1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun #define pr_fmt(fmt) "efi: " fmt
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <linux/module.h>
6*4882a593Smuzhiyun #include <linux/init.h>
7*4882a593Smuzhiyun #include <linux/efi.h>
8*4882a593Smuzhiyun #include <linux/libfdt.h>
9*4882a593Smuzhiyun #include <linux/of_fdt.h>
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include <asm/unaligned.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun enum {
14*4882a593Smuzhiyun SYSTAB,
15*4882a593Smuzhiyun MMBASE,
16*4882a593Smuzhiyun MMSIZE,
17*4882a593Smuzhiyun DCSIZE,
18*4882a593Smuzhiyun DCVERS,
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun PARAMCOUNT
21*4882a593Smuzhiyun };
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun static __initconst const char name[][22] = {
24*4882a593Smuzhiyun [SYSTAB] = "System Table ",
25*4882a593Smuzhiyun [MMBASE] = "MemMap Address ",
26*4882a593Smuzhiyun [MMSIZE] = "MemMap Size ",
27*4882a593Smuzhiyun [DCSIZE] = "MemMap Desc. Size ",
28*4882a593Smuzhiyun [DCVERS] = "MemMap Desc. Version ",
29*4882a593Smuzhiyun };
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun static __initconst const struct {
32*4882a593Smuzhiyun const char path[17];
33*4882a593Smuzhiyun const char params[PARAMCOUNT][26];
34*4882a593Smuzhiyun } dt_params[] = {
35*4882a593Smuzhiyun {
36*4882a593Smuzhiyun #ifdef CONFIG_XEN // <-------17------>
37*4882a593Smuzhiyun .path = "/hypervisor/uefi",
38*4882a593Smuzhiyun .params = {
39*4882a593Smuzhiyun [SYSTAB] = "xen,uefi-system-table",
40*4882a593Smuzhiyun [MMBASE] = "xen,uefi-mmap-start",
41*4882a593Smuzhiyun [MMSIZE] = "xen,uefi-mmap-size",
42*4882a593Smuzhiyun [DCSIZE] = "xen,uefi-mmap-desc-size",
43*4882a593Smuzhiyun [DCVERS] = "xen,uefi-mmap-desc-ver",
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun }, {
46*4882a593Smuzhiyun #endif
47*4882a593Smuzhiyun .path = "/chosen",
48*4882a593Smuzhiyun .params = { // <-----------26----------->
49*4882a593Smuzhiyun [SYSTAB] = "linux,uefi-system-table",
50*4882a593Smuzhiyun [MMBASE] = "linux,uefi-mmap-start",
51*4882a593Smuzhiyun [MMSIZE] = "linux,uefi-mmap-size",
52*4882a593Smuzhiyun [DCSIZE] = "linux,uefi-mmap-desc-size",
53*4882a593Smuzhiyun [DCVERS] = "linux,uefi-mmap-desc-ver",
54*4882a593Smuzhiyun }
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun };
57*4882a593Smuzhiyun
efi_get_fdt_prop(const void * fdt,int node,const char * pname,const char * rname,void * var,int size)58*4882a593Smuzhiyun static int __init efi_get_fdt_prop(const void *fdt, int node, const char *pname,
59*4882a593Smuzhiyun const char *rname, void *var, int size)
60*4882a593Smuzhiyun {
61*4882a593Smuzhiyun const void *prop;
62*4882a593Smuzhiyun int len;
63*4882a593Smuzhiyun u64 val;
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun prop = fdt_getprop(fdt, node, pname, &len);
66*4882a593Smuzhiyun if (!prop)
67*4882a593Smuzhiyun return 1;
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun val = (len == 4) ? (u64)be32_to_cpup(prop) : get_unaligned_be64(prop);
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun if (size == 8)
72*4882a593Smuzhiyun *(u64 *)var = val;
73*4882a593Smuzhiyun else
74*4882a593Smuzhiyun *(u32 *)var = (val < U32_MAX) ? val : U32_MAX; // saturate
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun if (efi_enabled(EFI_DBG))
77*4882a593Smuzhiyun pr_info(" %s: 0x%0*llx\n", rname, size * 2, val);
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun return 0;
80*4882a593Smuzhiyun }
81*4882a593Smuzhiyun
efi_get_fdt_params(struct efi_memory_map_data * mm)82*4882a593Smuzhiyun u64 __init efi_get_fdt_params(struct efi_memory_map_data *mm)
83*4882a593Smuzhiyun {
84*4882a593Smuzhiyun const void *fdt = initial_boot_params;
85*4882a593Smuzhiyun unsigned long systab;
86*4882a593Smuzhiyun int i, j, node;
87*4882a593Smuzhiyun struct {
88*4882a593Smuzhiyun void *var;
89*4882a593Smuzhiyun int size;
90*4882a593Smuzhiyun } target[] = {
91*4882a593Smuzhiyun [SYSTAB] = { &systab, sizeof(systab) },
92*4882a593Smuzhiyun [MMBASE] = { &mm->phys_map, sizeof(mm->phys_map) },
93*4882a593Smuzhiyun [MMSIZE] = { &mm->size, sizeof(mm->size) },
94*4882a593Smuzhiyun [DCSIZE] = { &mm->desc_size, sizeof(mm->desc_size) },
95*4882a593Smuzhiyun [DCVERS] = { &mm->desc_version, sizeof(mm->desc_version) },
96*4882a593Smuzhiyun };
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun BUILD_BUG_ON(ARRAY_SIZE(target) != ARRAY_SIZE(name));
99*4882a593Smuzhiyun BUILD_BUG_ON(ARRAY_SIZE(target) != ARRAY_SIZE(dt_params[0].params));
100*4882a593Smuzhiyun
101*4882a593Smuzhiyun if (!fdt)
102*4882a593Smuzhiyun return 0;
103*4882a593Smuzhiyun
104*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
105*4882a593Smuzhiyun node = fdt_path_offset(fdt, dt_params[i].path);
106*4882a593Smuzhiyun if (node < 0)
107*4882a593Smuzhiyun continue;
108*4882a593Smuzhiyun
109*4882a593Smuzhiyun if (efi_enabled(EFI_DBG))
110*4882a593Smuzhiyun pr_info("Getting UEFI parameters from %s in DT:\n",
111*4882a593Smuzhiyun dt_params[i].path);
112*4882a593Smuzhiyun
113*4882a593Smuzhiyun for (j = 0; j < ARRAY_SIZE(target); j++) {
114*4882a593Smuzhiyun const char *pname = dt_params[i].params[j];
115*4882a593Smuzhiyun
116*4882a593Smuzhiyun if (!efi_get_fdt_prop(fdt, node, pname, name[j],
117*4882a593Smuzhiyun target[j].var, target[j].size))
118*4882a593Smuzhiyun continue;
119*4882a593Smuzhiyun if (!j)
120*4882a593Smuzhiyun goto notfound;
121*4882a593Smuzhiyun pr_err("Can't find property '%s' in DT!\n", pname);
122*4882a593Smuzhiyun return 0;
123*4882a593Smuzhiyun }
124*4882a593Smuzhiyun return systab;
125*4882a593Smuzhiyun }
126*4882a593Smuzhiyun notfound:
127*4882a593Smuzhiyun pr_info("UEFI not found.\n");
128*4882a593Smuzhiyun return 0;
129*4882a593Smuzhiyun }
130