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, 71 deletions

diff --git a/arch/cris/arch-v10/boot/compressed/misc.c b/arch/cris/arch-v10/boot/compressed/misc.c
index 18e13bce1400..d933c89889db 100644
--- a/arch/cris/arch-v10/boot/compressed/misc.c
+++ b/arch/cris/arch-v10/boot/compressed/misc.c
@@ -102,50 +102,16 @@ extern char *input_data;  /* lives in head.S */
 static long bytes_out = 0;
 static uch *output_data;
 static unsigned long output_ptr = 0;
-
-static void *malloc(int size);
-static void free(void *where);
-static void gzip_mark(void **);
-static void gzip_release(void **);
-
 static void puts(const char *);
 
 /* the "heap" is put directly after the BSS ends, at end */
 
 extern int _end;
 static long free_mem_ptr = (long)&_end;
+static long free_mem_end_ptr;
 
 #include "../../../../../lib/inflate.c"
 
-static void *malloc(int size)
-{
-        void *p;
-
-        if (size < 0)
-                error("Malloc error");
-
-        free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
-
-        p = (void *)free_mem_ptr;
-        free_mem_ptr += size;
-
-        return p;
-}
-
-static void free(void *where)
-{       /* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-        *ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-        free_mem_ptr = (long) *ptr;
-}
-
 /* decompressor info and error messages to serial console */
 
 static void
diff --git a/arch/cris/arch-v32/boot/compressed/misc.c b/arch/cris/arch-v32/boot/compressed/misc.c
index 55b2695c5d70..3595e16e82bc 100644
--- a/arch/cris/arch-v32/boot/compressed/misc.c
+++ b/arch/cris/arch-v32/boot/compressed/misc.c
@@ -89,20 +89,14 @@ static unsigned outcnt = 0;  /* bytes in output buffer */
 
 static void flush_window(void);
 static void error(char *m);
-static void gzip_mark(void **);
-static void gzip_release(void **);
 
 extern char *input_data;  /* lives in head.S */
 
-static long bytes_out = 0;
+static long bytes_out;
 static uch *output_data;
-static unsigned long output_ptr = 0;
+static unsigned long output_ptr;
 
-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 puts(const char *);
 
@@ -110,37 +104,10 @@ static void puts(const char *);
 
 extern int _end;
 static long free_mem_ptr = (long)&_end;
+static long free_mem_end_ptr;
 
 #include "../../../../../lib/inflate.c"
 
-static void *malloc(int size)
-{
-        void *p;
-
-        if (size <0) error("Malloc error");
-
-        free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
-
-        p = (void *)free_mem_ptr;
-        free_mem_ptr += size;
-
-        return p;
-}
-
-static void free(void *where)
-{       /* Don't care */
-}
-
-static void gzip_mark(void **ptr)
-{
-        *ptr = (void *) free_mem_ptr;
-}
-
-static void gzip_release(void **ptr)
-{
-        free_mem_ptr = (long) *ptr;
-}
-
 /* decompressor info and error messages to serial console */
 
 static inline void