1 files changed, 85 insertions, 0 deletions
diff --git a/arch/s390/boot/decompressor.c b/arch/s390/boot/decompressor.c
new file mode 100644
index 000000000000..e27c2140d620
--- /dev/null
+++ b/arch/s390/boot/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
+
+#undef memset
+#undef memcpy
+#undef memmove
+#define memmove memmove
+#define memzero(s, n) memset((s), 0, (n))
+
+#ifdef CONFIG_KERNEL_BZIP2
+#define BOOT_HEAP_SIZE	0x400000
+#elif CONFIG_KERNEL_ZSTD
+#define BOOT_HEAP_SIZE	0x30000
+#else
+#define BOOT_HEAP_SIZE	0x10000
+#endif
+
+static unsigned long free_mem_ptr = (unsigned long) _end;
+static unsigned long free_mem_end_ptr = (unsigned long) _end + BOOT_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
+
+#ifdef CONFIG_KERNEL_ZSTD
+#include "../../../../lib/decompress_unzstd.c"
+#endif
+
+#define decompress_offset ALIGN((unsigned long)_end + BOOT_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;
+}