From patchwork Fri Sep 17 18:22:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 12502907 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AF81C433EF for ; Fri, 17 Sep 2021 18:23:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 459BB611C4 for ; Fri, 17 Sep 2021 18:23:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245451AbhIQSYv (ORCPT ); Fri, 17 Sep 2021 14:24:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244170AbhIQSYM (ORCPT ); Fri, 17 Sep 2021 14:24:12 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AC9FC061757; Fri, 17 Sep 2021 11:22:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=+bAxPNXEkjOLG0J16lJ79/BZjrPhBIO0OVG4jkta3IU=; b=0iVI7z+X129Mv0/pbPx3RKPj/k hxZMBYWuTcr10TBXzIXvlSWek7JhKLJexctVeUzwzM00et4epv9Nqv9BJ7bak9Z8H7tBFuHDCcoyw EWdX4D1o6FPa0MLP82YVOLadoF9RIM4LfNMRDL7twHJaB+os60U/5GYRiIl2V559w8p2Wl0SkVWJE aJLRFTuPo2U/barhlN8MsMRMLrWHYLiO7g4Nb4QDyaQIgCnWyFCMzfh1gP4vV6GaR0durL++P8I1K NzR2JlKf4klU/brjqKaI0qMCV/O22IaNfuYIMKWxZLc3OfKiPcqwcxRqrcdnoKYvivJVgC+dg2K7c W4BwdnGw==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mRIVI-00Ep5Y-AF; Fri, 17 Sep 2021 18:22:28 +0000 From: "Luis R. Rodriguez" To: gregkh@linuxfoundation.org Cc: bp@suse.de, akpm@linux-foundation.org, josh@joshtriplett.org, rishabhb@codeaurora.org, kubakici@wp.pl, maco@android.com, david.brown@linaro.org, bjorn.andersson@linaro.org, linux-wireless@vger.kernel.org, keescook@chromium.org, shuah@kernel.org, mfuzzey@parkeon.com, zohar@linux.vnet.ibm.com, dhowells@redhat.com, pali.rohar@gmail.com, tiwai@suse.de, arend.vanspriel@broadcom.com, zajec5@gmail.com, nbroeking@me.com, broonie@kernel.org, dmitry.torokhov@gmail.com, dwmw2@infradead.org, torvalds@linux-foundation.org, Abhay_Salunke@dell.com, jewalt@lgsinnovations.com, cantabile.desu@gmail.com, ast@fb.com, andresx7@gmail.com, dan.rue@linaro.org, brendanhiggins@google.com, yzaikin@google.com, sfr@canb.auug.org.au, rdunlap@infradead.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Luis Chamberlain Subject: [PATCH 05/14] firmware_loader: formalize built-in firmware API Date: Fri, 17 Sep 2021 11:22:17 -0700 Message-Id: <20210917182226.3532898-6-mcgrof@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210917182226.3532898-1-mcgrof@kernel.org> References: <20210917182226.3532898-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Luis Chamberlain Now that we have a kconfig entry to represent built-in firmware support, formalize its use with a proper API. This can later be used by other callers where all they need is built-in firmware. We export the firmware_request_builtin() call for now only under the TEST_FIRMWARE symbol namespace as there are no direct modular users for it. If they pop up they are free to export it generally. Built-in code always gets access to the callers and we'll demonstrate a hidden user which has been lurking in the kernel for a while and the reason why using a proper API was better long term. Reviewed-by: Borislav Petkov Signed-off-by: Luis Chamberlain --- drivers/base/firmware_loader/builtin/Makefile | 6 +- drivers/base/firmware_loader/builtin/main.c | 95 +++++++++++++++++++ drivers/base/firmware_loader/firmware.h | 17 ++++ drivers/base/firmware_loader/main.c | 78 +-------------- include/linux/firmware.h | 11 +++ 5 files changed, 128 insertions(+), 79 deletions(-) create mode 100644 drivers/base/firmware_loader/builtin/main.c diff --git a/drivers/base/firmware_loader/builtin/Makefile b/drivers/base/firmware_loader/builtin/Makefile index 101754ad48d9..eb4be452062a 100644 --- a/drivers/base/firmware_loader/builtin/Makefile +++ b/drivers/base/firmware_loader/builtin/Makefile @@ -1,11 +1,13 @@ # SPDX-License-Identifier: GPL-2.0 +obj-y += main.o # Create $(fwdir) from $(CONFIG_EXTRA_FIRMWARE_DIR) -- if it doesn't have a # leading /, it's relative to $(srctree). fwdir := $(subst $(quote),,$(CONFIG_EXTRA_FIRMWARE_DIR)) fwdir := $(addprefix $(srctree)/,$(filter-out /%,$(fwdir)))$(filter /%,$(fwdir)) -obj-y := $(addsuffix .gen.o, $(subst $(quote),,$(CONFIG_EXTRA_FIRMWARE))) +firmware := $(addsuffix .gen.o, $(subst $(quote),,$(CONFIG_EXTRA_FIRMWARE))) +obj-y += $(firmware) FWNAME = $(patsubst $(obj)/%.gen.S,%,$@) FWSTR = $(subst $(comma),_,$(subst /,_,$(subst .,_,$(subst -,_,$(FWNAME))))) @@ -34,7 +36,7 @@ $(obj)/%.gen.S: FORCE $(call filechk,fwbin) # The .o files depend on the binaries directly; the .S files don't. -$(addprefix $(obj)/, $(obj-y)): $(obj)/%.gen.o: $(fwdir)/% +$(addprefix $(obj)/, $(firmware)): $(obj)/%.gen.o: $(fwdir)/% targets := $(patsubst $(obj)/%,%, \ $(shell find $(obj) -name \*.gen.S 2>/dev/null)) diff --git a/drivers/base/firmware_loader/builtin/main.c b/drivers/base/firmware_loader/builtin/main.c new file mode 100644 index 000000000000..2af0e58f3f9f --- /dev/null +++ b/drivers/base/firmware_loader/builtin/main.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Builtin firmware support */ + +#include +#include "../firmware.h" + +extern struct builtin_fw __start_builtin_fw[]; +extern struct builtin_fw __end_builtin_fw[]; + +static bool fw_copy_to_prealloc_buf(struct firmware *fw, + void *buf, size_t size) +{ + if (!buf) + return true; + if (size < fw->size) + return false; + memcpy(buf, fw->data, fw->size); + return true; +} + +/** + * firmware_request_builtin() - load builtin firmware + * @fw: pointer to firmware struct + * @name: name of firmware file + * + * Some use cases in the kernel have a requirement so that no memory allocator + * is involved as these calls take place early in boot process. An example is + * the x86 CPU microcode loader. In these cases all the caller wants is to see + * if the firmware was built-in and if so use it right away. This can be used + * for such cases. + * + * This looks for the firmware in the built-in kernel. Only if the kernel was + * built-in with the firmware you are looking for will this return successfully. + * + * Callers of this API do not need to use release_firmware() as the pointer to + * the firmware is expected to be provided locally on the stack of the caller. + **/ +bool firmware_request_builtin(struct firmware *fw, const char *name) +{ + struct builtin_fw *b_fw; + + if (!fw) + return false; + + for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) { + if (strcmp(name, b_fw->name) == 0) { + fw->size = b_fw->size; + fw->data = b_fw->data; + return true; + } + } + + return false; +} +EXPORT_SYMBOL_NS_GPL(firmware_request_builtin, TEST_FIRMWARE); + +/** + * firmware_request_builtin_buf() - load builtin firmware into optional buffer + * @fw: pointer to firmware struct + * @name: name of firmware file + * @buf: If set this lets you use a pre-allocated buffer so that the built-in + * firmware into is copied into. This field can be NULL. It is used by + * callers such as request_firmware_into_buf() and + * request_partial_firmware_into_buf() + * @size: if buf was provided, the max size of the allocated buffer available. + * If the built-in firmware does not fit into the pre-allocated @buf this + * call will fail. + * + * This looks for the firmware in the built-in kernel. Only if the kernel was + * built-in with the firmware you are looking for will this call possibly + * succeed. If you passed a @buf the firmware will be copied into it *iff* the + * built-in firmware fits into the pre-allocated buffer size specified in + * @size. + * + * This caller is to be used internally by the firmware_loader only. + **/ +bool firmware_request_builtin_buf(struct firmware *fw, const char *name, + void *buf, size_t size) +{ + if (!firmware_request_builtin(fw, name)) + return false; + + return fw_copy_to_prealloc_buf(fw, buf, size); +} + +bool firmware_is_builtin(const struct firmware *fw) +{ + struct builtin_fw *b_fw; + + for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) + if (fw->data == b_fw->data) + return true; + + return false; +} diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h index a3014e9e2c85..7e38827ad006 100644 --- a/drivers/base/firmware_loader/firmware.h +++ b/drivers/base/firmware_loader/firmware.h @@ -151,6 +151,23 @@ static inline void fw_state_done(struct fw_priv *fw_priv) int assign_fw(struct firmware *fw, struct device *device); +#ifdef CONFIG_FW_LOADER_BUILTIN +bool firmware_is_builtin(const struct firmware *fw); +bool firmware_request_builtin_buf(struct firmware *fw, const char *name, + void *buf, size_t size); +#else +static inline bool firmware_is_builtin(const struct firmware *fw) +{ + return false; +} +static inline bool firmware_request_builtin_buf(struct firmware *fw, + const char *name, + void *buf, size_t size) +{ + return false; +} +#endif + #ifdef CONFIG_FW_LOADER_PAGED_BUF void fw_free_paged_buf(struct fw_priv *fw_priv); int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed); diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c index 45075c7f9290..94d1789a233e 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -93,82 +93,6 @@ DEFINE_MUTEX(fw_lock); static struct firmware_cache fw_cache; -/* Builtin firmware support */ - -#ifdef CONFIG_FW_LOADER_BUILTIN - -extern struct builtin_fw __start_builtin_fw[]; -extern struct builtin_fw __end_builtin_fw[]; - -static bool fw_copy_to_prealloc_buf(struct firmware *fw, - void *buf, size_t size) -{ - if (!buf) - return true; - if (size < fw->size) - return false; - memcpy(buf, fw->data, fw->size); - return true; -} - -static bool firmware_request_builtin(struct firmware *fw, const char *name) -{ - struct builtin_fw *b_fw; - - if (!fw) - return false; - - for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) { - if (strcmp(name, b_fw->name) == 0) { - fw->size = b_fw->size; - fw->data = b_fw->data; - return true; - } - } - - return false; -} - -static bool firmware_request_builtin_buf(struct firmware *fw, const char *name, - void *buf, size_t size) -{ - if (!firmware_request_builtin(fw, name)) - return false; - return fw_copy_to_prealloc_buf(fw, buf, size); -} - -static bool fw_is_builtin_firmware(const struct firmware *fw) -{ - struct builtin_fw *b_fw; - - for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) - if (fw->data == b_fw->data) - return true; - - return false; -} - -#else - -static inline bool firmware_request_builtin(struct firmware *fw, - const char *name) -{ - return false; -} - -static inline bool firmware_request_builtin_buf(struct firmware *fw, - const char *name, void *buf, - size_t size) -{ - return false; -} - -static inline bool fw_is_builtin_firmware(const struct firmware *fw) -{ - return false; -} -#endif - static void fw_state_init(struct fw_priv *fw_priv) { struct fw_state *fw_st = &fw_priv->fw_st; @@ -1068,7 +992,7 @@ EXPORT_SYMBOL(request_partial_firmware_into_buf); void release_firmware(const struct firmware *fw) { if (fw) { - if (!fw_is_builtin_firmware(fw)) + if (!firmware_is_builtin(fw)) firmware_free_data(fw); kfree(fw); } diff --git a/include/linux/firmware.h b/include/linux/firmware.h index 25109192cebe..29d17a05ead6 100644 --- a/include/linux/firmware.h +++ b/include/linux/firmware.h @@ -20,12 +20,15 @@ struct firmware { struct module; struct device; +#ifdef CONFIG_FW_LOADER_BUILTIN struct builtin_fw { char *name; void *data; unsigned long size; }; +bool firmware_request_builtin(struct firmware *fw, const char *name); + /* We have to play tricks here much like stringify() to get the __COUNTER__ macro to be expanded as we want it */ #define __fw_concat1(x, y) x##y @@ -38,6 +41,14 @@ struct builtin_fw { static const struct builtin_fw __fw_concat(__builtin_fw,__COUNTER__) \ __used __section(".builtin_fw") = { name, blob, size } +#else +static inline bool firmware_request_builtin(struct firmware *fw, + const char *name) +{ + return false; +} +#endif + #if defined(CONFIG_FW_LOADER) || (defined(CONFIG_FW_LOADER_MODULE) && defined(MODULE)) int request_firmware(const struct firmware **fw, const char *name, struct device *device);