+/*
+ * XZ-compressed firmware support
+ */
+#ifdef CONFIG_FW_LOADER_COMPRESS
+/* show an error and return the standard error code */
+static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
+{
+ if (xz_ret != XZ_STREAM_END) {
+ dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
+ return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
+ }
+ return 0;
+}
+
+/* single-shot decompression onto the pre-allocated buffer */
+static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
+ size_t in_size, const void *in_buffer)
+{
+ struct xz_dec *xz_dec;
+ struct xz_buf xz_buf;
+ enum xz_ret xz_ret;
+
+ xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
+ if (!xz_dec)
+ return -ENOMEM;
+
+ xz_buf.in_size = in_size;
+ xz_buf.in = in_buffer;
+ xz_buf.in_pos = 0;
+ xz_buf.out_size = fw_priv->allocated_size;
+ xz_buf.out = fw_priv->data;
+ xz_buf.out_pos = 0;
+
+ xz_ret = xz_dec_run(xz_dec, &xz_buf);
+ xz_dec_end(xz_dec);
+
+ fw_priv->size = xz_buf.out_pos;
+ return fw_decompress_xz_error(dev, xz_ret);
+}
+
+/* decompression on paged buffer and map it */
+static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
+ size_t in_size, const void *in_buffer)
+{
+ struct xz_dec *xz_dec;
+ struct xz_buf xz_buf;
+ enum xz_ret xz_ret;
+ struct page *page;
+ int err = 0;
+
+ xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
+ if (!xz_dec)
+ return -ENOMEM;
+
+ xz_buf.in_size = in_size;
+ xz_buf.in = in_buffer;
+ xz_buf.in_pos = 0;
+
+ fw_priv->is_paged_buf = true;
+ fw_priv->size = 0;
+ do {
+ if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ /* decompress onto the new allocated page */
+ page = fw_priv->pages[fw_priv->nr_pages - 1];
+ xz_buf.out = kmap(page);
+ xz_buf.out_pos = 0;
+ xz_buf.out_size = PAGE_SIZE;
+ xz_ret = xz_dec_run(xz_dec, &xz_buf);
+ kunmap(page);
+ fw_priv->size += xz_buf.out_pos;
+ /* partial decompression means either end or error */
+ if (xz_buf.out_pos != PAGE_SIZE)
+ break;
+ } while (xz_ret == XZ_OK);
+
+ err = fw_decompress_xz_error(dev, xz_ret);
+ if (!err)
+ err = fw_map_paged_buf(fw_priv);
+
+ out:
+ xz_dec_end(xz_dec);
+ return err;
+}
+
+static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
+ size_t in_size, const void *in_buffer)
+{
+ /* if the buffer is pre-allocated, we can perform in single-shot mode */
+ if (fw_priv->data)
+ return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
+ else
+ return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
+}
+#endif /* CONFIG_FW_LOADER_COMPRESS */
+