s390/decompressor: clean up and rename compressed/misc.c

Since compressed/misc.c is conditionally compiled move error reporting
code to boot/main.c. With that being done compressed/misc.c has no
"miscellaneous" functions left and is all about plain decompression
now. Rename it accordingly.

Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/boot/compressed/decompressor.c

@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Definitions and wrapper functions for kernel decompressor
+ *
+ * Copyright IBM Corp. 2010
+ *
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <asm/page.h>
+#include "decompressor.h"
+
+/*
+ * gzip declarations
+ */
+#define STATIC static
+#define STATIC_RW_DATA static __section(.data)
+
+#undef memset
+#undef memcpy
+#undef memmove
+#define memmove memmove
+#define memzero(s, n) memset((s), 0, (n))
+
+/* Symbols defined by linker scripts */
+extern char _end[];
+extern unsigned char _compressed_start[];
+extern unsigned char _compressed_end[];
+
+#ifdef CONFIG_HAVE_KERNEL_BZIP2
+#define HEAP_SIZE	0x400000
+#else
+#define HEAP_SIZE	0x10000
+#endif
+
+static unsigned long free_mem_ptr = (unsigned long) _end;
+static unsigned long free_mem_end_ptr = (unsigned long) _end + HEAP_SIZE;
+
+#ifdef CONFIG_KERNEL_GZIP
+#include "../../../../lib/decompress_inflate.c"
+#endif
+
+#ifdef CONFIG_KERNEL_BZIP2
+#include "../../../../lib/decompress_bunzip2.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZ4
+#include "../../../../lib/decompress_unlz4.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZMA
+#include "../../../../lib/decompress_unlzma.c"
+#endif
+
+#ifdef CONFIG_KERNEL_LZO
+#include "../../../../lib/decompress_unlzo.c"
+#endif
+
+#ifdef CONFIG_KERNEL_XZ
+#include "../../../../lib/decompress_unxz.c"
+#endif
+
+#define decompress_offset ALIGN((unsigned long)_end + HEAP_SIZE, PAGE_SIZE)
+
+unsigned long mem_safe_offset(void)
+{
+	/*
+	 * due to 4MB HEAD_SIZE for bzip2
+	 * 'decompress_offset + vmlinux.image_size' could be larger than
+	 * kernel at final position + its .bss, so take the larger of two
+	 */
+	return max(decompress_offset + vmlinux.image_size,
+		   vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size);
+}
+
+void *decompress_kernel(void)
+{
+	void *output = (void *)decompress_offset;
+
+	__decompress(_compressed_start, _compressed_end - _compressed_start,
+		     NULL, NULL, output, 0, NULL, error);
+	return output;
+}