xref: /openbmc/linux/arch/arm64/kernel/acpi.c (revision 2359ccdd)
1 /*
2  *  ARM64 Specific Low-Level ACPI Boot Support
3  *
4  *  Copyright (C) 2013-2014, Linaro Ltd.
5  *	Author: Al Stone <al.stone@linaro.org>
6  *	Author: Graeme Gregory <graeme.gregory@linaro.org>
7  *	Author: Hanjun Guo <hanjun.guo@linaro.org>
8  *	Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
9  *	Author: Naresh Bhat <naresh.bhat@linaro.org>
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License version 2 as
13  *  published by the Free Software Foundation.
14  */
15 
16 #define pr_fmt(fmt) "ACPI: " fmt
17 
18 #include <linux/acpi.h>
19 #include <linux/bootmem.h>
20 #include <linux/cpumask.h>
21 #include <linux/efi-bgrt.h>
22 #include <linux/init.h>
23 #include <linux/irq.h>
24 #include <linux/irqdomain.h>
25 #include <linux/memblock.h>
26 #include <linux/of_fdt.h>
27 #include <linux/smp.h>
28 #include <linux/serial_core.h>
29 
30 #include <asm/cputype.h>
31 #include <asm/cpu_ops.h>
32 #include <asm/smp_plat.h>
33 
34 #ifdef CONFIG_ACPI_APEI
35 # include <linux/efi.h>
36 # include <asm/pgtable.h>
37 #endif
38 
39 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
40 int acpi_disabled = 1;
41 EXPORT_SYMBOL(acpi_disabled);
42 
43 int acpi_pci_disabled = 1;	/* skip ACPI PCI scan and IRQ initialization */
44 EXPORT_SYMBOL(acpi_pci_disabled);
45 
46 static bool param_acpi_off __initdata;
47 static bool param_acpi_on __initdata;
48 static bool param_acpi_force __initdata;
49 
50 static int __init parse_acpi(char *arg)
51 {
52 	if (!arg)
53 		return -EINVAL;
54 
55 	/* "acpi=off" disables both ACPI table parsing and interpreter */
56 	if (strcmp(arg, "off") == 0)
57 		param_acpi_off = true;
58 	else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
59 		param_acpi_on = true;
60 	else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
61 		param_acpi_force = true;
62 	else
63 		return -EINVAL;	/* Core will print when we return error */
64 
65 	return 0;
66 }
67 early_param("acpi", parse_acpi);
68 
69 static int __init dt_scan_depth1_nodes(unsigned long node,
70 				       const char *uname, int depth,
71 				       void *data)
72 {
73 	/*
74 	 * Ignore anything not directly under the root node; we'll
75 	 * catch its parent instead.
76 	 */
77 	if (depth != 1)
78 		return 0;
79 
80 	if (strcmp(uname, "chosen") == 0)
81 		return 0;
82 
83 	if (strcmp(uname, "hypervisor") == 0 &&
84 	    of_flat_dt_is_compatible(node, "xen,xen"))
85 		return 0;
86 
87 	/*
88 	 * This node at depth 1 is neither a chosen node nor a xen node,
89 	 * which we do not expect.
90 	 */
91 	return 1;
92 }
93 
94 /*
95  * __acpi_map_table() will be called before page_init(), so early_ioremap()
96  * or early_memremap() should be called here to for ACPI table mapping.
97  */
98 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
99 {
100 	if (!size)
101 		return NULL;
102 
103 	return early_memremap(phys, size);
104 }
105 
106 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
107 {
108 	if (!map || !size)
109 		return;
110 
111 	early_memunmap(map, size);
112 }
113 
114 bool __init acpi_psci_present(void)
115 {
116 	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
117 }
118 
119 /* Whether HVC must be used instead of SMC as the PSCI conduit */
120 bool acpi_psci_use_hvc(void)
121 {
122 	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
123 }
124 
125 /*
126  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
127  *			      checks on it
128  *
129  * Return 0 on success,  <0 on failure
130  */
131 static int __init acpi_fadt_sanity_check(void)
132 {
133 	struct acpi_table_header *table;
134 	struct acpi_table_fadt *fadt;
135 	acpi_status status;
136 	int ret = 0;
137 
138 	/*
139 	 * FADT is required on arm64; retrieve it to check its presence
140 	 * and carry out revision and ACPI HW reduced compliancy tests
141 	 */
142 	status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
143 	if (ACPI_FAILURE(status)) {
144 		const char *msg = acpi_format_exception(status);
145 
146 		pr_err("Failed to get FADT table, %s\n", msg);
147 		return -ENODEV;
148 	}
149 
150 	fadt = (struct acpi_table_fadt *)table;
151 
152 	/*
153 	 * Revision in table header is the FADT Major revision, and there
154 	 * is a minor revision of FADT which was introduced by ACPI 5.1,
155 	 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
156 	 * boot protocol configuration data.
157 	 */
158 	if (table->revision < 5 ||
159 	   (table->revision == 5 && fadt->minor_revision < 1)) {
160 		pr_err("Unsupported FADT revision %d.%d, should be 5.1+\n",
161 		       table->revision, fadt->minor_revision);
162 		ret = -EINVAL;
163 		goto out;
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  */
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 
242 #ifdef CONFIG_ACPI_APEI
243 pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
244 {
245 	/*
246 	 * According to "Table 8 Map: EFI memory types to AArch64 memory
247 	 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
248 	 * mapped to a corresponding MAIR attribute encoding.
249 	 * The EFI memory attribute advises all possible capabilities
250 	 * of a memory region. We use the most efficient capability.
251 	 */
252 
253 	u64 attr;
254 
255 	attr = efi_mem_attributes(addr);
256 	if (attr & EFI_MEMORY_WB)
257 		return PAGE_KERNEL;
258 	if (attr & EFI_MEMORY_WT)
259 		return __pgprot(PROT_NORMAL_WT);
260 	if (attr & EFI_MEMORY_WC)
261 		return __pgprot(PROT_NORMAL_NC);
262 	return __pgprot(PROT_DEVICE_nGnRnE);
263 }
264 #endif
265