inflate: refactor inflate malloc code

Inflate requires some dynamic memory allocation very early in the boot
process and this is provided with a set of four functions:
malloc/free/gzip_mark/gzip_release.

The old inflate code used a mark/release strategy rather than implement
free.  This new version instead keeps a count on the number of outstanding
allocations and when it hits zero, it resets the malloc arena.

This allows removing all the mark and release implementations and unifying
all the malloc/free implementations.

The architecture-dependent code must define two addresses:
 - free_mem_ptr, the address of the beginning of the area in which
   allocations should be made
 - free_mem_end_ptr, the address of the end of the area in which
   allocations should be made. If set to 0, then no check is made on
   the number of allocations, it just grows as much as needed

The architecture-dependent code can also provide an arch_decomp_wdog()
function call.  This function will be called several times during the
decompression process, and allow to notify the watchdog that the system is
still running.  If an architecture provides such a call, then it must
define ARCH_HAS_DECOMP_WDOG so that the generic inflate code calls
arch_decomp_wdog().

Work initially done by Matt Mackall, updated to a recent version of the
kernel and improved by me.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Mikael Starvik <mikael.starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 4 insertions, 43 deletions

diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
index 470a328d1454..fedef93b586f 100644
--- a/init/do_mounts_rd.c
+++ b/init/do_mounts_rd.c
@@ -303,32 +303,11 @@ static int crd_infd, crd_outfd;
 
 static int  __init fill_inbuf(void);
 static void __init flush_window(void);
-static void __init *malloc(size_t size);
-static void __init free(void *where);
 static void __init error(char *m);
-static void __init gzip_mark(void **);
-static void __init gzip_release(void **);
 
-#include "../lib/inflate.c"
-
-static void __init *malloc(size_t size)
-{
-	return kmalloc(size, GFP_KERNEL);
-}
-
-static void __init free(void *where)
-{
-	kfree(where);
-}
-
-static void __init gzip_mark(void **ptr)
-{
-}
-
-static void __init gzip_release(void **ptr)
-{
-}
+#define NO_INFLATE_MALLOC
 
+#include "../lib/inflate.c"
 
 /* ===========================================================================
  * Fill the input buffer. This is called only when the buffer is empty
diff --git a/init/initramfs.c b/init/initramfs.c
index 8eeeccb328c9..644fc01ad5f0 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -14,16 +14,6 @@ static void __init error(char *x)
 		message = x;
 }
 
-static void __init *malloc(size_t size)
-{
-	return kmalloc(size, GFP_KERNEL);
-}
-
-static void __init free(void *where)
-{
-	kfree(where);
-}
-
 /* link hash */
 
 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
@@ -407,18 +397,10 @@ static long bytes_out;
 
 static void __init flush_window(void);
 static void __init error(char *m);
-static void __init gzip_mark(void **);
-static void __init gzip_release(void **);
 
-#include "../lib/inflate.c"
+#define NO_INFLATE_MALLOC
 
-static void __init gzip_mark(void **ptr)
-{
-}
-
-static void __init gzip_release(void **ptr)
-{
-}
+#include "../lib/inflate.c"
 
 /* ===========================================================================
  * Write the output window window[0..outcnt-1] and update crc and bytes_out.