Re: [PATCH wireless-next v2 08/12] brcmfmac: firmware: Allow platform to override macaddr

["Alvin Šipraga" <ALSI@bang-olufsen.dk>]

On Mon, Sep 12, 2022 at 10:53:17AM +0100, Russell King wrote:
> From: Hector Martin <marcan@marcan.st>
> 
> On Device Tree platforms, it is customary to be able to set the MAC
> address via the Device Tree, as it is often stored in system firmware.
> This is particularly relevant for Apple ARM64 platforms, where this
> information comes from system configuration and passed through by the
> bootloader into the DT.
> 
> Implement support for this by fetching the platform MAC address and
> adding or replacing the macaddr= property in nvram. This becomes the
> dongle's default MAC address.
> 
> On platforms with an SROM MAC address, this overrides it. On platforms
> without one, such as Apple ARM64 devices, this is required for the
> firmware to boot (it will fail if it does not have a valid MAC at all).
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Hector Martin <marcan@marcan.st>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> ---
>  .../broadcom/brcm80211/brcmfmac/firmware.c    | 31 +++++++++++++++++--
>  1 file changed, 29 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
> index 371c086d1f48..c109e20fc5c6 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
> @@ -21,6 +21,8 @@
>  #define BRCMF_FW_NVRAM_DEVPATH_LEN		19	/* devpath0=pcie/1/4/ */
>  #define BRCMF_FW_NVRAM_PCIEDEV_LEN		10	/* pcie/1/4/ + \0 */
>  #define BRCMF_FW_DEFAULT_BOARDREV		"boardrev=0xff"
> +#define BRCMF_FW_MACADDR_FMT			"macaddr=%pM"
> +#define BRCMF_FW_MACADDR_LEN			(7 + ETH_ALEN * 3)
>  
>  enum nvram_parser_state {
>  	IDLE,
> @@ -57,6 +59,7 @@ struct nvram_parser {
>  	bool multi_dev_v1;
>  	bool multi_dev_v2;
>  	bool boardrev_found;
> +	bool strip_mac;

  CC [M]  drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.o
drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c:63: warning: Function parameter or member 'strip_mac' not described in 'nvram_parser'

Otherwise looks OK and you can add

Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>


>  };
>  
>  /*
> @@ -121,6 +124,10 @@ static enum nvram_parser_state brcmf_nvram_handle_key(struct nvram_parser *nvp)
>  			nvp->multi_dev_v2 = true;
>  		if (strncmp(&nvp->data[nvp->entry], "boardrev", 8) == 0)
>  			nvp->boardrev_found = true;
> +		/* strip macaddr if platform MAC overrides */
> +		if (nvp->strip_mac &&
> +		    strncmp(&nvp->data[nvp->entry], "macaddr", 7) == 0)
> +			st = COMMENT;
>  	} else if (!is_nvram_char(c) || c == ' ') {
>  		brcmf_dbg(INFO, "warning: ln=%d:col=%d: '=' expected, skip invalid key entry\n",
>  			  nvp->line, nvp->column);
> @@ -209,6 +216,7 @@ static int brcmf_init_nvram_parser(struct nvram_parser *nvp,
>  		size = data_len;
>  	/* Add space for properties we may add */
>  	size += strlen(BRCMF_FW_DEFAULT_BOARDREV) + 1;
> +	size += BRCMF_FW_MACADDR_LEN + 1;
>  	/* Alloc for extra 0 byte + roundup by 4 + length field */
>  	size += 1 + 3 + sizeof(u32);
>  	nvp->nvram = kzalloc(size, GFP_KERNEL);
> @@ -368,22 +376,37 @@ static void brcmf_fw_add_defaults(struct nvram_parser *nvp)
>  	nvp->nvram_len++;
>  }
>  
> +static void brcmf_fw_add_macaddr(struct nvram_parser *nvp, u8 *mac)
> +{
> +	int len;
> +
> +	len = scnprintf(&nvp->nvram[nvp->nvram_len], BRCMF_FW_MACADDR_LEN + 1,
> +			BRCMF_FW_MACADDR_FMT, mac);
> +	WARN_ON(len != BRCMF_FW_MACADDR_LEN);
> +	nvp->nvram_len += len + 1;
> +}
> +
>  /* brcmf_nvram_strip :Takes a buffer of "<var>=<value>\n" lines read from a fil
>   * and ending in a NUL. Removes carriage returns, empty lines, comment lines,
>   * and converts newlines to NULs. Shortens buffer as needed and pads with NULs.
>   * End of buffer is completed with token identifying length of buffer.
>   */
>  static void *brcmf_fw_nvram_strip(const u8 *data, size_t data_len,
> -				  u32 *new_length, u16 domain_nr, u16 bus_nr)
> +				  u32 *new_length, u16 domain_nr, u16 bus_nr,
> +				  struct device *dev)
>  {
>  	struct nvram_parser nvp;
>  	u32 pad;
>  	u32 token;
>  	__le32 token_le;
> +	u8 mac[ETH_ALEN];
>  
>  	if (brcmf_init_nvram_parser(&nvp, data, data_len) < 0)
>  		return NULL;
>  
> +	if (eth_platform_get_mac_address(dev, mac) == 0)
> +		nvp.strip_mac = true;
> +
>  	while (nvp.pos < data_len) {
>  		nvp.state = nv_parser_states[nvp.state](&nvp);
>  		if (nvp.state == END)
> @@ -404,6 +427,9 @@ static void *brcmf_fw_nvram_strip(const u8 *data, size_t data_len,
>  
>  	brcmf_fw_add_defaults(&nvp);
>  
> +	if (nvp.strip_mac)
> +		brcmf_fw_add_macaddr(&nvp, mac);
> +
>  	pad = nvp.nvram_len;
>  	*new_length = roundup(nvp.nvram_len + 1, 4);
>  	while (pad != *new_length) {
> @@ -538,7 +564,8 @@ static int brcmf_fw_request_nvram_done(const struct firmware *fw, void *ctx)
>  	if (data)
>  		nvram = brcmf_fw_nvram_strip(data, data_len, &nvram_length,
>  					     fwctx->req->domain_nr,
> -					     fwctx->req->bus_nr);
> +					     fwctx->req->bus_nr,
> +					     fwctx->dev);
>  
>  	if (free_bcm47xx_nvram)
>  		bcm47xx_nvram_release_contents(data);
> -- 
> 2.30.2
>
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