xref: /openbmc/linux/arch/arm64/kernel/acpi.c (revision d7a3d85e)
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/init.h>
22 #include <linux/irq.h>
23 #include <linux/irqdomain.h>
24 #include <linux/memblock.h>
25 #include <linux/of_fdt.h>
26 #include <linux/smp.h>
27 
28 #include <asm/cputype.h>
29 #include <asm/cpu_ops.h>
30 #include <asm/smp_plat.h>
31 
32 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
33 int acpi_disabled = 1;
34 EXPORT_SYMBOL(acpi_disabled);
35 
36 int acpi_pci_disabled = 1;	/* skip ACPI PCI scan and IRQ initialization */
37 EXPORT_SYMBOL(acpi_pci_disabled);
38 
39 /* Processors with enabled flag and sane MPIDR */
40 static int enabled_cpus;
41 
42 /* Boot CPU is valid or not in MADT */
43 static bool bootcpu_valid  __initdata;
44 
45 static bool param_acpi_off __initdata;
46 static bool param_acpi_force __initdata;
47 
48 static int __init parse_acpi(char *arg)
49 {
50 	if (!arg)
51 		return -EINVAL;
52 
53 	/* "acpi=off" disables both ACPI table parsing and interpreter */
54 	if (strcmp(arg, "off") == 0)
55 		param_acpi_off = 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 
65 static int __init dt_scan_depth1_nodes(unsigned long node,
66 				       const char *uname, int depth,
67 				       void *data)
68 {
69 	/*
70 	 * Return 1 as soon as we encounter a node at depth 1 that is
71 	 * not the /chosen node.
72 	 */
73 	if (depth == 1 && (strcmp(uname, "chosen") != 0))
74 		return 1;
75 	return 0;
76 }
77 
78 /*
79  * __acpi_map_table() will be called before page_init(), so early_ioremap()
80  * or early_memremap() should be called here to for ACPI table mapping.
81  */
82 char *__init __acpi_map_table(unsigned long phys, unsigned long size)
83 {
84 	if (!size)
85 		return NULL;
86 
87 	return early_memremap(phys, size);
88 }
89 
90 void __init __acpi_unmap_table(char *map, unsigned long size)
91 {
92 	if (!map || !size)
93 		return;
94 
95 	early_memunmap(map, size);
96 }
97 
98 /**
99  * acpi_map_gic_cpu_interface - generates a logical cpu number
100  * and map to MPIDR represented by GICC structure
101  */
102 static void __init
103 acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
104 {
105 	int i;
106 	u64 mpidr = processor->arm_mpidr & MPIDR_HWID_BITMASK;
107 	bool enabled = !!(processor->flags & ACPI_MADT_ENABLED);
108 
109 	if (mpidr == INVALID_HWID) {
110 		pr_info("Skip MADT cpu entry with invalid MPIDR\n");
111 		return;
112 	}
113 
114 	total_cpus++;
115 	if (!enabled)
116 		return;
117 
118 	if (enabled_cpus >=  NR_CPUS) {
119 		pr_warn("NR_CPUS limit of %d reached, Processor %d/0x%llx ignored.\n",
120 			NR_CPUS, total_cpus, mpidr);
121 		return;
122 	}
123 
124 	/* Check if GICC structure of boot CPU is available in the MADT */
125 	if (cpu_logical_map(0) == mpidr) {
126 		if (bootcpu_valid) {
127 			pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
128 			       mpidr);
129 			return;
130 		}
131 
132 		bootcpu_valid = true;
133 	}
134 
135 	/*
136 	 * Duplicate MPIDRs are a recipe for disaster. Scan
137 	 * all initialized entries and check for
138 	 * duplicates. If any is found just ignore the CPU.
139 	 */
140 	for (i = 1; i < enabled_cpus; i++) {
141 		if (cpu_logical_map(i) == mpidr) {
142 			pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
143 			       mpidr);
144 			return;
145 		}
146 	}
147 
148 	if (!acpi_psci_present())
149 		return;
150 
151 	cpu_ops[enabled_cpus] = cpu_get_ops("psci");
152 	/* CPU 0 was already initialized */
153 	if (enabled_cpus) {
154 		if (!cpu_ops[enabled_cpus])
155 			return;
156 
157 		if (cpu_ops[enabled_cpus]->cpu_init(NULL, enabled_cpus))
158 			return;
159 
160 		/* map the logical cpu id to cpu MPIDR */
161 		cpu_logical_map(enabled_cpus) = mpidr;
162 	}
163 
164 	enabled_cpus++;
165 }
166 
167 static int __init
168 acpi_parse_gic_cpu_interface(struct acpi_subtable_header *header,
169 				const unsigned long end)
170 {
171 	struct acpi_madt_generic_interrupt *processor;
172 
173 	processor = (struct acpi_madt_generic_interrupt *)header;
174 
175 	if (BAD_MADT_ENTRY(processor, end))
176 		return -EINVAL;
177 
178 	acpi_table_print_madt_entry(header);
179 	acpi_map_gic_cpu_interface(processor);
180 	return 0;
181 }
182 
183 /* Parse GIC cpu interface entries in MADT for SMP init */
184 void __init acpi_init_cpus(void)
185 {
186 	int count, i;
187 
188 	/*
189 	 * do a partial walk of MADT to determine how many CPUs
190 	 * we have including disabled CPUs, and get information
191 	 * we need for SMP init
192 	 */
193 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
194 			acpi_parse_gic_cpu_interface, 0);
195 
196 	if (!count) {
197 		pr_err("No GIC CPU interface entries present\n");
198 		return;
199 	} else if (count < 0) {
200 		pr_err("Error parsing GIC CPU interface entry\n");
201 		return;
202 	}
203 
204 	if (!bootcpu_valid) {
205 		pr_err("MADT missing boot CPU MPIDR, not enabling secondaries\n");
206 		return;
207 	}
208 
209 	for (i = 0; i < enabled_cpus; i++)
210 		set_cpu_possible(i, true);
211 
212 	/* Make boot-up look pretty */
213 	pr_info("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus);
214 }
215 
216 /*
217  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
218  *			      checks on it
219  *
220  * Return 0 on success,  <0 on failure
221  */
222 static int __init acpi_fadt_sanity_check(void)
223 {
224 	struct acpi_table_header *table;
225 	struct acpi_table_fadt *fadt;
226 	acpi_status status;
227 	acpi_size tbl_size;
228 	int ret = 0;
229 
230 	/*
231 	 * FADT is required on arm64; retrieve it to check its presence
232 	 * and carry out revision and ACPI HW reduced compliancy tests
233 	 */
234 	status = acpi_get_table_with_size(ACPI_SIG_FADT, 0, &table, &tbl_size);
235 	if (ACPI_FAILURE(status)) {
236 		const char *msg = acpi_format_exception(status);
237 
238 		pr_err("Failed to get FADT table, %s\n", msg);
239 		return -ENODEV;
240 	}
241 
242 	fadt = (struct acpi_table_fadt *)table;
243 
244 	/*
245 	 * Revision in table header is the FADT Major revision, and there
246 	 * is a minor revision of FADT which was introduced by ACPI 5.1,
247 	 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
248 	 * boot protocol configuration data.
249 	 */
250 	if (table->revision < 5 ||
251 	   (table->revision == 5 && fadt->minor_revision < 1)) {
252 		pr_err("Unsupported FADT revision %d.%d, should be 5.1+\n",
253 		       table->revision, fadt->minor_revision);
254 		ret = -EINVAL;
255 		goto out;
256 	}
257 
258 	if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
259 		pr_err("FADT not ACPI hardware reduced compliant\n");
260 		ret = -EINVAL;
261 	}
262 
263 out:
264 	/*
265 	 * acpi_get_table_with_size() creates FADT table mapping that
266 	 * should be released after parsing and before resuming boot
267 	 */
268 	early_acpi_os_unmap_memory(table, tbl_size);
269 	return ret;
270 }
271 
272 /*
273  * acpi_boot_table_init() called from setup_arch(), always.
274  *	1. find RSDP and get its address, and then find XSDT
275  *	2. extract all tables and checksums them all
276  *	3. check ACPI FADT revision
277  *	4. check ACPI FADT HW reduced flag
278  *
279  * We can parse ACPI boot-time tables such as MADT after
280  * this function is called.
281  *
282  * On return ACPI is enabled if either:
283  *
284  * - ACPI tables are initialized and sanity checks passed
285  * - acpi=force was passed in the command line and ACPI was not disabled
286  *   explicitly through acpi=off command line parameter
287  *
288  * ACPI is disabled on function return otherwise
289  */
290 void __init acpi_boot_table_init(void)
291 {
292 	/*
293 	 * Enable ACPI instead of device tree unless
294 	 * - ACPI has been disabled explicitly (acpi=off), or
295 	 * - the device tree is not empty (it has more than just a /chosen node)
296 	 *   and ACPI has not been force enabled (acpi=force)
297 	 */
298 	if (param_acpi_off ||
299 	    (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
300 		return;
301 
302 	/*
303 	 * ACPI is disabled at this point. Enable it in order to parse
304 	 * the ACPI tables and carry out sanity checks
305 	 */
306 	enable_acpi();
307 
308 	/*
309 	 * If ACPI tables are initialized and FADT sanity checks passed,
310 	 * leave ACPI enabled and carry on booting; otherwise disable ACPI
311 	 * on initialization error.
312 	 * If acpi=force was passed on the command line it forces ACPI
313 	 * to be enabled even if its initialization failed.
314 	 */
315 	if (acpi_table_init() || acpi_fadt_sanity_check()) {
316 		pr_err("Failed to init ACPI tables\n");
317 		if (!param_acpi_force)
318 			disable_acpi();
319 	}
320 }
321 
322 void __init acpi_gic_init(void)
323 {
324 	struct acpi_table_header *table;
325 	acpi_status status;
326 	acpi_size tbl_size;
327 	int err;
328 
329 	if (acpi_disabled)
330 		return;
331 
332 	status = acpi_get_table_with_size(ACPI_SIG_MADT, 0, &table, &tbl_size);
333 	if (ACPI_FAILURE(status)) {
334 		const char *msg = acpi_format_exception(status);
335 
336 		pr_err("Failed to get MADT table, %s\n", msg);
337 		return;
338 	}
339 
340 	err = gic_v2_acpi_init(table);
341 	if (err)
342 		pr_err("Failed to initialize GIC IRQ controller");
343 
344 	early_acpi_os_unmap_memory((char *)table, tbl_size);
345 }
346