From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Mon, 3 Apr 2017 11:24:31 +0900 Subject: [PATCH v35 03/14] arm64: limit memory regions based on DT property, usable-memory-range In-Reply-To: <20170403022139.12383-1-takahiro.akashi@linaro.org> References: <20170403022139.12383-1-takahiro.akashi@linaro.org> Message-ID: <20170403022440.12515-1-takahiro.akashi@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Crash dump kernel uses only a limited range of available memory as System RAM. On arm64 kdump, This memory range is advertised to crash dump kernel via a device-tree property under /chosen, linux,usable-memory-range = Crash dump kernel reads this property at boot time and calls memblock_cap_memory_range() to limit usable memory which are listed either in UEFI memory map table or "memory" nodes of a device tree blob. Signed-off-by: AKASHI Takahiro Reviewed-by: Geoff Levand Acked-by: Catalin Marinas Acked-by: Mark Rutland Reviewed-by: Ard Biesheuvel --- arch/arm64/mm/init.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index e19e06593e37..290794b1a0f1 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -188,10 +188,45 @@ 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 = data; + const __be32 *reg; + int len; + + if (depth != 1 || strcmp(uname, "chosen") != 0) + return 0; + + reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &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 = { + .size = 0, + }; + + of_scan_flat_dt(early_init_dt_scan_usablemem, ®); + + if (reg.size) + memblock_cap_memory_range(reg.base, reg.size); +} + void __init arm64_memblock_init(void) { const s64 linear_region_size = -(s64)PAGE_OFFSET; + /* Handle linux,usable-memory-range 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 -- 2.11.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg0-x22f.google.com ([2607:f8b0:400e:c05::22f]) by merlin.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1curcy-0004Dj-8b for kexec@lists.infradead.org; Mon, 03 Apr 2017 02:21:57 +0000 Received: by mail-pg0-x22f.google.com with SMTP id 81so105615741pgh.2 for ; Sun, 02 Apr 2017 19:21:35 -0700 (PDT) From: AKASHI Takahiro Subject: [PATCH v35 03/14] arm64: limit memory regions based on DT property, usable-memory-range Date: Mon, 3 Apr 2017 11:24:31 +0900 Message-Id: <20170403022440.12515-1-takahiro.akashi@linaro.org> In-Reply-To: <20170403022139.12383-1-takahiro.akashi@linaro.org> References: <20170403022139.12383-1-takahiro.akashi@linaro.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: catalin.marinas@arm.com, will.deacon@arm.com Cc: mark.rutland@arm.com, panand@redhat.com, ard.biesheuvel@linaro.org, geoff@infradead.org, dwmw2@infradead.org, kexec@lists.infradead.org, AKASHI Takahiro , james.morse@arm.com, bauerman@linux.vnet.ibm.com, sgoel@codeaurora.org, dyoung@redhat.com, linux-arm-kernel@lists.infradead.org Crash dump kernel uses only a limited range of available memory as System RAM. On arm64 kdump, This memory range is advertised to crash dump kernel via a device-tree property under /chosen, linux,usable-memory-range = Crash dump kernel reads this property at boot time and calls memblock_cap_memory_range() to limit usable memory which are listed either in UEFI memory map table or "memory" nodes of a device tree blob. Signed-off-by: AKASHI Takahiro Reviewed-by: Geoff Levand Acked-by: Catalin Marinas Acked-by: Mark Rutland Reviewed-by: Ard Biesheuvel --- arch/arm64/mm/init.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index e19e06593e37..290794b1a0f1 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -188,10 +188,45 @@ 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 = data; + const __be32 *reg; + int len; + + if (depth != 1 || strcmp(uname, "chosen") != 0) + return 0; + + reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &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 = { + .size = 0, + }; + + of_scan_flat_dt(early_init_dt_scan_usablemem, ®); + + if (reg.size) + memblock_cap_memory_range(reg.base, reg.size); +} + void __init arm64_memblock_init(void) { const s64 linear_region_size = -(s64)PAGE_OFFSET; + /* Handle linux,usable-memory-range 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 -- 2.11.1 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec