zboot-decompress-zstd.c

 1// SPDX-License-Identifier: GPL-2.0
 2
 3#include <linux/efi.h>
 4#include <linux/zstd.h>
 5
 6#include <asm/efi.h>
 7
 8#include "decompress_sources.h"
 9#include "efistub.h"
10
11extern unsigned char _gzdata_start[], _gzdata_end[];
12extern u32 __aligned(1) payload_size;
13
14static size_t wksp_size;
15static void *wksp;
16
17efi_status_t efi_zboot_decompress_init(unsigned long *alloc_size)
18{
19	efi_status_t status;
20
21	wksp_size = zstd_dctx_workspace_bound();
22	status = efi_allocate_pages(wksp_size, (unsigned long *)&wksp, ULONG_MAX);
23	if (status != EFI_SUCCESS)
24		return status;
25
26	*alloc_size = payload_size;
27	return EFI_SUCCESS;
28}
29
30efi_status_t efi_zboot_decompress(u8 *out, unsigned long outlen)
31{
32	zstd_dctx *dctx = zstd_init_dctx(wksp, wksp_size);
33	size_t ret;
34	int retval;
35
36	ret = zstd_decompress_dctx(dctx, out, outlen, _gzdata_start,
37				   _gzdata_end - _gzdata_start - 4);
38	efi_free(wksp_size, (unsigned long)wksp);
39
40	retval = zstd_get_error_code(ret);
41	if (retval) {
42		efi_err("ZSTD-decompression failed with status %d\n", retval);
43		return EFI_LOAD_ERROR;
44	}
45
46	efi_cache_sync_image((unsigned long)out, outlen);
47
48	return EFI_SUCCESS;
49}