diff mbox

[v26,1/7] arm64: kdump: reserve memory for crash dump kernel

Message ID 20160907042908.6232-2-takahiro.akashi@linaro.org
State Superseded
Headers show

Commit Message

AKASHI Takahiro Sept. 7, 2016, 4:29 a.m. UTC
On the startup of primary kernel, the memory region used by crash dump
kernel must be specified by "crashkernel=" kernel parameter.
reserve_crashkernel() will allocate and reserve the region for later use.

User space tools, like kexec-tools, will be able to find that region as
	- "Crash kernel" in /proc/iomem, or
	- "linux,crashkernel-base" and "linux,crashkernel-size" under
	  /sys/firmware/devicetree/base/chosen

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

Signed-off-by: Mark Salter <msalter@redhat.com>

Signed-off-by: Pratyush Anand <panand@redhat.com>

Reviewed-by: James Morse <james.morse@arm.com>

---
 arch/arm64/kernel/setup.c |   7 ++-
 arch/arm64/mm/init.c      | 113 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 119 insertions(+), 1 deletion(-)

-- 
2.9.0


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Comments

AKASHI Takahiro Sept. 23, 2016, 8:37 a.m. UTC | #1
On Thu, Sep 22, 2016 at 12:23:08PM +0200, Matthias Bruger wrote:
> 

> 

> On 09/07/2016 06:29 AM, AKASHI Takahiro wrote:

> >On the startup of primary kernel, the memory region used by crash dump

> >kernel must be specified by "crashkernel=" kernel parameter.

> >reserve_crashkernel() will allocate and reserve the region for later use.

> >

> >User space tools, like kexec-tools, will be able to find that region as

> >	- "Crash kernel" in /proc/iomem, or

> >	- "linux,crashkernel-base" and "linux,crashkernel-size" under

> >	  /sys/firmware/devicetree/base/chosen

> >

> >Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>

> >Signed-off-by: Mark Salter <msalter@redhat.com>

> >Signed-off-by: Pratyush Anand <panand@redhat.com>

> >Reviewed-by: James Morse <james.morse@arm.com>

> >---

> > arch/arm64/kernel/setup.c |   7 ++-

> > arch/arm64/mm/init.c      | 113 ++++++++++++++++++++++++++++++++++++++++++++++

> > 2 files changed, 119 insertions(+), 1 deletion(-)

> >

> >diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c

> >index 514b4e3..38589b5 100644

> >--- a/arch/arm64/kernel/setup.c

> >+++ b/arch/arm64/kernel/setup.c

> >@@ -31,7 +31,6 @@

> > #include <linux/screen_info.h>

> > #include <linux/init.h>

> > #include <linux/kexec.h>

> >-#include <linux/crash_dump.h>

> > #include <linux/root_dev.h>

> > #include <linux/cpu.h>

> > #include <linux/interrupt.h>

> >@@ -225,6 +224,12 @@ static void __init request_standard_resources(void)

> > 		    kernel_data.end <= res->end)

> > 			request_resource(res, &kernel_data);

> > 	}

> >+

> >+#ifdef CONFIG_KEXEC_CORE

> >+	/* User space tools will find "Crash kernel" region in /proc/iomem. */

> >+	if (crashk_res.end)

> >+		insert_resource(&iomem_resource, &crashk_res);

> >+#endif

> > }

> >

> > u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };

> >diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c

> >index bbb7ee7..dd273ec 100644

> >--- a/arch/arm64/mm/init.c

> >+++ b/arch/arm64/mm/init.c

> >@@ -29,11 +29,13 @@

> > #include <linux/gfp.h>

> > #include <linux/memblock.h>

> > #include <linux/sort.h>

> >+#include <linux/of.h>

> > #include <linux/of_fdt.h>

> > #include <linux/dma-mapping.h>

> > #include <linux/dma-contiguous.h>

> > #include <linux/efi.h>

> > #include <linux/swiotlb.h>

> >+#include <linux/kexec.h>

> >

> > #include <asm/boot.h>

> > #include <asm/fixmap.h>

> >@@ -76,6 +78,114 @@ static int __init early_initrd(char *p)

> > early_param("initrd", early_initrd);

> > #endif

> >

> >+#ifdef CONFIG_KEXEC_CORE

> >+static unsigned long long crash_size, crash_base;

> >+static struct property crash_base_prop = {

> >+	.name = "linux,crashkernel-base",

> >+	.length = sizeof(u64),

> >+	.value = &crash_base

> >+};

> >+static struct property crash_size_prop = {

> >+	.name = "linux,crashkernel-size",

> >+	.length = sizeof(u64),

> >+	.value = &crash_size,

> >+};

> >+

> >+static int __init export_crashkernel(void)

> >+{

> >+	struct device_node *node;

> >+	int ret;

> >+

> >+	if (!crashk_res.end)

> >+		return 0;

> >+

> >+	crash_base = cpu_to_be64(crashk_res.start);

> >+	crash_size = cpu_to_be64(crashk_res.end - crashk_res.start + 1);

> >+

> 

> Shouldn't that be the same values as in reserve_crashkernel()?

> IMHO this does not need to be recalculated here.


Right. crashk_res is calculated from crash_base/size.
So I should and will remove those lines.

Thanks,
-Takahiro AKASHI

> Regards,

> Matthias

> 

> >+	/* Add /chosen/linux,crashkernel-* properties */

> >+	node = of_find_node_by_path("/chosen");

> >+	if (!node)

> >+		return -ENOENT;

> >+

> >+	/*

> >+	 * There might be existing crash kernel properties, but we can't

> >+	 * be sure what's in them, so remove them.

> >+	 */

> >+	of_remove_property(node, of_find_property(node,

> >+				"linux,crashkernel-base", NULL));

> >+	of_remove_property(node, of_find_property(node,

> >+				"linux,crashkernel-size", NULL));

> >+

> >+	ret = of_add_property(node, &crash_base_prop);

> >+	if (ret)

> >+		goto ret_err;

> >+

> >+	ret = of_add_property(node, &crash_size_prop);

> >+	if (ret)

> >+		goto ret_err;

> >+

> >+	return 0;

> >+

> >+ret_err:

> >+	pr_warn("Exporting crashkernel region to device tree failed\n");

> >+	return ret;

> >+}

> >+late_initcall(export_crashkernel);

> >+

> >+/*

> >+ * reserve_crashkernel() - reserves memory for crash kernel

> >+ *

> >+ * This function reserves memory area given in "crashkernel=" kernel command

> >+ * line parameter. The memory reserved is used by dump capture kernel when

> >+ * primary kernel is crashing.

> >+ */

> >+static void __init reserve_crashkernel(void)

> >+{

> >+	int ret;

> >+

> >+	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),

> >+				&crash_size, &crash_base);

> >+	/* no crashkernel= or invalid value specified */

> >+	if (ret || !crash_size)

> >+		return;

> >+

> >+	if (crash_base == 0) {

> >+		/* Current arm64 boot protocol requires 2MB alignment */

> >+		crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT,

> >+				crash_size, SZ_2M);

> >+		if (crash_base == 0) {

> >+			pr_warn("Unable to allocate crashkernel (size:%llx)\n",

> >+				crash_size);

> >+			return;

> >+		}

> >+	} else {

> >+		/* User specifies base address explicitly. */

> >+		if (!memblock_is_region_memory(crash_base, crash_size) ||

> >+			memblock_is_region_reserved(crash_base, crash_size)) {

> >+			pr_warn("crashkernel has wrong address or size\n");

> >+			return;

> >+		}

> >+

> >+		if (!IS_ALIGNED(crash_base, SZ_2M)) {

> >+			pr_warn("crashkernel base address is not 2MB aligned\n");

> >+			return;

> >+		}

> >+	}

> >+	memblock_reserve(crash_base, crash_size);

> >+

> >+	pr_info("Reserving %lldMB of memory at %lldMB for crashkernel\n",

> >+		crash_size >> 20, crash_base >> 20);

> >+

> >+	crashk_res.start = crash_base;

> >+	crashk_res.end = crash_base + crash_size - 1;

> >+}

> >+#else

> >+static void __init reserve_crashkernel(void)

> >+{

> >+	;

> >+}

> >+#endif /* CONFIG_KEXEC_CORE */

> >+

> > /*

> >  * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It

> >  * currently assumes that for memory starting above 4G, 32-bit devices will

> >@@ -296,6 +406,9 @@ void __init arm64_memblock_init(void)

> > 		arm64_dma_phys_limit = max_zone_dma_phys();

> > 	else

> > 		arm64_dma_phys_limit = PHYS_MASK + 1;

> >+

> >+	reserve_crashkernel();

> >+

> > 	dma_contiguous_reserve(arm64_dma_phys_limit);

> >

> > 	memblock_allow_resize();

> >


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diff mbox

Patch

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 514b4e3..38589b5 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -31,7 +31,6 @@ 
 #include <linux/screen_info.h>
 #include <linux/init.h>
 #include <linux/kexec.h>
-#include <linux/crash_dump.h>
 #include <linux/root_dev.h>
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
@@ -225,6 +224,12 @@  static void __init request_standard_resources(void)
 		    kernel_data.end <= res->end)
 			request_resource(res, &kernel_data);
 	}
+
+#ifdef CONFIG_KEXEC_CORE
+	/* User space tools will find "Crash kernel" region in /proc/iomem. */
+	if (crashk_res.end)
+		insert_resource(&iomem_resource, &crashk_res);
+#endif
 }
 
 u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index bbb7ee7..dd273ec 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -29,11 +29,13 @@ 
 #include <linux/gfp.h>
 #include <linux/memblock.h>
 #include <linux/sort.h>
+#include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-contiguous.h>
 #include <linux/efi.h>
 #include <linux/swiotlb.h>
+#include <linux/kexec.h>
 
 #include <asm/boot.h>
 #include <asm/fixmap.h>
@@ -76,6 +78,114 @@  static int __init early_initrd(char *p)
 early_param("initrd", early_initrd);
 #endif
 
+#ifdef CONFIG_KEXEC_CORE
+static unsigned long long crash_size, crash_base;
+static struct property crash_base_prop = {
+	.name = "linux,crashkernel-base",
+	.length = sizeof(u64),
+	.value = &crash_base
+};
+static struct property crash_size_prop = {
+	.name = "linux,crashkernel-size",
+	.length = sizeof(u64),
+	.value = &crash_size,
+};
+
+static int __init export_crashkernel(void)
+{
+	struct device_node *node;
+	int ret;
+
+	if (!crashk_res.end)
+		return 0;
+
+	crash_base = cpu_to_be64(crashk_res.start);
+	crash_size = cpu_to_be64(crashk_res.end - crashk_res.start + 1);
+
+	/* Add /chosen/linux,crashkernel-* properties */
+	node = of_find_node_by_path("/chosen");
+	if (!node)
+		return -ENOENT;
+
+	/*
+	 * There might be existing crash kernel properties, but we can't
+	 * be sure what's in them, so remove them.
+	 */
+	of_remove_property(node, of_find_property(node,
+				"linux,crashkernel-base", NULL));
+	of_remove_property(node, of_find_property(node,
+				"linux,crashkernel-size", NULL));
+
+	ret = of_add_property(node, &crash_base_prop);
+	if (ret)
+		goto ret_err;
+
+	ret = of_add_property(node, &crash_size_prop);
+	if (ret)
+		goto ret_err;
+
+	return 0;
+
+ret_err:
+	pr_warn("Exporting crashkernel region to device tree failed\n");
+	return ret;
+}
+late_initcall(export_crashkernel);
+
+/*
+ * reserve_crashkernel() - reserves memory for crash kernel
+ *
+ * This function reserves memory area given in "crashkernel=" kernel command
+ * line parameter. The memory reserved is used by dump capture kernel when
+ * primary kernel is crashing.
+ */
+static void __init reserve_crashkernel(void)
+{
+	int ret;
+
+	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
+				&crash_size, &crash_base);
+	/* no crashkernel= or invalid value specified */
+	if (ret || !crash_size)
+		return;
+
+	if (crash_base == 0) {
+		/* Current arm64 boot protocol requires 2MB alignment */
+		crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT,
+				crash_size, SZ_2M);
+		if (crash_base == 0) {
+			pr_warn("Unable to allocate crashkernel (size:%llx)\n",
+				crash_size);
+			return;
+		}
+	} else {
+		/* User specifies base address explicitly. */
+		if (!memblock_is_region_memory(crash_base, crash_size) ||
+			memblock_is_region_reserved(crash_base, crash_size)) {
+			pr_warn("crashkernel has wrong address or size\n");
+			return;
+		}
+
+		if (!IS_ALIGNED(crash_base, SZ_2M)) {
+			pr_warn("crashkernel base address is not 2MB aligned\n");
+			return;
+		}
+	}
+	memblock_reserve(crash_base, crash_size);
+
+	pr_info("Reserving %lldMB of memory at %lldMB for crashkernel\n",
+		crash_size >> 20, crash_base >> 20);
+
+	crashk_res.start = crash_base;
+	crashk_res.end = crash_base + crash_size - 1;
+}
+#else
+static void __init reserve_crashkernel(void)
+{
+	;
+}
+#endif /* CONFIG_KEXEC_CORE */
+
 /*
  * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
  * currently assumes that for memory starting above 4G, 32-bit devices will
@@ -296,6 +406,9 @@  void __init arm64_memblock_init(void)
 		arm64_dma_phys_limit = max_zone_dma_phys();
 	else
 		arm64_dma_phys_limit = PHYS_MASK + 1;
+
+	reserve_crashkernel();
+
 	dma_contiguous_reserve(arm64_dma_phys_limit);
 
 	memblock_allow_resize();