From patchwork Thu Jun 9 20:08:44 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geoff Levand X-Patchwork-Id: 9167851 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 5F1C160467 for ; Thu, 9 Jun 2016 20:12:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5083228047 for ; Thu, 9 Jun 2016 20:12:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4524528356; Thu, 9 Jun 2016 20:12:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E675128047 for ; Thu, 9 Jun 2016 20:12:07 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bB6Hl-0005RV-3r; Thu, 09 Jun 2016 20:10:37 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1bB6Fy-0002aX-S3; Thu, 09 Jun 2016 20:08:46 +0000 Received: from geoff by merlin.infradead.org with local (Exim 4.85_2 #1 (Red Hat Linux)) id 1bB6Fw-00046a-RI; Thu, 09 Jun 2016 20:08:44 +0000 Message-Id: <745e8f496b25ec2d226f520de307c86a770f3cc9.1465502767.git.geoff@infradead.org> In-Reply-To: References: From: Geoff Levand Patch-Date: Tue, 26 Jan 2016 15:29:29 +0900 Subject: [PATCH v18 07/13] arm64: limit memory regions based on DT property, usable-memory To: Catalin Marinas , Will Deacon Date: Thu, 09 Jun 2016 20:08:44 +0000 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , marc.zyngier@arm.com, kexec@lists.infradead.org, AKASHI Takahiro , James Morse , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: AKASHI Takahiro Crash dump kernel will be run with a limited range of memory as System RAM. On arm64, we will use a device-tree property under /chosen, linux,usable-memory = in order for primary kernel either on uefi or non-uefi (device tree only) system to hand over the information about usable memory region to crash dump kernel. This property will supercede entries in uefi memory map table and "memory" nodes in a device tree. Signed-off-by: AKASHI Takahiro --- arch/arm64/mm/init.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 45f1319..f679918 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -249,10 +249,48 @@ static int __init early_mem(char *p) } early_param("mem", early_mem); +static int __init early_init_dt_scan_usablemem(unsigned long node, + const char *uname, int depth, void *data) +{ + struct memblock_region *usablemem = (struct memblock_region *)data; + const __be32 *reg; + int len; + + usablemem->size = 0; + + if (depth != 1 || strcmp(uname, "chosen") != 0) + return 0; + + reg = of_get_flat_dt_prop(node, "linux,usable-memory", &len); + if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) + return 1; + + usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); + usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); + + return 1; +} + +static void __init fdt_enforce_memory_region(void) +{ + struct memblock_region reg; + + of_scan_flat_dt(early_init_dt_scan_usablemem, ®); + + if (reg.size) { + memblock_remove(0, PAGE_ALIGN(reg.base)); + memblock_remove(round_down(reg.base + reg.size, PAGE_SIZE), + ULLONG_MAX); + } +} + void __init arm64_memblock_init(void) { const s64 linear_region_size = -(s64)PAGE_OFFSET; + /* Handle linux,usable-memory property */ + fdt_enforce_memory_region(); + /* * Ensure that the linear region takes up exactly half of the kernel * virtual address space. This way, we can distinguish a linear address