1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * RISC-V Specific Low-Level ACPI Boot Support
4 *
5 * Copyright (C) 2013-2014, Linaro Ltd.
6 * Author: Al Stone <al.stone@linaro.org>
7 * Author: Graeme Gregory <graeme.gregory@linaro.org>
8 * Author: Hanjun Guo <hanjun.guo@linaro.org>
9 * Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
10 * Author: Naresh Bhat <naresh.bhat@linaro.org>
11 *
12 * Copyright (C) 2021-2023, Ventana Micro Systems Inc.
13 * Author: Sunil V L <sunilvl@ventanamicro.com>
14 */
15
16 #include <linux/acpi.h>
17 #include <linux/io.h>
18 #include <linux/pci.h>
19 #include <linux/efi.h>
20
21 int acpi_noirq = 1; /* skip ACPI IRQ initialization */
22 int acpi_disabled = 1;
23 EXPORT_SYMBOL(acpi_disabled);
24
25 int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
26 EXPORT_SYMBOL(acpi_pci_disabled);
27
28 static bool param_acpi_off __initdata;
29 static bool param_acpi_on __initdata;
30 static bool param_acpi_force __initdata;
31
32 static struct acpi_madt_rintc cpu_madt_rintc[NR_CPUS];
33
parse_acpi(char * arg)34 static int __init parse_acpi(char *arg)
35 {
36 if (!arg)
37 return -EINVAL;
38
39 /* "acpi=off" disables both ACPI table parsing and interpreter */
40 if (strcmp(arg, "off") == 0)
41 param_acpi_off = true;
42 else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
43 param_acpi_on = true;
44 else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
45 param_acpi_force = true;
46 else
47 return -EINVAL; /* Core will print when we return error */
48
49 return 0;
50 }
51 early_param("acpi", parse_acpi);
52
53 /*
54 * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
55 * checks on it
56 *
57 * Return 0 on success, <0 on failure
58 */
acpi_fadt_sanity_check(void)59 static int __init acpi_fadt_sanity_check(void)
60 {
61 struct acpi_table_header *table;
62 struct acpi_table_fadt *fadt;
63 acpi_status status;
64 int ret = 0;
65
66 /*
67 * FADT is required on riscv; retrieve it to check its presence
68 * and carry out revision and ACPI HW reduced compliancy tests
69 */
70 status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
71 if (ACPI_FAILURE(status)) {
72 const char *msg = acpi_format_exception(status);
73
74 pr_err("Failed to get FADT table, %s\n", msg);
75 return -ENODEV;
76 }
77
78 fadt = (struct acpi_table_fadt *)table;
79
80 /*
81 * The revision in the table header is the FADT's Major revision. The
82 * FADT also has a minor revision, which is stored in the FADT itself.
83 *
84 * TODO: Currently, we check for 6.5 as the minimum version to check
85 * for HW_REDUCED flag. However, once RISC-V updates are released in
86 * the ACPI spec, we need to update this check for exact minor revision
87 */
88 if (table->revision < 6 || (table->revision == 6 && fadt->minor_revision < 5))
89 pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 6.5+\n",
90 table->revision, fadt->minor_revision);
91
92 if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
93 pr_err("FADT not ACPI hardware reduced compliant\n");
94 ret = -EINVAL;
95 }
96
97 /*
98 * acpi_get_table() creates FADT table mapping that
99 * should be released after parsing and before resuming boot
100 */
101 acpi_put_table(table);
102 return ret;
103 }
104
105 /*
106 * acpi_boot_table_init() called from setup_arch(), always.
107 * 1. find RSDP and get its address, and then find XSDT
108 * 2. extract all tables and checksums them all
109 * 3. check ACPI FADT HW reduced flag
110 *
111 * We can parse ACPI boot-time tables such as MADT after
112 * this function is called.
113 *
114 * On return ACPI is enabled if either:
115 *
116 * - ACPI tables are initialized and sanity checks passed
117 * - acpi=force was passed in the command line and ACPI was not disabled
118 * explicitly through acpi=off command line parameter
119 *
120 * ACPI is disabled on function return otherwise
121 */
acpi_boot_table_init(void)122 void __init acpi_boot_table_init(void)
123 {
124 /*
125 * Enable ACPI instead of device tree unless
126 * - ACPI has been disabled explicitly (acpi=off), or
127 * - firmware has not populated ACPI ptr in EFI system table
128 * and ACPI has not been [force] enabled (acpi=on|force)
129 */
130 if (param_acpi_off ||
131 (!param_acpi_on && !param_acpi_force &&
132 efi.acpi20 == EFI_INVALID_TABLE_ADDR))
133 return;
134
135 /*
136 * ACPI is disabled at this point. Enable it in order to parse
137 * the ACPI tables and carry out sanity checks
138 */
139 enable_acpi();
140
141 /*
142 * If ACPI tables are initialized and FADT sanity checks passed,
143 * leave ACPI enabled and carry on booting; otherwise disable ACPI
144 * on initialization error.
145 * If acpi=force was passed on the command line it forces ACPI
146 * to be enabled even if its initialization failed.
147 */
148 if (acpi_table_init() || acpi_fadt_sanity_check()) {
149 pr_err("Failed to init ACPI tables\n");
150 if (!param_acpi_force)
151 disable_acpi();
152 }
153 }
154
acpi_parse_madt_rintc(union acpi_subtable_headers * header,const unsigned long end)155 static int acpi_parse_madt_rintc(union acpi_subtable_headers *header, const unsigned long end)
156 {
157 struct acpi_madt_rintc *rintc = (struct acpi_madt_rintc *)header;
158 int cpuid;
159
160 if (!(rintc->flags & ACPI_MADT_ENABLED))
161 return 0;
162
163 cpuid = riscv_hartid_to_cpuid(rintc->hart_id);
164 /*
165 * When CONFIG_SMP is disabled, mapping won't be created for
166 * all cpus.
167 * CPUs more than num_possible_cpus, will be ignored.
168 */
169 if (cpuid >= 0 && cpuid < num_possible_cpus())
170 cpu_madt_rintc[cpuid] = *rintc;
171
172 return 0;
173 }
174
175 /*
176 * Instead of parsing (and freeing) the ACPI table, cache
177 * the RINTC structures since they are frequently used
178 * like in cpuinfo.
179 */
acpi_init_rintc_map(void)180 void __init acpi_init_rintc_map(void)
181 {
182 if (acpi_table_parse_madt(ACPI_MADT_TYPE_RINTC, acpi_parse_madt_rintc, 0) <= 0) {
183 pr_err("No valid RINTC entries exist\n");
184 BUG();
185 }
186 }
187
acpi_cpu_get_madt_rintc(int cpu)188 struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu)
189 {
190 return &cpu_madt_rintc[cpu];
191 }
192
get_acpi_id_for_cpu(int cpu)193 u32 get_acpi_id_for_cpu(int cpu)
194 {
195 return acpi_cpu_get_madt_rintc(cpu)->uid;
196 }
197
198 /*
199 * __acpi_map_table() will be called before paging_init(), so early_ioremap()
200 * or early_memremap() should be called here to for ACPI table mapping.
201 */
__acpi_map_table(unsigned long phys,unsigned long size)202 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
203 {
204 if (!size)
205 return NULL;
206
207 return early_memremap(phys, size);
208 }
209
__acpi_unmap_table(void __iomem * map,unsigned long size)210 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
211 {
212 if (!map || !size)
213 return;
214
215 early_memunmap(map, size);
216 }
217
acpi_os_ioremap(acpi_physical_address phys,acpi_size size)218 void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
219 {
220 return (void __iomem *)memremap(phys, size, MEMREMAP_WB);
221 }
222
223 #ifdef CONFIG_PCI
224
225 /*
226 * These interfaces are defined just to enable building ACPI core.
227 * TODO: Update it with actual implementation when external interrupt
228 * controller support is added in RISC-V ACPI.
229 */
raw_pci_read(unsigned int domain,unsigned int bus,unsigned int devfn,int reg,int len,u32 * val)230 int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
231 int reg, int len, u32 *val)
232 {
233 return PCIBIOS_DEVICE_NOT_FOUND;
234 }
235
raw_pci_write(unsigned int domain,unsigned int bus,unsigned int devfn,int reg,int len,u32 val)236 int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
237 int reg, int len, u32 val)
238 {
239 return PCIBIOS_DEVICE_NOT_FOUND;
240 }
241
acpi_pci_bus_find_domain_nr(struct pci_bus * bus)242 int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
243 {
244 return -1;
245 }
246
pci_acpi_scan_root(struct acpi_pci_root * root)247 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
248 {
249 return NULL;
250 }
251 #endif /* CONFIG_PCI */
252