From patchwork Wed Sep 4 23:47:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13791495 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 975A818950B; Wed, 4 Sep 2024 23:48:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725493703; cv=none; b=sYDiIueje9DN/QXnug+dSLlSN71uvUXEybXDhh2oMDJXUQC3CJj1Qd1RTRY7DGDt+0kWi31EIs2RqorR9KpCs1eJr09fzzgUOiaW3ZDGw8fYB+dwwzA6Kv+DWPEVY8cqy9edEmcjgf0CNkS+1Wt0z6NQnxbZSGtYpKKDGWKDgiM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725493703; c=relaxed/simple; bh=nsKwaA1C+DPeHbXqGcBjvOLIHgXiFg4rrFKZpG8IZuo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=d7isZF91I4KmIEWWeIDByY9L8GIzV1cw8a42MYC2JyIZMjbSoJfSV4cYOQO3KheVMjSZP4uZgiBYtoa1wm3GAHUCXY/ojJ/UlBrUQ2jspbN77Lo/QOA9SIKY1CoyXK2rrFvVB652AFaWSI9nZ/Nyv8W9YDFwduW0vJEvo4crUXE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=X36dfIG0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="X36dfIG0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C6CDC4CEC2; Wed, 4 Sep 2024 23:48:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725493703; bh=nsKwaA1C+DPeHbXqGcBjvOLIHgXiFg4rrFKZpG8IZuo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X36dfIG0wtcgWQzkkeDHpAyyy7pGPLtXcd3jbuFGMOXbrfAVNzUobsJqzX/p+sC0Q AbUbU4aws5JbrmphPMcCQ7MYHbG4F4boFFsW+/e/i+qXTMSUjRU4T5aczjlIxJ5Pw4 t34G6/LKKvTJvVADNXak2AQF8cQK4NlwOLTxdGz+AhrhppnCiWJ4jsI7ZxQQNvw7fD gAsnyHevuSc63Bwbr0Q/VSIwdAKzcjAeU6dX84uJhzAfhzlTAXAzhg/p7+CklJ0Utp R+UYNm9msmK+XOypnjCuSyfhyqmTPDq2PfN6hPFsL9cn097TWpteabOhfpjZyRNBaf B8Fg46ryR3CeQ== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: linux-arch@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org, Michal Simek , Rob Herring , devicetree@vger.kernel.org, linux-mips@vger.kernel.org, linux-openrisc@vger.kernel.org, Dinh Nguyen , Masahiro Yamada Subject: [PATCH 04/15] kbuild: add generic support for built-in boot DTBs Date: Thu, 5 Sep 2024 08:47:40 +0900 Message-ID: <20240904234803.698424-5-masahiroy@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240904234803.698424-1-masahiroy@kernel.org> References: <20240904234803.698424-1-masahiroy@kernel.org> Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Some architectures embed boot DTBs in vmlinux. A potential issue for these architectures is a race condition during parallel builds because Kbuild descends into arch/*/boot/dts/ twice. One build thread is initiated by the 'dtbs' target, which is a prerequisite of the 'all' target in the top-level Makefile: ifdef CONFIG_OF_EARLY_FLATTREE all: dtbs endif For architectures that support the embedded boot dtb, arch/*/boot/dts/ is visited also during the ordinary directory traversal in order to build obj-y objects that wrap DTBs. Since these build threads are unaware of each other, they can run simultaneously during parallel builds. This commit introduces a generic build rule to scripts/Makefile.vmlinux to support embedded boot DTBs in a race-free way. Architectures that want to use this rule need to select CONFIG_GENERIC_BUILTIN_DTB. After the migration, Makefiles under arch/*/boot/dts/ will be visited only once to build only *.dtb files. This change also aims to unify the CONFIG options used for embedded DTBs support. Currently, different architectures use different CONFIG options for the same purposes. The CONFIG options are unified as follows: - CONFIG_GENERIC_BUILTIN_DTB This enables the generic rule for embedded boot DTBs. This will be renamed to CONFIG_BUILTIN_DTB after all architectures migrate to the generic rule. - CONFIG_BUILTIN_DTB_NAME This specifies the path to the embedded DTB. (relative to arch/*/boot/dts/) - CONFIG_BUILTIN_DTB_ALL If this is enabled, all DTB files compiled under arch/*/boot/dts/ are embedded into vmlinux. Only used by MIPS. Signed-off-by: Masahiro Yamada --- Makefile | 7 ++++++- drivers/of/Kconfig | 6 ++++++ scripts/Makefile.vmlinux | 44 ++++++++++++++++++++++++++++++++++++++++ scripts/link-vmlinux.sh | 4 ++++ 4 files changed, 60 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 145112bf281a..1c765c12ab9e 100644 --- a/Makefile +++ b/Makefile @@ -1417,6 +1417,10 @@ ifdef CONFIG_OF_EARLY_FLATTREE all: dtbs endif +ifdef CONFIG_GENERIC_BUILTIN_DTB +vmlinux: dtbs +endif + endif PHONY += scripts_dtc @@ -1483,7 +1487,8 @@ endif # CONFIG_MODULES CLEAN_FILES += vmlinux.symvers modules-only.symvers \ modules.builtin modules.builtin.modinfo modules.nsdeps \ compile_commands.json rust/test \ - rust-project.json .vmlinux.objs .vmlinux.export.c + rust-project.json .vmlinux.objs .vmlinux.export.c \ + .builtin-dtbs-list .builtin-dtb.S # Directories & files removed with 'make mrproper' MRPROPER_FILES += include/config include/generated \ diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index dd726c7056bf..5142e7d7fef8 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -2,6 +2,12 @@ config DTC bool +config GENERIC_BUILTIN_DTB + bool + +config BUILTIN_DTB_ALL + bool + menuconfig OF bool "Device Tree and Open Firmware support" help diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux index 5ceecbed31eb..4626b472da49 100644 --- a/scripts/Makefile.vmlinux +++ b/scripts/Makefile.vmlinux @@ -17,6 +17,50 @@ quiet_cmd_cc_o_c = CC $@ %.o: %.c FORCE $(call if_changed_dep,cc_o_c) +quiet_cmd_as_o_S = AS $@ + cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< + +%.o: %.S FORCE + $(call if_changed_dep,as_o_S) + +# Built-in dtb +# --------------------------------------------------------------------------- + +quiet_cmd_wrap_dtbs = WRAP $@ + cmd_wrap_dtbs = { \ + echo '\#include '; \ + echo '.section .dtb.init.rodata,"a"'; \ + while read dtb; do \ + symbase=__dtb_$$(basename -s .dtb "$${dtb}" | tr - _); \ + echo '.balign STRUCT_ALIGNMENT'; \ + echo ".global $${symbase}_begin"; \ + echo "$${symbase}_begin:"; \ + echo '.incbin "'$$dtb'" '; \ + echo ".global $${symbase}_end"; \ + echo "$${symbase}_end:"; \ + done < $<; \ + } > $@ + +.builtin-dtbs.S: .builtin-dtbs-list FORCE + $(call if_changed,wrap_dtbs) + +quiet_cmd_gen_dtbs_list = GEN $@ + cmd_gen_dtbs_list = \ + $(if $(CONFIG_BUILTIN_DTB_NAME), echo "arch/$(SRCARCH)/boot/dts/$(CONFIG_BUILTIN_DTB_NAME).dtb",:) > $@ + +.builtin-dtbs-list: arch/$(SRCARCH)/boot/dts/dtbs-list FORCE + $(call if_changed,$(if $(CONFIG_BUILTIN_DTB_ALL),copy,gen_dtbs_list)) + +targets += .builtin-dtbs-list + +ifdef CONFIG_GENERIC_BUILTIN_DTB +targets += .builtin-dtbs.S .builtin-dtbs.o +vmlinux: .builtin-dtbs.o +endif + +# vmlinux +# --------------------------------------------------------------------------- + ifdef CONFIG_MODULES targets += .vmlinux.export.o vmlinux: .vmlinux.export.o diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index c27b4e969f20..bd196944e350 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -68,6 +68,10 @@ vmlinux_link() libs="${KBUILD_VMLINUX_LIBS}" fi + if is_enabled CONFIG_GENERIC_BUILTIN_DTB; then + objs="${objs} .builtin-dtbs.o" + fi + if is_enabled CONFIG_MODULES; then objs="${objs} .vmlinux.export.o" fi