diff options
| author |   Hector Martin <marcan@marcan.st> | 2023-02-14 17:00:34 +0900 |
|---|---|---|
| committer |   Kalle Valo <kvalo@kernel.org> | 2023-02-27 12:41:05 +0200 |
| commit | 91918ce88d9fef408bb12c46a27c73d79b604c20 (patch) | |
| tree | a54bfcfff1cdda182c8467958866a4e3845cfd84 | |
| parent | wifi: brcmfmac: acpi: Add support for fetching Apple ACPI properties (diff) | |
| download | linux-91918ce88d9fef408bb12c46a27c73d79b604c20.tar.xz linux-91918ce88d9fef408bb12c46a27c73d79b604c20.zip | |
wifi: brcmfmac: pcie: Provide a buffer of random bytes to the device
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 <linus.walleij@linaro.org>
Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230214080034.3828-3-marcan@marcan.st
| -rw-r--r-- | drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c index a9b9b2dc62d4..2835ef4edb18 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c @@ -15,6 +15,7 @@ #include <linux/sched/signal.h> #include <linux/kthread.h> #include <linux/io.h> +#include <linux/random.h> #include <asm/unaligned.h> #include <soc.h> @@ -1653,6 +1654,13 @@ 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, @@ -1689,6 +1697,30 @@ 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); |