1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ARM64 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
13 #define pr_fmt(fmt) "ACPI: " fmt
14
15 #include <linux/acpi.h>
16 #include <linux/cpumask.h>
17 #include <linux/efi.h>
18 #include <linux/efi-bgrt.h>
19 #include <linux/init.h>
20 #include <linux/irq.h>
21 #include <linux/irqdomain.h>
22 #include <linux/irq_work.h>
23 #include <linux/memblock.h>
24 #include <linux/of_fdt.h>
25 #include <linux/smp.h>
26 #include <linux/serial_core.h>
27
28 #include <acpi/ghes.h>
29 #include <asm/cputype.h>
30 #include <asm/cpu_ops.h>
31 #include <asm/daifflags.h>
32 #include <asm/pgtable.h>
33 #include <asm/smp_plat.h>
34
35 int acpi_noirq = 1; /* skip ACPI IRQ initialization */
36 int acpi_disabled = 1;
37 EXPORT_SYMBOL(acpi_disabled);
38
39 int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
40 EXPORT_SYMBOL(acpi_pci_disabled);
41
42 static bool param_acpi_off __initdata;
43 static bool param_acpi_on __initdata;
44 static bool param_acpi_force __initdata;
45
parse_acpi(char * arg)46 static int __init parse_acpi(char *arg)
47 {
48 if (!arg)
49 return -EINVAL;
50
51 /* "acpi=off" disables both ACPI table parsing and interpreter */
52 if (strcmp(arg, "off") == 0)
53 param_acpi_off = true;
54 else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
55 param_acpi_on = true;
56 else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
57 param_acpi_force = true;
58 else
59 return -EINVAL; /* Core will print when we return error */
60
61 return 0;
62 }
63 early_param("acpi", parse_acpi);
64
dt_scan_depth1_nodes(unsigned long node,const char * uname,int depth,void * data)65 static int __init dt_scan_depth1_nodes(unsigned long node,
66 const char *uname, int depth,
67 void *data)
68 {
69 /*
70 * Ignore anything not directly under the root node; we'll
71 * catch its parent instead.
72 */
73 if (depth != 1)
74 return 0;
75
76 if (strcmp(uname, "chosen") == 0)
77 return 0;
78
79 if (strcmp(uname, "hypervisor") == 0 &&
80 of_flat_dt_is_compatible(node, "xen,xen"))
81 return 0;
82
83 /*
84 * This node at depth 1 is neither a chosen node nor a xen node,
85 * which we do not expect.
86 */
87 return 1;
88 }
89
90 /*
91 * __acpi_map_table() will be called before page_init(), so early_ioremap()
92 * or early_memremap() should be called here to for ACPI table mapping.
93 */
__acpi_map_table(unsigned long phys,unsigned long size)94 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
95 {
96 if (!size)
97 return NULL;
98
99 return early_memremap(phys, size);
100 }
101
__acpi_unmap_table(void __iomem * map,unsigned long size)102 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
103 {
104 if (!map || !size)
105 return;
106
107 early_memunmap(map, size);
108 }
109
acpi_psci_present(void)110 bool __init acpi_psci_present(void)
111 {
112 return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
113 }
114
115 /* Whether HVC must be used instead of SMC as the PSCI conduit */
acpi_psci_use_hvc(void)116 bool acpi_psci_use_hvc(void)
117 {
118 return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
119 }
120
121 /*
122 * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
123 * checks on it
124 *
125 * Return 0 on success, <0 on failure
126 */
acpi_fadt_sanity_check(void)127 static int __init acpi_fadt_sanity_check(void)
128 {
129 struct acpi_table_header *table;
130 struct acpi_table_fadt *fadt;
131 acpi_status status;
132 int ret = 0;
133
134 /*
135 * FADT is required on arm64; retrieve it to check its presence
136 * and carry out revision and ACPI HW reduced compliancy tests
137 */
138 status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
139 if (ACPI_FAILURE(status)) {
140 const char *msg = acpi_format_exception(status);
141
142 pr_err("Failed to get FADT table, %s\n", msg);
143 return -ENODEV;
144 }
145
146 fadt = (struct acpi_table_fadt *)table;
147
148 /*
149 * Revision in table header is the FADT Major revision, and there
150 * is a minor revision of FADT which was introduced by ACPI 5.1,
151 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
152 * boot protocol configuration data.
153 */
154 if (table->revision < 5 ||
155 (table->revision == 5 && fadt->minor_revision < 1)) {
156 pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 5.1+\n",
157 table->revision, fadt->minor_revision);
158
159 if (!fadt->arm_boot_flags) {
160 ret = -EINVAL;
161 goto out;
162 }
163 pr_err("FADT has ARM boot flags set, assuming 5.1\n");
164 }
165
166 if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
167 pr_err("FADT not ACPI hardware reduced compliant\n");
168 ret = -EINVAL;
169 }
170
171 out:
172 /*
173 * acpi_get_table() creates FADT table mapping that
174 * should be released after parsing and before resuming boot
175 */
176 acpi_put_table(table);
177 return ret;
178 }
179
180 /*
181 * acpi_boot_table_init() called from setup_arch(), always.
182 * 1. find RSDP and get its address, and then find XSDT
183 * 2. extract all tables and checksums them all
184 * 3. check ACPI FADT revision
185 * 4. check ACPI FADT HW reduced flag
186 *
187 * We can parse ACPI boot-time tables such as MADT after
188 * this function is called.
189 *
190 * On return ACPI is enabled if either:
191 *
192 * - ACPI tables are initialized and sanity checks passed
193 * - acpi=force was passed in the command line and ACPI was not disabled
194 * explicitly through acpi=off command line parameter
195 *
196 * ACPI is disabled on function return otherwise
197 */
acpi_boot_table_init(void)198 void __init acpi_boot_table_init(void)
199 {
200 /*
201 * Enable ACPI instead of device tree unless
202 * - ACPI has been disabled explicitly (acpi=off), or
203 * - the device tree is not empty (it has more than just a /chosen node,
204 * and a /hypervisor node when running on Xen)
205 * and ACPI has not been [force] enabled (acpi=on|force)
206 */
207 if (param_acpi_off ||
208 (!param_acpi_on && !param_acpi_force &&
209 of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
210 goto done;
211
212 /*
213 * ACPI is disabled at this point. Enable it in order to parse
214 * the ACPI tables and carry out sanity checks
215 */
216 enable_acpi();
217
218 /*
219 * If ACPI tables are initialized and FADT sanity checks passed,
220 * leave ACPI enabled and carry on booting; otherwise disable ACPI
221 * on initialization error.
222 * If acpi=force was passed on the command line it forces ACPI
223 * to be enabled even if its initialization failed.
224 */
225 if (acpi_table_init() || acpi_fadt_sanity_check()) {
226 pr_err("Failed to init ACPI tables\n");
227 if (!param_acpi_force)
228 disable_acpi();
229 }
230
231 done:
232 if (acpi_disabled) {
233 if (earlycon_acpi_spcr_enable)
234 early_init_dt_scan_chosen_stdout();
235 } else {
236 acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
237 if (IS_ENABLED(CONFIG_ACPI_BGRT))
238 acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
239 }
240 }
241
__acpi_get_mem_attribute(phys_addr_t addr)242 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
243 {
244 /*
245 * According to "Table 8 Map: EFI memory types to AArch64 memory
246 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
247 * mapped to a corresponding MAIR attribute encoding.
248 * The EFI memory attribute advises all possible capabilities
249 * of a memory region. We use the most efficient capability.
250 */
251
252 u64 attr;
253
254 attr = efi_mem_attributes(addr);
255 if (attr & EFI_MEMORY_WB)
256 return PAGE_KERNEL;
257 if (attr & EFI_MEMORY_WT)
258 return __pgprot(PROT_NORMAL_WT);
259 if (attr & EFI_MEMORY_WC)
260 return __pgprot(PROT_NORMAL_NC);
261 return __pgprot(PROT_DEVICE_nGnRnE);
262 }
263
264 /*
265 * Claim Synchronous External Aborts as a firmware first notification.
266 *
267 * Used by KVM and the arch do_sea handler.
268 * @regs may be NULL when called from process context.
269 */
apei_claim_sea(struct pt_regs * regs)270 int apei_claim_sea(struct pt_regs *regs)
271 {
272 int err = -ENOENT;
273 bool return_to_irqs_enabled;
274 unsigned long current_flags;
275
276 if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
277 return err;
278
279 current_flags = local_daif_save_flags();
280
281 /* current_flags isn't useful here as daif doesn't tell us about pNMI */
282 return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags());
283
284 if (regs)
285 return_to_irqs_enabled = interrupts_enabled(regs);
286
287 /*
288 * SEA can interrupt SError, mask it and describe this as an NMI so
289 * that APEI defers the handling.
290 */
291 local_daif_restore(DAIF_ERRCTX);
292 nmi_enter();
293 err = ghes_notify_sea();
294 nmi_exit();
295
296 /*
297 * APEI NMI-like notifications are deferred to irq_work. Unless
298 * we interrupted irqs-masked code, we can do that now.
299 */
300 if (!err) {
301 if (return_to_irqs_enabled) {
302 local_daif_restore(DAIF_PROCCTX_NOIRQ);
303 __irq_enter();
304 irq_work_run();
305 __irq_exit();
306 } else {
307 pr_warn_ratelimited("APEI work queued but not completed");
308 err = -EINPROGRESS;
309 }
310 }
311
312 local_daif_restore(current_flags);
313
314 return err;
315 }
316