From patchwork Tue Jan 4 07:26:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hector Martin X-Patchwork-Id: 530318 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6FA87C433F5 for ; Tue, 4 Jan 2022 07:30:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233461AbiADHaL (ORCPT ); Tue, 4 Jan 2022 02:30:11 -0500 Received: from marcansoft.com ([212.63.210.85]:46646 "EHLO mail.marcansoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233485AbiADHaC (ORCPT ); Tue, 4 Jan 2022 02:30:02 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: hector@marcansoft.com) by mail.marcansoft.com (Postfix) with ESMTPSA id 8C0E4422CC; Tue, 4 Jan 2022 07:29:53 +0000 (UTC) From: Hector Martin To: Kalle Valo , "David S. Miller" , Jakub Kicinski , Rob Herring , "Rafael J. Wysocki" , Len Brown , Arend van Spriel , Franky Lin , Hante Meuleman , Chi-hsien Lin , Wright Feng , Dmitry Osipenko Cc: Hector Martin , Sven Peter , Alyssa Rosenzweig , Mark Kettenis , =?utf-8?b?UmFmYcWCIE1pxYJlY2tp?= , Pieter-Paul Giesberts , Linus Walleij , Hans de Goede , "John W. Linville" , "brian m. carlson" , Andy Shevchenko , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, brcm80211-dev-list.pdl@broadcom.com, SHA-cyfmac-dev-list@infineon.com Subject: [PATCH v2 17/35] brcmfmac: pcie: Provide a buffer of random bytes to the device Date: Tue, 4 Jan 2022 16:26:40 +0900 Message-Id: <20220104072658.69756-18-marcan@marcan.st> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20220104072658.69756-1-marcan@marcan.st> References: <20220104072658.69756-1-marcan@marcan.st> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org 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. Reviewed-by: Linus Walleij Signed-off-by: Hector Martin --- .../broadcom/brcm80211/brcmfmac/pcie.c | 30 +++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c index cc76f00724e6..a8cccfbea20b 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include @@ -1662,6 +1663,13 @@ 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, @@ -1693,11 +1701,33 @@ static int brcmf_pcie_download_fw_nvram(struct brcmf_pciedev_info *devinfo, brcmf_pcie_write_ram32(devinfo, devinfo->ci->ramsize - 4, 0); if (nvram) { + 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; + brcmf_dbg(PCIE, "Download NVRAM %s\n", devinfo->nvram_name); address = devinfo->ci->rambase + devinfo->ci->ramsize - nvram_len; brcmf_pcie_copy_mem_todev(devinfo, address, nvram, nvram_len); brcmf_fw_nvram_free(nvram); + + /* 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); + brcmf_pcie_copy_mem_todev(devinfo, address, &footer, + sizeof(footer)); + + address -= rand_len; + randbuf = kzalloc(rand_len, GFP_KERNEL); + get_random_bytes(randbuf, rand_len); + brcmf_pcie_copy_mem_todev(devinfo, address, randbuf, rand_len); + kfree(randbuf); } else { brcmf_dbg(PCIE, "No matching NVRAM file found %s\n", devinfo->nvram_name);