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bcm53xx: add the latest fix version of brcm_nvram

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It was just sent for upstream.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit 943bd3c9f6244c928cd168302d638a6a218fd4e6)
This commit is contained in:
Rafał Miłecki
2023-11-02 09:08:54 +01:00
parent 0dec0e0f19
commit 41f27bbb6d
1 changed files with 256 additions and 0 deletions
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256
target/linux/bcm53xx/patches-5.15/181-nvmem-brcm_nvram-store-a-copy-of-NVRAM-content.patch Normal file
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@@ -0,0 +1,256 @@
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
Date: Thu, 14 Sep 2023 07:59:09 +0200
Subject: [PATCH] nvmem: brcm_nvram: store a copy of NVRAM content
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This driver uses MMIO access for reading NVRAM from a flash device.
Underneath there is a flash controller that reads data and provides
mapping window.
Using MMIO interface affects controller configuration and may break real
controller driver. It was reported by multiple users of devices with
NVRAM stored on NAND.
Modify driver to read & cache NVRAM content during init and use that
copy to provide NVMEM data when requested. On NAND flashes due to their
alignment NVRAM partitions can be quite big (1 MiB and more) while
actual NVRAM content stays quite small (usually 16 to 32 KiB). To avoid
allocating so much memory check for actual data length.
Link: https://lore.kernel.org/linux-mtd/CACna6rwf3_9QVjYcM+847biTX=K0EoWXuXcSMkJO1Vy_5vmVqA@mail.gmail.com/
Fixes: 3fef9ed0627a ("nvmem: brcm_nvram: new driver exposing Broadcom's NVRAM")
Cc: Arınç ÜNAL <arinc.unal@arinc9.com>
Cc: Florian Fainelli <florian.fainelli@broadcom.com>
Cc: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Arınç ÜNAL <arinc.unal@arinc9.com>
---
drivers/nvmem/brcm_nvram.c | 134 ++++++++++++++++++++++++++-----------
1 file changed, 94 insertions(+), 40 deletions(-)
--- a/drivers/nvmem/brcm_nvram.c
+++ b/drivers/nvmem/brcm_nvram.c
@@ -17,9 +17,23 @@
#define NVRAM_MAGIC "FLSH"
+/**
+ * struct brcm_nvram - driver state internal struct
+ *
+ * @dev: NVMEM device pointer
+ * @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
+ * @cells: Array of discovered NVMEM cells
+ * @ncells: Number of elements in cells
+ */
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 +50,47 @@ static int brcm_nvram_read(void *context
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);
- while (bytes--)
- *dst++ = readb(priv->base + offset++);
+ priv->data = devm_kzalloc(priv->dev, priv->data_len, GFP_KERNEL);
+ if (!priv->data)
+ return -ENOMEM;
+
+ memcpy_fromio(priv->data, base, priv->data_len);
+
+ bcm47xx_nvram_init_from_iomem(base, priv->data_len);
return 0;
}
@@ -67,8 +118,13 @@ static int brcm_nvram_add_cells(struct b
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 +134,68 @@ static int brcm_nvram_add_cells(struct b
}
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 +207,6 @@ static int brcm_nvram_probe(struct platf
.reg_read = brcm_nvram_read,
};
struct device *dev = &pdev->dev;
- struct resource *res;
struct brcm_nvram *priv;
int err;
@@ -159,21 +215,19 @@ static int brcm_nvram_probe(struct platf
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));
}