1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * SBI initialilization and all extension implementation.
4 *
5 * Copyright (c) 2020 Western Digital Corporation or its affiliates.
6 */
7
8 #include <linux/bits.h>
9 #include <linux/init.h>
10 #include <linux/mm.h>
11 #include <linux/pm.h>
12 #include <linux/reboot.h>
13 #include <asm/sbi.h>
14 #include <asm/smp.h>
15 #include <asm/tlbflush.h>
16
17 /* default SBI version is 0.1 */
18 unsigned long sbi_spec_version __ro_after_init = SBI_SPEC_VERSION_DEFAULT;
19 EXPORT_SYMBOL(sbi_spec_version);
20
21 static void (*__sbi_set_timer)(uint64_t stime) __ro_after_init;
22 static void (*__sbi_send_ipi)(unsigned int cpu) __ro_after_init;
23 static int (*__sbi_rfence)(int fid, const struct cpumask *cpu_mask,
24 unsigned long start, unsigned long size,
25 unsigned long arg4, unsigned long arg5) __ro_after_init;
26
27 #ifdef CONFIG_RISCV_SBI_V01
__sbi_v01_cpumask_to_hartmask(const struct cpumask * cpu_mask)28 static unsigned long __sbi_v01_cpumask_to_hartmask(const struct cpumask *cpu_mask)
29 {
30 unsigned long cpuid, hartid;
31 unsigned long hmask = 0;
32
33 /*
34 * There is no maximum hartid concept in RISC-V and NR_CPUS must not be
35 * associated with hartid. As SBI v0.1 is only kept for backward compatibility
36 * and will be removed in the future, there is no point in supporting hartid
37 * greater than BITS_PER_LONG (32 for RV32 and 64 for RV64). Ideally, SBI v0.2
38 * should be used for platforms with hartid greater than BITS_PER_LONG.
39 */
40 for_each_cpu(cpuid, cpu_mask) {
41 hartid = cpuid_to_hartid_map(cpuid);
42 if (hartid >= BITS_PER_LONG) {
43 pr_warn("Unable to send any request to hartid > BITS_PER_LONG for SBI v0.1\n");
44 break;
45 }
46 hmask |= BIT(hartid);
47 }
48
49 return hmask;
50 }
51
52 /**
53 * sbi_console_putchar() - Writes given character to the console device.
54 * @ch: The data to be written to the console.
55 *
56 * Return: None
57 */
sbi_console_putchar(int ch)58 void sbi_console_putchar(int ch)
59 {
60 sbi_ecall(SBI_EXT_0_1_CONSOLE_PUTCHAR, 0, ch, 0, 0, 0, 0, 0);
61 }
62 EXPORT_SYMBOL(sbi_console_putchar);
63
64 /**
65 * sbi_console_getchar() - Reads a byte from console device.
66 *
67 * Returns the value read from console.
68 */
sbi_console_getchar(void)69 int sbi_console_getchar(void)
70 {
71 struct sbiret ret;
72
73 ret = sbi_ecall(SBI_EXT_0_1_CONSOLE_GETCHAR, 0, 0, 0, 0, 0, 0, 0);
74
75 return ret.error;
76 }
77 EXPORT_SYMBOL(sbi_console_getchar);
78
79 /**
80 * sbi_shutdown() - Remove all the harts from executing supervisor code.
81 *
82 * Return: None
83 */
sbi_shutdown(void)84 void sbi_shutdown(void)
85 {
86 sbi_ecall(SBI_EXT_0_1_SHUTDOWN, 0, 0, 0, 0, 0, 0, 0);
87 }
88 EXPORT_SYMBOL(sbi_shutdown);
89
90 /**
91 * __sbi_set_timer_v01() - Program the timer for next timer event.
92 * @stime_value: The value after which next timer event should fire.
93 *
94 * Return: None
95 */
__sbi_set_timer_v01(uint64_t stime_value)96 static void __sbi_set_timer_v01(uint64_t stime_value)
97 {
98 #if __riscv_xlen == 32
99 sbi_ecall(SBI_EXT_0_1_SET_TIMER, 0, stime_value,
100 stime_value >> 32, 0, 0, 0, 0);
101 #else
102 sbi_ecall(SBI_EXT_0_1_SET_TIMER, 0, stime_value, 0, 0, 0, 0, 0);
103 #endif
104 }
105
__sbi_send_ipi_v01(unsigned int cpu)106 static void __sbi_send_ipi_v01(unsigned int cpu)
107 {
108 unsigned long hart_mask =
109 __sbi_v01_cpumask_to_hartmask(cpumask_of(cpu));
110 sbi_ecall(SBI_EXT_0_1_SEND_IPI, 0, (unsigned long)(&hart_mask),
111 0, 0, 0, 0, 0);
112 }
113
__sbi_rfence_v01(int fid,const struct cpumask * cpu_mask,unsigned long start,unsigned long size,unsigned long arg4,unsigned long arg5)114 static int __sbi_rfence_v01(int fid, const struct cpumask *cpu_mask,
115 unsigned long start, unsigned long size,
116 unsigned long arg4, unsigned long arg5)
117 {
118 int result = 0;
119 unsigned long hart_mask;
120
121 if (!cpu_mask || cpumask_empty(cpu_mask))
122 cpu_mask = cpu_online_mask;
123 hart_mask = __sbi_v01_cpumask_to_hartmask(cpu_mask);
124
125 /* v0.2 function IDs are equivalent to v0.1 extension IDs */
126 switch (fid) {
127 case SBI_EXT_RFENCE_REMOTE_FENCE_I:
128 sbi_ecall(SBI_EXT_0_1_REMOTE_FENCE_I, 0,
129 (unsigned long)&hart_mask, 0, 0, 0, 0, 0);
130 break;
131 case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
132 sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA, 0,
133 (unsigned long)&hart_mask, start, size,
134 0, 0, 0);
135 break;
136 case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
137 sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, 0,
138 (unsigned long)&hart_mask, start, size,
139 arg4, 0, 0);
140 break;
141 default:
142 pr_err("SBI call [%d]not supported in SBI v0.1\n", fid);
143 result = -EINVAL;
144 }
145
146 return result;
147 }
148
sbi_set_power_off(void)149 static void sbi_set_power_off(void)
150 {
151 pm_power_off = sbi_shutdown;
152 }
153 #else
__sbi_set_timer_v01(uint64_t stime_value)154 static void __sbi_set_timer_v01(uint64_t stime_value)
155 {
156 pr_warn("Timer extension is not available in SBI v%lu.%lu\n",
157 sbi_major_version(), sbi_minor_version());
158 }
159
__sbi_send_ipi_v01(unsigned int cpu)160 static void __sbi_send_ipi_v01(unsigned int cpu)
161 {
162 pr_warn("IPI extension is not available in SBI v%lu.%lu\n",
163 sbi_major_version(), sbi_minor_version());
164 }
165
__sbi_rfence_v01(int fid,const struct cpumask * cpu_mask,unsigned long start,unsigned long size,unsigned long arg4,unsigned long arg5)166 static int __sbi_rfence_v01(int fid, const struct cpumask *cpu_mask,
167 unsigned long start, unsigned long size,
168 unsigned long arg4, unsigned long arg5)
169 {
170 pr_warn("remote fence extension is not available in SBI v%lu.%lu\n",
171 sbi_major_version(), sbi_minor_version());
172
173 return 0;
174 }
175
sbi_set_power_off(void)176 static void sbi_set_power_off(void) {}
177 #endif /* CONFIG_RISCV_SBI_V01 */
178
__sbi_set_timer_v02(uint64_t stime_value)179 static void __sbi_set_timer_v02(uint64_t stime_value)
180 {
181 #if __riscv_xlen == 32
182 sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value,
183 stime_value >> 32, 0, 0, 0, 0);
184 #else
185 sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0,
186 0, 0, 0, 0);
187 #endif
188 }
189
__sbi_send_ipi_v02(unsigned int cpu)190 static void __sbi_send_ipi_v02(unsigned int cpu)
191 {
192 int result;
193 struct sbiret ret = {0};
194
195 ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI,
196 1UL, cpuid_to_hartid_map(cpu), 0, 0, 0, 0);
197 if (ret.error) {
198 result = sbi_err_map_linux_errno(ret.error);
199 pr_err("%s: hbase = [%lu] failed (error [%d])\n",
200 __func__, cpuid_to_hartid_map(cpu), result);
201 }
202 }
203
__sbi_rfence_v02_call(unsigned long fid,unsigned long hmask,unsigned long hbase,unsigned long start,unsigned long size,unsigned long arg4,unsigned long arg5)204 static int __sbi_rfence_v02_call(unsigned long fid, unsigned long hmask,
205 unsigned long hbase, unsigned long start,
206 unsigned long size, unsigned long arg4,
207 unsigned long arg5)
208 {
209 struct sbiret ret = {0};
210 int ext = SBI_EXT_RFENCE;
211 int result = 0;
212
213 switch (fid) {
214 case SBI_EXT_RFENCE_REMOTE_FENCE_I:
215 ret = sbi_ecall(ext, fid, hmask, hbase, 0, 0, 0, 0);
216 break;
217 case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
218 ret = sbi_ecall(ext, fid, hmask, hbase, start,
219 size, 0, 0);
220 break;
221 case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
222 ret = sbi_ecall(ext, fid, hmask, hbase, start,
223 size, arg4, 0);
224 break;
225
226 case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA:
227 ret = sbi_ecall(ext, fid, hmask, hbase, start,
228 size, 0, 0);
229 break;
230 case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID:
231 ret = sbi_ecall(ext, fid, hmask, hbase, start,
232 size, arg4, 0);
233 break;
234 case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA:
235 ret = sbi_ecall(ext, fid, hmask, hbase, start,
236 size, 0, 0);
237 break;
238 case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID:
239 ret = sbi_ecall(ext, fid, hmask, hbase, start,
240 size, arg4, 0);
241 break;
242 default:
243 pr_err("unknown function ID [%lu] for SBI extension [%d]\n",
244 fid, ext);
245 result = -EINVAL;
246 }
247
248 if (ret.error) {
249 result = sbi_err_map_linux_errno(ret.error);
250 pr_err("%s: hbase = [%lu] hmask = [0x%lx] failed (error [%d])\n",
251 __func__, hbase, hmask, result);
252 }
253
254 return result;
255 }
256
__sbi_rfence_v02(int fid,const struct cpumask * cpu_mask,unsigned long start,unsigned long size,unsigned long arg4,unsigned long arg5)257 static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask,
258 unsigned long start, unsigned long size,
259 unsigned long arg4, unsigned long arg5)
260 {
261 unsigned long hartid, cpuid, hmask = 0, hbase = 0, htop = 0;
262 int result;
263
264 if (!cpu_mask || cpumask_empty(cpu_mask))
265 cpu_mask = cpu_online_mask;
266
267 for_each_cpu(cpuid, cpu_mask) {
268 hartid = cpuid_to_hartid_map(cpuid);
269 if (hmask) {
270 if (hartid + BITS_PER_LONG <= htop ||
271 hbase + BITS_PER_LONG <= hartid) {
272 result = __sbi_rfence_v02_call(fid, hmask,
273 hbase, start, size, arg4, arg5);
274 if (result)
275 return result;
276 hmask = 0;
277 } else if (hartid < hbase) {
278 /* shift the mask to fit lower hartid */
279 hmask <<= hbase - hartid;
280 hbase = hartid;
281 }
282 }
283 if (!hmask) {
284 hbase = hartid;
285 htop = hartid;
286 } else if (hartid > htop) {
287 htop = hartid;
288 }
289 hmask |= BIT(hartid - hbase);
290 }
291
292 if (hmask) {
293 result = __sbi_rfence_v02_call(fid, hmask, hbase,
294 start, size, arg4, arg5);
295 if (result)
296 return result;
297 }
298
299 return 0;
300 }
301
302 /**
303 * sbi_set_timer() - Program the timer for next timer event.
304 * @stime_value: The value after which next timer event should fire.
305 *
306 * Return: None.
307 */
sbi_set_timer(uint64_t stime_value)308 void sbi_set_timer(uint64_t stime_value)
309 {
310 __sbi_set_timer(stime_value);
311 }
312
313 /**
314 * sbi_send_ipi() - Send an IPI to any hart.
315 * @cpu: Logical id of the target CPU.
316 */
sbi_send_ipi(unsigned int cpu)317 void sbi_send_ipi(unsigned int cpu)
318 {
319 __sbi_send_ipi(cpu);
320 }
321 EXPORT_SYMBOL(sbi_send_ipi);
322
323 /**
324 * sbi_remote_fence_i() - Execute FENCE.I instruction on given remote harts.
325 * @cpu_mask: A cpu mask containing all the target harts.
326 *
327 * Return: 0 on success, appropriate linux error code otherwise.
328 */
sbi_remote_fence_i(const struct cpumask * cpu_mask)329 int sbi_remote_fence_i(const struct cpumask *cpu_mask)
330 {
331 return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_FENCE_I,
332 cpu_mask, 0, 0, 0, 0);
333 }
334 EXPORT_SYMBOL(sbi_remote_fence_i);
335
336 /**
337 * sbi_remote_sfence_vma_asid() - Execute SFENCE.VMA instructions on given
338 * remote harts for a virtual address range belonging to a specific ASID or not.
339 *
340 * @cpu_mask: A cpu mask containing all the target harts.
341 * @start: Start of the virtual address
342 * @size: Total size of the virtual address range.
343 * @asid: The value of address space identifier (ASID), or FLUSH_TLB_NO_ASID
344 * for flushing all address spaces.
345 *
346 * Return: 0 on success, appropriate linux error code otherwise.
347 */
sbi_remote_sfence_vma_asid(const struct cpumask * cpu_mask,unsigned long start,unsigned long size,unsigned long asid)348 int sbi_remote_sfence_vma_asid(const struct cpumask *cpu_mask,
349 unsigned long start,
350 unsigned long size,
351 unsigned long asid)
352 {
353 if (asid == FLUSH_TLB_NO_ASID)
354 return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_SFENCE_VMA,
355 cpu_mask, start, size, 0, 0);
356 else
357 return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID,
358 cpu_mask, start, size, asid, 0);
359 }
360 EXPORT_SYMBOL(sbi_remote_sfence_vma_asid);
361
362 /**
363 * sbi_remote_hfence_gvma() - Execute HFENCE.GVMA instructions on given remote
364 * harts for the specified guest physical address range.
365 * @cpu_mask: A cpu mask containing all the target harts.
366 * @start: Start of the guest physical address
367 * @size: Total size of the guest physical address range.
368 *
369 * Return: None
370 */
sbi_remote_hfence_gvma(const struct cpumask * cpu_mask,unsigned long start,unsigned long size)371 int sbi_remote_hfence_gvma(const struct cpumask *cpu_mask,
372 unsigned long start,
373 unsigned long size)
374 {
375 return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA,
376 cpu_mask, start, size, 0, 0);
377 }
378 EXPORT_SYMBOL_GPL(sbi_remote_hfence_gvma);
379
380 /**
381 * sbi_remote_hfence_gvma_vmid() - Execute HFENCE.GVMA instructions on given
382 * remote harts for a guest physical address range belonging to a specific VMID.
383 *
384 * @cpu_mask: A cpu mask containing all the target harts.
385 * @start: Start of the guest physical address
386 * @size: Total size of the guest physical address range.
387 * @vmid: The value of guest ID (VMID).
388 *
389 * Return: 0 if success, Error otherwise.
390 */
sbi_remote_hfence_gvma_vmid(const struct cpumask * cpu_mask,unsigned long start,unsigned long size,unsigned long vmid)391 int sbi_remote_hfence_gvma_vmid(const struct cpumask *cpu_mask,
392 unsigned long start,
393 unsigned long size,
394 unsigned long vmid)
395 {
396 return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID,
397 cpu_mask, start, size, vmid, 0);
398 }
399 EXPORT_SYMBOL(sbi_remote_hfence_gvma_vmid);
400
401 /**
402 * sbi_remote_hfence_vvma() - Execute HFENCE.VVMA instructions on given remote
403 * harts for the current guest virtual address range.
404 * @cpu_mask: A cpu mask containing all the target harts.
405 * @start: Start of the current guest virtual address
406 * @size: Total size of the current guest virtual address range.
407 *
408 * Return: None
409 */
sbi_remote_hfence_vvma(const struct cpumask * cpu_mask,unsigned long start,unsigned long size)410 int sbi_remote_hfence_vvma(const struct cpumask *cpu_mask,
411 unsigned long start,
412 unsigned long size)
413 {
414 return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA,
415 cpu_mask, start, size, 0, 0);
416 }
417 EXPORT_SYMBOL(sbi_remote_hfence_vvma);
418
419 /**
420 * sbi_remote_hfence_vvma_asid() - Execute HFENCE.VVMA instructions on given
421 * remote harts for current guest virtual address range belonging to a specific
422 * ASID.
423 *
424 * @cpu_mask: A cpu mask containing all the target harts.
425 * @start: Start of the current guest virtual address
426 * @size: Total size of the current guest virtual address range.
427 * @asid: The value of address space identifier (ASID).
428 *
429 * Return: None
430 */
sbi_remote_hfence_vvma_asid(const struct cpumask * cpu_mask,unsigned long start,unsigned long size,unsigned long asid)431 int sbi_remote_hfence_vvma_asid(const struct cpumask *cpu_mask,
432 unsigned long start,
433 unsigned long size,
434 unsigned long asid)
435 {
436 return __sbi_rfence(SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID,
437 cpu_mask, start, size, asid, 0);
438 }
439 EXPORT_SYMBOL(sbi_remote_hfence_vvma_asid);
440
sbi_srst_reset(unsigned long type,unsigned long reason)441 static void sbi_srst_reset(unsigned long type, unsigned long reason)
442 {
443 sbi_ecall(SBI_EXT_SRST, SBI_EXT_SRST_RESET, type, reason,
444 0, 0, 0, 0);
445 pr_warn("%s: type=0x%lx reason=0x%lx failed\n",
446 __func__, type, reason);
447 }
448
sbi_srst_reboot(struct notifier_block * this,unsigned long mode,void * cmd)449 static int sbi_srst_reboot(struct notifier_block *this,
450 unsigned long mode, void *cmd)
451 {
452 sbi_srst_reset((mode == REBOOT_WARM || mode == REBOOT_SOFT) ?
453 SBI_SRST_RESET_TYPE_WARM_REBOOT :
454 SBI_SRST_RESET_TYPE_COLD_REBOOT,
455 SBI_SRST_RESET_REASON_NONE);
456 return NOTIFY_DONE;
457 }
458
459 static struct notifier_block sbi_srst_reboot_nb;
460
sbi_srst_power_off(void)461 static void sbi_srst_power_off(void)
462 {
463 sbi_srst_reset(SBI_SRST_RESET_TYPE_SHUTDOWN,
464 SBI_SRST_RESET_REASON_NONE);
465 }
466
467 /**
468 * sbi_probe_extension() - Check if an SBI extension ID is supported or not.
469 * @extid: The extension ID to be probed.
470 *
471 * Return: 1 or an extension specific nonzero value if yes, 0 otherwise.
472 */
sbi_probe_extension(int extid)473 long sbi_probe_extension(int extid)
474 {
475 struct sbiret ret;
476
477 ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, extid,
478 0, 0, 0, 0, 0);
479 if (!ret.error)
480 return ret.value;
481
482 return 0;
483 }
484 EXPORT_SYMBOL(sbi_probe_extension);
485
sbi_get_spec_version(void)486 static inline long sbi_get_spec_version(void)
487 {
488 return __sbi_base_ecall(SBI_EXT_BASE_GET_SPEC_VERSION);
489 }
490
sbi_get_firmware_id(void)491 static inline long sbi_get_firmware_id(void)
492 {
493 return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_ID);
494 }
495
sbi_get_firmware_version(void)496 static inline long sbi_get_firmware_version(void)
497 {
498 return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_VERSION);
499 }
500
sbi_get_mvendorid(void)501 long sbi_get_mvendorid(void)
502 {
503 return __sbi_base_ecall(SBI_EXT_BASE_GET_MVENDORID);
504 }
505 EXPORT_SYMBOL_GPL(sbi_get_mvendorid);
506
sbi_get_marchid(void)507 long sbi_get_marchid(void)
508 {
509 return __sbi_base_ecall(SBI_EXT_BASE_GET_MARCHID);
510 }
511 EXPORT_SYMBOL_GPL(sbi_get_marchid);
512
sbi_get_mimpid(void)513 long sbi_get_mimpid(void)
514 {
515 return __sbi_base_ecall(SBI_EXT_BASE_GET_MIMPID);
516 }
517 EXPORT_SYMBOL_GPL(sbi_get_mimpid);
518
519 bool sbi_debug_console_available;
520
sbi_debug_console_write(const char * bytes,unsigned int num_bytes)521 int sbi_debug_console_write(const char *bytes, unsigned int num_bytes)
522 {
523 phys_addr_t base_addr;
524 struct sbiret ret;
525
526 if (!sbi_debug_console_available)
527 return -EOPNOTSUPP;
528
529 if (is_vmalloc_addr(bytes))
530 base_addr = page_to_phys(vmalloc_to_page(bytes)) +
531 offset_in_page(bytes);
532 else
533 base_addr = __pa(bytes);
534 if (PAGE_SIZE < (offset_in_page(bytes) + num_bytes))
535 num_bytes = PAGE_SIZE - offset_in_page(bytes);
536
537 if (IS_ENABLED(CONFIG_32BIT))
538 ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
539 num_bytes, lower_32_bits(base_addr),
540 upper_32_bits(base_addr), 0, 0, 0);
541 else
542 ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_WRITE,
543 num_bytes, base_addr, 0, 0, 0, 0);
544
545 if (ret.error == SBI_ERR_FAILURE)
546 return -EIO;
547 return ret.error ? sbi_err_map_linux_errno(ret.error) : ret.value;
548 }
549
sbi_debug_console_read(char * bytes,unsigned int num_bytes)550 int sbi_debug_console_read(char *bytes, unsigned int num_bytes)
551 {
552 phys_addr_t base_addr;
553 struct sbiret ret;
554
555 if (!sbi_debug_console_available)
556 return -EOPNOTSUPP;
557
558 if (is_vmalloc_addr(bytes))
559 base_addr = page_to_phys(vmalloc_to_page(bytes)) +
560 offset_in_page(bytes);
561 else
562 base_addr = __pa(bytes);
563 if (PAGE_SIZE < (offset_in_page(bytes) + num_bytes))
564 num_bytes = PAGE_SIZE - offset_in_page(bytes);
565
566 if (IS_ENABLED(CONFIG_32BIT))
567 ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ,
568 num_bytes, lower_32_bits(base_addr),
569 upper_32_bits(base_addr), 0, 0, 0);
570 else
571 ret = sbi_ecall(SBI_EXT_DBCN, SBI_EXT_DBCN_CONSOLE_READ,
572 num_bytes, base_addr, 0, 0, 0, 0);
573
574 if (ret.error == SBI_ERR_FAILURE)
575 return -EIO;
576 return ret.error ? sbi_err_map_linux_errno(ret.error) : ret.value;
577 }
578
sbi_init(void)579 void __init sbi_init(void)
580 {
581 int ret;
582
583 sbi_set_power_off();
584 ret = sbi_get_spec_version();
585 if (ret > 0)
586 sbi_spec_version = ret;
587
588 pr_info("SBI specification v%lu.%lu detected\n",
589 sbi_major_version(), sbi_minor_version());
590
591 if (!sbi_spec_is_0_1()) {
592 pr_info("SBI implementation ID=0x%lx Version=0x%lx\n",
593 sbi_get_firmware_id(), sbi_get_firmware_version());
594 if (sbi_probe_extension(SBI_EXT_TIME)) {
595 __sbi_set_timer = __sbi_set_timer_v02;
596 pr_info("SBI TIME extension detected\n");
597 } else {
598 __sbi_set_timer = __sbi_set_timer_v01;
599 }
600 if (sbi_probe_extension(SBI_EXT_IPI)) {
601 __sbi_send_ipi = __sbi_send_ipi_v02;
602 pr_info("SBI IPI extension detected\n");
603 } else {
604 __sbi_send_ipi = __sbi_send_ipi_v01;
605 }
606 if (sbi_probe_extension(SBI_EXT_RFENCE)) {
607 __sbi_rfence = __sbi_rfence_v02;
608 pr_info("SBI RFENCE extension detected\n");
609 } else {
610 __sbi_rfence = __sbi_rfence_v01;
611 }
612 if ((sbi_spec_version >= sbi_mk_version(0, 3)) &&
613 sbi_probe_extension(SBI_EXT_SRST)) {
614 pr_info("SBI SRST extension detected\n");
615 pm_power_off = sbi_srst_power_off;
616 sbi_srst_reboot_nb.notifier_call = sbi_srst_reboot;
617 sbi_srst_reboot_nb.priority = 192;
618 register_restart_handler(&sbi_srst_reboot_nb);
619 }
620 if ((sbi_spec_version >= sbi_mk_version(2, 0)) &&
621 (sbi_probe_extension(SBI_EXT_DBCN) > 0)) {
622 pr_info("SBI DBCN extension detected\n");
623 sbi_debug_console_available = true;
624 }
625 } else {
626 __sbi_set_timer = __sbi_set_timer_v01;
627 __sbi_send_ipi = __sbi_send_ipi_v01;
628 __sbi_rfence = __sbi_rfence_v01;
629 }
630 }
631