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>

1 files changed, 7 insertions, 52 deletions

diff --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c
index 9b444022cb9b..7145cc7c04f0 100644
--- a/arch/arm/boot/compressed/misc.c
+++ b/arch/arm/boot/compressed/misc.c
@@ -217,8 +217,6 @@ static unsigned outcnt;		/* bytes in output buffer */
 static int  fill_inbuf(void);
 static void flush_window(void);
 static void error(char *m);
-static void gzip_mark(void **);
-static void gzip_release(void **);
 
 extern char input_data[];
 extern char input_data_end[];
@@ -227,64 +225,21 @@ static uch *output_data;
 static ulg output_ptr;
 static ulg bytes_out;
 
-static void *malloc(int size);
-static void free(void *where);
 static void error(char *m);
-static void gzip_mark(void **);
-static void gzip_release(void **);
 
 static void putstr(const char *);
 
 extern int end;
 static ulg free_mem_ptr;
-static ulg free_mem_ptr_end;
+static ulg free_mem_end_ptr;
 
-#define HEAP_SIZE 0x3000
-
-#include "../../../../lib/inflate.c"
-
-#ifndef STANDALONE_DEBUG
-static void *malloc(int size)
-{
-	void *p;
-
-	if (size <0) error("Malloc error");
-	if (free_mem_ptr <= 0) error("Memory error");
-
-	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */
-
-	p = (void *)free_mem_ptr;
-	free_mem_ptr += size;
-
-	if (free_mem_ptr >= free_mem_ptr_end)
-		error("Out of memory");
-	return p;
-}
-
-static void free(void *where)
-{ /* gzip_mark & gzip_release do the free */
-}
-
-static void gzip_mark(void **ptr)
-{
-	arch_decomp_wdog();
-	*ptr = (void *) free_mem_ptr;
-}
+#ifdef STANDALONE_DEBUG
+#define NO_INFLATE_MALLOC
+#endif
 
-static void gzip_release(void **ptr)
-{
-	arch_decomp_wdog();
-	free_mem_ptr = (long) *ptr;
-}
-#else
-static void gzip_mark(void **ptr)
-{
-}
+#define ARCH_HAS_DECOMP_WDOG
 
-static void gzip_release(void **ptr)
-{
-}
-#endif
+#include "../../../../lib/inflate.c"
 
 /* ===========================================================================
  * Fill the input buffer. This is called only when the buffer is empty
@@ -348,7 +303,7 @@ decompress_kernel(ulg output_start, ulg free_mem_ptr_p, ulg free_mem_ptr_end_p,
 {
 	output_data		= (uch *)output_start;	/* Points to kernel start */
 	free_mem_ptr		= free_mem_ptr_p;
-	free_mem_ptr_end	= free_mem_ptr_end_p;
+	free_mem_end_ptr	= free_mem_ptr_end_p;
 	__machine_arch_type	= arch_id;
 
 	arch_decomp_setup();