bcm53xx: store a copy of NVRAM content in NVMEM driver

This stops NVMEM driver from using MMIO access past booting and messing
with NAND controller state.

Link: https://forum.openwrt.org/t/asus-rt-ac88u-hw-a6-broken-in-22-03-3/147882
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

diff --git a/target/linux/bcm53xx/patches-5.15/800-nvmem-brcm_nvram-store-a-copy-of-NVRAM-content.patch b/target/linux/bcm53xx/patches-5.15/800-nvmem-brcm_nvram-store-a-copy-of-NVRAM-content.patch
new file mode 100644 (file)
index 0000000..901bb6d
--- /dev/null
+++ b/target/linux/bcm53xx/patches-5.15/800-nvmem-brcm_nvram-store-a-copy-of-NVRAM-content.patch
@@ -0,0 +1,128 @@
+From a18378409fee1cac0f0c58a4770ff557b498c778 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Fri, 1 Sep 2023 10:44:26 +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
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+---
+ drivers/nvmem/brcm_nvram.c | 54 +++++++++++++++++++-------------------
+ 1 file changed, 27 insertions(+), 27 deletions(-)
+
+--- a/drivers/nvmem/brcm_nvram.c
++++ b/drivers/nvmem/brcm_nvram.c
+@@ -19,7 +19,7 @@
+ 
+ struct brcm_nvram {
+       struct device *dev;
+-      void __iomem *base;
++      uint8_t *data;
+       struct nvmem_cell_info *cells;
+       int ncells;
+ };
+@@ -36,10 +36,8 @@ static int brcm_nvram_read(void *context
+                          size_t bytes)
+ {
+       struct brcm_nvram *priv = context;
+-      u8 *dst = val;
+ 
+-      while (bytes--)
+-              *dst++ = readb(priv->base + offset++);
++      memcpy(val, priv->data + offset, bytes);
+ 
+       return 0;
+ }
+@@ -110,35 +108,27 @@ static int brcm_nvram_add_cells(struct b
+ 
+ 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;
++      uint8_t tmp;
+       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);
++      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';
++      tmp = priv->data[len - 1];
++      priv->data[len - 1] = '\0';
+ 
+-      err = brcm_nvram_add_cells(priv, data, len);
+-      if (err) {
++      err = brcm_nvram_add_cells(priv, priv->data, len);
++      if (err)
+               dev_err(dev, "Failed to add cells: %d\n", err);
+-              return err;
+-      }
+ 
+-      kfree(data);
++      priv->data[len - 1] = tmp;
+ 
+       return 0;
+ }
+@@ -150,8 +140,10 @@ static int brcm_nvram_probe(struct platf
+               .reg_read = brcm_nvram_read,
+       };
+       struct device *dev = &pdev->dev;
+-      struct resource *res;
+       struct brcm_nvram *priv;
++      struct resource *res;
++      void __iomem *base;
++      size_t size;
+       int err;
+ 
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+@@ -159,21 +151,29 @@ 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);
++      base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
++      if (IS_ERR(base))
++              return PTR_ERR(base);
++
++      size = resource_size(res);
++
++      priv->data = kzalloc(size, GFP_KERNEL);
++      if (!priv->data)
++              return -ENOMEM;
++
++      memcpy_fromio(priv->data, base, size);
+ 
+       err = brcm_nvram_parse(priv);
+       if (err)
+               return err;
+ 
+-      bcm47xx_nvram_init_from_iomem(priv->base, resource_size(res));
++      bcm47xx_nvram_init_from_iomem(base, size);
+ 
+       config.dev = dev;
+       config.cells = priv->cells;
+       config.ncells = priv->ncells;
+       config.priv = priv;
+-      config.size = resource_size(res);
++      config.size = size;
+ 
+       return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
+ }

diff --git a/target/linux/bcm53xx/patches-6.1/800-nvmem-brcm_nvram-store-a-copy-of-NVRAM-content.patch b/target/linux/bcm53xx/patches-6.1/800-nvmem-brcm_nvram-store-a-copy-of-NVRAM-content.patch
new file mode 100644 (file)
index 0000000..901bb6d
--- /dev/null
+++ b/target/linux/bcm53xx/patches-6.1/800-nvmem-brcm_nvram-store-a-copy-of-NVRAM-content.patch
@@ -0,0 +1,128 @@
+From a18378409fee1cac0f0c58a4770ff557b498c778 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Fri, 1 Sep 2023 10:44:26 +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
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+---
+ drivers/nvmem/brcm_nvram.c | 54 +++++++++++++++++++-------------------
+ 1 file changed, 27 insertions(+), 27 deletions(-)
+
+--- a/drivers/nvmem/brcm_nvram.c
++++ b/drivers/nvmem/brcm_nvram.c
+@@ -19,7 +19,7 @@
+ 
+ struct brcm_nvram {
+       struct device *dev;
+-      void __iomem *base;
++      uint8_t *data;
+       struct nvmem_cell_info *cells;
+       int ncells;
+ };
+@@ -36,10 +36,8 @@ static int brcm_nvram_read(void *context
+                          size_t bytes)
+ {
+       struct brcm_nvram *priv = context;
+-      u8 *dst = val;
+ 
+-      while (bytes--)
+-              *dst++ = readb(priv->base + offset++);
++      memcpy(val, priv->data + offset, bytes);
+ 
+       return 0;
+ }
+@@ -110,35 +108,27 @@ static int brcm_nvram_add_cells(struct b
+ 
+ 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;
++      uint8_t tmp;
+       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);
++      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';
++      tmp = priv->data[len - 1];
++      priv->data[len - 1] = '\0';
+ 
+-      err = brcm_nvram_add_cells(priv, data, len);
+-      if (err) {
++      err = brcm_nvram_add_cells(priv, priv->data, len);
++      if (err)
+               dev_err(dev, "Failed to add cells: %d\n", err);
+-              return err;
+-      }
+ 
+-      kfree(data);
++      priv->data[len - 1] = tmp;
+ 
+       return 0;
+ }
+@@ -150,8 +140,10 @@ static int brcm_nvram_probe(struct platf
+               .reg_read = brcm_nvram_read,
+       };
+       struct device *dev = &pdev->dev;
+-      struct resource *res;
+       struct brcm_nvram *priv;
++      struct resource *res;
++      void __iomem *base;
++      size_t size;
+       int err;
+ 
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+@@ -159,21 +151,29 @@ 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);
++      base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
++      if (IS_ERR(base))
++              return PTR_ERR(base);
++
++      size = resource_size(res);
++
++      priv->data = kzalloc(size, GFP_KERNEL);
++      if (!priv->data)
++              return -ENOMEM;
++
++      memcpy_fromio(priv->data, base, size);
+ 
+       err = brcm_nvram_parse(priv);
+       if (err)
+               return err;
+ 
+-      bcm47xx_nvram_init_from_iomem(priv->base, resource_size(res));
++      bcm47xx_nvram_init_from_iomem(base, size);
+ 
+       config.dev = dev;
+       config.cells = priv->cells;
+       config.ncells = priv->ncells;
+       config.priv = priv;
+-      config.size = resource_size(res);
++      config.size = size;
+ 
+       return PTR_ERR_OR_ZERO(devm_nvmem_register(dev, &config));
+ }