1*f1a116c0SArd Biesheuvel // SPDX-License-Identifier: GPL-2.0
2*f1a116c0SArd Biesheuvel /*
3*f1a116c0SArd Biesheuvel * Copyright (C) 2020 Western Digital Corporation or its affiliates.
4*f1a116c0SArd Biesheuvel */
5*f1a116c0SArd Biesheuvel
6*f1a116c0SArd Biesheuvel #include <linux/efi.h>
7*f1a116c0SArd Biesheuvel #include <linux/libfdt.h>
8*f1a116c0SArd Biesheuvel
9*f1a116c0SArd Biesheuvel #include <asm/efi.h>
10*f1a116c0SArd Biesheuvel #include <asm/unaligned.h>
11*f1a116c0SArd Biesheuvel
12*f1a116c0SArd Biesheuvel #include "efistub.h"
13*f1a116c0SArd Biesheuvel
14*f1a116c0SArd Biesheuvel typedef void __noreturn (*jump_kernel_func)(unsigned long, unsigned long);
15*f1a116c0SArd Biesheuvel
16*f1a116c0SArd Biesheuvel static unsigned long hartid;
17*f1a116c0SArd Biesheuvel
get_boot_hartid_from_fdt(void)18*f1a116c0SArd Biesheuvel static int get_boot_hartid_from_fdt(void)
19*f1a116c0SArd Biesheuvel {
20*f1a116c0SArd Biesheuvel const void *fdt;
21*f1a116c0SArd Biesheuvel int chosen_node, len;
22*f1a116c0SArd Biesheuvel const void *prop;
23*f1a116c0SArd Biesheuvel
24*f1a116c0SArd Biesheuvel fdt = get_efi_config_table(DEVICE_TREE_GUID);
25*f1a116c0SArd Biesheuvel if (!fdt)
26*f1a116c0SArd Biesheuvel return -EINVAL;
27*f1a116c0SArd Biesheuvel
28*f1a116c0SArd Biesheuvel chosen_node = fdt_path_offset(fdt, "/chosen");
29*f1a116c0SArd Biesheuvel if (chosen_node < 0)
30*f1a116c0SArd Biesheuvel return -EINVAL;
31*f1a116c0SArd Biesheuvel
32*f1a116c0SArd Biesheuvel prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len);
33*f1a116c0SArd Biesheuvel if (!prop)
34*f1a116c0SArd Biesheuvel return -EINVAL;
35*f1a116c0SArd Biesheuvel
36*f1a116c0SArd Biesheuvel if (len == sizeof(u32))
37*f1a116c0SArd Biesheuvel hartid = (unsigned long) fdt32_to_cpu(*(fdt32_t *)prop);
38*f1a116c0SArd Biesheuvel else if (len == sizeof(u64))
39*f1a116c0SArd Biesheuvel hartid = (unsigned long) fdt64_to_cpu(__get_unaligned_t(fdt64_t, prop));
40*f1a116c0SArd Biesheuvel else
41*f1a116c0SArd Biesheuvel return -EINVAL;
42*f1a116c0SArd Biesheuvel
43*f1a116c0SArd Biesheuvel return 0;
44*f1a116c0SArd Biesheuvel }
45*f1a116c0SArd Biesheuvel
get_boot_hartid_from_efi(void)46*f1a116c0SArd Biesheuvel static efi_status_t get_boot_hartid_from_efi(void)
47*f1a116c0SArd Biesheuvel {
48*f1a116c0SArd Biesheuvel efi_guid_t boot_protocol_guid = RISCV_EFI_BOOT_PROTOCOL_GUID;
49*f1a116c0SArd Biesheuvel struct riscv_efi_boot_protocol *boot_protocol;
50*f1a116c0SArd Biesheuvel efi_status_t status;
51*f1a116c0SArd Biesheuvel
52*f1a116c0SArd Biesheuvel status = efi_bs_call(locate_protocol, &boot_protocol_guid, NULL,
53*f1a116c0SArd Biesheuvel (void **)&boot_protocol);
54*f1a116c0SArd Biesheuvel if (status != EFI_SUCCESS)
55*f1a116c0SArd Biesheuvel return status;
56*f1a116c0SArd Biesheuvel return efi_call_proto(boot_protocol, get_boot_hartid, &hartid);
57*f1a116c0SArd Biesheuvel }
58*f1a116c0SArd Biesheuvel
check_platform_features(void)59*f1a116c0SArd Biesheuvel efi_status_t check_platform_features(void)
60*f1a116c0SArd Biesheuvel {
61*f1a116c0SArd Biesheuvel efi_status_t status;
62*f1a116c0SArd Biesheuvel int ret;
63*f1a116c0SArd Biesheuvel
64*f1a116c0SArd Biesheuvel status = get_boot_hartid_from_efi();
65*f1a116c0SArd Biesheuvel if (status != EFI_SUCCESS) {
66*f1a116c0SArd Biesheuvel ret = get_boot_hartid_from_fdt();
67*f1a116c0SArd Biesheuvel if (ret) {
68*f1a116c0SArd Biesheuvel efi_err("Failed to get boot hartid!\n");
69*f1a116c0SArd Biesheuvel return EFI_UNSUPPORTED;
70*f1a116c0SArd Biesheuvel }
71*f1a116c0SArd Biesheuvel }
72*f1a116c0SArd Biesheuvel return EFI_SUCCESS;
73*f1a116c0SArd Biesheuvel }
74*f1a116c0SArd Biesheuvel
stext_offset(void)75*f1a116c0SArd Biesheuvel unsigned long __weak stext_offset(void)
76*f1a116c0SArd Biesheuvel {
77*f1a116c0SArd Biesheuvel /*
78*f1a116c0SArd Biesheuvel * This fallback definition is used by the EFI zboot stub, which loads
79*f1a116c0SArd Biesheuvel * the entire image so it can branch via the image header at offset #0.
80*f1a116c0SArd Biesheuvel */
81*f1a116c0SArd Biesheuvel return 0;
82*f1a116c0SArd Biesheuvel }
83*f1a116c0SArd Biesheuvel
efi_enter_kernel(unsigned long entrypoint,unsigned long fdt,unsigned long fdt_size)84*f1a116c0SArd Biesheuvel void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt,
85*f1a116c0SArd Biesheuvel unsigned long fdt_size)
86*f1a116c0SArd Biesheuvel {
87*f1a116c0SArd Biesheuvel unsigned long kernel_entry = entrypoint + stext_offset();
88*f1a116c0SArd Biesheuvel jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry;
89*f1a116c0SArd Biesheuvel
90*f1a116c0SArd Biesheuvel /*
91*f1a116c0SArd Biesheuvel * Jump to real kernel here with following constraints.
92*f1a116c0SArd Biesheuvel * 1. MMU should be disabled.
93*f1a116c0SArd Biesheuvel * 2. a0 should contain hartid
94*f1a116c0SArd Biesheuvel * 3. a1 should DT address
95*f1a116c0SArd Biesheuvel */
96*f1a116c0SArd Biesheuvel csr_write(CSR_SATP, 0);
97*f1a116c0SArd Biesheuvel jump_kernel(hartid, fdt);
98*f1a116c0SArd Biesheuvel }
99