From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 96D3AC2D0CE for ; Tue, 21 Jan 2020 19:27:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7299E2073A for ; Tue, 21 Jan 2020 19:27:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727360AbgAUT15 (ORCPT ); Tue, 21 Jan 2020 14:27:57 -0500 Received: from laurent.telenet-ops.be ([195.130.137.89]:37048 "EHLO laurent.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726926AbgAUT15 (ORCPT ); Tue, 21 Jan 2020 14:27:57 -0500 Received: from ramsan ([84.195.182.253]) by laurent.telenet-ops.be with bizsmtp id t7Tt210045USYZQ017TtSP; Tue, 21 Jan 2020 20:27:54 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan with esmtp (Exim 4.90_1) (envelope-from ) id 1itzBp-00037m-6H; Tue, 21 Jan 2020 20:27:53 +0100 Received: from geert by rox.of.borg with local (Exim 4.90_1) (envelope-from ) id 1itzBp-0005NH-3x; Tue, 21 Jan 2020 20:27:53 +0100 From: Geert Uytterhoeven To: Russell King , Nicolas Pitre , Arnd Bergmann , Eric Miao , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Cc: Chris Brandt , linux-arm-kernel@lists.infradead.org, linux-renesas-soc@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH] ARM: boot: Obtain start of physical memory from DTB Date: Tue, 21 Jan 2020 20:27:41 +0100 Message-Id: <20200121192741.20597-1-geert+renesas@glider.be> X-Mailer: git-send-email 2.17.1 Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Currently, the start address of physical memory is obtained by masking the program counter with a fixed mask of 0xf8000000. This mask value was chosen as a balance between the requirements of different platforms. However, this does require that the start address of physical memory is a multiple of 128 MiB, precluding booting Linux on platforms where this requirement is not fulfilled. Fix this limitation by obtaining the start address from the passed DTB instead, if available. Note that for now this is limited to DTBs passed explicitly by the boot loader. DTBs appended to a zImage or uImage are not inspected. Fall back to the traditional method when needed. This allows to boot Linux on r7s9210/rza2mevb using the 64 MiB of SDRAM on the RZA2MEVB sub board, which is located at 0x0C000000 (CS3 space), i.e. not at a multiple of 128 MiB. Suggested-by: Nicolas Pitre Signed-off-by: Geert Uytterhoeven --- Against arm/for-next. Tested with the following configurations: - zImage + DTB (r8a7791/koelsch): physical memory start address obtained from DT, - uImage + DTB (r8a73a4/ape6evm, r7s72100/rskrza1, r7s9210/rza2mevb): physical memory start address obtained from DT, - zImage with appended DTB (r8a7740/armadillo, sh73a0/kzm9g): physical memory start address obtained by masking, as before. An appended DTB is currently processed after the start of physical memory is obtained. Hence obtaining that address from an appended DTB requires moving/copying that copy. Given the complexity w.r.t. the "restart" label, and the lack of a need for me to support this, I didn't implement that part. --- arch/arm/boot/compressed/Makefile | 6 ++- arch/arm/boot/compressed/fdt_get_mem_start.c | 52 ++++++++++++++++++++ arch/arm/boot/compressed/head.S | 16 +++++- 3 files changed, 72 insertions(+), 2 deletions(-) create mode 100644 arch/arm/boot/compressed/fdt_get_mem_start.c diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index da599c3a11934332..bbfecd648a1a3b57 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -86,12 +86,15 @@ libfdt_objs := $(addsuffix .o, $(basename $(libfdt))) $(addprefix $(obj)/,$(libfdt) $(libfdt_hdrs)): $(obj)/%: $(srctree)/scripts/dtc/libfdt/% $(call cmd,shipped) -$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o): \ +$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o fdt_get_mem_start.o): \ $(addprefix $(obj)/,$(libfdt_hdrs)) ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y) OBJS += $(libfdt_objs) atags_to_fdt.o endif +ifeq ($(CONFIG_USE_OF),y) +OBJS += $(libfdt_objs) fdt_get_mem_start.o +endif targets := vmlinux vmlinux.lds piggy_data piggy.o \ lib1funcs.o ashldi3.o bswapsdi2.o \ @@ -116,6 +119,7 @@ CFLAGS_fdt.o := $(nossp-flags-y) CFLAGS_fdt_ro.o := $(nossp-flags-y) CFLAGS_fdt_rw.o := $(nossp-flags-y) CFLAGS_fdt_wip.o := $(nossp-flags-y) +CFLAGS_fdt_get_mem_start.o := $(nossp-flags-y) ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin -I$(obj) asflags-y := -DZIMAGE diff --git a/arch/arm/boot/compressed/fdt_get_mem_start.c b/arch/arm/boot/compressed/fdt_get_mem_start.c new file mode 100644 index 0000000000000000..2c5ac47f656317ee --- /dev/null +++ b/arch/arm/boot/compressed/fdt_get_mem_start.c @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include + +static const void *getprop(const void *fdt, const char *node_path, + const char *property) +{ + int offset = fdt_path_offset(fdt, node_path); + + if (offset == -FDT_ERR_NOTFOUND) + return NULL; + + return fdt_getprop(fdt, offset, property, NULL); +} + +static uint32_t get_addr_size(const void *fdt) +{ + const __be32 *addr_len = getprop(fdt, "/", "#address-cells"); + + if (!addr_len) { + /* default */ + return 1; + } + + return fdt32_to_cpu(*addr_len); +} + +/* + * Get the start of physical memory + */ + +unsigned long fdt_get_mem_start(const void *fdt) +{ + const __be32 *memory; + uint32_t addr_size; + + if (!fdt) + return -1; + + if (*(__be32 *)fdt != cpu_to_fdt32(FDT_MAGIC)) + return -1; + + /* Find the first memory node */ + memory = getprop(fdt, "/memory", "reg"); + if (!memory) + return -1; + + /* There may be multiple cells on LPAE platforms */ + addr_size = get_addr_size(fdt); + + return fdt32_to_cpu(memory[addr_size - 1]); +} diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 927f5dc413d7dff2..cb4e6a84b156c204 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -235,8 +235,20 @@ not_angel: .text #ifdef CONFIG_AUTO_ZRELADDR +#ifdef CONFIG_USE_OF /* - * Find the start of physical memory. As we are executing + * Find the start of physical memory. + * Try the passed DTB first, if available. + */ + mov r0, r8 + bl fdt_get_mem_start + mov r4, r0 + cmn r0, #1 + bne 1f +#endif + + /* + * Fall back to the traditional method. As we are executing * without the MMU on, we are in the physical address space. * We just need to get rid of any offset by aligning the * address. @@ -254,6 +266,8 @@ not_angel: */ mov r4, pc and r4, r4, #0xf8000000 + +1: /* Determine final kernel image address. */ add r4, r4, #TEXT_OFFSET #else -- 2.17.1