~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/riscv/kernel/sbi.c

Version: ~ [ linux-6.11.5 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.58 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.114 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.169 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.228 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.284 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.322 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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
 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  */
 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  */
 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  */
 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  */
 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 
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 
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 
149 static void sbi_set_power_off(void)
150 {
151         pm_power_off = sbi_shutdown;
152 }
153 #else
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 
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 
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 
176 static void sbi_set_power_off(void) {}
177 #endif /* CONFIG_RISCV_SBI_V01 */
178 
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 
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 
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 
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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 
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 
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 
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  */
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 
486 static inline long sbi_get_spec_version(void)
487 {
488         return __sbi_base_ecall(SBI_EXT_BASE_GET_SPEC_VERSION);
489 }
490 
491 static inline long sbi_get_firmware_id(void)
492 {
493         return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_ID);
494 }
495 
496 static inline long sbi_get_firmware_version(void)
497 {
498         return __sbi_base_ecall(SBI_EXT_BASE_GET_IMP_VERSION);
499 }
500 
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 
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 
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 
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 
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 
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 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

sflogo.php