xref: /freebsd/sys/riscv/riscv/machdep.c (revision 4d213c595ac3247a85cea5d3ea521db14151a427)
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_ddb.h"
37 #include "opt_kstack_pages.h"
38 #include "opt_platform.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/boot.h>
43 #include <sys/buf.h>
44 #include <sys/bus.h>
45 #include <sys/cons.h>
46 #include <sys/cpu.h>
47 #include <sys/devmap.h>
48 #include <sys/exec.h>
49 #include <sys/imgact.h>
50 #include <sys/kdb.h>
51 #include <sys/kernel.h>
52 #include <sys/ktr.h>
53 #include <sys/limits.h>
54 #include <sys/linker.h>
55 #include <sys/msgbuf.h>
56 #include <sys/pcpu.h>
57 #include <sys/physmem.h>
58 #include <sys/proc.h>
59 #include <sys/ptrace.h>
60 #include <sys/reboot.h>
61 #include <sys/reg.h>
62 #include <sys/rwlock.h>
63 #include <sys/sched.h>
64 #include <sys/signalvar.h>
65 #include <sys/syscallsubr.h>
66 #include <sys/sysent.h>
67 #include <sys/sysproto.h>
68 #include <sys/tslog.h>
69 #include <sys/ucontext.h>
70 #include <sys/vmmeter.h>
71 
72 #include <vm/vm.h>
73 #include <vm/vm_param.h>
74 #include <vm/vm_kern.h>
75 #include <vm/vm_object.h>
76 #include <vm/vm_page.h>
77 #include <vm/vm_phys.h>
78 #include <vm/pmap.h>
79 #include <vm/vm_map.h>
80 #include <vm/vm_pager.h>
81 
82 #include <machine/cpu.h>
83 #include <machine/fpe.h>
84 #include <machine/intr.h>
85 #include <machine/kdb.h>
86 #include <machine/machdep.h>
87 #include <machine/metadata.h>
88 #include <machine/pcb.h>
89 #include <machine/pte.h>
90 #include <machine/riscvreg.h>
91 #include <machine/sbi.h>
92 #include <machine/trap.h>
93 #include <machine/vmparam.h>
94 
95 #ifdef DDB
96 #include <ddb/ddb.h>
97 #endif
98 
99 #ifdef FDT
100 #include <contrib/libfdt/libfdt.h>
101 #include <dev/fdt/fdt_common.h>
102 #include <dev/ofw/openfirm.h>
103 #endif
104 
105 struct pcpu __pcpu[MAXCPU];
106 
107 static struct trapframe proc0_tf;
108 
109 int early_boot = 1;
110 int cold = 1;
111 
112 #define	DTB_SIZE_MAX	(1024 * 1024)
113 
114 struct kva_md_info kmi;
115 
116 #define BOOT_HART_INVALID	0xffffffff
117 uint32_t boot_hart = BOOT_HART_INVALID;	/* The hart we booted on. */
118 
119 cpuset_t all_harts;
120 
121 extern int *end;
122 
123 static char static_kenv[PAGE_SIZE];
124 
125 static void
cpu_startup(void * dummy)126 cpu_startup(void *dummy)
127 {
128 
129 	sbi_print_version();
130 	printcpuinfo(0);
131 
132 	printf("real memory  = %ju (%ju MB)\n", ptoa((uintmax_t)realmem),
133 	    ptoa((uintmax_t)realmem) / (1024 * 1024));
134 
135 	/*
136 	 * Display any holes after the first chunk of extended memory.
137 	 */
138 	if (bootverbose) {
139 		int indx;
140 
141 		printf("Physical memory chunk(s):\n");
142 		for (indx = 0; phys_avail[indx + 1] != 0; indx += 2) {
143 			vm_paddr_t size;
144 
145 			size = phys_avail[indx + 1] - phys_avail[indx];
146 			printf(
147 			    "0x%016jx - 0x%016jx, %ju bytes (%ju pages)\n",
148 			    (uintmax_t)phys_avail[indx],
149 			    (uintmax_t)phys_avail[indx + 1] - 1,
150 			    (uintmax_t)size, (uintmax_t)size / PAGE_SIZE);
151 		}
152 	}
153 
154 	vm_ksubmap_init(&kmi);
155 
156 	printf("avail memory = %ju (%ju MB)\n",
157 	    ptoa((uintmax_t)vm_free_count()),
158 	    ptoa((uintmax_t)vm_free_count()) / (1024 * 1024));
159 	if (bootverbose)
160 		devmap_print_table();
161 
162 	bufinit();
163 	vm_pager_bufferinit();
164 }
165 
166 SYSINIT(cpu, SI_SUB_CPU, SI_ORDER_FIRST, cpu_startup, NULL);
167 
168 int
cpu_idle_wakeup(int cpu)169 cpu_idle_wakeup(int cpu)
170 {
171 
172 	return (0);
173 }
174 
175 void
cpu_idle(int busy)176 cpu_idle(int busy)
177 {
178 
179 	spinlock_enter();
180 	if (!busy)
181 		cpu_idleclock();
182 	if (!sched_runnable())
183 		__asm __volatile(
184 		    "fence \n"
185 		    "wfi   \n");
186 	if (!busy)
187 		cpu_activeclock();
188 	spinlock_exit();
189 }
190 
191 void
cpu_halt(void)192 cpu_halt(void)
193 {
194 
195 	/*
196 	 * Try to power down using the HSM SBI extension and fall back to a
197 	 * simple wfi loop.
198 	 */
199 	intr_disable();
200 	if (sbi_probe_extension(SBI_EXT_ID_HSM) != 0)
201 		sbi_hsm_hart_stop();
202 	for (;;)
203 		__asm __volatile("wfi");
204 	/* NOTREACHED */
205 }
206 
207 /*
208  * Flush the D-cache for non-DMA I/O so that the I-cache can
209  * be made coherent later.
210  */
211 void
cpu_flush_dcache(void * ptr,size_t len)212 cpu_flush_dcache(void *ptr, size_t len)
213 {
214 
215 	/* TBD */
216 }
217 
218 /* Get current clock frequency for the given CPU ID. */
219 int
cpu_est_clockrate(int cpu_id,uint64_t * rate)220 cpu_est_clockrate(int cpu_id, uint64_t *rate)
221 {
222 	struct pcpu *pc;
223 
224 	pc = pcpu_find(cpu_id);
225 	if (pc == NULL || rate == NULL)
226 		return (EINVAL);
227 
228 	if (pc->pc_clock == 0)
229 		return (EOPNOTSUPP);
230 
231 	*rate = pc->pc_clock;
232 
233 	return (0);
234 }
235 
236 void
cpu_pcpu_init(struct pcpu * pcpu,int cpuid,size_t size)237 cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
238 {
239 }
240 
241 void
spinlock_enter(void)242 spinlock_enter(void)
243 {
244 	struct thread *td;
245 	register_t reg;
246 
247 	td = curthread;
248 	if (td->td_md.md_spinlock_count == 0) {
249 		reg = intr_disable();
250 		td->td_md.md_spinlock_count = 1;
251 		td->td_md.md_saved_sstatus_ie = reg;
252 		critical_enter();
253 	} else
254 		td->td_md.md_spinlock_count++;
255 }
256 
257 void
spinlock_exit(void)258 spinlock_exit(void)
259 {
260 	struct thread *td;
261 	register_t sstatus_ie;
262 
263 	td = curthread;
264 	sstatus_ie = td->td_md.md_saved_sstatus_ie;
265 	td->td_md.md_spinlock_count--;
266 	if (td->td_md.md_spinlock_count == 0) {
267 		critical_exit();
268 		intr_restore(sstatus_ie);
269 	}
270 }
271 
272 /*
273  * Construct a PCB from a trapframe. This is called from kdb_trap() where
274  * we want to start a backtrace from the function that caused us to enter
275  * the debugger. We have the context in the trapframe, but base the trace
276  * on the PCB. The PCB doesn't have to be perfect, as long as it contains
277  * enough for a backtrace.
278  */
279 void
makectx(struct trapframe * tf,struct pcb * pcb)280 makectx(struct trapframe *tf, struct pcb *pcb)
281 {
282 
283 	memcpy(pcb->pcb_s, tf->tf_s, sizeof(tf->tf_s));
284 
285 	pcb->pcb_ra = tf->tf_sepc;
286 	pcb->pcb_sp = tf->tf_sp;
287 	pcb->pcb_gp = tf->tf_gp;
288 	pcb->pcb_tp = tf->tf_tp;
289 }
290 
291 static void
init_proc0(vm_offset_t kstack)292 init_proc0(vm_offset_t kstack)
293 {
294 	struct pcpu *pcpup;
295 
296 	pcpup = &__pcpu[0];
297 
298 	proc_linkup0(&proc0, &thread0);
299 	thread0.td_kstack = kstack;
300 	thread0.td_kstack_pages = KSTACK_PAGES;
301 	thread0.td_pcb = (struct pcb *)(thread0.td_kstack +
302 	    thread0.td_kstack_pages * PAGE_SIZE) - 1;
303 	thread0.td_pcb->pcb_fpflags = 0;
304 	thread0.td_frame = &proc0_tf;
305 	pcpup->pc_curpcb = thread0.td_pcb;
306 }
307 
308 #ifdef FDT
309 static void
try_load_dtb(void)310 try_load_dtb(void)
311 {
312 	vm_offset_t dtbp;
313 
314 	dtbp = MD_FETCH(preload_kmdp, MODINFOMD_DTBP, vm_offset_t);
315 
316 #if defined(FDT_DTB_STATIC)
317 	/*
318 	 * In case the device tree blob was not retrieved (from metadata) try
319 	 * to use the statically embedded one.
320 	 */
321 	if (dtbp == (vm_offset_t)NULL)
322 		dtbp = (vm_offset_t)&fdt_static_dtb;
323 #endif
324 
325 	if (dtbp == (vm_offset_t)NULL) {
326 		printf("ERROR loading DTB\n");
327 		return;
328 	}
329 
330 	if (!OF_install(OFW_FDT, 0))
331 		panic("Cannot install FDT");
332 
333 	if (OF_init((void *)dtbp) != 0)
334 		panic("OF_init failed with the found device tree");
335 }
336 #endif
337 
338 /*
339  * Fake up a boot descriptor table.
340  */
341 static void
fake_preload_metadata(struct riscv_bootparams * rvbp)342 fake_preload_metadata(struct riscv_bootparams *rvbp)
343 {
344 	static uint32_t fake_preload[48];
345 	vm_offset_t lastaddr;
346 	size_t fake_size, dtb_size;
347 
348 #define PRELOAD_PUSH_VALUE(type, value) do {			\
349 	*(type *)((char *)fake_preload + fake_size) = (value);	\
350 	fake_size += sizeof(type);				\
351 } while (0)
352 
353 #define PRELOAD_PUSH_STRING(str) do {				\
354 	uint32_t ssize;						\
355 	ssize = strlen(str) + 1;				\
356 	PRELOAD_PUSH_VALUE(uint32_t, ssize);			\
357 	strcpy(((char *)fake_preload + fake_size), str);	\
358 	fake_size += ssize;					\
359 	fake_size = roundup(fake_size, sizeof(u_long));		\
360 } while (0)
361 
362 	fake_size = 0;
363 	lastaddr = (vm_offset_t)&end;
364 
365 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_NAME);
366 	PRELOAD_PUSH_STRING("kernel");
367 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_TYPE);
368 	PRELOAD_PUSH_STRING(preload_kerntype);
369 
370 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_ADDR);
371 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
372 	PRELOAD_PUSH_VALUE(uint64_t, KERNBASE);
373 
374 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_SIZE);
375 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(size_t));
376 	PRELOAD_PUSH_VALUE(uint64_t, (size_t)((vm_offset_t)&end - KERNBASE));
377 
378 	/*
379 	 * Copy the DTB to KVA space. We are able to dereference the physical
380 	 * address due to the identity map created in locore.
381 	 */
382 	lastaddr = roundup(lastaddr, sizeof(int));
383 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_METADATA | MODINFOMD_DTBP);
384 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
385 	PRELOAD_PUSH_VALUE(vm_offset_t, lastaddr);
386 	dtb_size = fdt_totalsize(rvbp->dtbp_phys);
387 	memmove((void *)lastaddr, (const void *)rvbp->dtbp_phys, dtb_size);
388 	lastaddr = roundup(lastaddr + dtb_size, sizeof(int));
389 
390 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_METADATA | MODINFOMD_KERNEND);
391 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(vm_offset_t));
392 	PRELOAD_PUSH_VALUE(vm_offset_t, lastaddr);
393 
394 	PRELOAD_PUSH_VALUE(uint32_t, MODINFO_METADATA | MODINFOMD_HOWTO);
395 	PRELOAD_PUSH_VALUE(uint32_t, sizeof(int));
396 	PRELOAD_PUSH_VALUE(int, RB_VERBOSE);
397 
398 	/* End marker */
399 	PRELOAD_PUSH_VALUE(uint32_t, 0);
400 	PRELOAD_PUSH_VALUE(uint32_t, 0);
401 	preload_metadata = (caddr_t)fake_preload;
402 
403 	/* Check if bootloader clobbered part of the kernel with the DTB. */
404 	KASSERT(rvbp->dtbp_phys + dtb_size <= rvbp->kern_phys ||
405 		rvbp->dtbp_phys >= rvbp->kern_phys + (lastaddr - KERNBASE),
406 	    ("FDT (%lx-%lx) and kernel (%lx-%lx) overlap", rvbp->dtbp_phys,
407 		rvbp->dtbp_phys + dtb_size, rvbp->kern_phys,
408 		rvbp->kern_phys + (lastaddr - KERNBASE)));
409 	KASSERT(fake_size < sizeof(fake_preload),
410 	    ("Too many fake_preload items"));
411 
412 	if (boothowto & RB_VERBOSE)
413 		printf("FDT phys (%lx-%lx), kernel phys (%lx-%lx)\n",
414 		    rvbp->dtbp_phys, rvbp->dtbp_phys + dtb_size,
415 		    rvbp->kern_phys, rvbp->kern_phys + (lastaddr - KERNBASE));
416 }
417 
418 /* Support for FDT configurations only. */
419 CTASSERT(FDT);
420 
421 #ifdef FDT
422 static void
parse_fdt_bootargs(void)423 parse_fdt_bootargs(void)
424 {
425 	char bootargs[512];
426 
427 	bootargs[sizeof(bootargs) - 1] = '\0';
428 	if (fdt_get_chosen_bootargs(bootargs, sizeof(bootargs) - 1) == 0) {
429 		boothowto |= boot_parse_cmdline(bootargs);
430 	}
431 }
432 #endif
433 
434 static vm_offset_t
parse_metadata(void)435 parse_metadata(void)
436 {
437 	vm_offset_t lastaddr;
438 #ifdef DDB
439 	vm_offset_t ksym_start, ksym_end;
440 #endif
441 	char *kern_envp;
442 
443 	/* Initialize preload_kmdp */
444 	preload_initkmdp(true);
445 
446 	/* Read the boot metadata */
447 	boothowto = MD_FETCH(preload_kmdp, MODINFOMD_HOWTO, int);
448 	lastaddr = MD_FETCH(preload_kmdp, MODINFOMD_KERNEND, vm_offset_t);
449 	kern_envp = MD_FETCH(preload_kmdp, MODINFOMD_ENVP, char *);
450 	if (kern_envp != NULL)
451 		init_static_kenv(kern_envp, 0);
452 	else
453 		init_static_kenv(static_kenv, sizeof(static_kenv));
454 #ifdef DDB
455 	ksym_start = MD_FETCH(preload_kmdp, MODINFOMD_SSYM, uintptr_t);
456 	ksym_end = MD_FETCH(preload_kmdp, MODINFOMD_ESYM, uintptr_t);
457 	db_fetch_ksymtab(ksym_start, ksym_end, 0);
458 #endif
459 #ifdef FDT
460 	try_load_dtb();
461 	if (kern_envp == NULL)
462 		parse_fdt_bootargs();
463 #endif
464 	return (lastaddr);
465 }
466 
467 void
initriscv(struct riscv_bootparams * rvbp)468 initriscv(struct riscv_bootparams *rvbp)
469 {
470 	struct mem_region mem_regions[FDT_MEM_REGIONS];
471 	struct pcpu *pcpup;
472 	int mem_regions_sz;
473 	vm_offset_t lastaddr;
474 	vm_size_t kernlen;
475 #ifdef FDT
476 	phandle_t chosen;
477 	uint32_t hart;
478 #endif
479 	char *env;
480 
481 	TSRAW(&thread0, TS_ENTER, __func__, NULL);
482 
483 	/* Set the pcpu data, this is needed by pmap_bootstrap */
484 	pcpup = &__pcpu[0];
485 	pcpu_init(pcpup, 0, sizeof(struct pcpu));
486 
487 	/* Set the pcpu pointer */
488 	__asm __volatile("mv tp, %0" :: "r"(pcpup));
489 
490 	PCPU_SET(curthread, &thread0);
491 
492 	/* Initialize SBI interface. */
493 	sbi_init();
494 
495 	/* Parse the boot metadata. */
496 	if (rvbp->modulep != 0) {
497 		preload_metadata = (caddr_t)rvbp->modulep;
498 	} else {
499 		fake_preload_metadata(rvbp);
500 	}
501 	lastaddr = parse_metadata();
502 
503 #ifdef FDT
504 	/*
505 	 * Look for the boot hart ID. This was either passed in directly from
506 	 * the SBI firmware and handled by locore, or was stored in the device
507 	 * tree by an earlier boot stage.
508 	 */
509 	chosen = OF_finddevice("/chosen");
510 	if (OF_getencprop(chosen, "boot-hartid", &hart, sizeof(hart)) != -1) {
511 		boot_hart = hart;
512 	}
513 #endif
514 	if (boot_hart == BOOT_HART_INVALID) {
515 		panic("Boot hart ID was not properly set");
516 	}
517 	pcpup->pc_hart = boot_hart;
518 
519 #ifdef FDT
520 	/*
521 	 * Exclude reserved memory specified by the device tree. Typically,
522 	 * this contains an entry for memory used by the runtime SBI firmware.
523 	 */
524 	if (fdt_get_reserved_mem(mem_regions, &mem_regions_sz) == 0) {
525 		physmem_exclude_regions(mem_regions, mem_regions_sz,
526 		    EXFLAG_NODUMP | EXFLAG_NOALLOC);
527 	}
528 
529 	/* Grab physical memory regions information from device tree. */
530 	if (fdt_get_mem_regions(mem_regions, &mem_regions_sz, NULL) != 0) {
531 		panic("Cannot get physical memory regions");
532 	}
533 	physmem_hardware_regions(mem_regions, mem_regions_sz);
534 #endif
535 
536 	/*
537 	 * Identify CPU/ISA features.
538 	 */
539 	identify_cpu(0);
540 
541 	/* Do basic tuning, hz etc */
542 	init_param1();
543 
544 #ifdef FDT
545 	/*
546 	 * XXX: Unconditionally exclude the lowest 2MB of physical memory, as
547 	 * this area is assumed to contain the SBI firmware. This is a little
548 	 * fragile, but it is consistent with the platforms we support so far.
549 	 *
550 	 * TODO: remove this when the all regular booting methods properly
551 	 * report their reserved memory in the device tree.
552 	 */
553 	physmem_exclude_region(mem_regions[0].mr_start, L2_SIZE,
554 	    EXFLAG_NODUMP | EXFLAG_NOALLOC);
555 #endif
556 
557 	/* Bootstrap enough of pmap to enter the kernel proper */
558 	kernlen = (lastaddr - KERNBASE);
559 	pmap_bootstrap(rvbp->kern_phys, kernlen);
560 
561 	physmem_init_kernel_globals();
562 
563 	/* Establish static device mappings */
564 	devmap_bootstrap();
565 
566 	cninit();
567 
568 	/*
569 	 * Dump the boot metadata. We have to wait for cninit() since console
570 	 * output is required. If it's grossly incorrect the kernel will never
571 	 * make it this far.
572 	 */
573 	if (getenv_is_true("debug.dump_modinfo_at_boot"))
574 		preload_dump();
575 
576 	init_proc0(rvbp->kern_stack);
577 
578 	msgbufinit(msgbufp, msgbufsize);
579 	mutex_init();
580 	init_param2(physmem);
581 	kdb_init();
582 #ifdef KDB
583 	if ((boothowto & RB_KDB) != 0)
584 		kdb_enter(KDB_WHY_BOOTFLAGS, "Boot flags requested debugger");
585 #endif
586 
587 	env = kern_getenv("kernelname");
588 	if (env != NULL)
589 		strlcpy(kernelname, env, sizeof(kernelname));
590 
591 	if (boothowto & RB_VERBOSE)
592 		physmem_print_tables();
593 
594 	early_boot = 0;
595 
596 	if (bootverbose && kstack_pages != KSTACK_PAGES)
597 		printf("kern.kstack_pages = %d ignored for thread0\n",
598 		    kstack_pages);
599 
600 	TSEXIT();
601 }
602