1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Extensible Firmware Interface
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2020 Western Digital Corporation or its affiliates.
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Based on Extensible Firmware Interface Specification version 2.4
8*4882a593Smuzhiyun * Adapted from drivers/firmware/efi/arm-runtime.c
9*4882a593Smuzhiyun *
10*4882a593Smuzhiyun */
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include <linux/dmi.h>
13*4882a593Smuzhiyun #include <linux/efi.h>
14*4882a593Smuzhiyun #include <linux/io.h>
15*4882a593Smuzhiyun #include <linux/memblock.h>
16*4882a593Smuzhiyun #include <linux/mm_types.h>
17*4882a593Smuzhiyun #include <linux/preempt.h>
18*4882a593Smuzhiyun #include <linux/rbtree.h>
19*4882a593Smuzhiyun #include <linux/rwsem.h>
20*4882a593Smuzhiyun #include <linux/sched.h>
21*4882a593Smuzhiyun #include <linux/slab.h>
22*4882a593Smuzhiyun #include <linux/spinlock.h>
23*4882a593Smuzhiyun #include <linux/pgtable.h>
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun #include <asm/cacheflush.h>
26*4882a593Smuzhiyun #include <asm/efi.h>
27*4882a593Smuzhiyun #include <asm/mmu.h>
28*4882a593Smuzhiyun #include <asm/pgalloc.h>
29*4882a593Smuzhiyun
efi_virtmap_init(void)30*4882a593Smuzhiyun static bool __init efi_virtmap_init(void)
31*4882a593Smuzhiyun {
32*4882a593Smuzhiyun efi_memory_desc_t *md;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun efi_mm.pgd = pgd_alloc(&efi_mm);
35*4882a593Smuzhiyun mm_init_cpumask(&efi_mm);
36*4882a593Smuzhiyun init_new_context(NULL, &efi_mm);
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun for_each_efi_memory_desc(md) {
39*4882a593Smuzhiyun phys_addr_t phys = md->phys_addr;
40*4882a593Smuzhiyun int ret;
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun if (!(md->attribute & EFI_MEMORY_RUNTIME))
43*4882a593Smuzhiyun continue;
44*4882a593Smuzhiyun if (md->virt_addr == 0)
45*4882a593Smuzhiyun return false;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun ret = efi_create_mapping(&efi_mm, md);
48*4882a593Smuzhiyun if (ret) {
49*4882a593Smuzhiyun pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
50*4882a593Smuzhiyun &phys, ret);
51*4882a593Smuzhiyun return false;
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
56*4882a593Smuzhiyun return false;
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun return true;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun /*
62*4882a593Smuzhiyun * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
63*4882a593Smuzhiyun * non-early mapping of the UEFI system table and virtual mappings for all
64*4882a593Smuzhiyun * EFI_MEMORY_RUNTIME regions.
65*4882a593Smuzhiyun */
riscv_enable_runtime_services(void)66*4882a593Smuzhiyun static int __init riscv_enable_runtime_services(void)
67*4882a593Smuzhiyun {
68*4882a593Smuzhiyun u64 mapsize;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun if (!efi_enabled(EFI_BOOT)) {
71*4882a593Smuzhiyun pr_info("EFI services will not be available.\n");
72*4882a593Smuzhiyun return 0;
73*4882a593Smuzhiyun }
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun efi_memmap_unmap();
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
80*4882a593Smuzhiyun pr_err("Failed to remap EFI memory map\n");
81*4882a593Smuzhiyun return 0;
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun if (efi_soft_reserve_enabled()) {
85*4882a593Smuzhiyun efi_memory_desc_t *md;
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun for_each_efi_memory_desc(md) {
88*4882a593Smuzhiyun int md_size = md->num_pages << EFI_PAGE_SHIFT;
89*4882a593Smuzhiyun struct resource *res;
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun if (!(md->attribute & EFI_MEMORY_SP))
92*4882a593Smuzhiyun continue;
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun res = kzalloc(sizeof(*res), GFP_KERNEL);
95*4882a593Smuzhiyun if (WARN_ON(!res))
96*4882a593Smuzhiyun break;
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun res->start = md->phys_addr;
99*4882a593Smuzhiyun res->end = md->phys_addr + md_size - 1;
100*4882a593Smuzhiyun res->name = "Soft Reserved";
101*4882a593Smuzhiyun res->flags = IORESOURCE_MEM;
102*4882a593Smuzhiyun res->desc = IORES_DESC_SOFT_RESERVED;
103*4882a593Smuzhiyun
104*4882a593Smuzhiyun insert_resource(&iomem_resource, res);
105*4882a593Smuzhiyun }
106*4882a593Smuzhiyun }
107*4882a593Smuzhiyun
108*4882a593Smuzhiyun if (efi_runtime_disabled()) {
109*4882a593Smuzhiyun pr_info("EFI runtime services will be disabled.\n");
110*4882a593Smuzhiyun return 0;
111*4882a593Smuzhiyun }
112*4882a593Smuzhiyun
113*4882a593Smuzhiyun if (efi_enabled(EFI_RUNTIME_SERVICES)) {
114*4882a593Smuzhiyun pr_info("EFI runtime services access via paravirt.\n");
115*4882a593Smuzhiyun return 0;
116*4882a593Smuzhiyun }
117*4882a593Smuzhiyun
118*4882a593Smuzhiyun pr_info("Remapping and enabling EFI services.\n");
119*4882a593Smuzhiyun
120*4882a593Smuzhiyun if (!efi_virtmap_init()) {
121*4882a593Smuzhiyun pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
122*4882a593Smuzhiyun return -ENOMEM;
123*4882a593Smuzhiyun }
124*4882a593Smuzhiyun
125*4882a593Smuzhiyun /* Set up runtime services function pointers */
126*4882a593Smuzhiyun efi_native_runtime_setup();
127*4882a593Smuzhiyun set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
128*4882a593Smuzhiyun
129*4882a593Smuzhiyun return 0;
130*4882a593Smuzhiyun }
131*4882a593Smuzhiyun early_initcall(riscv_enable_runtime_services);
132*4882a593Smuzhiyun
efi_virtmap_load(void)133*4882a593Smuzhiyun void efi_virtmap_load(void)
134*4882a593Smuzhiyun {
135*4882a593Smuzhiyun preempt_disable();
136*4882a593Smuzhiyun switch_mm(current->active_mm, &efi_mm, NULL);
137*4882a593Smuzhiyun }
138*4882a593Smuzhiyun
efi_virtmap_unload(void)139*4882a593Smuzhiyun void efi_virtmap_unload(void)
140*4882a593Smuzhiyun {
141*4882a593Smuzhiyun switch_mm(&efi_mm, current->active_mm, NULL);
142*4882a593Smuzhiyun preempt_enable();
143*4882a593Smuzhiyun }
144