linux-kernel - [PATCH v5 03/13] kexec_file: Factor out kexec_locate_mem_hole from kexec_add

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Date:	Thu, 11 Aug 2016 20:08:08 -0300
From:	Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>
To:	kexec@...ts.infradead.org
Cc:	linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
	x86@...nel.org, Eric Biederman <ebiederm@...ssion.com>,
	Dave Young <dyoung@...hat.com>,
	Vivek Goyal <vgoyal@...hat.com>, Baoquan He <bhe@...hat.com>,
	Michael Ellerman <mpe@...erman.id.au>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Paul Mackerras <paulus@...ba.org>,
	Stewart Smith <stewart@...ux.vnet.ibm.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>
Subject: [PATCH v5 03/13] kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.

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@...ux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@...hat.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