From c35105f375b530bc27e03ea9250b1c26dd4cae86 Mon Sep 17 00:00:00 2001 From: Hector Martin Date: Tue, 14 Feb 2023 17:00:34 +0900 Subject: [PATCH] wifi: brcmfmac: pcie: Provide a buffer of random bytes to the device [ Upstream commit 91918ce88d9fef408bb12c46a27c73d79b604c20 ] Newer Apple firmwares on chipsets without a hardware RNG require the host to provide a buffer of 256 random bytes to the device on initialization. This buffer is present immediately before NVRAM, suffixed by a footer containing a magic number and the buffer length. This won't affect chips/firmwares that do not use this feature, so do it unconditionally for all Apple platforms (those with an Apple OTP). Reviewed-by: Linus Walleij Signed-off-by: Hector Martin Reviewed-by: Julian Calaby Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20230214080034.3828-3-marcan@marcan.st Signed-off-by: Sasha Levin --- .../wireless/broadcom/brcm80211/brcmfmac/pcie.c | 32 ++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c index 067ea01..3b1277a 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -1631,6 +1632,13 @@ brcmf_pcie_init_share_ram_info(struct brcmf_pciedev_info *devinfo, return 0; } +struct brcmf_random_seed_footer { + __le32 length; + __le32 magic; +}; + +#define BRCMF_RANDOM_SEED_MAGIC 0xfeedc0de +#define BRCMF_RANDOM_SEED_LENGTH 0x100 static int brcmf_pcie_download_fw_nvram(struct brcmf_pciedev_info *devinfo, const struct firmware *fw, void *nvram, @@ -1667,6 +1675,30 @@ static int brcmf_pcie_download_fw_nvram(struct brcmf_pciedev_info *devinfo, nvram_len; memcpy_toio(devinfo->tcm + address, nvram, nvram_len); brcmf_fw_nvram_free(nvram); + + if (devinfo->otp.valid) { + size_t rand_len = BRCMF_RANDOM_SEED_LENGTH; + struct brcmf_random_seed_footer footer = { + .length = cpu_to_le32(rand_len), + .magic = cpu_to_le32(BRCMF_RANDOM_SEED_MAGIC), + }; + void *randbuf; + + /* Some Apple chips/firmwares expect a buffer of random + * data to be present before NVRAM + */ + brcmf_dbg(PCIE, "Download random seed\n"); + + address -= sizeof(footer); + memcpy_toio(devinfo->tcm + address, &footer, + sizeof(footer)); + + address -= rand_len; + randbuf = kzalloc(rand_len, GFP_KERNEL); + get_random_bytes(randbuf, rand_len); + memcpy_toio(devinfo->tcm + address, randbuf, rand_len); + kfree(randbuf); + } } else { brcmf_dbg(PCIE, "No matching NVRAM file found %s\n", devinfo->nvram_name); -- 2.7.4