[PATCH v4 3/9] kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.

Thiago Jung Bauermann
2016-07-07T16:50:18Z

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 <bauerman@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@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 ff5fa7707bd7..803f563df81d 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -174,6 +174,7 @@ 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);
#endif /* CONFIG_KEXEC_FILE */

struct kimage {
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 82ccfc4ee97e..3125d1689712 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -450,6 +450,23 @@ 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.
*
@@ -489,11 +506,9 @@ 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