1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/zboot-decompress-zstd.c b/drivers/firmware/efi/libstub/zboot-decompress-zstd.c
new file mode 100644
index 000000000000..bde9d94dd2e3
--- /dev/null
+++ b/drivers/firmware/efi/libstub/zboot-decompress-zstd.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/efi.h>
+#include <linux/zstd.h>
+
+#include <asm/efi.h>
+
+#include "decompress_sources.h"
+#include "efistub.h"
+
+extern unsigned char _gzdata_start[], _gzdata_end[];
+extern u32 __aligned(1) payload_size;
+
+static size_t wksp_size;
+static void *wksp;
+
+efi_status_t efi_zboot_decompress_init(unsigned long *alloc_size)
+{
+	efi_status_t status;
+
+	wksp_size = zstd_dctx_workspace_bound();
+	status = efi_allocate_pages(wksp_size, (unsigned long *)&wksp, ULONG_MAX);
+	if (status != EFI_SUCCESS)
+		return status;
+
+	*alloc_size = payload_size;
+	return EFI_SUCCESS;
+}
+
+efi_status_t efi_zboot_decompress(u8 *out, unsigned long outlen)
+{
+	zstd_dctx *dctx = zstd_init_dctx(wksp, wksp_size);
+	size_t ret;
+	int retval;
+
+	ret = zstd_decompress_dctx(dctx, out, outlen, _gzdata_start,
+				   _gzdata_end - _gzdata_start - 4);
+	efi_free(wksp_size, (unsigned long)wksp);
+
+	retval = zstd_get_error_code(ret);
+	if (retval) {
+		efi_err("ZSTD-decompression failed with status %d\n", retval);
+		return EFI_LOAD_ERROR;
+	}
+
+	efi_cache_sync_image((unsigned long)out, outlen);
+
+	return EFI_SUCCESS;
+}