Introduce a symbol and export it to vmcoreinfo. Dumping
applications such as makedumpfile, with this variable, they are able to
restore a linked list which contained the memmap region located in
device.
With this mechanism, nvdimm/pmem which allows placing memmap in device
is able to export the its memmap(page array) to kdump kernel via
vmcoreinfo.
CC: Baoquan He <bhe@xxxxxxxxxx>
CC: Vivek Goyal <vgoyal@xxxxxxxxxx>
CC: Dave Young <dyoung@xxxxxxxxxx>
Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
---
include/linux/crash_core.h | 8 +++++
kernel/crash_core.c | 61 ++++++++++++++++++++++++++++++++++++++
2 files changed, 69 insertions(+)
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index de62a722431e..05ec2777f4fd 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -84,4 +84,12 @@ int parse_crashkernel_high(char *cmdline, unsigned long long system_ram,
int parse_crashkernel_low(char *cmdline, unsigned long long system_ram,
unsigned long long *crash_size, unsigned long long *crash_base);
+#ifdef CONFIG_CRASH_CORE
+void devm_memmap_vmcore_delete(void *match);
+void devm_memmap_vmcore_update(void *match, u64 pfn, u64 npfn, bool dev);
+#else
+#define devm_memmap_vmcore_delete(match) do {} while (0)
+#define devm_memmap_vmcore_update(match, pfn, npfn, dev) do {} while (0)
+#endif
+
#endif /* LINUX_CRASH_CORE_H */
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 755f5f08ab38..f28cbd98f28b 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -401,6 +401,61 @@ phys_addr_t __weak paddr_vmcoreinfo_note(void)
}
EXPORT_SYMBOL(paddr_vmcoreinfo_note);
+struct devm_memmap_vmcore {
+ struct list_head entry;
+ unsigned long start;
+ unsigned long end;
+ void *match;
+};
+
+static struct devm_memmap_vmcore devm_memmap_vmcore_head = {
+ .entry = LIST_HEAD_INIT(devm_memmap_vmcore_head.entry),
+};
+static DEFINE_MUTEX(devm_memmap_vmcore_mutex);
+
+static void devm_memmap_vmcore_add(void *match, u64 pfn, u64 npfn)
+{
+ struct devm_memmap_vmcore *metadata;
+
+ metadata = kzalloc(sizeof(*metadata), GFP_KERNEL);
+ if (!metadata) {
+ pr_err("No enough memory");
+ return;
+ }
+
+ metadata->start = pfn;
+ metadata->end = pfn + npfn;
+ metadata->match = match;
+
+ mutex_lock(&devm_memmap_vmcore_mutex);
+ list_add(&metadata->entry, &devm_memmap_vmcore_head.entry);
+ mutex_unlock(&devm_memmap_vmcore_mutex);
+}
+
+void devm_memmap_vmcore_delete(void *match)
+{
+ struct devm_memmap_vmcore *metadata;
+
+ mutex_lock(&devm_memmap_vmcore_mutex);
+ list_for_each_entry(metadata, &devm_memmap_vmcore_head.entry, entry) {
+ if (metadata->match == match) {
+ list_del(&metadata->entry);
+ kfree(metadata);
+ break;
+ }
+ }
+ mutex_unlock(&devm_memmap_vmcore_mutex);
+}
+EXPORT_SYMBOL_GPL(devm_memmap_vmcore_delete);
+
+void devm_memmap_vmcore_update(void *match, u64 start_pfn, u64 npfn, bool dev)
+{
+ devm_memmap_vmcore_delete(match);
+ if (dev)
+ devm_memmap_vmcore_add(match, start_pfn, npfn);
+}
+EXPORT_SYMBOL_GPL(devm_memmap_vmcore_update);
+
static int __init crash_save_vmcoreinfo_init(void)
{
vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
@@ -436,6 +491,12 @@ static int __init crash_save_vmcoreinfo_init(void)
VMCOREINFO_SYMBOL(contig_page_data);
#endif
#ifdef CONFIG_SPARSEMEM
+ VMCOREINFO_SYMBOL(devm_memmap_vmcore_head);
+ VMCOREINFO_STRUCT_SIZE(devm_memmap_vmcore);
+ VMCOREINFO_OFFSET(devm_memmap_vmcore, entry);
+ VMCOREINFO_OFFSET(devm_memmap_vmcore, start);
+ VMCOREINFO_OFFSET(devm_memmap_vmcore, end);
+
VMCOREINFO_SYMBOL_ARRAY(mem_section);
VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
VMCOREINFO_STRUCT_SIZE(mem_section);
--
2.29.2
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