[PATCH v3 1/2] xen: move perform_gunzip to common

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

The current gunzip code to decompress the Dom0 kernel is implemented in
inflate.c which is included by bzimage.c.

I am looking to doing the same on ARM64 but there is quite a bit of
boilerplate definitions that I would need to import in order for
inflate.c to work correctly.

Instead of copying/pasting the code from x86/bzimage.c, move those
definitions to a new common file, gunzip.c. Export only perform_gunzip
and gzip_check. Leave output_length where it is.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: JBeulich@suse.com
CC: andrew.cooper3@citrix.com

---
Changes in v3:
- build gunzip.c as gunzip.init.o
- remove #include <xen/config.h>
- remove __init from declarations

Changes in v2:
- the patch has been reworked from scratch
---
 xen/arch/x86/bzimage.c   |  134 +--------------------------------------------
 xen/common/Makefile      |    1 +
 xen/common/gunzip.c      |  137 ++++++++++++++++++++++++++++++++++++++++++++++
 xen/include/xen/gunzip.h |    7 +++
 4 files changed, 146 insertions(+), 133 deletions(-)
 create mode 100644 xen/common/gunzip.c
 create mode 100644 xen/include/xen/gunzip.h

diff --git a/xen/arch/x86/bzimage.c b/xen/arch/x86/bzimage.c
index c86c39e..50ebb84 100644
--- a/xen/arch/x86/bzimage.c
+++ b/xen/arch/x86/bzimage.c
@@ -4,148 +4,16 @@
 #include <xen/mm.h>
 #include <xen/string.h>
 #include <xen/types.h>
+#include <xen/gunzip.h>
 #include <xen/decompress.h>
 #include <xen/libelf.h>
 #include <asm/bzimage.h>
 
-#define HEAPORDER 3
-
-static unsigned char *__initdata window;
-#define memptr long
-static memptr __initdata free_mem_ptr;
-static memptr __initdata free_mem_end_ptr;
-
-#define WSIZE           0x80000000
-
-static unsigned char *__initdata inbuf;
-static unsigned __initdata insize;
-
-/* Index of next byte to be processed in inbuf: */
-static unsigned __initdata inptr;
-
-/* Bytes in output buffer: */
-static unsigned __initdata outcnt;
-
-#define OF(args)        args
-#define STATIC          static
-
-#define memzero(s, n)   memset((s), 0, (n))
-
-typedef unsigned char   uch;
-typedef unsigned short  ush;
-typedef unsigned long   ulg;
-
-#define INIT            __init
-#define INITDATA        __initdata
-
-#define get_byte()      (inptr < insize ? inbuf[inptr++] : fill_inbuf())
-
-/* Diagnostic functions */
-#ifdef DEBUG
-#  define Assert(cond, msg) do { if (!(cond)) error(msg); } while (0)
-#  define Trace(x)      do { fprintf x; } while (0)
-#  define Tracev(x)     do { if (verbose) fprintf x ; } while (0)
-#  define Tracevv(x)    do { if (verbose > 1) fprintf x ; } while (0)
-#  define Tracec(c, x)  do { if (verbose && (c)) fprintf x ; } while (0)
-#  define Tracecv(c, x) do { if (verbose > 1 && (c)) fprintf x ; } while (0)
-#else
-#  define Assert(cond, msg)
-#  define Trace(x)
-#  define Tracev(x)
-#  define Tracevv(x)
-#  define Tracec(c, x)
-#  define Tracecv(c, x)
-#endif
-
-static long __initdata bytes_out;
-static void flush_window(void);
-
-static __init void error(char *x)
-{
-    panic("%s", x);
-}
-
-static __init int fill_inbuf(void)
-{
-        error("ran out of input data");
-        return 0;
-}
-
-
-#include "../../common/inflate.c"
-
-static __init void flush_window(void)
-{
-    /*
-     * The window is equal to the output buffer therefore only need to
-     * compute the crc.
-     */
-    unsigned long c = crc;
-    unsigned n;
-    unsigned char *in, ch;
-
-    in = window;
-    for ( n = 0; n < outcnt; n++ )
-    {
-        ch = *in++;
-        c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
-    }
-    crc = c;
-
-    bytes_out += (unsigned long)outcnt;
-    outcnt = 0;
-}
-
 static __init unsigned long output_length(char *image, unsigned long image_len)
 {
     return *(uint32_t *)&image[image_len - 4];
 }
 
-static __init int gzip_check(char *image, unsigned long image_len)
-{
-    unsigned char magic0, magic1;
-
-    if ( image_len < 2 )
-        return 0;
-
-    magic0 = (unsigned char)image[0];
-    magic1 = (unsigned char)image[1];
-
-    return (magic0 == 0x1f) && ((magic1 == 0x8b) || (magic1 == 0x9e));
-}
-
-static __init int perform_gunzip(char *output, char *image, unsigned long image_len)
-{
-    int rc;
-
-    if ( !gzip_check(image, image_len) )
-        return 1;
-
-    window = (unsigned char *)output;
-
-    free_mem_ptr = (unsigned long)alloc_xenheap_pages(HEAPORDER, 0);
-    free_mem_end_ptr = free_mem_ptr + (PAGE_SIZE << HEAPORDER);
-
-    inbuf = (unsigned char *)image;
-    insize = image_len;
-    inptr = 0;
-
-    makecrc();
-
-    if ( gunzip() < 0 )
-    {
-        rc = -EINVAL;
-    }
-    else
-    {
-        rc = 0;
-    }
-
-    free_xenheap_pages((void *)free_mem_ptr, HEAPORDER);
-
-    return rc;
-}
-
 struct __packed setup_header {
         uint8_t         _pad0[0x1f1];           /* skip uninteresting stuff */
         uint8_t         setup_sects;
diff --git a/xen/common/Makefile b/xen/common/Makefile
index 3fdf931..e5713fa 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -55,6 +55,7 @@ obj-y += vmap.o
 obj-y += vsprintf.o
 obj-y += wait.o
 obj-y += xmalloc_tlsf.o
+obj-bin-y += gunzip.init.o
 
 obj-bin-$(CONFIG_X86) += $(foreach n,decompress bunzip2 unxz unlzma unlzo unlz4 earlycpio,$(n).init.o)
 
diff --git a/xen/common/gunzip.c b/xen/common/gunzip.c
new file mode 100644
index 0000000..41d71ef
--- /dev/null
+++ b/xen/common/gunzip.c
@@ -0,0 +1,137 @@
+#include <xen/errno.h>
+#include <xen/init.h>
+#include <xen/lib.h>
+#include <xen/mm.h>
+
+#define HEAPORDER 3
+
+static unsigned char *__initdata window;
+#define memptr long
+static memptr __initdata free_mem_ptr;
+static memptr __initdata free_mem_end_ptr;
+
+#define WSIZE           0x80000000
+
+static unsigned char *__initdata inbuf;
+static unsigned __initdata insize;
+
+/* Index of next byte to be processed in inbuf: */
+static unsigned __initdata inptr;
+
+/* Bytes in output buffer: */
+static unsigned __initdata outcnt;
+
+#define OF(args)        args
+#define STATIC          static
+
+#define memzero(s, n)   memset((s), 0, (n))
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+#define INIT            __init
+#define INITDATA        __initdata
+
+#define get_byte()      (inptr < insize ? inbuf[inptr++] : fill_inbuf())
+
+/* Diagnostic functions */
+#ifdef DEBUG
+#  define Assert(cond, msg) do { if (!(cond)) error(msg); } while (0)
+#  define Trace(x)      do { fprintf x; } while (0)
+#  define Tracev(x)     do { if (verbose) fprintf x ; } while (0)
+#  define Tracevv(x)    do { if (verbose > 1) fprintf x ; } while (0)
+#  define Tracec(c, x)  do { if (verbose && (c)) fprintf x ; } while (0)
+#  define Tracecv(c, x) do { if (verbose > 1 && (c)) fprintf x ; } while (0)
+#else
+#  define Assert(cond, msg)
+#  define Trace(x)
+#  define Tracev(x)
+#  define Tracevv(x)
+#  define Tracec(c, x)
+#  define Tracecv(c, x)
+#endif
+
+static long __initdata bytes_out;
+static void flush_window(void);
+
+static __init void error(char *x)
+{
+    panic("%s", x);
+}
+
+static __init int fill_inbuf(void)
+{
+        error("ran out of input data");
+        return 0;
+}
+
+
+#include "inflate.c"
+
+static __init void flush_window(void)
+{
+    /*
+     * The window is equal to the output buffer therefore only need to
+     * compute the crc.
+     */
+    unsigned long c = crc;
+    unsigned n;
+    unsigned char *in, ch;
+
+    in = window;
+    for ( n = 0; n < outcnt; n++ )
+    {
+        ch = *in++;
+        c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
+    }
+    crc = c;
+
+    bytes_out += (unsigned long)outcnt;
+    outcnt = 0;
+}
+
+__init int gzip_check(char *image, unsigned long image_len)
+{
+    unsigned char magic0, magic1;
+
+    if ( image_len < 2 )
+        return 0;
+
+    magic0 = (unsigned char)image[0];
+    magic1 = (unsigned char)image[1];
+
+    return (magic0 == 0x1f) && ((magic1 == 0x8b) || (magic1 == 0x9e));
+}
+
+__init int perform_gunzip(char *output, char *image, unsigned long image_len)
+{
+    int rc;
+
+    if ( !gzip_check(image, image_len) )
+        return 1;
+
+    window = (unsigned char *)output;
+
+    free_mem_ptr = (unsigned long)alloc_xenheap_pages(HEAPORDER, 0);
+    free_mem_end_ptr = free_mem_ptr + (PAGE_SIZE << HEAPORDER);
+
+    inbuf = (unsigned char *)image;
+    insize = image_len;
+    inptr = 0;
+
+    makecrc();
+
+    if ( gunzip() < 0 )
+    {
+        rc = -EINVAL;
+    }
+    else
+    {
+        rc = 0;
+    }
+
+    free_xenheap_pages((void *)free_mem_ptr, HEAPORDER);
+
+    return rc;
+}
diff --git a/xen/include/xen/gunzip.h b/xen/include/xen/gunzip.h
new file mode 100644
index 0000000..8058331
--- /dev/null
+++ b/xen/include/xen/gunzip.h
@@ -0,0 +1,7 @@
+#ifndef __XEN_GUNZIP_H
+#define __XEN_GUNZIP_H
+
+int gzip_check(char *image, unsigned long image_len);
+int perform_gunzip(char *output, char *image, unsigned long image_len);
+
+#endif
-- 
1.7.10.4