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/errno.h>
12 #include <linux/threads.h>
13 #include <linux/cpumask.h>
14 #include <linux/string.h>
15 #include <linux/kernel.h>
16 #include <linux/ctype.h>
17 #include <linux/init.h>
18 #include <linux/hardirq.h>
19 #include <linux/module.h>
20 #include <asm/smp.h>
21 #include <asm/apic.h>
22 #include <asm/ipi.h>
23 
24 #ifdef CONFIG_ACPI
25 #include <acpi/acpi_bus.h>
26 #endif
27 
28 static struct apic apic_physflat;
29 static struct apic apic_flat;
30 
31 struct apic __read_mostly *apic = &apic_flat;
32 EXPORT_SYMBOL_GPL(apic);
33 
34 static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
35 {
36 	return 1;
37 }
38 
39 static const struct cpumask *flat_target_cpus(void)
40 {
41 	return cpu_online_mask;
42 }
43 
44 static void flat_vector_allocation_domain(int cpu, struct cpumask *retmask)
45 {
46 	/* Careful. Some cpus do not strictly honor the set of cpus
47 	 * specified in the interrupt destination when using lowest
48 	 * priority interrupt delivery mode.
49 	 *
50 	 * In particular there was a hyperthreading cpu observed to
51 	 * deliver interrupts to the wrong hyperthread when only one
52 	 * hyperthread was specified in the interrupt desitination.
53 	 */
54 	cpumask_clear(retmask);
55 	cpumask_bits(retmask)[0] = APIC_ALL_CPUS;
56 }
57 
58 /*
59  * Set up the logical destination ID.
60  *
61  * Intel recommends to set DFR, LDR and TPR before enabling
62  * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
63  * document number 292116).  So here it goes...
64  */
65 void flat_init_apic_ldr(void)
66 {
67 	unsigned long val;
68 	unsigned long num, id;
69 
70 	num = smp_processor_id();
71 	id = 1UL << num;
72 	apic_write(APIC_DFR, APIC_DFR_FLAT);
73 	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
74 	val |= SET_APIC_LOGICAL_ID(id);
75 	apic_write(APIC_LDR, val);
76 }
77 
78 static inline void _flat_send_IPI_mask(unsigned long mask, int vector)
79 {
80 	unsigned long flags;
81 
82 	local_irq_save(flags);
83 	__default_send_IPI_dest_field(mask, vector, apic->dest_logical);
84 	local_irq_restore(flags);
85 }
86 
87 static void flat_send_IPI_mask(const struct cpumask *cpumask, int vector)
88 {
89 	unsigned long mask = cpumask_bits(cpumask)[0];
90 
91 	_flat_send_IPI_mask(mask, vector);
92 }
93 
94 static void
95  flat_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector)
96 {
97 	unsigned long mask = cpumask_bits(cpumask)[0];
98 	int cpu = smp_processor_id();
99 
100 	if (cpu < BITS_PER_LONG)
101 		clear_bit(cpu, &mask);
102 
103 	_flat_send_IPI_mask(mask, vector);
104 }
105 
106 static void flat_send_IPI_allbutself(int vector)
107 {
108 	int cpu = smp_processor_id();
109 #ifdef	CONFIG_HOTPLUG_CPU
110 	int hotplug = 1;
111 #else
112 	int hotplug = 0;
113 #endif
114 	if (hotplug || vector == NMI_VECTOR) {
115 		if (!cpumask_equal(cpu_online_mask, cpumask_of(cpu))) {
116 			unsigned long mask = cpumask_bits(cpu_online_mask)[0];
117 
118 			if (cpu < BITS_PER_LONG)
119 				clear_bit(cpu, &mask);
120 
121 			_flat_send_IPI_mask(mask, vector);
122 		}
123 	} else if (num_online_cpus() > 1) {
124 		__default_send_IPI_shortcut(APIC_DEST_ALLBUT,
125 					    vector, apic->dest_logical);
126 	}
127 }
128 
129 static void flat_send_IPI_all(int vector)
130 {
131 	if (vector == NMI_VECTOR) {
132 		flat_send_IPI_mask(cpu_online_mask, vector);
133 	} else {
134 		__default_send_IPI_shortcut(APIC_DEST_ALLINC,
135 					    vector, apic->dest_logical);
136 	}
137 }
138 
139 static unsigned int flat_get_apic_id(unsigned long x)
140 {
141 	unsigned int id;
142 
143 	id = (((x)>>24) & 0xFFu);
144 
145 	return id;
146 }
147 
148 static unsigned long set_apic_id(unsigned int id)
149 {
150 	unsigned long x;
151 
152 	x = ((id & 0xFFu)<<24);
153 	return x;
154 }
155 
156 static unsigned int read_xapic_id(void)
157 {
158 	unsigned int id;
159 
160 	id = flat_get_apic_id(apic_read(APIC_ID));
161 	return id;
162 }
163 
164 static int flat_apic_id_registered(void)
165 {
166 	return physid_isset(read_xapic_id(), phys_cpu_present_map);
167 }
168 
169 static int flat_phys_pkg_id(int initial_apic_id, int index_msb)
170 {
171 	return initial_apic_id >> index_msb;
172 }
173 
174 static int flat_probe(void)
175 {
176 	return 1;
177 }
178 
179 static struct apic apic_flat =  {
180 	.name				= "flat",
181 	.probe				= flat_probe,
182 	.acpi_madt_oem_check		= flat_acpi_madt_oem_check,
183 	.apic_id_valid			= default_apic_id_valid,
184 	.apic_id_registered		= flat_apic_id_registered,
185 
186 	.irq_delivery_mode		= dest_LowestPrio,
187 	.irq_dest_mode			= 1, /* logical */
188 
189 	.target_cpus			= flat_target_cpus,
190 	.disable_esr			= 0,
191 	.dest_logical			= APIC_DEST_LOGICAL,
192 	.check_apicid_used		= NULL,
193 	.check_apicid_present		= NULL,
194 
195 	.vector_allocation_domain	= flat_vector_allocation_domain,
196 	.init_apic_ldr			= flat_init_apic_ldr,
197 
198 	.ioapic_phys_id_map		= NULL,
199 	.setup_apic_routing		= NULL,
200 	.multi_timer_check		= NULL,
201 	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
202 	.apicid_to_cpu_present		= NULL,
203 	.setup_portio_remap		= NULL,
204 	.check_phys_apicid_present	= default_check_phys_apicid_present,
205 	.enable_apic_mode		= NULL,
206 	.phys_pkg_id			= flat_phys_pkg_id,
207 	.mps_oem_check			= NULL,
208 
209 	.get_apic_id			= flat_get_apic_id,
210 	.set_apic_id			= set_apic_id,
211 	.apic_id_mask			= 0xFFu << 24,
212 
213 	.cpu_mask_to_apicid		= default_cpu_mask_to_apicid,
214 	.cpu_mask_to_apicid_and		= default_cpu_mask_to_apicid_and,
215 
216 	.send_IPI_mask			= flat_send_IPI_mask,
217 	.send_IPI_mask_allbutself	= flat_send_IPI_mask_allbutself,
218 	.send_IPI_allbutself		= flat_send_IPI_allbutself,
219 	.send_IPI_all			= flat_send_IPI_all,
220 	.send_IPI_self			= apic_send_IPI_self,
221 
222 	.trampoline_phys_low		= DEFAULT_TRAMPOLINE_PHYS_LOW,
223 	.trampoline_phys_high		= DEFAULT_TRAMPOLINE_PHYS_HIGH,
224 	.wait_for_init_deassert		= NULL,
225 	.smp_callin_clear_local_apic	= NULL,
226 	.inquire_remote_apic		= default_inquire_remote_apic,
227 
228 	.read				= native_apic_mem_read,
229 	.write				= native_apic_mem_write,
230 	.icr_read			= native_apic_icr_read,
231 	.icr_write			= native_apic_icr_write,
232 	.wait_icr_idle			= native_apic_wait_icr_idle,
233 	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
234 };
235 
236 /*
237  * Physflat mode is used when there are more than 8 CPUs on a system.
238  * We cannot use logical delivery in this case because the mask
239  * overflows, so use physical mode.
240  */
241 static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
242 {
243 #ifdef CONFIG_ACPI
244 	/*
245 	 * Quirk: some x86_64 machines can only use physical APIC mode
246 	 * regardless of how many processors are present (x86_64 ES7000
247 	 * is an example).
248 	 */
249 	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
250 		(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
251 		printk(KERN_DEBUG "system APIC only can use physical flat");
252 		return 1;
253 	}
254 
255 	if (!strncmp(oem_id, "IBM", 3) && !strncmp(oem_table_id, "EXA", 3)) {
256 		printk(KERN_DEBUG "IBM Summit detected, will use apic physical");
257 		return 1;
258 	}
259 #endif
260 
261 	return 0;
262 }
263 
264 static const struct cpumask *physflat_target_cpus(void)
265 {
266 	return cpu_online_mask;
267 }
268 
269 static void physflat_vector_allocation_domain(int cpu, struct cpumask *retmask)
270 {
271 	cpumask_clear(retmask);
272 	cpumask_set_cpu(cpu, retmask);
273 }
274 
275 static void physflat_send_IPI_mask(const struct cpumask *cpumask, int vector)
276 {
277 	default_send_IPI_mask_sequence_phys(cpumask, vector);
278 }
279 
280 static void physflat_send_IPI_mask_allbutself(const struct cpumask *cpumask,
281 					      int vector)
282 {
283 	default_send_IPI_mask_allbutself_phys(cpumask, vector);
284 }
285 
286 static void physflat_send_IPI_allbutself(int vector)
287 {
288 	default_send_IPI_mask_allbutself_phys(cpu_online_mask, vector);
289 }
290 
291 static void physflat_send_IPI_all(int vector)
292 {
293 	physflat_send_IPI_mask(cpu_online_mask, vector);
294 }
295 
296 static unsigned int physflat_cpu_mask_to_apicid(const struct cpumask *cpumask)
297 {
298 	int cpu;
299 
300 	/*
301 	 * We're using fixed IRQ delivery, can only return one phys APIC ID.
302 	 * May as well be the first.
303 	 */
304 	cpu = cpumask_first(cpumask);
305 	if ((unsigned)cpu < nr_cpu_ids)
306 		return per_cpu(x86_cpu_to_apicid, cpu);
307 	else
308 		return BAD_APICID;
309 }
310 
311 static unsigned int
312 physflat_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
313 				const struct cpumask *andmask)
314 {
315 	int cpu;
316 
317 	/*
318 	 * We're using fixed IRQ delivery, can only return one phys APIC ID.
319 	 * May as well be the first.
320 	 */
321 	for_each_cpu_and(cpu, cpumask, andmask) {
322 		if (cpumask_test_cpu(cpu, cpu_online_mask))
323 			break;
324 	}
325 	return per_cpu(x86_cpu_to_apicid, cpu);
326 }
327 
328 static int physflat_probe(void)
329 {
330 	if (apic == &apic_physflat || num_possible_cpus() > 8)
331 		return 1;
332 
333 	return 0;
334 }
335 
336 static struct apic apic_physflat =  {
337 
338 	.name				= "physical flat",
339 	.probe				= physflat_probe,
340 	.acpi_madt_oem_check		= physflat_acpi_madt_oem_check,
341 	.apic_id_valid			= default_apic_id_valid,
342 	.apic_id_registered		= flat_apic_id_registered,
343 
344 	.irq_delivery_mode		= dest_Fixed,
345 	.irq_dest_mode			= 0, /* physical */
346 
347 	.target_cpus			= physflat_target_cpus,
348 	.disable_esr			= 0,
349 	.dest_logical			= 0,
350 	.check_apicid_used		= NULL,
351 	.check_apicid_present		= NULL,
352 
353 	.vector_allocation_domain	= physflat_vector_allocation_domain,
354 	/* not needed, but shouldn't hurt: */
355 	.init_apic_ldr			= flat_init_apic_ldr,
356 
357 	.ioapic_phys_id_map		= NULL,
358 	.setup_apic_routing		= NULL,
359 	.multi_timer_check		= NULL,
360 	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
361 	.apicid_to_cpu_present		= NULL,
362 	.setup_portio_remap		= NULL,
363 	.check_phys_apicid_present	= default_check_phys_apicid_present,
364 	.enable_apic_mode		= NULL,
365 	.phys_pkg_id			= flat_phys_pkg_id,
366 	.mps_oem_check			= NULL,
367 
368 	.get_apic_id			= flat_get_apic_id,
369 	.set_apic_id			= set_apic_id,
370 	.apic_id_mask			= 0xFFu << 24,
371 
372 	.cpu_mask_to_apicid		= physflat_cpu_mask_to_apicid,
373 	.cpu_mask_to_apicid_and		= physflat_cpu_mask_to_apicid_and,
374 
375 	.send_IPI_mask			= physflat_send_IPI_mask,
376 	.send_IPI_mask_allbutself	= physflat_send_IPI_mask_allbutself,
377 	.send_IPI_allbutself		= physflat_send_IPI_allbutself,
378 	.send_IPI_all			= physflat_send_IPI_all,
379 	.send_IPI_self			= apic_send_IPI_self,
380 
381 	.trampoline_phys_low		= DEFAULT_TRAMPOLINE_PHYS_LOW,
382 	.trampoline_phys_high		= DEFAULT_TRAMPOLINE_PHYS_HIGH,
383 	.wait_for_init_deassert		= NULL,
384 	.smp_callin_clear_local_apic	= NULL,
385 	.inquire_remote_apic		= default_inquire_remote_apic,
386 
387 	.read				= native_apic_mem_read,
388 	.write				= native_apic_mem_write,
389 	.icr_read			= native_apic_icr_read,
390 	.icr_write			= native_apic_icr_write,
391 	.wait_icr_idle			= native_apic_wait_icr_idle,
392 	.safe_wait_icr_idle		= native_safe_apic_wait_icr_idle,
393 };
394 
395 /*
396  * We need to check for physflat first, so this order is important.
397  */
398 apic_drivers(apic_physflat, apic_flat);
399