1 /*
2  * Copyright 2004 James Cleverdon, IBM.
3  * Subject to the GNU Public License, v.2
4  *
5  * Flat APIC subarch code.
6  *
7  * Hacked for x86-64 by James Cleverdon from i386 architecture code by
8  * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
9  * James Cleverdon.
10  */
11 #include <linux/acpi.h>
12 #include <linux/errno.h>
13 #include <linux/threads.h>
14 #include <linux/cpumask.h>
15 #include <linux/string.h>
16 #include <linux/kernel.h>
17 #include <linux/ctype.h>
18 #include <linux/hardirq.h>
19 #include <linux/export.h>
20 
21 #include <asm/smp.h>
22 #include <asm/ipi.h>
23 #include <asm/apic.h>
24 #include <asm/apic_flat_64.h>
25 #include <asm/jailhouse_para.h>
26 
27 static struct apic apic_physflat;
28 static struct apic apic_flat;
29 
30 struct apic *apic __ro_after_init = &apic_flat;
31 EXPORT_SYMBOL_GPL(apic);
32 
33 static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
34 {
35 	return 1;
36 }
37 
38 /*
39  * Set up the logical destination ID.
40  *
41  * Intel recommends to set DFR, LDR and TPR before enabling
42  * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
43  * document number 292116).  So here it goes...
44  */
45 void flat_init_apic_ldr(void)
46 {
47 	unsigned long val;
48 	unsigned long num, id;
49 
50 	num = smp_processor_id();
51 	id = 1UL << num;
52 	apic_write(APIC_DFR, APIC_DFR_FLAT);
53 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
54 	val |= SET_APIC_LOGICAL_ID(id);
55 	apic_write(APIC_LDR, val);
56 }
57 
58 static void _flat_send_IPI_mask(unsigned long mask, int vector)
59 {
60 	unsigned long flags;
61 
62 	local_irq_save(flags);
63 	__default_send_IPI_dest_field(mask, vector, apic->dest_logical);
64 	local_irq_restore(flags);
65 }
66 
67 static void flat_send_IPI_mask(const struct cpumask *cpumask, int vector)
68 {
69 	unsigned long mask = cpumask_bits(cpumask)[0];
70 
71 	_flat_send_IPI_mask(mask, vector);
72 }
73 
74 static void
75 flat_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector)
76 {
77 	unsigned long mask = cpumask_bits(cpumask)[0];
78 	int cpu = smp_processor_id();
79 
80 	if (cpu < BITS_PER_LONG)
81 		clear_bit(cpu, &mask);
82 
83 	_flat_send_IPI_mask(mask, vector);
84 }
85 
86 static void flat_send_IPI_allbutself(int vector)
87 {
88 	int cpu = smp_processor_id();
89 
90 	if (IS_ENABLED(CONFIG_HOTPLUG_CPU) || vector == NMI_VECTOR) {
91 		if (!cpumask_equal(cpu_online_mask, cpumask_of(cpu))) {
92 			unsigned long mask = cpumask_bits(cpu_online_mask)[0];
93 
94 			if (cpu < BITS_PER_LONG)
95 				clear_bit(cpu, &mask);
96 
97 			_flat_send_IPI_mask(mask, vector);
98 		}
99 	} else if (num_online_cpus() > 1) {
100 		__default_send_IPI_shortcut(APIC_DEST_ALLBUT,
101 					    vector, apic->dest_logical);
102 	}
103 }
104 
105 static void flat_send_IPI_all(int vector)
106 {
107 	if (vector == NMI_VECTOR) {
108 		flat_send_IPI_mask(cpu_online_mask, vector);
109 	} else {
110 		__default_send_IPI_shortcut(APIC_DEST_ALLINC,
111 					    vector, apic->dest_logical);
112 	}
113 }
114 
115 static unsigned int flat_get_apic_id(unsigned long x)
116 {
117 	return (x >> 24) & 0xFF;
118 }
119 
120 static u32 set_apic_id(unsigned int id)
121 {
122 	return (id & 0xFF) << 24;
123 }
124 
125 static unsigned int read_xapic_id(void)
126 {
127 	return flat_get_apic_id(apic_read(APIC_ID));
128 }
129 
130 static int flat_apic_id_registered(void)
131 {
132 	return physid_isset(read_xapic_id(), phys_cpu_present_map);
133 }
134 
135 static int flat_phys_pkg_id(int initial_apic_id, int index_msb)
136 {
137 	return initial_apic_id >> index_msb;
138 }
139 
140 static int flat_probe(void)
141 {
142 	return 1;
143 }
144 
145 static struct apic apic_flat __ro_after_init = {
146 	.name				= "flat",
147 	.probe				= flat_probe,
148 	.acpi_madt_oem_check		= flat_acpi_madt_oem_check,
149 	.apic_id_valid			= default_apic_id_valid,
150 	.apic_id_registered		= flat_apic_id_registered,
151 
152 	.irq_delivery_mode		= dest_Fixed,
153 	.irq_dest_mode			= 1, /* logical */
154 
155 	.disable_esr			= 0,
156 	.dest_logical			= APIC_DEST_LOGICAL,
157 	.check_apicid_used		= NULL,
158 
159 	.init_apic_ldr			= flat_init_apic_ldr,
160 
161 	.ioapic_phys_id_map		= NULL,
162 	.setup_apic_routing		= NULL,
163 	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
164 	.apicid_to_cpu_present		= NULL,
165 	.check_phys_apicid_present	= default_check_phys_apicid_present,
166 	.phys_pkg_id			= flat_phys_pkg_id,
167 
168 	.get_apic_id			= flat_get_apic_id,
169 	.set_apic_id			= set_apic_id,
170 
171 	.calc_dest_apicid		= apic_flat_calc_apicid,
172 
173 	.send_IPI			= default_send_IPI_single,
174 	.send_IPI_mask			= flat_send_IPI_mask,
175 	.send_IPI_mask_allbutself	= flat_send_IPI_mask_allbutself,
176 	.send_IPI_allbutself		= flat_send_IPI_allbutself,
177 	.send_IPI_all			= flat_send_IPI_all,
178 	.send_IPI_self			= apic_send_IPI_self,
179 
180 	.inquire_remote_apic		= default_inquire_remote_apic,
181 
182 	.read				= native_apic_mem_read,
183 	.write				= native_apic_mem_write,
184 	.eoi_write			= native_apic_mem_write,
185 	.icr_read			= native_apic_icr_read,
186 	.icr_write			= native_apic_icr_write,
187 	.wait_icr_idle			= native_apic_wait_icr_idle,
188 	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
189 };
190 
191 /*
192  * Physflat mode is used when there are more than 8 CPUs on a system.
193  * We cannot use logical delivery in this case because the mask
194  * overflows, so use physical mode.
195  */
196 static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
197 {
198 #ifdef CONFIG_ACPI
199 	/*
200 	 * Quirk: some x86_64 machines can only use physical APIC mode
201 	 * regardless of how many processors are present (x86_64 ES7000
202 	 * is an example).
203 	 */
204 	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
205 		(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
206 		printk(KERN_DEBUG "system APIC only can use physical flat");
207 		return 1;
208 	}
209 
210 	if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) {
211 		printk(KERN_DEBUG "IBM Summit detected, will use apic physical");
212 		return 1;
213 	}
214 #endif
215 
216 	return 0;
217 }
218 
219 static void physflat_init_apic_ldr(void)
220 {
221 	/*
222 	 * LDR and DFR are not involved in physflat mode, rather:
223 	 * "In physical destination mode, the destination processor is
224 	 * specified by its local APIC ID [...]." (Intel SDM, 10.6.2.1)
225 	 */
226 }
227 
228 static void physflat_send_IPI_allbutself(int vector)
229 {
230 	default_send_IPI_mask_allbutself_phys(cpu_online_mask, vector);
231 }
232 
233 static void physflat_send_IPI_all(int vector)
234 {
235 	default_send_IPI_mask_sequence_phys(cpu_online_mask, vector);
236 }
237 
238 static int physflat_probe(void)
239 {
240 	if (apic == &apic_physflat || num_possible_cpus() > 8 ||
241 	    jailhouse_paravirt())
242 		return 1;
243 
244 	return 0;
245 }
246 
247 static struct apic apic_physflat __ro_after_init = {
248 
249 	.name				= "physical flat",
250 	.probe				= physflat_probe,
251 	.acpi_madt_oem_check		= physflat_acpi_madt_oem_check,
252 	.apic_id_valid			= default_apic_id_valid,
253 	.apic_id_registered		= flat_apic_id_registered,
254 
255 	.irq_delivery_mode		= dest_Fixed,
256 	.irq_dest_mode			= 0, /* physical */
257 
258 	.disable_esr			= 0,
259 	.dest_logical			= 0,
260 	.check_apicid_used		= NULL,
261 
262 	.init_apic_ldr			= physflat_init_apic_ldr,
263 
264 	.ioapic_phys_id_map		= NULL,
265 	.setup_apic_routing		= NULL,
266 	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
267 	.apicid_to_cpu_present		= NULL,
268 	.check_phys_apicid_present	= default_check_phys_apicid_present,
269 	.phys_pkg_id			= flat_phys_pkg_id,
270 
271 	.get_apic_id			= flat_get_apic_id,
272 	.set_apic_id			= set_apic_id,
273 
274 	.calc_dest_apicid		= apic_default_calc_apicid,
275 
276 	.send_IPI			= default_send_IPI_single_phys,
277 	.send_IPI_mask			= default_send_IPI_mask_sequence_phys,
278 	.send_IPI_mask_allbutself	= default_send_IPI_mask_allbutself_phys,
279 	.send_IPI_allbutself		= physflat_send_IPI_allbutself,
280 	.send_IPI_all			= physflat_send_IPI_all,
281 	.send_IPI_self			= apic_send_IPI_self,
282 
283 	.inquire_remote_apic		= default_inquire_remote_apic,
284 
285 	.read				= native_apic_mem_read,
286 	.write				= native_apic_mem_write,
287 	.eoi_write			= native_apic_mem_write,
288 	.icr_read			= native_apic_icr_read,
289 	.icr_write			= native_apic_icr_write,
290 	.wait_icr_idle			= native_apic_wait_icr_idle,
291 	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
292 };
293 
294 /*
295  * We need to check for physflat first, so this order is important.
296  */
297 apic_drivers(apic_physflat, apic_flat);
298