1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) 2015 Google, Inc
4 * Written by Simon Glass <sjg@chromium.org>
5 */
6
7 /*
8 * Intel Simple Firmware Interface (SFI)
9 *
10 * Yet another way to pass information to the Linux kernel.
11 *
12 * See https://simplefirmware.org/ for details
13 */
14
15 #include <common.h>
16 #include <cpu.h>
17 #include <dm.h>
18 #include <asm/cpu.h>
19 #include <asm/ioapic.h>
20 #include <asm/sfi.h>
21 #include <asm/tables.h>
22 #include <dm/uclass-internal.h>
23
24 struct table_info {
25 u32 base;
26 int ptr;
27 u32 entry_start;
28 u64 table[SFI_TABLE_MAX_ENTRIES];
29 int count;
30 };
31
get_entry_start(struct table_info * tab)32 static void *get_entry_start(struct table_info *tab)
33 {
34 if (tab->count == SFI_TABLE_MAX_ENTRIES)
35 return NULL;
36 tab->entry_start = tab->base + tab->ptr;
37 tab->table[tab->count] = tab->entry_start;
38 tab->entry_start += sizeof(struct sfi_table_header);
39
40 return (void *)(uintptr_t)tab->entry_start;
41 }
42
finish_table(struct table_info * tab,const char * sig,void * entry)43 static void finish_table(struct table_info *tab, const char *sig, void *entry)
44 {
45 struct sfi_table_header *hdr;
46
47 hdr = (struct sfi_table_header *)(uintptr_t)(tab->base + tab->ptr);
48 strcpy(hdr->sig, sig);
49 hdr->len = sizeof(*hdr) + ((ulong)entry - tab->entry_start);
50 hdr->rev = 1;
51 strncpy(hdr->oem_id, "U-Boot", SFI_OEM_ID_SIZE);
52 strncpy(hdr->oem_table_id, "Table v1", SFI_OEM_TABLE_ID_SIZE);
53 hdr->csum = 0;
54 hdr->csum = table_compute_checksum(hdr, hdr->len);
55 tab->ptr += hdr->len;
56 tab->ptr = ALIGN(tab->ptr, 16);
57 tab->count++;
58 }
59
sfi_write_system_header(struct table_info * tab)60 static int sfi_write_system_header(struct table_info *tab)
61 {
62 u64 *entry = get_entry_start(tab);
63 int i;
64
65 if (!entry)
66 return -ENOSPC;
67
68 for (i = 0; i < tab->count; i++)
69 *entry++ = tab->table[i];
70 finish_table(tab, SFI_SIG_SYST, entry);
71
72 return 0;
73 }
74
sfi_write_cpus(struct table_info * tab)75 static int sfi_write_cpus(struct table_info *tab)
76 {
77 struct sfi_cpu_table_entry *entry = get_entry_start(tab);
78 struct udevice *dev;
79 int count = 0;
80
81 if (!entry)
82 return -ENOSPC;
83
84 for (uclass_find_first_device(UCLASS_CPU, &dev);
85 dev;
86 uclass_find_next_device(&dev)) {
87 struct cpu_platdata *plat = dev_get_parent_platdata(dev);
88
89 if (!device_active(dev))
90 continue;
91 entry->apic_id = plat->cpu_id;
92 entry++;
93 count++;
94 }
95
96 /* Omit the table if there is only one CPU */
97 if (count > 1)
98 finish_table(tab, SFI_SIG_CPUS, entry);
99
100 return 0;
101 }
102
sfi_write_apic(struct table_info * tab)103 static int sfi_write_apic(struct table_info *tab)
104 {
105 struct sfi_apic_table_entry *entry = get_entry_start(tab);
106
107 if (!entry)
108 return -ENOSPC;
109
110 entry->phys_addr = IO_APIC_ADDR;
111 entry++;
112 finish_table(tab, SFI_SIG_APIC, entry);
113
114 return 0;
115 }
116
sfi_write_xsdt(struct table_info * tab)117 static int sfi_write_xsdt(struct table_info *tab)
118 {
119 struct sfi_xsdt_header *entry = get_entry_start(tab);
120
121 if (!entry)
122 return -ENOSPC;
123
124 entry->oem_revision = 1;
125 entry->creator_id = 1;
126 entry->creator_revision = 1;
127 entry++;
128 finish_table(tab, SFI_SIG_XSDT, entry);
129
130 return 0;
131 }
132
write_sfi_table(ulong base)133 ulong write_sfi_table(ulong base)
134 {
135 struct table_info table;
136
137 table.base = base;
138 table.ptr = 0;
139 table.count = 0;
140 sfi_write_cpus(&table);
141 sfi_write_apic(&table);
142
143 /*
144 * The SFI specification marks the XSDT table as option, but Linux 4.0
145 * crashes on start-up when it is not provided.
146 */
147 sfi_write_xsdt(&table);
148
149 /* Finally, write out the system header which points to the others */
150 sfi_write_system_header(&table);
151
152 return base + table.ptr;
153 }
154