xref: /openbmc/linux/arch/arm64/kernel/acpi.c (revision 81de3bf3)
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/memblock.h>
23 #include <linux/of_fdt.h>
24 #include <linux/smp.h>
25 #include <linux/serial_core.h>
26 
27 #include <acpi/ghes.h>
28 #include <asm/cputype.h>
29 #include <asm/cpu_ops.h>
30 #include <asm/daifflags.h>
31 #include <asm/pgtable.h>
32 #include <asm/smp_plat.h>
33 
34 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
35 int acpi_disabled = 1;
36 EXPORT_SYMBOL(acpi_disabled);
37 
38 int acpi_pci_disabled = 1;	/* skip ACPI PCI scan and IRQ initialization */
39 EXPORT_SYMBOL(acpi_pci_disabled);
40 
41 static bool param_acpi_off __initdata;
42 static bool param_acpi_on __initdata;
43 static bool param_acpi_force __initdata;
44 
45 static int __init parse_acpi(char *arg)
46 {
47 	if (!arg)
48 		return -EINVAL;
49 
50 	/* "acpi=off" disables both ACPI table parsing and interpreter */
51 	if (strcmp(arg, "off") == 0)
52 		param_acpi_off = true;
53 	else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
54 		param_acpi_on = true;
55 	else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
56 		param_acpi_force = true;
57 	else
58 		return -EINVAL;	/* Core will print when we return error */
59 
60 	return 0;
61 }
62 early_param("acpi", parse_acpi);
63 
64 static int __init dt_scan_depth1_nodes(unsigned long node,
65 				       const char *uname, int depth,
66 				       void *data)
67 {
68 	/*
69 	 * Ignore anything not directly under the root node; we'll
70 	 * catch its parent instead.
71 	 */
72 	if (depth != 1)
73 		return 0;
74 
75 	if (strcmp(uname, "chosen") == 0)
76 		return 0;
77 
78 	if (strcmp(uname, "hypervisor") == 0 &&
79 	    of_flat_dt_is_compatible(node, "xen,xen"))
80 		return 0;
81 
82 	/*
83 	 * This node at depth 1 is neither a chosen node nor a xen node,
84 	 * which we do not expect.
85 	 */
86 	return 1;
87 }
88 
89 /*
90  * __acpi_map_table() will be called before page_init(), so early_ioremap()
91  * or early_memremap() should be called here to for ACPI table mapping.
92  */
93 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
94 {
95 	if (!size)
96 		return NULL;
97 
98 	return early_memremap(phys, size);
99 }
100 
101 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
102 {
103 	if (!map || !size)
104 		return;
105 
106 	early_memunmap(map, size);
107 }
108 
109 bool __init acpi_psci_present(void)
110 {
111 	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
112 }
113 
114 /* Whether HVC must be used instead of SMC as the PSCI conduit */
115 bool acpi_psci_use_hvc(void)
116 {
117 	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
118 }
119 
120 /*
121  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
122  *			      checks on it
123  *
124  * Return 0 on success,  <0 on failure
125  */
126 static int __init acpi_fadt_sanity_check(void)
127 {
128 	struct acpi_table_header *table;
129 	struct acpi_table_fadt *fadt;
130 	acpi_status status;
131 	int ret = 0;
132 
133 	/*
134 	 * FADT is required on arm64; retrieve it to check its presence
135 	 * and carry out revision and ACPI HW reduced compliancy tests
136 	 */
137 	status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
138 	if (ACPI_FAILURE(status)) {
139 		const char *msg = acpi_format_exception(status);
140 
141 		pr_err("Failed to get FADT table, %s\n", msg);
142 		return -ENODEV;
143 	}
144 
145 	fadt = (struct acpi_table_fadt *)table;
146 
147 	/*
148 	 * Revision in table header is the FADT Major revision, and there
149 	 * is a minor revision of FADT which was introduced by ACPI 5.1,
150 	 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
151 	 * boot protocol configuration data.
152 	 */
153 	if (table->revision < 5 ||
154 	   (table->revision == 5 && fadt->minor_revision < 1)) {
155 		pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 5.1+\n",
156 		       table->revision, fadt->minor_revision);
157 
158 		if (!fadt->arm_boot_flags) {
159 			ret = -EINVAL;
160 			goto out;
161 		}
162 		pr_err("FADT has ARM boot flags set, assuming 5.1\n");
163 	}
164 
165 	if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
166 		pr_err("FADT not ACPI hardware reduced compliant\n");
167 		ret = -EINVAL;
168 	}
169 
170 out:
171 	/*
172 	 * acpi_get_table() creates FADT table mapping that
173 	 * should be released after parsing and before resuming boot
174 	 */
175 	acpi_put_table(table);
176 	return ret;
177 }
178 
179 /*
180  * acpi_boot_table_init() called from setup_arch(), always.
181  *	1. find RSDP and get its address, and then find XSDT
182  *	2. extract all tables and checksums them all
183  *	3. check ACPI FADT revision
184  *	4. check ACPI FADT HW reduced flag
185  *
186  * We can parse ACPI boot-time tables such as MADT after
187  * this function is called.
188  *
189  * On return ACPI is enabled if either:
190  *
191  * - ACPI tables are initialized and sanity checks passed
192  * - acpi=force was passed in the command line and ACPI was not disabled
193  *   explicitly through acpi=off command line parameter
194  *
195  * ACPI is disabled on function return otherwise
196  */
197 void __init acpi_boot_table_init(void)
198 {
199 	/*
200 	 * Enable ACPI instead of device tree unless
201 	 * - ACPI has been disabled explicitly (acpi=off), or
202 	 * - the device tree is not empty (it has more than just a /chosen node,
203 	 *   and a /hypervisor node when running on Xen)
204 	 *   and ACPI has not been [force] enabled (acpi=on|force)
205 	 */
206 	if (param_acpi_off ||
207 	    (!param_acpi_on && !param_acpi_force &&
208 	     of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
209 		goto done;
210 
211 	/*
212 	 * ACPI is disabled at this point. Enable it in order to parse
213 	 * the ACPI tables and carry out sanity checks
214 	 */
215 	enable_acpi();
216 
217 	/*
218 	 * If ACPI tables are initialized and FADT sanity checks passed,
219 	 * leave ACPI enabled and carry on booting; otherwise disable ACPI
220 	 * on initialization error.
221 	 * If acpi=force was passed on the command line it forces ACPI
222 	 * to be enabled even if its initialization failed.
223 	 */
224 	if (acpi_table_init() || acpi_fadt_sanity_check()) {
225 		pr_err("Failed to init ACPI tables\n");
226 		if (!param_acpi_force)
227 			disable_acpi();
228 	}
229 
230 done:
231 	if (acpi_disabled) {
232 		if (earlycon_acpi_spcr_enable)
233 			early_init_dt_scan_chosen_stdout();
234 	} else {
235 		acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
236 		if (IS_ENABLED(CONFIG_ACPI_BGRT))
237 			acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
238 	}
239 }
240 
241 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr)
242 {
243 	/*
244 	 * According to "Table 8 Map: EFI memory types to AArch64 memory
245 	 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
246 	 * mapped to a corresponding MAIR attribute encoding.
247 	 * The EFI memory attribute advises all possible capabilities
248 	 * of a memory region. We use the most efficient capability.
249 	 */
250 
251 	u64 attr;
252 
253 	attr = efi_mem_attributes(addr);
254 	if (attr & EFI_MEMORY_WB)
255 		return PAGE_KERNEL;
256 	if (attr & EFI_MEMORY_WT)
257 		return __pgprot(PROT_NORMAL_WT);
258 	if (attr & EFI_MEMORY_WC)
259 		return __pgprot(PROT_NORMAL_NC);
260 	return __pgprot(PROT_DEVICE_nGnRnE);
261 }
262 
263 /*
264  * Claim Synchronous External Aborts as a firmware first notification.
265  *
266  * Used by KVM and the arch do_sea handler.
267  * @regs may be NULL when called from process context.
268  */
269 int apei_claim_sea(struct pt_regs *regs)
270 {
271 	int err = -ENOENT;
272 	unsigned long current_flags;
273 
274 	if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
275 		return err;
276 
277 	current_flags = arch_local_save_flags();
278 
279 	/*
280 	 * SEA can interrupt SError, mask it and describe this as an NMI so
281 	 * that APEI defers the handling.
282 	 */
283 	local_daif_restore(DAIF_ERRCTX);
284 	nmi_enter();
285 	err = ghes_notify_sea();
286 	nmi_exit();
287 	local_daif_restore(current_flags);
288 
289 	return err;
290 }
291