1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2015 Google, Inc
4 *
5 * Based on code from the coreboot file of the same name
6 */
7
8 #include <common.h>
9 #include <cpu.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <malloc.h>
13 #include <qfw.h>
14 #include <asm/atomic.h>
15 #include <asm/cpu.h>
16 #include <asm/interrupt.h>
17 #include <asm/lapic.h>
18 #include <asm/microcode.h>
19 #include <asm/mp.h>
20 #include <asm/msr.h>
21 #include <asm/mtrr.h>
22 #include <asm/processor.h>
23 #include <asm/sipi.h>
24 #include <dm/device-internal.h>
25 #include <dm/uclass-internal.h>
26 #include <dm/lists.h>
27 #include <dm/root.h>
28 #include <linux/linkage.h>
29
30 DECLARE_GLOBAL_DATA_PTR;
31
32 /* Total CPUs include BSP */
33 static int num_cpus;
34
35 /* This also needs to match the sipi.S assembly code for saved MSR encoding */
36 struct saved_msr {
37 uint32_t index;
38 uint32_t lo;
39 uint32_t hi;
40 } __packed;
41
42
43 struct mp_flight_plan {
44 int num_records;
45 struct mp_flight_record *records;
46 };
47
48 static struct mp_flight_plan mp_info;
49
50 struct cpu_map {
51 struct udevice *dev;
52 int apic_id;
53 int err_code;
54 };
55
barrier_wait(atomic_t * b)56 static inline void barrier_wait(atomic_t *b)
57 {
58 while (atomic_read(b) == 0)
59 asm("pause");
60 mfence();
61 }
62
release_barrier(atomic_t * b)63 static inline void release_barrier(atomic_t *b)
64 {
65 mfence();
66 atomic_set(b, 1);
67 }
68
stop_this_cpu(void)69 static inline void stop_this_cpu(void)
70 {
71 /* Called by an AP when it is ready to halt and wait for a new task */
72 for (;;)
73 cpu_hlt();
74 }
75
76 /* Returns 1 if timeout waiting for APs. 0 if target APs found */
wait_for_aps(atomic_t * val,int target,int total_delay,int delay_step)77 static int wait_for_aps(atomic_t *val, int target, int total_delay,
78 int delay_step)
79 {
80 int timeout = 0;
81 int delayed = 0;
82
83 while (atomic_read(val) != target) {
84 udelay(delay_step);
85 delayed += delay_step;
86 if (delayed >= total_delay) {
87 timeout = 1;
88 break;
89 }
90 }
91
92 return timeout;
93 }
94
ap_do_flight_plan(struct udevice * cpu)95 static void ap_do_flight_plan(struct udevice *cpu)
96 {
97 int i;
98
99 for (i = 0; i < mp_info.num_records; i++) {
100 struct mp_flight_record *rec = &mp_info.records[i];
101
102 atomic_inc(&rec->cpus_entered);
103 barrier_wait(&rec->barrier);
104
105 if (rec->ap_call != NULL)
106 rec->ap_call(cpu, rec->ap_arg);
107 }
108 }
109
find_cpu_by_apic_id(int apic_id,struct udevice ** devp)110 static int find_cpu_by_apic_id(int apic_id, struct udevice **devp)
111 {
112 struct udevice *dev;
113
114 *devp = NULL;
115 for (uclass_find_first_device(UCLASS_CPU, &dev);
116 dev;
117 uclass_find_next_device(&dev)) {
118 struct cpu_platdata *plat = dev_get_parent_platdata(dev);
119
120 if (plat->cpu_id == apic_id) {
121 *devp = dev;
122 return 0;
123 }
124 }
125
126 return -ENOENT;
127 }
128
129 /*
130 * By the time APs call ap_init() caching has been setup, and microcode has
131 * been loaded
132 */
ap_init(unsigned int cpu_index)133 static void ap_init(unsigned int cpu_index)
134 {
135 struct udevice *dev;
136 int apic_id;
137 int ret;
138
139 /* Ensure the local apic is enabled */
140 enable_lapic();
141
142 apic_id = lapicid();
143 ret = find_cpu_by_apic_id(apic_id, &dev);
144 if (ret) {
145 debug("Unknown CPU apic_id %x\n", apic_id);
146 goto done;
147 }
148
149 debug("AP: slot %d apic_id %x, dev %s\n", cpu_index, apic_id,
150 dev ? dev->name : "(apic_id not found)");
151
152 /* Walk the flight plan */
153 ap_do_flight_plan(dev);
154
155 /* Park the AP */
156 debug("parking\n");
157 done:
158 stop_this_cpu();
159 }
160
161 static const unsigned int fixed_mtrrs[NUM_FIXED_MTRRS] = {
162 MTRR_FIX_64K_00000_MSR, MTRR_FIX_16K_80000_MSR, MTRR_FIX_16K_A0000_MSR,
163 MTRR_FIX_4K_C0000_MSR, MTRR_FIX_4K_C8000_MSR, MTRR_FIX_4K_D0000_MSR,
164 MTRR_FIX_4K_D8000_MSR, MTRR_FIX_4K_E0000_MSR, MTRR_FIX_4K_E8000_MSR,
165 MTRR_FIX_4K_F0000_MSR, MTRR_FIX_4K_F8000_MSR,
166 };
167
save_msr(int index,struct saved_msr * entry)168 static inline struct saved_msr *save_msr(int index, struct saved_msr *entry)
169 {
170 msr_t msr;
171
172 msr = msr_read(index);
173 entry->index = index;
174 entry->lo = msr.lo;
175 entry->hi = msr.hi;
176
177 /* Return the next entry */
178 entry++;
179 return entry;
180 }
181
save_bsp_msrs(char * start,int size)182 static int save_bsp_msrs(char *start, int size)
183 {
184 int msr_count;
185 int num_var_mtrrs;
186 struct saved_msr *msr_entry;
187 int i;
188 msr_t msr;
189
190 /* Determine number of MTRRs need to be saved */
191 msr = msr_read(MTRR_CAP_MSR);
192 num_var_mtrrs = msr.lo & 0xff;
193
194 /* 2 * num_var_mtrrs for base and mask. +1 for IA32_MTRR_DEF_TYPE */
195 msr_count = 2 * num_var_mtrrs + NUM_FIXED_MTRRS + 1;
196
197 if ((msr_count * sizeof(struct saved_msr)) > size) {
198 printf("Cannot mirror all %d msrs\n", msr_count);
199 return -ENOSPC;
200 }
201
202 msr_entry = (void *)start;
203 for (i = 0; i < NUM_FIXED_MTRRS; i++)
204 msr_entry = save_msr(fixed_mtrrs[i], msr_entry);
205
206 for (i = 0; i < num_var_mtrrs; i++) {
207 msr_entry = save_msr(MTRR_PHYS_BASE_MSR(i), msr_entry);
208 msr_entry = save_msr(MTRR_PHYS_MASK_MSR(i), msr_entry);
209 }
210
211 msr_entry = save_msr(MTRR_DEF_TYPE_MSR, msr_entry);
212
213 return msr_count;
214 }
215
load_sipi_vector(atomic_t ** ap_countp,int num_cpus)216 static int load_sipi_vector(atomic_t **ap_countp, int num_cpus)
217 {
218 struct sipi_params_16bit *params16;
219 struct sipi_params *params;
220 static char msr_save[512];
221 char *stack;
222 ulong addr;
223 int code_len;
224 int size;
225 int ret;
226
227 /* Copy in the code */
228 code_len = ap_start16_code_end - ap_start16;
229 debug("Copying SIPI code to %x: %d bytes\n", AP_DEFAULT_BASE,
230 code_len);
231 memcpy((void *)AP_DEFAULT_BASE, ap_start16, code_len);
232
233 addr = AP_DEFAULT_BASE + (ulong)sipi_params_16bit - (ulong)ap_start16;
234 params16 = (struct sipi_params_16bit *)addr;
235 params16->ap_start = (uint32_t)ap_start;
236 params16->gdt = (uint32_t)gd->arch.gdt;
237 params16->gdt_limit = X86_GDT_SIZE - 1;
238 debug("gdt = %x, gdt_limit = %x\n", params16->gdt, params16->gdt_limit);
239
240 params = (struct sipi_params *)sipi_params;
241 debug("SIPI 32-bit params at %p\n", params);
242 params->idt_ptr = (uint32_t)x86_get_idt();
243
244 params->stack_size = CONFIG_AP_STACK_SIZE;
245 size = params->stack_size * num_cpus;
246 stack = memalign(4096, size);
247 if (!stack)
248 return -ENOMEM;
249 params->stack_top = (u32)(stack + size);
250 #if !defined(CONFIG_QEMU) && !defined(CONFIG_HAVE_FSP) && \
251 !defined(CONFIG_INTEL_MID)
252 params->microcode_ptr = ucode_base;
253 debug("Microcode at %x\n", params->microcode_ptr);
254 #endif
255 params->msr_table_ptr = (u32)msr_save;
256 ret = save_bsp_msrs(msr_save, sizeof(msr_save));
257 if (ret < 0)
258 return ret;
259 params->msr_count = ret;
260
261 params->c_handler = (uint32_t)&ap_init;
262
263 *ap_countp = ¶ms->ap_count;
264 atomic_set(*ap_countp, 0);
265 debug("SIPI vector is ready\n");
266
267 return 0;
268 }
269
check_cpu_devices(int expected_cpus)270 static int check_cpu_devices(int expected_cpus)
271 {
272 int i;
273
274 for (i = 0; i < expected_cpus; i++) {
275 struct udevice *dev;
276 int ret;
277
278 ret = uclass_find_device(UCLASS_CPU, i, &dev);
279 if (ret) {
280 debug("Cannot find CPU %d in device tree\n", i);
281 return ret;
282 }
283 }
284
285 return 0;
286 }
287
288 /* Returns 1 for timeout. 0 on success */
apic_wait_timeout(int total_delay,const char * msg)289 static int apic_wait_timeout(int total_delay, const char *msg)
290 {
291 int total = 0;
292
293 if (!(lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY))
294 return 0;
295
296 debug("Waiting for %s...", msg);
297 while (lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY) {
298 udelay(50);
299 total += 50;
300 if (total >= total_delay) {
301 debug("timed out: aborting\n");
302 return -ETIMEDOUT;
303 }
304 }
305 debug("done\n");
306
307 return 0;
308 }
309
start_aps(int ap_count,atomic_t * num_aps)310 static int start_aps(int ap_count, atomic_t *num_aps)
311 {
312 int sipi_vector;
313 /* Max location is 4KiB below 1MiB */
314 const int max_vector_loc = ((1 << 20) - (1 << 12)) >> 12;
315
316 if (ap_count == 0)
317 return 0;
318
319 /* The vector is sent as a 4k aligned address in one byte */
320 sipi_vector = AP_DEFAULT_BASE >> 12;
321
322 if (sipi_vector > max_vector_loc) {
323 printf("SIPI vector too large! 0x%08x\n",
324 sipi_vector);
325 return -1;
326 }
327
328 debug("Attempting to start %d APs\n", ap_count);
329
330 if (apic_wait_timeout(1000, "ICR not to be busy"))
331 return -ETIMEDOUT;
332
333 /* Send INIT IPI to all but self */
334 lapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(0));
335 lapic_write(LAPIC_ICR, LAPIC_DEST_ALLBUT | LAPIC_INT_ASSERT |
336 LAPIC_DM_INIT);
337 debug("Waiting for 10ms after sending INIT\n");
338 mdelay(10);
339
340 /* Send 1st SIPI */
341 if (apic_wait_timeout(1000, "ICR not to be busy"))
342 return -ETIMEDOUT;
343
344 lapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(0));
345 lapic_write(LAPIC_ICR, LAPIC_DEST_ALLBUT | LAPIC_INT_ASSERT |
346 LAPIC_DM_STARTUP | sipi_vector);
347 if (apic_wait_timeout(10000, "first SIPI to complete"))
348 return -ETIMEDOUT;
349
350 /* Wait for CPUs to check in up to 200 us */
351 wait_for_aps(num_aps, ap_count, 200, 15);
352
353 /* Send 2nd SIPI */
354 if (apic_wait_timeout(1000, "ICR not to be busy"))
355 return -ETIMEDOUT;
356
357 lapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(0));
358 lapic_write(LAPIC_ICR, LAPIC_DEST_ALLBUT | LAPIC_INT_ASSERT |
359 LAPIC_DM_STARTUP | sipi_vector);
360 if (apic_wait_timeout(10000, "second SIPI to complete"))
361 return -ETIMEDOUT;
362
363 /* Wait for CPUs to check in */
364 if (wait_for_aps(num_aps, ap_count, 10000, 50)) {
365 debug("Not all APs checked in: %d/%d\n",
366 atomic_read(num_aps), ap_count);
367 return -1;
368 }
369
370 return 0;
371 }
372
bsp_do_flight_plan(struct udevice * cpu,struct mp_params * mp_params)373 static int bsp_do_flight_plan(struct udevice *cpu, struct mp_params *mp_params)
374 {
375 int i;
376 int ret = 0;
377 const int timeout_us = 100000;
378 const int step_us = 100;
379 int num_aps = num_cpus - 1;
380
381 for (i = 0; i < mp_params->num_records; i++) {
382 struct mp_flight_record *rec = &mp_params->flight_plan[i];
383
384 /* Wait for APs if the record is not released */
385 if (atomic_read(&rec->barrier) == 0) {
386 /* Wait for the APs to check in */
387 if (wait_for_aps(&rec->cpus_entered, num_aps,
388 timeout_us, step_us)) {
389 debug("MP record %d timeout\n", i);
390 ret = -1;
391 }
392 }
393
394 if (rec->bsp_call != NULL)
395 rec->bsp_call(cpu, rec->bsp_arg);
396
397 release_barrier(&rec->barrier);
398 }
399 return ret;
400 }
401
init_bsp(struct udevice ** devp)402 static int init_bsp(struct udevice **devp)
403 {
404 char processor_name[CPU_MAX_NAME_LEN];
405 int apic_id;
406 int ret;
407
408 cpu_get_name(processor_name);
409 debug("CPU: %s\n", processor_name);
410
411 apic_id = lapicid();
412 ret = find_cpu_by_apic_id(apic_id, devp);
413 if (ret) {
414 printf("Cannot find boot CPU, APIC ID %d\n", apic_id);
415 return ret;
416 }
417
418 return 0;
419 }
420
421 #ifdef CONFIG_QFW
qemu_cpu_fixup(void)422 static int qemu_cpu_fixup(void)
423 {
424 int ret;
425 int cpu_num;
426 int cpu_online;
427 struct udevice *dev, *pdev;
428 struct cpu_platdata *plat;
429 char *cpu;
430
431 /* first we need to find '/cpus' */
432 for (device_find_first_child(dm_root(), &pdev);
433 pdev;
434 device_find_next_child(&pdev)) {
435 if (!strcmp(pdev->name, "cpus"))
436 break;
437 }
438 if (!pdev) {
439 printf("unable to find cpus device\n");
440 return -ENODEV;
441 }
442
443 /* calculate cpus that are already bound */
444 cpu_num = 0;
445 for (uclass_find_first_device(UCLASS_CPU, &dev);
446 dev;
447 uclass_find_next_device(&dev)) {
448 cpu_num++;
449 }
450
451 /* get actual cpu number */
452 cpu_online = qemu_fwcfg_online_cpus();
453 if (cpu_online < 0) {
454 printf("unable to get online cpu number: %d\n", cpu_online);
455 return cpu_online;
456 }
457
458 /* bind addtional cpus */
459 dev = NULL;
460 for (; cpu_num < cpu_online; cpu_num++) {
461 /*
462 * allocate device name here as device_bind_driver() does
463 * not copy device name, 8 bytes are enough for
464 * sizeof("cpu@") + 3 digits cpu number + '\0'
465 */
466 cpu = malloc(8);
467 if (!cpu) {
468 printf("unable to allocate device name\n");
469 return -ENOMEM;
470 }
471 sprintf(cpu, "cpu@%d", cpu_num);
472 ret = device_bind_driver(pdev, "cpu_qemu", cpu, &dev);
473 if (ret) {
474 printf("binding cpu@%d failed: %d\n", cpu_num, ret);
475 return ret;
476 }
477 plat = dev_get_parent_platdata(dev);
478 plat->cpu_id = cpu_num;
479 }
480 return 0;
481 }
482 #endif
483
mp_init(struct mp_params * p)484 int mp_init(struct mp_params *p)
485 {
486 int num_aps;
487 atomic_t *ap_count;
488 struct udevice *cpu;
489 int ret;
490
491 /* This will cause the CPUs devices to be bound */
492 struct uclass *uc;
493 ret = uclass_get(UCLASS_CPU, &uc);
494 if (ret)
495 return ret;
496
497 #ifdef CONFIG_QFW
498 ret = qemu_cpu_fixup();
499 if (ret)
500 return ret;
501 #endif
502
503 ret = init_bsp(&cpu);
504 if (ret) {
505 debug("Cannot init boot CPU: err=%d\n", ret);
506 return ret;
507 }
508
509 if (p == NULL || p->flight_plan == NULL || p->num_records < 1) {
510 printf("Invalid MP parameters\n");
511 return -1;
512 }
513
514 num_cpus = cpu_get_count(cpu);
515 if (num_cpus < 0) {
516 debug("Cannot get number of CPUs: err=%d\n", num_cpus);
517 return num_cpus;
518 }
519
520 if (num_cpus < 2)
521 debug("Warning: Only 1 CPU is detected\n");
522
523 ret = check_cpu_devices(num_cpus);
524 if (ret)
525 debug("Warning: Device tree does not describe all CPUs. Extra ones will not be started correctly\n");
526
527 /* Copy needed parameters so that APs have a reference to the plan */
528 mp_info.num_records = p->num_records;
529 mp_info.records = p->flight_plan;
530
531 /* Load the SIPI vector */
532 ret = load_sipi_vector(&ap_count, num_cpus);
533 if (ap_count == NULL)
534 return -1;
535
536 /*
537 * Make sure SIPI data hits RAM so the APs that come up will see
538 * the startup code even if the caches are disabled
539 */
540 wbinvd();
541
542 /* Start the APs providing number of APs and the cpus_entered field */
543 num_aps = num_cpus - 1;
544 ret = start_aps(num_aps, ap_count);
545 if (ret) {
546 mdelay(1000);
547 debug("%d/%d eventually checked in?\n", atomic_read(ap_count),
548 num_aps);
549 return ret;
550 }
551
552 /* Walk the flight plan for the BSP */
553 ret = bsp_do_flight_plan(cpu, p);
554 if (ret) {
555 debug("CPU init failed: err=%d\n", ret);
556 return ret;
557 }
558
559 return 0;
560 }
561
mp_init_cpu(struct udevice * cpu,void * unused)562 int mp_init_cpu(struct udevice *cpu, void *unused)
563 {
564 struct cpu_platdata *plat = dev_get_parent_platdata(cpu);
565
566 /*
567 * Multiple APs are brought up simultaneously and they may get the same
568 * seq num in the uclass_resolve_seq() during device_probe(). To avoid
569 * this, set req_seq to the reg number in the device tree in advance.
570 */
571 cpu->req_seq = fdtdec_get_int(gd->fdt_blob, dev_of_offset(cpu), "reg",
572 -1);
573 plat->ucode_version = microcode_read_rev();
574 plat->device_id = gd->arch.x86_device;
575
576 return device_probe(cpu);
577 }
578