[S390] add support for compressed kernels

Add the "bzImage" compile target and the necessary code  to generate
compressed kernel images. The old style uncompressed "image" target
is preserved, a simple make will build them both.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/boot/compressed/Makefile

@@ -0,0 +1,60 @@
+#
+# linux/arch/s390/boot/compressed/Makefile
+#
+# create a compressed vmlinux image from the original vmlinux
+#
+
+BITS := $(if $(CONFIG_64BIT),64,31)
+
+targets	:= vmlinux.lds vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 \
+	   vmlinux.bin.lzma misc.o piggy.o sizes.h head$(BITS).o
+
+KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2
+KBUILD_CFLAGS += $(cflags-y)
+KBUILD_CFLAGS += $(call cc-option,-mpacked-stack)
+KBUILD_CFLAGS += $(call cc-option,-ffreestanding)
+
+GCOV_PROFILE := n
+
+OBJECTS := $(addprefix $(objtree)/arch/s390/kernel/, head.o sclp.o ebcdic.o)
+OBJECTS += $(obj)/head$(BITS).o $(obj)/misc.o $(obj)/piggy.o
+
+LDFLAGS_vmlinux := --oformat $(LD_BFD) -e startup -T
+$(obj)/vmlinux: $(obj)/vmlinux.lds $(OBJECTS)
+	$(call if_changed,ld)
+	@:
+
+sed-sizes := -e 's/^\([0-9a-fA-F]*\) . \(__bss_start\|_end\)$$/\#define SZ\2 0x\1/p'
+
+quiet_cmd_sizes = GEN $@
+      cmd_sizes = $(NM) $< | sed -n $(sed-sizes) > $@
+
+$(obj)/sizes.h: vmlinux
+	$(call if_changed,sizes)
+
+AFLAGS_head$(BITS).o += -I$(obj)
+$(obj)/head$(BITS).o: $(obj)/sizes.h
+
+CFLAGS_misc.o += -I$(obj)
+$(obj)/misc.o: $(obj)/sizes.h
+
+OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
+$(obj)/vmlinux.bin: vmlinux
+	$(call if_changed,objcopy)
+
+vmlinux.bin.all-y := $(obj)/vmlinux.bin
+
+suffix-$(CONFIG_KERNEL_GZIP)  := gz
+suffix-$(CONFIG_KERNEL_BZIP2) := bz2
+suffix-$(CONFIG_KERNEL_LZMA)  := lzma
+
+$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y)
+	$(call if_changed,gzip)
+$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y)
+	$(call if_changed,bzip2)
+$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y)
+	$(call if_changed,lzma)
+
+LDFLAGS_piggy.o := -r --format binary --oformat $(LD_BFD) -T
+$(obj)/piggy.o: $(obj)/vmlinux.scr $(obj)/vmlinux.bin.$(suffix-y)
+	$(call if_changed,ld)

arch/s390/boot/compressed/head31.S

@@ -0,0 +1,51 @@
+/*
+ * Startup glue code to uncompress the kernel
+ *
+ * Copyright IBM Corp. 2010
+ *
+ *   Author(s):	Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/init.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+#include <asm/page.h>
+#include "sizes.h"
+
+__HEAD
+	.globl	startup_continue
+startup_continue:
+	basr	%r13,0			# get base
+.LPG1:
+	# setup stack
+	l	%r15,.Lstack-.LPG1(%r13)
+	ahi	%r15,-96
+	l	%r1,.Ldecompress-.LPG1(%r13)
+	basr	%r14,%r1
+	# setup registers for memory mover & branch to target
+	lr	%r4,%r2
+	l	%r2,.Loffset-.LPG1(%r13)
+	la	%r4,0(%r2,%r4)
+	l	%r3,.Lmvsize-.LPG1(%r13)
+	lr	%r5,%r3
+	# move the memory mover someplace safe
+	la	%r1,0x200
+	mvc	0(mover_end-mover,%r1),mover-.LPG1(%r13)
+	# decompress image is started at 0x11000
+	lr	%r6,%r2
+	br	%r1
+mover:
+	mvcle	%r2,%r4,0
+	jo	mover
+	br	%r6
+mover_end:
+
+	.align	8
+.Lstack:
+	.long	0x8000 + (1<<(PAGE_SHIFT+THREAD_ORDER))
+.Ldecompress:
+	.long	decompress_kernel
+.Loffset:
+	.long	0x11000
+.Lmvsize:
+	.long	SZ__bss_start

arch/s390/boot/compressed/head64.S

@@ -0,0 +1,48 @@
+/*
+ * Startup glue code to uncompress the kernel
+ *
+ * Copyright IBM Corp. 2010
+ *
+ *   Author(s):	Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/init.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+#include <asm/page.h>
+#include "sizes.h"
+
+__HEAD
+	.globl	startup_continue
+startup_continue:
+	basr	%r13,0			# get base
+.LPG1:
+	# setup stack
+	lg	%r15,.Lstack-.LPG1(%r13)
+	aghi	%r15,-160
+	brasl	%r14,decompress_kernel
+	# setup registers for memory mover & branch to target
+	lgr	%r4,%r2
+	lg	%r2,.Loffset-.LPG1(%r13)
+	la	%r4,0(%r2,%r4)
+	lg	%r3,.Lmvsize-.LPG1(%r13)
+	lgr	%r5,%r3
+	# move the memory mover someplace safe
+	la	%r1,0x200
+	mvc	0(mover_end-mover,%r1),mover-.LPG1(%r13)
+	# decompress image is started at 0x11000
+	lgr	%r6,%r2
+	br	%r1
+mover:
+	mvcle	%r2,%r4,0
+	jo	mover
+	br	%r6
+mover_end:
+
+	.align	8
+.Lstack:
+	.quad	0x8000 + (1<<(PAGE_SHIFT+THREAD_ORDER))
+.Loffset:
+	.quad	0x11000
+.Lmvsize:
+	.quad	SZ__bss_start

arch/s390/boot/compressed/misc.c

@@ -0,0 +1,158 @@
+/*
+ * Definitions and wrapper functions for kernel decompressor
+ *
+ * Copyright IBM Corp. 2010
+ *
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/ipl.h>
+#include "sizes.h"
+
+/*
+ * gzip declarations
+ */
+#define STATIC static
+
+#undef memset
+#undef memcpy
+#undef memmove
+#define memzero(s, n) memset((s), 0, (n))
+
+/* Symbols defined by linker scripts */
+extern char input_data[];
+extern int input_len;
+extern int _text;
+extern int _end;
+
+static void error(char *m);
+
+static unsigned long free_mem_ptr;
+static unsigned long free_mem_end_ptr;
+
+#ifdef CONFIG_HAVE_KERNEL_BZIP2
+#define HEAP_SIZE	0x400000
+#else
+#define HEAP_SIZE	0x10000
+#endif
+
+#ifdef CONFIG_KERNEL_GZIP
+#include "../../../../lib/decompress_inflate.c"
+#endif
+
+#ifdef CONFIG_KERNEL_BZIP2
+#include "../../../../lib/decompress_bunzip2.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZMA
+#include "../../../../lib/decompress_unlzma.c"
+#endif
+
+extern _sclp_print_early(const char *);
+
+int puts(const char *s)
+{
+	_sclp_print_early(s);
+	return 0;
+}
+
+void *memset(void *s, int c, size_t n)
+{
+	char *xs;
+
+	if (c == 0)
+		return __builtin_memset(s, 0, n);
+
+	xs = (char *) s;
+	if (n > 0)
+		do {
+			*xs++ = c;
+		} while (--n > 0);
+	return s;
+}
+
+void *memcpy(void *__dest, __const void *__src, size_t __n)
+{
+	return __builtin_memcpy(__dest, __src, __n);
+}
+
+void *memmove(void *__dest, __const void *__src, size_t __n)
+{
+	char *d;
+	const char *s;
+
+	if (__dest <= __src)
+		return __builtin_memcpy(__dest, __src, __n);
+	d = __dest + __n;
+	s = __src + __n;
+	while (__n--)
+		*--d = *--s;
+	return __dest;
+}
+
+static void error(char *x)
+{
+	unsigned long long psw = 0x000a0000deadbeefULL;
+
+	puts("\n\n");
+	puts(x);
+	puts("\n\n -- System halted");
+
+	asm volatile("lpsw %0" : : "Q" (psw));
+}
+
+/*
+ * Safe guard the ipl parameter block against a memory area that will be
+ * overwritten. The validity check for the ipl parameter block is complex
+ * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
+ * the ipl parameter block intersects with the passed memory area we can
+ * safely assume that we can read from that memory. In that case just copy
+ * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
+ * block.
+ */
+static void check_ipl_parmblock(void *start, unsigned long size)
+{
+	void *src, *dst;
+
+	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
+	if (src + PAGE_SIZE <= start || src >= start + size)
+		return;
+	dst = (void *) IPL_PARMBLOCK_ORIGIN;
+	memmove(dst, src, PAGE_SIZE);
+	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
+}
+
+unsigned long decompress_kernel(void)
+{
+	unsigned long output_addr;
+	unsigned char *output;
+
+	free_mem_ptr = (unsigned long)&_end;
+	free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
+	output = (unsigned char *) ((free_mem_end_ptr + 4095UL) & -4096UL);
+
+	check_ipl_parmblock((void *) 0, (unsigned long) output + SZ__bss_start);
+
+#ifdef CONFIG_BLK_DEV_INITRD
+	/*
+	 * Move the initrd right behind the end of the decompressed
+	 * kernel image.
+	 */
+	if (INITRD_START && INITRD_SIZE &&
+	    INITRD_START < (unsigned long) output + SZ__bss_start) {
+		check_ipl_parmblock(output + SZ__bss_start,
+				    INITRD_START + INITRD_SIZE);
+		memmove(output + SZ__bss_start,
+			(void *) INITRD_START, INITRD_SIZE);
+		INITRD_START = (unsigned long) output + SZ__bss_start;
+	}
+#endif
+
+	puts("Uncompressing Linux... ");
+	decompress(input_data, input_len, NULL, NULL, output, NULL, error);
+	puts("Ok, booting the kernel.\n");
+	return (unsigned long) output;
+}
+

arch/s390/boot/compressed/vmlinux.lds.S

@@ -0,0 +1,55 @@
+#include <asm-generic/vmlinux.lds.h>
+
+#ifdef CONFIG_64BIT
+OUTPUT_FORMAT("elf64-s390", "elf64-s390", "elf64-s390")
+OUTPUT_ARCH(s390:64-bit)
+#else
+OUTPUT_FORMAT("elf32-s390", "elf32-s390", "elf32-s390")
+OUTPUT_ARCH(s390)
+#endif
+
+ENTRY(startup)
+
+SECTIONS
+{
+	/* Be careful parts of head_64.S assume startup_32 is at
+	 * address 0.
+	 */
+	. = 0;
+	.head.text : {
+		_head = . ;
+		HEAD_TEXT
+		_ehead = . ;
+	}
+	.rodata.compressed : {
+		*(.rodata.compressed)
+	}
+	.text :	{
+		_text = .;	/* Text */
+		*(.text)
+		*(.text.*)
+		_etext = . ;
+	}
+	.rodata : {
+		_rodata = . ;
+		*(.rodata)	 /* read-only data */
+		*(.rodata.*)
+		_erodata = . ;
+	}
+	.data :	{
+		_data = . ;
+		*(.data)
+		*(.data.*)
+		_edata = . ;
+	}
+	. = ALIGN(256);
+	.bss : {
+		_bss = . ;
+		*(.bss)
+		*(.bss.*)
+		*(COMMON)
+		. = ALIGN(8);	/* For convenience during zeroing */
+		_ebss = .;
+	}
+	_end = .;
+}

arch/s390/boot/compressed/vmlinux.scr

@@ -0,0 +1,10 @@
+SECTIONS
+{
+  .rodata.compressed : {
+	input_len = .;
+	LONG(input_data_end - input_data) input_data = .;
+	*(.data)
+	output_len = . - 4;
+	input_data_end = .;
+	}
+}