On 12/07/16 06:05, 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 <[email protected]>
Signed-off-by: Mark Salter <[email protected]>
Signed-off-by: Pratyush Anand <[email protected]>
Reviewed-by: James Morse <[email protected]>
Minor nits below.
---
arch/arm64/kernel/setup.c | 7 ++-
arch/arm64/mm/init.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 121 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index c1509e6..cb5eee0 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>
@@ -222,6 +221,12 @@ 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
nit: Could we not do this from reserve_crashkernel() ?
#include <asm/boot.h>
#include <asm/fixmap.h>
@@ -76,6 +78,117 @@ 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,
+};
+
+
+/*
+ * 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) {
...
+ memblock_reserve(crash_base, crash_size);
+
+ } else {
...
+
+ memblock_reserve(crash_base, crash_size);
+ }
Nit: you could move the memblock_reserve() here to a single place.
+
+ 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;
As mentioned above, may be we could move the insert_resource() here, which
would keep the generic setup.c code cleaner and is a bit more reader friendly.
+}
+#else
Suzuki
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