3 files changed, 50 insertions, 25 deletions

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 406c33dcae13..5e320ddaaa82 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -148,7 +148,34 @@ struct kexec_file_ops {
         kexec_verify_sig_t *verify_sig;
 #endif
 };
-#endif
+
+/**
+ * struct kexec_buf - parameters for finding a place for a buffer in memory
+ * @image:      kexec image in which memory to search.
+ * @buffer:     Contents which will be copied to the allocated memory.
+ * @bufsz:      Size of @buffer.
+ * @mem:        On return will have address of the buffer in memory.
+ * @memsz:      Size for the buffer in memory.
+ * @buf_align:  Minimum alignment needed.
+ * @buf_min:    The buffer can't be placed below this address.
+ * @buf_max:    The buffer can't be placed above this address.
+ * @top_down:   Allocate from top of memory.
+ */
+struct kexec_buf {
+        struct kimage *image;
+        char *buffer;
+        unsigned long bufsz;
+        unsigned long mem;
+        unsigned long memsz;
+        unsigned long buf_align;
+        unsigned long buf_min;
+        unsigned long buf_max;
+        bool top_down;
+};
+
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+                               int (*func)(u64, u64, void *));
+#endif /* CONFIG_KEXEC_FILE */
 
 struct kimage {
         kimage_entry_t head;
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 037c321c5618..f865674bff51 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -428,6 +428,27 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
         return locate_mem_hole_bottom_up(start, end, kbuf);
 }
 
+/**
+ * arch_kexec_walk_mem - call func(data) on free memory regions
+ * @kbuf:       Context info for the search. Also passed to @func.
+ * @func:       Function to call for each memory region.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+                               int (*func)(u64, u64, void *))
+{
+        if (kbuf->image->type == KEXEC_TYPE_CRASH)
+                return walk_iomem_res_desc(crashk_res.desc,
+                                           IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+                                           crashk_res.start, crashk_res.end,
+                                           kbuf, func);
+        else
+                return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
 /*
  * Helper function for placing a buffer in a kexec segment. This assumes
  * that kexec_mutex is held.
@@ -474,14 +495,7 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
         kbuf->top_down = top_down;
 
         /* Walk the RAM ranges and allocate a suitable range for the buffer */
-        if (image->type == KEXEC_TYPE_CRASH)
-                ret = walk_iomem_res_desc(crashk_res.desc,
-                                IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
-                                crashk_res.start, crashk_res.end, kbuf,
-                                locate_mem_hole_callback);
-        else
-                ret = walk_system_ram_res(0, -1, kbuf,
-                                          locate_mem_hole_callback);
+        ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
         if (ret != 1) {
                 /* A suitable memory range could not be found for buffer */
                 return -EADDRNOTAVAIL;
diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h
index 0a52315d9c62..4cef7e4706b0 100644
--- a/kernel/kexec_internal.h
+++ b/kernel/kexec_internal.h
@@ -20,22 +20,6 @@ struct kexec_sha_region {
         unsigned long len;
 };
 
-/*
- * Keeps track of buffer parameters as provided by caller for requesting
- * memory placement of buffer.
- */
-struct kexec_buf {
-        struct kimage *image;
-        char *buffer;
-        unsigned long bufsz;
-        unsigned long mem;
-        unsigned long memsz;
-        unsigned long buf_align;
-        unsigned long buf_min;
-        unsigned long buf_max;
-        bool top_down;          /* allocate from top of memory hole */
-};
-
 void kimage_file_post_load_cleanup(struct kimage *image);
 #else /* CONFIG_KEXEC_FILE */
 static inline void kimage_file_post_load_cleanup(struct kimage *image) { }