[PATCH v4] arm64: use generic free_initrd_mem()

[Mike Rapoport <rppt@kernel.org>]

From: Mike Rapoport <rppt@linux.ibm.com>

arm64 calls memblock_free() for the initrd area in its implementation of
free_initrd_mem(), but this call has no actual effect that late in the boot
process. By the time initrd is freed, all the reserved memory is managed by
the page allocator and the memblock.reserved is unused, so the only purpose
of the memblock_free() call is to keep track of initrd memory for debugging
and accounting.

Without the memblock_free() call the only difference between arm64 and the
generic versions of free_initrd_mem() is the memory poisoning.

Move memblock_free() call to the generic code, enable it there
for the architectures that define ARCH_KEEP_MEMBLOCK and use the generic
implementation of free_initrd_mem() on arm64.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---

v4:
* memblock_free() aligned area around the initrd

v3:
* fix powerpc build

v2:
* add memblock_free() to the generic free_initrd_mem()
* rebase on the current upstream


 arch/arm64/mm/init.c | 12 ------------
 init/initramfs.c     |  8 ++++++++
 2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 45c00a5..87a0e3b 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -580,18 +580,6 @@ void free_initmem(void)
 	unmap_kernel_range((u64)__init_begin, (u64)(__init_end - __init_begin));
 }
 
-#ifdef CONFIG_BLK_DEV_INITRD
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
-	unsigned long aligned_start, aligned_end;
-
-	aligned_start = __virt_to_phys(start) & PAGE_MASK;
-	aligned_end = PAGE_ALIGN(__virt_to_phys(end));
-	memblock_free(aligned_start, aligned_end - aligned_start);
-	free_reserved_area((void *)start, (void *)end, 0, "initrd");
-}
-#endif
-
 /*
  * Dump out memory limit information on panic.
  */
diff --git a/init/initramfs.c b/init/initramfs.c
index c47dad0..8ec1be4 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -10,6 +10,7 @@
 #include <linux/syscalls.h>
 #include <linux/utime.h>
 #include <linux/file.h>
+#include <linux/memblock.h>
 
 static ssize_t __init xwrite(int fd, const char *p, size_t count)
 {
@@ -529,6 +530,13 @@ extern unsigned long __initramfs_size;
 
 void __weak free_initrd_mem(unsigned long start, unsigned long end)
 {
+#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
+	unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
+	unsigned long aligned_end = ALIGN(end, PAGE_SIZE);
+
+	memblock_free(__pa(aligned_start), aligned_end - aligned_start);
+#endif
+
 	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 			"initrd");
 }
-- 
2.7.4