xref: /freebsd/sys/riscv/riscv/machdep.c (revision bdd1243d)
1 /*-
2  * Copyright (c) 2014 Andrew Turner
3  * Copyright (c) 2015-2017 Ruslan Bukin <br@bsdpad.com>
4  * All rights reserved.
5  *
6  * Portions of this software were developed by SRI International and the
7  * University of Cambridge Computer Laboratory under DARPA/AFRL contract
8  * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
9  *
10  * Portions of this software were developed by the University of Cambridge
11  * Computer Laboratory as part of the CTSRD Project, with support from the
12  * UK Higher Education Innovation Fund (HEIF).
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "opt_platform.h"
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/boot.h>
44 #include <sys/buf.h>
45 #include <sys/bus.h>
46 #include <sys/cons.h>
47 #include <sys/cpu.h>
48 #include <sys/devmap.h>
49 #include <sys/exec.h>
50 #include <sys/imgact.h>
51 #include <sys/kdb.h>
52 #include <sys/kernel.h>
53 #include <sys/ktr.h>
54 #include <sys/limits.h>
55 #include <sys/linker.h>
56 #include <sys/msgbuf.h>
57 #include <sys/pcpu.h>
58 #include <sys/physmem.h>
59 #include <sys/proc.h>
60 #include <sys/ptrace.h>
61 #include <sys/reboot.h>
62 #include <sys/reg.h>
63 #include <sys/rwlock.h>
64 #include <sys/sched.h>
65 #include <sys/signalvar.h>
66 #include <sys/syscallsubr.h>
67 #include <sys/sysent.h>
68 #include <sys/sysproto.h>
69 #include <sys/tslog.h>
70 #include <sys/ucontext.h>
71 #include <sys/vmmeter.h>
72 
73 #include <vm/vm.h>
74 #include <vm/vm_param.h>
75 #include <vm/vm_kern.h>
76 #include <vm/vm_object.h>
77 #include <vm/vm_page.h>
78 #include <vm/vm_phys.h>
79 #include <vm/pmap.h>
80 #include <vm/vm_map.h>
81 #include <vm/vm_pager.h>
82 
83 #include <machine/cpu.h>
84 #include <machine/fpe.h>
85 #include <machine/intr.h>
86 #include <machine/kdb.h>
87 #include <machine/machdep.h>
88 #include <machine/metadata.h>
89 #include <machine/pcb.h>
90 #include <machine/pte.h>
91 #include <machine/riscvreg.h>
92 #include <machine/sbi.h>
93 #include <machine/trap.h>
94 #include <machine/vmparam.h>
95 
96 #ifdef FDT
97 #include <contrib/libfdt/libfdt.h>
98 #include <dev/fdt/fdt_common.h>
99 #include <dev/ofw/openfirm.h>
100 #endif
101 
102 struct pcpu __pcpu[MAXCPU];
103 
104 static struct trapframe proc0_tf;
105 
106 int early_boot = 1;
107 int cold = 1;
108 
109 #define	DTB_SIZE_MAX	(1024 * 1024)
110 
111 struct kva_md_info kmi;
112 
113 int64_t dcache_line_size;	/* The minimum D cache line size */
114 int64_t icache_line_size;	/* The minimum I cache line size */
115 int64_t idcache_line_size;	/* The minimum cache line size */
116 
117 #define BOOT_HART_INVALID	0xffffffff
118 uint32_t boot_hart = BOOT_HART_INVALID;	/* The hart we booted on. */
119 
120 cpuset_t all_harts;
121 
122 extern int *end;
123 
124 static char static_kenv[PAGE_SIZE];
125 
126 static void
127 cpu_startup(void *dummy)
128 {
129 
130 	sbi_print_version();
131 	printcpuinfo(0);
132 
133 	printf("real memory  = %ju (%ju MB)\n", ptoa((uintmax_t)realmem),
134 	    ptoa((uintmax_t)realmem) / (1024 * 1024));
135 
136 	/*
137 	 * Display any holes after the first chunk of extended memory.
138 	 */
139 	if (bootverbose) {
140 		int indx;
141 
142 		printf("Physical memory chunk(s):\n");
143 		for (indx = 0; phys_avail[indx + 1] != 0; indx += 2) {
144 			vm_paddr_t size;
145 
146 			size = phys_avail[indx + 1] - phys_avail[indx];
147 			printf(
148 			    "0x%016jx - 0x%016jx, %ju bytes (%ju pages)\n",
149 			    (uintmax_t)phys_avail[indx],
150 			    (uintmax_t)phys_avail[indx + 1] - 1,
151 			    (uintmax_t)size, (uintmax_t)size / PAGE_SIZE);
152 		}
153 	}
154 
155 	vm_ksubmap_init(&kmi);
156 
157 	printf("avail memory = %ju (%ju MB)\n",
158 	    ptoa((uintmax_t)vm_free_count()),
159 	    ptoa((uintmax_t)vm_free_count()) / (1024 * 1024));
160 	if (bootverbose)
161 		devmap_print_table();
162 
163 	bufinit();
164 	vm_pager_bufferinit();
165 }
166 
167 SYSINIT(cpu, SI_SUB_CPU, SI_ORDER_FIRST, cpu_startup, NULL);
168 
169 int
170 cpu_idle_wakeup(int cpu)
171 {
172 
173 	return (0);
174 }
175 
176 void
177 cpu_idle(int busy)
178 {
179 
180 	spinlock_enter();
181 	if (!busy)
182 		cpu_idleclock();
183 	if (!sched_runnable())
184 		__asm __volatile(
185 		    "fence \n"
186 		    "wfi   \n");
187 	if (!busy)
188 		cpu_activeclock();
189 	spinlock_exit();
190 }
191 
192 void
193 cpu_halt(void)
194 {
195 
196 	/*
197 	 * Try to power down using the HSM SBI extension and fall back to a
198 	 * simple wfi loop.
199 	 */
200 	intr_disable();
201 	if (sbi_probe_extension(SBI_EXT_ID_HSM) != 0)
202 		sbi_hsm_hart_stop();
203 	for (;;)
204 		__asm __volatile("wfi");
205 	/* NOTREACHED */
206 }
207 
208 /*
209  * Flush the D-cache for non-DMA I/O so that the I-cache can
210  * be made coherent later.
211  */
212 void
213 cpu_flush_dcache(void *ptr, size_t len)
214 {
215 
216 	/* TBD */
217 }
218 
219 /* Get current clock frequency for the given CPU ID. */
220 int
221 cpu_est_clockrate(int cpu_id, uint64_t *rate)
222 {
223 
224 	panic("cpu_est_clockrate");
225 }
226 
227 void
228 cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
229 {
230 }
231 
232 void
233 spinlock_enter(void)
234 {
235 	struct thread *td;
236 	register_t reg;
237 
238 	td = curthread;
239 	if (td->td_md.md_spinlock_count == 0) {
240 		reg = intr_disable();
241 		td->td_md.md_spinlock_count = 1;
242 		td->td_md.md_saved_sstatus_ie = reg;
243 		critical_enter();
244 	} else
245 		td->td_md.md_spinlock_count++;
246 }
247 
248 void
249 spinlock_exit(void)
250 {
251 	struct thread *td;
252 	register_t sstatus_ie;
253 
254 	td = curthread;
255 	sstatus_ie = td->td_md.md_saved_sstatus_ie;
256 	td->td_md.md_spinlock_count--;
257 	if (td->td_md.md_spinlock_count == 0) {
258 		critical_exit();
259 		intr_restore(sstatus_ie);
260 	}
261 }
262 
263 /*
264  * Construct a PCB from a trapframe. This is called from kdb_trap() where
265  * we want to start a backtrace from the function that caused us to enter
266  * the debugger. We have the context in the trapframe, but base the trace
267  * on the PCB. The PCB doesn't have to be perfect, as long as it contains
268  * enough for a backtrace.
269  */
270 void
271 makectx(struct trapframe *tf, struct pcb *pcb)
272 {
273 
274 	memcpy(pcb->pcb_s, tf->tf_s, sizeof(tf->tf_s));
275 
276 	pcb->pcb_ra = tf->tf_sepc;
277 	pcb->pcb_sp = tf->tf_sp;
278 	pcb->pcb_gp = tf->tf_gp;
279 	pcb->pcb_tp = tf->tf_tp;
280 }
281 
282 static void
283 init_proc0(vm_offset_t kstack)
284 {
285 	struct pcpu *pcpup;
286 
287 	pcpup = &__pcpu[0];
288 
289 	proc_linkup0(&proc0, &thread0);
290 	thread0.td_kstack = kstack;
291 	thread0.td_kstack_pages = kstack_pages;
292 	thread0.td_pcb = (struct pcb *)(thread0.td_kstack +
293 	    thread0.td_kstack_pages * PAGE_SIZE) - 1;
294 	thread0.td_pcb->pcb_fpflags = 0;
295 	thread0.td_frame = &proc0_tf;
296 	pcpup->pc_curpcb = thread0.td_pcb;
297 }
298 
299 #ifdef FDT
300 static void
301 try_load_dtb(caddr_t kmdp)
302 {
303 	vm_offset_t dtbp;
304 
305 	dtbp = MD_FETCH(kmdp, MODINFOMD_DTBP, vm_offset_t);
306 
307 #if defined(FDT_DTB_STATIC)
308 	/*
309 	 * In case the device tree blob was not retrieved (from metadata) try
310 	 * to use the statically embedded one.
311 	 */
312 	if (dtbp == (vm_offset_t)NULL)
313 		dtbp = (vm_offset_t)&fdt_static_dtb;
314 #endif
315 
316 	if (dtbp == (vm_offset_t)NULL) {
317 		printf("ERROR loading DTB\n");
318 		return;
319 	}
320 
321 	if (OF_install(OFW_FDT, 0) == FALSE)
322 		panic("Cannot install FDT");
323 
324 	if (OF_init((void *)dtbp) != 0)
325 		panic("OF_init failed with the found device tree");
326 }
327 #endif
328 
329 static void
330 cache_setup(void)
331 {
332 
333 	/* TODO */
334 
335 	dcache_line_size = 0;
336 	icache_line_size = 0;
337 	idcache_line_size = 0;
338 }
339 
340 /*
341  * Fake up a boot descriptor table.
342  */
343 static void
344 fake_preload_metadata(struct riscv_bootparams *rvbp)
345 {
346 	static uint32_t fake_preload[48];
347 	vm_offset_t lastaddr;
348 	size_t fake_size, dtb_size;
349 
350 #define PRELOAD_PUSH_VALUE(type, value) do {			\
351 	*(type *)((char *)fake_preload + fake_size) = (value);	\
352 	fake_size += sizeof(type);				\
353 } while (0)
354 
355 #define PRELOAD_PUSH_STRING(str) do {				\
356 	uint32_t ssize;						\
357 	ssize = strlen(str) + 1;				\
358 	PRELOAD_PUSH_VALUE(uint32_t, ssize);			\
359 	strcpy(((char *)fake_preload + fake_size), str);	\
360 	fake_size += ssize;					\
361 	fake_size = roundup(fake_size, sizeof(u_long));		\
362 } while (0)
363 
364 	fake_size = 0;
365 	lastaddr = (vm_offset_t)&end;
366 
367 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_NAME);
368 	PRELOAD_PUSH_STRING("kernel");
369 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_TYPE);
370 	PRELOAD_PUSH_STRING("elf kernel");
371 
372 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_ADDR);
373 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
374 	PRELOAD_PUSH_VALUE(uint64_t, KERNBASE);
375 
376 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_SIZE);
377 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(size_t));
378 	PRELOAD_PUSH_VALUE(uint64_t, (size_t)((vm_offset_t)&end - KERNBASE));
379 
380 	/* Copy the DTB to KVA space. */
381 	lastaddr = roundup(lastaddr, sizeof(int));
382 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_METADATA | MODINFOMD_DTBP);
383 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
384 	PRELOAD_PUSH_VALUE(vm_offset_t, lastaddr);
385 	dtb_size = fdt_totalsize(rvbp->dtbp_virt);
386 	memmove((void *)lastaddr, (const void *)rvbp->dtbp_virt, dtb_size);
387 	lastaddr = roundup(lastaddr + dtb_size, sizeof(int));
388 
389 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_METADATA | MODINFOMD_KERNEND);
390 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
391 	PRELOAD_PUSH_VALUE(vm_offset_t, lastaddr);
392 
393 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_METADATA | MODINFOMD_HOWTO);
394 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(int));
395 	PRELOAD_PUSH_VALUE(int, RB_VERBOSE);
396 
397 	/* End marker */
398 	PRELOAD_PUSH_VALUE(uint32_t, 0);
399 	PRELOAD_PUSH_VALUE(uint32_t, 0);
400 	preload_metadata = (caddr_t)fake_preload;
401 
402 	/* Check if bootloader clobbered part of the kernel with the DTB. */
403 	KASSERT(rvbp->dtbp_phys + dtb_size <= rvbp->kern_phys ||
404 		rvbp->dtbp_phys >= rvbp->kern_phys + (lastaddr - KERNBASE),
405 	    ("FDT (%lx-%lx) and kernel (%lx-%lx) overlap", rvbp->dtbp_phys,
406 		rvbp->dtbp_phys + dtb_size, rvbp->kern_phys,
407 		rvbp->kern_phys + (lastaddr - KERNBASE)));
408 	KASSERT(fake_size < sizeof(fake_preload),
409 	    ("Too many fake_preload items"));
410 
411 	if (boothowto & RB_VERBOSE)
412 		printf("FDT phys (%lx-%lx), kernel phys (%lx-%lx)\n",
413 		    rvbp->dtbp_phys, rvbp->dtbp_phys + dtb_size,
414 		    rvbp->kern_phys, rvbp->kern_phys + (lastaddr - KERNBASE));
415 }
416 
417 /* Support for FDT configurations only. */
418 CTASSERT(FDT);
419 
420 #ifdef FDT
421 static void
422 parse_fdt_bootargs(void)
423 {
424 	char bootargs[512];
425 
426 	bootargs[sizeof(bootargs) - 1] = '\0';
427 	if (fdt_get_chosen_bootargs(bootargs, sizeof(bootargs) - 1) == 0) {
428 		boothowto |= boot_parse_cmdline(bootargs);
429 	}
430 }
431 #endif
432 
433 static vm_offset_t
434 parse_metadata(void)
435 {
436 	caddr_t kmdp;
437 	vm_offset_t lastaddr;
438 #ifdef DDB
439 	vm_offset_t ksym_start, ksym_end;
440 #endif
441 	char *kern_envp;
442 
443 	/* Find the kernel address */
444 	kmdp = preload_search_by_type("elf kernel");
445 	if (kmdp == NULL)
446 		kmdp = preload_search_by_type("elf64 kernel");
447 	KASSERT(kmdp != NULL, ("No preload metadata found!"));
448 
449 	/* Read the boot metadata */
450 	boothowto = MD_FETCH(kmdp, MODINFOMD_HOWTO, int);
451 	lastaddr = MD_FETCH(kmdp, MODINFOMD_KERNEND, vm_offset_t);
452 	kern_envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *);
453 	if (kern_envp != NULL)
454 		init_static_kenv(kern_envp, 0);
455 	else
456 		init_static_kenv(static_kenv, sizeof(static_kenv));
457 #ifdef DDB
458 	ksym_start = MD_FETCH(kmdp, MODINFOMD_SSYM, uintptr_t);
459 	ksym_end = MD_FETCH(kmdp, MODINFOMD_ESYM, uintptr_t);
460 	db_fetch_ksymtab(ksym_start, ksym_end);
461 #endif
462 #ifdef FDT
463 	try_load_dtb(kmdp);
464 	if (kern_envp == NULL)
465 		parse_fdt_bootargs();
466 #endif
467 	return (lastaddr);
468 }
469 
470 void
471 initriscv(struct riscv_bootparams *rvbp)
472 {
473 	struct mem_region mem_regions[FDT_MEM_REGIONS];
474 	struct pcpu *pcpup;
475 	int mem_regions_sz;
476 	vm_offset_t lastaddr;
477 	vm_size_t kernlen;
478 #ifdef FDT
479 	phandle_t chosen;
480 	uint32_t hart;
481 #endif
482 	char *env;
483 
484 	TSRAW(&thread0, TS_ENTER, __func__, NULL);
485 
486 	/* Set the pcpu data, this is needed by pmap_bootstrap */
487 	pcpup = &__pcpu[0];
488 	pcpu_init(pcpup, 0, sizeof(struct pcpu));
489 
490 	/* Set the pcpu pointer */
491 	__asm __volatile("mv tp, %0" :: "r"(pcpup));
492 
493 	PCPU_SET(curthread, &thread0);
494 
495 	/* Initialize SBI interface. */
496 	sbi_init();
497 
498 	/* Parse the boot metadata. */
499 	if (rvbp->modulep != 0) {
500 		preload_metadata = (caddr_t)rvbp->modulep;
501 	} else {
502 		fake_preload_metadata(rvbp);
503 	}
504 	lastaddr = parse_metadata();
505 
506 #ifdef FDT
507 	/*
508 	 * Look for the boot hart ID. This was either passed in directly from
509 	 * the SBI firmware and handled by locore, or was stored in the device
510 	 * tree by an earlier boot stage.
511 	 */
512 	chosen = OF_finddevice("/chosen");
513 	if (OF_getencprop(chosen, "boot-hartid", &hart, sizeof(hart)) != -1) {
514 		boot_hart = hart;
515 	}
516 #endif
517 	if (boot_hart == BOOT_HART_INVALID) {
518 		panic("Boot hart ID was not properly set");
519 	}
520 	pcpup->pc_hart = boot_hart;
521 
522 #ifdef FDT
523 	/*
524 	 * Exclude reserved memory specified by the device tree. Typically,
525 	 * this contains an entry for memory used by the runtime SBI firmware.
526 	 */
527 	if (fdt_get_reserved_mem(mem_regions, &mem_regions_sz) == 0) {
528 		physmem_exclude_regions(mem_regions, mem_regions_sz,
529 		    EXFLAG_NODUMP | EXFLAG_NOALLOC);
530 	}
531 
532 	/* Grab physical memory regions information from device tree. */
533 	if (fdt_get_mem_regions(mem_regions, &mem_regions_sz, NULL) != 0) {
534 		panic("Cannot get physical memory regions");
535 	}
536 	physmem_hardware_regions(mem_regions, mem_regions_sz);
537 #endif
538 
539 	/*
540 	 * Identify CPU/ISA features.
541 	 */
542 	identify_cpu(0);
543 
544 	/* Do basic tuning, hz etc */
545 	init_param1();
546 
547 	cache_setup();
548 
549 	/* Bootstrap enough of pmap to enter the kernel proper */
550 	kernlen = (lastaddr - KERNBASE);
551 	pmap_bootstrap(rvbp->kern_l1pt, rvbp->kern_phys, kernlen);
552 
553 #ifdef FDT
554 	/*
555 	 * XXX: Unconditionally exclude the lowest 2MB of physical memory, as
556 	 * this area is assumed to contain the SBI firmware. This is a little
557 	 * fragile, but it is consistent with the platforms we support so far.
558 	 *
559 	 * TODO: remove this when the all regular booting methods properly
560 	 * report their reserved memory in the device tree.
561 	 */
562 	physmem_exclude_region(mem_regions[0].mr_start, L2_SIZE,
563 	    EXFLAG_NODUMP | EXFLAG_NOALLOC);
564 #endif
565 	physmem_init_kernel_globals();
566 
567 	/* Establish static device mappings */
568 	devmap_bootstrap(0, NULL);
569 
570 	cninit();
571 
572 	/*
573 	 * Dump the boot metadata. We have to wait for cninit() since console
574 	 * output is required. If it's grossly incorrect the kernel will never
575 	 * make it this far.
576 	 */
577 	if (getenv_is_true("debug.dump_modinfo_at_boot"))
578 		preload_dump();
579 
580 	init_proc0(rvbp->kern_stack);
581 
582 	msgbufinit(msgbufp, msgbufsize);
583 	mutex_init();
584 	init_param2(physmem);
585 	kdb_init();
586 #ifdef KDB
587 	if ((boothowto & RB_KDB) != 0)
588 		kdb_enter(KDB_WHY_BOOTFLAGS, "Boot flags requested debugger");
589 #endif
590 
591 	env = kern_getenv("kernelname");
592 	if (env != NULL)
593 		strlcpy(kernelname, env, sizeof(kernelname));
594 
595 	if (boothowto & RB_VERBOSE)
596 		physmem_print_tables();
597 
598 	early_boot = 0;
599 
600 	TSEXIT();
601 }
602