[PATCH v5 03/13] kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.

[Thiago Jung Bauermann]

kexec_locate_mem_hole will be used by the PowerPC kexec_file_load
implementation to find free memory for the purgatory stack.

Signed-off-by: Thiago Jung Bauermann <bauer...@linux.vnet.ibm.com>
Acked-by: Dave Young <dyo...@redhat.com>
---
 include/linux/kexec.h |  1 +
 kernel/kexec_file.c   | 25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 28bc9f335d0d..ceccc5856aab 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -176,6 +176,7 @@ struct kexec_buf {
 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
                               int (*func)(u64, u64, void *));
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
+int kexec_locate_mem_hole(struct kexec_buf *kbuf);
 int __weak arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
                                    unsigned long size);
 #endif /* CONFIG_KEXEC_FILE */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 58818264ad0e..772cb491715e 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -524,6 +524,23 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 }
 
 /**
+ * kexec_locate_mem_hole - find free memory for the purgatory or the next 
kernel
+ * @kbuf:      Parameters for the memory search.
+ *
+ * On success, kbuf->mem will have the start address of the memory region 
found.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int kexec_locate_mem_hole(struct kexec_buf *kbuf)
+{
+       int ret;
+
+       ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
+
+       return ret == 1 ? 0 : -EADDRNOTAVAIL;
+}
+
+/**
  * kexec_add_buffer - place a buffer in a kexec segment
  * @kbuf:      Buffer contents and memory parameters.
  *
@@ -563,11 +580,9 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
        kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
 
        /* Walk the RAM ranges and allocate a suitable range for the buffer */
-       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;
-       }
+       ret = kexec_locate_mem_hole(kbuf);
+       if (ret)
+               return ret;
 
        /* Found a suitable memory range */
        ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
-- 
1.9.1