1 // SPDX-License-Identifier: GPL-2.0-only
3 #define pr_fmt(fmt) "efi: " fmt
5 #include <linux/module.h>
6 #include <linux/init.h>
8 #include <linux/libfdt.h>
9 #include <linux/of_fdt.h>
11 #include <asm/unaligned.h>
23 static __initconst const char name[][22] = {
24 [SYSTAB] = "System Table ",
25 [MMBASE] = "MemMap Address ",
26 [MMSIZE] = "MemMap Size ",
27 [DCSIZE] = "MemMap Desc. Size ",
28 [DCVERS] = "MemMap Desc. Version ",
31 static __initconst const struct {
33 const char params[PARAMCOUNT][26];
36 #ifdef CONFIG_XEN // <-------17------>
37 .path = "/hypervisor/uefi",
39 [SYSTAB] = "xen,uefi-system-table",
40 [MMBASE] = "xen,uefi-mmap-start",
41 [MMSIZE] = "xen,uefi-mmap-size",
42 [DCSIZE] = "xen,uefi-mmap-desc-size",
43 [DCVERS] = "xen,uefi-mmap-desc-ver",
48 .params = { // <-----------26----------->
49 [SYSTAB] = "linux,uefi-system-table",
50 [MMBASE] = "linux,uefi-mmap-start",
51 [MMSIZE] = "linux,uefi-mmap-size",
52 [DCSIZE] = "linux,uefi-mmap-desc-size",
53 [DCVERS] = "linux,uefi-mmap-desc-ver",
58 static int __init efi_get_fdt_prop(const void *fdt, int node, const char *pname,
59 const char *rname, void *var, int size)
65 prop = fdt_getprop(fdt, node, pname, &len);
69 val = (len == 4) ? (u64)be32_to_cpup(prop) : get_unaligned_be64(prop);
74 *(u32 *)var = (val < U32_MAX) ? val : U32_MAX; // saturate
76 if (efi_enabled(EFI_DBG))
77 pr_info(" %s: 0x%0*llx\n", rname, size * 2, val);
82 u64 __init efi_get_fdt_params(struct efi_memory_map_data *mm)
84 const void *fdt = initial_boot_params;
91 [SYSTAB] = { &systab, sizeof(systab) },
92 [MMBASE] = { &mm->phys_map, sizeof(mm->phys_map) },
93 [MMSIZE] = { &mm->size, sizeof(mm->size) },
94 [DCSIZE] = { &mm->desc_size, sizeof(mm->desc_size) },
95 [DCVERS] = { &mm->desc_version, sizeof(mm->desc_version) },
98 BUILD_BUG_ON(ARRAY_SIZE(target) != ARRAY_SIZE(name));
99 BUILD_BUG_ON(ARRAY_SIZE(target) != ARRAY_SIZE(dt_params[0].params));
104 for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
105 node = fdt_path_offset(fdt, dt_params[i].path);
109 if (efi_enabled(EFI_DBG))
110 pr_info("Getting UEFI parameters from %s in DT:\n",
113 for (j = 0; j < ARRAY_SIZE(target); j++) {
114 const char *pname = dt_params[i].params[j];
116 if (!efi_get_fdt_prop(fdt, node, pname, name[j],
117 target[j].var, target[j].size))
121 pr_err("Can't find property '%s' in DT!\n", pname);
127 pr_info("UEFI not found.\n");