lib: add Zstandard decompression support

Add the zstd library from Linux kernel (only decompression support).
There are minimal changes to build with U-Boot, otherwise the files are
identical to Linux commit dc35da16 from March 2018, the files had not
been touched since in kernel. Also SPDX lincese tags were added.

Signed-off-by: Marek Behún <marek.behun@nic.cz>

1 files changed, 65 insertions, 0 deletions

diff --git a/lib/zstd/zstd_common.c b/lib/zstd/zstd_common.c
new file mode 100644
index 00000000000..9a217e15739
--- /dev/null
+++ b/lib/zstd/zstd_common.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: (GPL-2.0 or BSD-3-Clause-Clear)
+/**
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ */
+
+/*-*************************************
+*  Dependencies
+***************************************/
+#include "error_private.h"
+#include "zstd_internal.h" /* declaration of ZSTD_isError, ZSTD_getErrorName, ZSTD_getErrorCode, ZSTD_getErrorString, ZSTD_versionNumber */
+#include <linux/kernel.h>
+
+/*=**************************************************************
+*  Custom allocator
+****************************************************************/
+
+#define stack_push(stack, size)                                 \
+	({                                                      \
+		void *const ptr = ZSTD_PTR_ALIGN((stack)->ptr); \
+		(stack)->ptr = (char *)ptr + (size);            \
+		(stack)->ptr <= (stack)->end ? ptr : NULL;      \
+	})
+
+ZSTD_customMem ZSTD_initStack(void *workspace, size_t workspaceSize)
+{
+	ZSTD_customMem stackMem = {ZSTD_stackAlloc, ZSTD_stackFree, workspace};
+	ZSTD_stack *stack = (ZSTD_stack *)workspace;
+	/* Verify preconditions */
+	if (!workspace || workspaceSize < sizeof(ZSTD_stack) || workspace != ZSTD_PTR_ALIGN(workspace)) {
+		ZSTD_customMem error = {NULL, NULL, NULL};
+		return error;
+	}
+	/* Initialize the stack */
+	stack->ptr = workspace;
+	stack->end = (char *)workspace + workspaceSize;
+	stack_push(stack, sizeof(ZSTD_stack));
+	return stackMem;
+}
+
+void *ZSTD_stackAllocAll(void *opaque, size_t *size)
+{
+	ZSTD_stack *stack = (ZSTD_stack *)opaque;
+	*size = (BYTE const *)stack->end - (BYTE *)ZSTD_PTR_ALIGN(stack->ptr);
+	return stack_push(stack, *size);
+}
+
+void *ZSTD_stackAlloc(void *opaque, size_t size)
+{
+	ZSTD_stack *stack = (ZSTD_stack *)opaque;
+	return stack_push(stack, size);
+}
+void ZSTD_stackFree(void *opaque, void *address)
+{
+	(void)opaque;
+	(void)address;
+}
+
+void *ZSTD_malloc(size_t size, ZSTD_customMem customMem) { return customMem.customAlloc(customMem.opaque, size); }
+
+void ZSTD_free(void *ptr, ZSTD_customMem customMem)
+{
+	if (ptr != NULL)
+		customMem.customFree(customMem.opaque, ptr);
+}