zstd: Create a function for use from U-Boot
The existing zstd API requires the same sequence of calls to perform its
task. Create a helper for U-Boot, to avoid code duplication, as is done
with other compression algorithms. Make use of of this from the image
code.
Note that the zstd code lacks a test in test/compression.c and this should
be added by the maintainer.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/zstd/Makefile b/lib/zstd/Makefile
index 33c1df4..1217089 100644
--- a/lib/zstd/Makefile
+++ b/lib/zstd/Makefile
@@ -1,4 +1,4 @@
obj-y += zstd_decompress.o
zstd_decompress-y := huf_decompress.o decompress.o \
- entropy_common.o fse_decompress.o zstd_common.o
+ entropy_common.o fse_decompress.o zstd_common.o zstd.o
diff --git a/lib/zstd/zstd.c b/lib/zstd/zstd.c
new file mode 100644
index 0000000..bf9cd19
--- /dev/null
+++ b/lib/zstd/zstd.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021 Google LLC
+ */
+
+#define LOG_CATEGORY LOGC_BOOT
+
+#include <common.h>
+#include <abuf.h>
+#include <log.h>
+#include <malloc.h>
+#include <linux/zstd.h>
+
+int zstd_decompress(struct abuf *in, struct abuf *out)
+{
+ ZSTD_DStream *dstream;
+ ZSTD_inBuffer in_buf;
+ ZSTD_outBuffer out_buf;
+ void *workspace;
+ size_t wsize;
+ int ret;
+
+ wsize = ZSTD_DStreamWorkspaceBound(abuf_size(in));
+ workspace = malloc(wsize);
+ if (!workspace) {
+ debug("%s: cannot allocate workspace of size %zu\n", __func__,
+ wsize);
+ return -ENOMEM;
+ }
+
+ dstream = ZSTD_initDStream(abuf_size(in), workspace, wsize);
+ if (!dstream) {
+ log_err("%s: ZSTD_initDStream failed\n", __func__);
+ ret = -EPERM;
+ goto do_free;
+ }
+
+ in_buf.src = abuf_data(in);
+ in_buf.pos = 0;
+ in_buf.size = abuf_size(in);
+
+ out_buf.dst = abuf_data(out);
+ out_buf.pos = 0;
+ out_buf.size = abuf_size(out);
+
+ while (1) {
+ size_t res;
+
+ res = ZSTD_decompressStream(dstream, &out_buf, &in_buf);
+ if (ZSTD_isError(res)) {
+ ret = ZSTD_getErrorCode(res);
+ log_err("ZSTD_decompressStream error %d\n", ret);
+ goto do_free;
+ }
+
+ if (in_buf.pos >= abuf_size(in) || !res)
+ break;
+ }
+
+ ret = out_buf.pos;
+do_free:
+ free(workspace);
+ return ret;
+}