Merge tag 'v5.16' into next

Sync up with mainline to bring in the latest API changes.

1 files changed, 24 insertions, 6 deletions

diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index 2618577a4d6d..620821549b23 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -8,8 +8,6 @@
 #include <linux/pgtable.h>
 #include <uapi/linux/vmcore.h>
 
-#include <linux/pgtable.h> /* for pgprot_t */
-
 /* For IS_ENABLED(CONFIG_CRASH_DUMP) */
 #define ELFCORE_ADDR_MAX	(-1ULL)
 #define ELFCORE_ADDR_ERR	(-2ULL)
@@ -91,12 +89,32 @@ static inline void vmcore_unusable(void)
 		elfcorehdr_addr = ELFCORE_ADDR_ERR;
 }
 
-#define HAVE_OLDMEM_PFN_IS_RAM 1
-extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
-extern void unregister_oldmem_pfn_is_ram(void);
+/**
+ * struct vmcore_cb - driver callbacks for /proc/vmcore handling
+ * @pfn_is_ram: check whether a PFN really is RAM and should be accessed when
+ *              reading the vmcore. Will return "true" if it is RAM or if the
+ *              callback cannot tell. If any callback returns "false", it's not
+ *              RAM and the page must not be accessed; zeroes should be
+ *              indicated in the vmcore instead. For example, a ballooned page
+ *              contains no data and reading from such a page will cause high
+ *              load in the hypervisor.
+ * @next: List head to manage registered callbacks internally; initialized by
+ *        register_vmcore_cb().
+ *
+ * vmcore callbacks allow drivers managing physical memory ranges to
+ * coordinate with vmcore handling code, for example, to prevent accessing
+ * physical memory ranges that should not be accessed when reading the vmcore,
+ * although included in the vmcore header as memory ranges to dump.
+ */
+struct vmcore_cb {
+	bool (*pfn_is_ram)(struct vmcore_cb *cb, unsigned long pfn);
+	struct list_head next;
+};
+extern void register_vmcore_cb(struct vmcore_cb *cb);
+extern void unregister_vmcore_cb(struct vmcore_cb *cb);
 
 #else /* !CONFIG_CRASH_DUMP */
-static inline bool is_kdump_kernel(void) { return 0; }
+static inline bool is_kdump_kernel(void) { return false; }
 #endif /* CONFIG_CRASH_DUMP */
 
 /* Device Dump information to be filled by drivers */