -ENOMEM;
+
+ memcpy_fromio(priv->data, base, priv->data_len);
- while (bytes--)
- *dst++ = readb(priv->base + offset++);
+ bcm47xx_nvram_init_from_iomem(base, priv->data_len);
return 0;
}
@@ -67,8 +115,13 @@ static int brcm_nvram_add_cells(struct brcm_nvram *priv, uint8_t *data,
size_t len)
{
struct device *dev = priv->dev;
- char *var, *value, *eq;
+ char *var, *value;
+ uint8_t tmp;
int idx;
+ int err = 0;
+
+ tmp = priv->data[len - 1];
+ priv->data[len - 1] = '\0';
priv->ncells = 0;
for (var = data + sizeof(struct brcm_nvram_header);
@@ -78,67 +131,68 @@ static int brcm_nvram_add_cells(struct brcm_nvram *priv, uint8_t *data,
}
priv->cells = devm_kcalloc(dev, priv->ncells, sizeof(*priv->cells), GFP_KERNEL);
- if (!priv->cells)
- return -ENOMEM;
+ if (!priv->cells) {
+ err = -ENOMEM;
+ goto out;
+ }
for (var = data + sizeof(struct brcm_nvram_header), idx = 0;
var < (char *)data + len && *var;
var = value + strlen(value) + 1, idx++) {
+ char *eq, *name;
+
eq = strchr(var, '=');
if (!eq)
break;
*eq = '\0';
+ name = devm_kstrdup(dev, var, GFP_KERNEL);
+ *eq = '=';
+ if (!name) {
+ err = -ENOMEM;
+ goto out;
+ }
value = eq + 1;
- priv->cells[idx].name = devm_kstrdup(dev, var, GFP_KERNEL);
- if (!priv->cells[idx].name)
- return -ENOMEM;
+ priv->cells[idx].name = name;
priv->cells[idx].offset = value - (char *)data;
priv->cells[idx].bytes = strlen(value);
priv->cells[idx].np = of_get_child_by_name(dev->of_node, priv->cells[idx].name);
- if (!strcmp(var, "et0macaddr") ||
- !strcmp(var, "et1macaddr") ||
- !strcmp(var, "et2macaddr")) {
+ if (!strcmp(name, "et0macaddr") ||
+ !strcmp(name, "et1macaddr") ||
+ !strcmp(name, "et2macaddr")) {
priv->cells[idx].raw_len = strlen(value);
priv->cells[idx].bytes = ETH_ALEN;
priv->cells[idx].read_post_process = brcm_nvram_read_post_process_macaddr;
}
}
- return 0;
+out:
+ priv->data[len - 1] = tmp;
+ return err;
}
static int brcm_nvram_parse(struct brcm_nvram *priv)
{
+ struct brcm_nvram_header *header = (struct brcm_nvram_header *)priv->data;
struct device *dev = priv->dev;
- struct brcm_nvram_header header;
- uint8_t *data;
size_t len;
int err;
- memcpy_fromio(&header, priv->base, sizeof(header));
-
- if (memcmp(header.magic, NVRAM_MAGIC, 4)) {
+ if (memcmp(header->magic, NVRAM_MAGIC, 4)) {
dev_err(dev, "Invalid NVRAM magic\n");
return -EINVAL;
}
- len = le32_to_cpu(header.len);
-
- data = kzalloc(len, GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- memcpy_fromio(data, priv->base, len);
- data[len - 1] = '\0';
-
- err = brcm_nvram_add_cells(priv, data, len);
- if (err) {
- dev_err(dev, "Failed to add cells: %d\n", err);
- return err;
+ len = le32_to_cpu(header->len);
+ if (len > priv->nvmem_size) {
+ dev_err(dev, "NVRAM length (%zd) exceeds mapped size (%zd)\n", len,
+ priv->nvmem_size);
+ return -EINVAL;
}
- kfree(data);
+ err = brcm_nvram_add_cells(priv, priv->data, len);
+ if (err)
+ dev_err(dev, "Failed to add cells: %d\n", err);
return 0;
}
@@ -150,7 +204,6 @@ static int brcm_nvram_probe(struct platform_device *pdev)
.reg_read = brcm_nvram_read,
};
struct device *dev = &pdev->dev;
- struct resource *res;
struct brcm_nvram *priv;
int err;
@@ -159,21 +212,19 @@ static int brcm_nvram_probe(struct platform_device *pdev)
return -ENOMEM;
priv->dev = dev;
- priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
- if (IS_ERR(priv->base))
- return PTR_ERR(priv->base);
+ err = brcm_nvram_copy_data(priv, pdev);
+ if (err)
+ return err;
err = brcm_nvram_parse(priv);
if (err)
return err;
- bcm47xx_nvram_init_from_iomem(priv->base, resource_size(res));
-
config.dev = dev;
config.cells = priv->cells;
config.ncells = priv->ncells;
config.priv = priv;
- config.size = resource_size(res);
+ config.size = priv->nvmem_size;
return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
}