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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 #ifdef CONFIG_ACPI_APEI
33 # include <linux/efi.h>
34 # include <asm/pgtable.h>
35 #endif
36 
37 int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
38 int acpi_disabled = 1;
39 EXPORT_SYMBOL(acpi_disabled);
40 
41 int acpi_pci_disabled = 1;	/* skip ACPI PCI scan and IRQ initialization */
42 EXPORT_SYMBOL(acpi_pci_disabled);
43 
44 static bool param_acpi_off __initdata;
45 static bool param_acpi_force __initdata;
46 
parse_acpi(char * arg)47 static int __init parse_acpi(char *arg)
48 {
49 	if (!arg)
50 		return -EINVAL;
51 
52 	/* "acpi=off" disables both ACPI table parsing and interpreter */
53 	if (strcmp(arg, "off") == 0)
54 		param_acpi_off = 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 
dt_scan_depth1_nodes(unsigned long node,const char * uname,int depth,void * data)64 static int __init dt_scan_depth1_nodes(unsigned long node,
65 				       const char *uname, int depth,
66 				       void *data)
67 {
68 	/*
69 	 * Return 1 as soon as we encounter a node at depth 1 that is
70 	 * not the /chosen node.
71 	 */
72 	if (depth == 1 && (strcmp(uname, "chosen") != 0))
73 		return 1;
74 	return 0;
75 }
76 
77 /*
78  * __acpi_map_table() will be called before page_init(), so early_ioremap()
79  * or early_memremap() should be called here to for ACPI table mapping.
80  */
__acpi_map_table(unsigned long phys,unsigned long size)81 char *__init __acpi_map_table(unsigned long phys, unsigned long size)
82 {
83 	if (!size)
84 		return NULL;
85 
86 	return early_memremap(phys, size);
87 }
88 
__acpi_unmap_table(char * map,unsigned long size)89 void __init __acpi_unmap_table(char *map, unsigned long size)
90 {
91 	if (!map || !size)
92 		return;
93 
94 	early_memunmap(map, size);
95 }
96 
acpi_psci_present(void)97 bool __init acpi_psci_present(void)
98 {
99 	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT;
100 }
101 
102 /* Whether HVC must be used instead of SMC as the PSCI conduit */
acpi_psci_use_hvc(void)103 bool __init acpi_psci_use_hvc(void)
104 {
105 	return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC;
106 }
107 
108 /*
109  * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
110  *			      checks on it
111  *
112  * Return 0 on success,  <0 on failure
113  */
acpi_fadt_sanity_check(void)114 static int __init acpi_fadt_sanity_check(void)
115 {
116 	struct acpi_table_header *table;
117 	struct acpi_table_fadt *fadt;
118 	acpi_status status;
119 	acpi_size tbl_size;
120 	int ret = 0;
121 
122 	/*
123 	 * FADT is required on arm64; retrieve it to check its presence
124 	 * and carry out revision and ACPI HW reduced compliancy tests
125 	 */
126 	status = acpi_get_table_with_size(ACPI_SIG_FADT, 0, &table, &tbl_size);
127 	if (ACPI_FAILURE(status)) {
128 		const char *msg = acpi_format_exception(status);
129 
130 		pr_err("Failed to get FADT table, %s\n", msg);
131 		return -ENODEV;
132 	}
133 
134 	fadt = (struct acpi_table_fadt *)table;
135 
136 	/*
137 	 * Revision in table header is the FADT Major revision, and there
138 	 * is a minor revision of FADT which was introduced by ACPI 5.1,
139 	 * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
140 	 * boot protocol configuration data.
141 	 */
142 	if (table->revision < 5 ||
143 	   (table->revision == 5 && fadt->minor_revision < 1)) {
144 		pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 5.1+\n",
145 		       table->revision, fadt->minor_revision);
146 
147 		if (!fadt->arm_boot_flags) {
148 			ret = -EINVAL;
149 			goto out;
150 		}
151 		pr_err("FADT has ARM boot flags set, assuming 5.1\n");
152 	}
153 
154 	if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
155 		pr_err("FADT not ACPI hardware reduced compliant\n");
156 		ret = -EINVAL;
157 	}
158 
159 out:
160 	/*
161 	 * acpi_get_table_with_size() creates FADT table mapping that
162 	 * should be released after parsing and before resuming boot
163 	 */
164 	early_acpi_os_unmap_memory(table, tbl_size);
165 	return ret;
166 }
167 
168 /*
169  * acpi_boot_table_init() called from setup_arch(), always.
170  *	1. find RSDP and get its address, and then find XSDT
171  *	2. extract all tables and checksums them all
172  *	3. check ACPI FADT revision
173  *	4. check ACPI FADT HW reduced flag
174  *
175  * We can parse ACPI boot-time tables such as MADT after
176  * this function is called.
177  *
178  * On return ACPI is enabled if either:
179  *
180  * - ACPI tables are initialized and sanity checks passed
181  * - acpi=force was passed in the command line and ACPI was not disabled
182  *   explicitly through acpi=off command line parameter
183  *
184  * ACPI is disabled on function return otherwise
185  */
acpi_boot_table_init(void)186 void __init acpi_boot_table_init(void)
187 {
188 	/*
189 	 * Enable ACPI instead of device tree unless
190 	 * - ACPI has been disabled explicitly (acpi=off), or
191 	 * - the device tree is not empty (it has more than just a /chosen node)
192 	 *   and ACPI has not been force enabled (acpi=force)
193 	 */
194 	if (param_acpi_off ||
195 	    (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
196 		return;
197 
198 	/*
199 	 * ACPI is disabled at this point. Enable it in order to parse
200 	 * the ACPI tables and carry out sanity checks
201 	 */
202 	enable_acpi();
203 
204 	/*
205 	 * If ACPI tables are initialized and FADT sanity checks passed,
206 	 * leave ACPI enabled and carry on booting; otherwise disable ACPI
207 	 * on initialization error.
208 	 * If acpi=force was passed on the command line it forces ACPI
209 	 * to be enabled even if its initialization failed.
210 	 */
211 	if (acpi_table_init() || acpi_fadt_sanity_check()) {
212 		pr_err("Failed to init ACPI tables\n");
213 		if (!param_acpi_force)
214 			disable_acpi();
215 	}
216 }
217 
218 #ifdef CONFIG_ACPI_APEI
arch_apei_get_mem_attribute(phys_addr_t addr)219 pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
220 {
221 	/*
222 	 * According to "Table 8 Map: EFI memory types to AArch64 memory
223 	 * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is
224 	 * mapped to a corresponding MAIR attribute encoding.
225 	 * The EFI memory attribute advises all possible capabilities
226 	 * of a memory region. We use the most efficient capability.
227 	 */
228 
229 	u64 attr;
230 
231 	attr = efi_mem_attributes(addr);
232 	if (attr & EFI_MEMORY_WB)
233 		return PAGE_KERNEL;
234 	if (attr & EFI_MEMORY_WT)
235 		return __pgprot(PROT_NORMAL_WT);
236 	if (attr & EFI_MEMORY_WC)
237 		return __pgprot(PROT_NORMAL_NC);
238 	return __pgprot(PROT_DEVICE_nGnRnE);
239 }
240 #endif
241