1 files changed, 75 insertions, 0 deletions

diff --git a/lib/zstd/zstd_common.c b/lib/zstd/zstd_common.c
new file mode 100644
index 000000000000..a282624ee155
--- /dev/null
+++ b/lib/zstd/zstd_common.c
@@ -0,0 +1,75 @@
+/**
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of https://github.com/facebook/zstd.
+ * An additional grant of patent rights can be found in the PATENTS file in the
+ * same directory.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation. This program is dual-licensed; you may select
+ * either version 2 of the GNU General Public License ("GPL") or BSD license
+ * ("BSD").
+ */
+
+/*-*************************************
+*  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);
+}