1 /*
2 * ePAPR hcall interface
3 *
4 * Copyright 2008-2011 Freescale Semiconductor, Inc.
5 *
6 * Author: Timur Tabi <timur@freescale.com>
7 *
8 * This file is provided under a dual BSD/GPL license. When using or
9 * redistributing this file, you may do so under either license.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions are met:
13 * * Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * * Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * * Neither the name of Freescale Semiconductor nor the
19 * names of its contributors may be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 *
23 * ALTERNATIVELY, this software may be distributed under the terms of the
24 * GNU General Public License ("GPL") as published by the Free Software
25 * Foundation, either version 2 of that License or (at your option) any
26 * later version.
27 *
28 * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
29 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
30 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
31 * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
32 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
33 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
35 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
37 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 /* A "hypercall" is an "sc 1" instruction. This header file file provides C
41 * wrapper functions for the ePAPR hypervisor interface. It is inteded
42 * for use by Linux device drivers and other operating systems.
43 *
44 * The hypercalls are implemented as inline assembly, rather than assembly
45 * language functions in a .S file, for optimization. It allows
46 * the caller to issue the hypercall instruction directly, improving both
47 * performance and memory footprint.
48 */
49
50 #ifndef _EPAPR_HCALLS_H
51 #define _EPAPR_HCALLS_H
52
53 #include <linux/types.h>
54 #include <linux/errno.h>
55 #include <asm/byteorder.h>
56
57 #define EV_BYTE_CHANNEL_SEND 1
58 #define EV_BYTE_CHANNEL_RECEIVE 2
59 #define EV_BYTE_CHANNEL_POLL 3
60 #define EV_INT_SET_CONFIG 4
61 #define EV_INT_GET_CONFIG 5
62 #define EV_INT_SET_MASK 6
63 #define EV_INT_GET_MASK 7
64 #define EV_INT_IACK 9
65 #define EV_INT_EOI 10
66 #define EV_INT_SEND_IPI 11
67 #define EV_INT_SET_TASK_PRIORITY 12
68 #define EV_INT_GET_TASK_PRIORITY 13
69 #define EV_DOORBELL_SEND 14
70 #define EV_MSGSND 15
71 #define EV_IDLE 16
72
73 /* vendor ID: epapr */
74 #define EV_LOCAL_VENDOR_ID 0 /* for private use */
75 #define EV_EPAPR_VENDOR_ID 1
76 #define EV_FSL_VENDOR_ID 2 /* Freescale Semiconductor */
77 #define EV_IBM_VENDOR_ID 3 /* IBM */
78 #define EV_GHS_VENDOR_ID 4 /* Green Hills Software */
79 #define EV_ENEA_VENDOR_ID 5 /* Enea */
80 #define EV_WR_VENDOR_ID 6 /* Wind River Systems */
81 #define EV_AMCC_VENDOR_ID 7 /* Applied Micro Circuits */
82 #define EV_KVM_VENDOR_ID 42 /* KVM */
83
84 /* The max number of bytes that a byte channel can send or receive per call */
85 #define EV_BYTE_CHANNEL_MAX_BYTES 16
86
87
88 #define _EV_HCALL_TOKEN(id, num) (((id) << 16) | (num))
89 #define EV_HCALL_TOKEN(hcall_num) _EV_HCALL_TOKEN(EV_EPAPR_VENDOR_ID, hcall_num)
90
91 /* epapr error codes */
92 #define EV_EPERM 1 /* Operation not permitted */
93 #define EV_ENOENT 2 /* Entry Not Found */
94 #define EV_EIO 3 /* I/O error occured */
95 #define EV_EAGAIN 4 /* The operation had insufficient
96 * resources to complete and should be
97 * retried
98 */
99 #define EV_ENOMEM 5 /* There was insufficient memory to
100 * complete the operation */
101 #define EV_EFAULT 6 /* Bad guest address */
102 #define EV_ENODEV 7 /* No such device */
103 #define EV_EINVAL 8 /* An argument supplied to the hcall
104 was out of range or invalid */
105 #define EV_INTERNAL 9 /* An internal error occured */
106 #define EV_CONFIG 10 /* A configuration error was detected */
107 #define EV_INVALID_STATE 11 /* The object is in an invalid state */
108 #define EV_UNIMPLEMENTED 12 /* Unimplemented hypercall */
109 #define EV_BUFFER_OVERFLOW 13 /* Caller-supplied buffer too small */
110
111 /*
112 * Hypercall register clobber list
113 *
114 * These macros are used to define the list of clobbered registers during a
115 * hypercall. Technically, registers r0 and r3-r12 are always clobbered,
116 * but the gcc inline assembly syntax does not allow us to specify registers
117 * on the clobber list that are also on the input/output list. Therefore,
118 * the lists of clobbered registers depends on the number of register
119 * parmeters ("+r" and "=r") passed to the hypercall.
120 *
121 * Each assembly block should use one of the HCALL_CLOBBERSx macros. As a
122 * general rule, 'x' is the number of parameters passed to the assembly
123 * block *except* for r11.
124 *
125 * If you're not sure, just use the smallest value of 'x' that does not
126 * generate a compilation error. Because these are static inline functions,
127 * the compiler will only check the clobber list for a function if you
128 * compile code that calls that function.
129 *
130 * r3 and r11 are not included in any clobbers list because they are always
131 * listed as output registers.
132 *
133 * XER, CTR, and LR are currently listed as clobbers because it's uncertain
134 * whether they will be clobbered.
135 *
136 * Note that r11 can be used as an output parameter.
137 */
138
139 /* List of common clobbered registers. Do not use this macro. */
140 #define EV_HCALL_CLOBBERS "r0", "r12", "xer", "ctr", "lr", "cc"
141
142 #define EV_HCALL_CLOBBERS8 EV_HCALL_CLOBBERS
143 #define EV_HCALL_CLOBBERS7 EV_HCALL_CLOBBERS8, "r10"
144 #define EV_HCALL_CLOBBERS6 EV_HCALL_CLOBBERS7, "r9"
145 #define EV_HCALL_CLOBBERS5 EV_HCALL_CLOBBERS6, "r8"
146 #define EV_HCALL_CLOBBERS4 EV_HCALL_CLOBBERS5, "r7"
147 #define EV_HCALL_CLOBBERS3 EV_HCALL_CLOBBERS4, "r6"
148 #define EV_HCALL_CLOBBERS2 EV_HCALL_CLOBBERS3, "r5"
149 #define EV_HCALL_CLOBBERS1 EV_HCALL_CLOBBERS2, "r4"
150
151
152 /*
153 * We use "uintptr_t" to define a register because it's guaranteed to be a
154 * 32-bit integer on a 32-bit platform, and a 64-bit integer on a 64-bit
155 * platform.
156 *
157 * All registers are either input/output or output only. Registers that are
158 * initialized before making the hypercall are input/output. All
159 * input/output registers are represented with "+r". Output-only registers
160 * are represented with "=r". Do not specify any unused registers. The
161 * clobber list will tell the compiler that the hypercall modifies those
162 * registers, which is good enough.
163 */
164
165 /**
166 * ev_int_set_config - configure the specified interrupt
167 * @interrupt: the interrupt number
168 * @config: configuration for this interrupt
169 * @priority: interrupt priority
170 * @destination: destination CPU number
171 *
172 * Returns 0 for success, or an error code.
173 */
ev_int_set_config(unsigned int interrupt,uint32_t config,unsigned int priority,uint32_t destination)174 static inline unsigned int ev_int_set_config(unsigned int interrupt,
175 uint32_t config, unsigned int priority, uint32_t destination)
176 {
177 register uintptr_t r11 __asm__("r11");
178 register uintptr_t r3 __asm__("r3");
179 register uintptr_t r4 __asm__("r4");
180 register uintptr_t r5 __asm__("r5");
181 register uintptr_t r6 __asm__("r6");
182
183 r11 = EV_HCALL_TOKEN(EV_INT_SET_CONFIG);
184 r3 = interrupt;
185 r4 = config;
186 r5 = priority;
187 r6 = destination;
188
189 __asm__ __volatile__ ("sc 1"
190 : "+r" (r11), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6)
191 : : EV_HCALL_CLOBBERS4
192 );
193
194 return r3;
195 }
196
197 /**
198 * ev_int_get_config - return the config of the specified interrupt
199 * @interrupt: the interrupt number
200 * @config: returned configuration for this interrupt
201 * @priority: returned interrupt priority
202 * @destination: returned destination CPU number
203 *
204 * Returns 0 for success, or an error code.
205 */
ev_int_get_config(unsigned int interrupt,uint32_t * config,unsigned int * priority,uint32_t * destination)206 static inline unsigned int ev_int_get_config(unsigned int interrupt,
207 uint32_t *config, unsigned int *priority, uint32_t *destination)
208 {
209 register uintptr_t r11 __asm__("r11");
210 register uintptr_t r3 __asm__("r3");
211 register uintptr_t r4 __asm__("r4");
212 register uintptr_t r5 __asm__("r5");
213 register uintptr_t r6 __asm__("r6");
214
215 r11 = EV_HCALL_TOKEN(EV_INT_GET_CONFIG);
216 r3 = interrupt;
217
218 __asm__ __volatile__ ("sc 1"
219 : "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5), "=r" (r6)
220 : : EV_HCALL_CLOBBERS4
221 );
222
223 *config = r4;
224 *priority = r5;
225 *destination = r6;
226
227 return r3;
228 }
229
230 /**
231 * ev_int_set_mask - sets the mask for the specified interrupt source
232 * @interrupt: the interrupt number
233 * @mask: 0=enable interrupts, 1=disable interrupts
234 *
235 * Returns 0 for success, or an error code.
236 */
ev_int_set_mask(unsigned int interrupt,unsigned int mask)237 static inline unsigned int ev_int_set_mask(unsigned int interrupt,
238 unsigned int mask)
239 {
240 register uintptr_t r11 __asm__("r11");
241 register uintptr_t r3 __asm__("r3");
242 register uintptr_t r4 __asm__("r4");
243
244 r11 = EV_HCALL_TOKEN(EV_INT_SET_MASK);
245 r3 = interrupt;
246 r4 = mask;
247
248 __asm__ __volatile__ ("sc 1"
249 : "+r" (r11), "+r" (r3), "+r" (r4)
250 : : EV_HCALL_CLOBBERS2
251 );
252
253 return r3;
254 }
255
256 /**
257 * ev_int_get_mask - returns the mask for the specified interrupt source
258 * @interrupt: the interrupt number
259 * @mask: returned mask for this interrupt (0=enabled, 1=disabled)
260 *
261 * Returns 0 for success, or an error code.
262 */
ev_int_get_mask(unsigned int interrupt,unsigned int * mask)263 static inline unsigned int ev_int_get_mask(unsigned int interrupt,
264 unsigned int *mask)
265 {
266 register uintptr_t r11 __asm__("r11");
267 register uintptr_t r3 __asm__("r3");
268 register uintptr_t r4 __asm__("r4");
269
270 r11 = EV_HCALL_TOKEN(EV_INT_GET_MASK);
271 r3 = interrupt;
272
273 __asm__ __volatile__ ("sc 1"
274 : "+r" (r11), "+r" (r3), "=r" (r4)
275 : : EV_HCALL_CLOBBERS2
276 );
277
278 *mask = r4;
279
280 return r3;
281 }
282
283 /**
284 * ev_int_eoi - signal the end of interrupt processing
285 * @interrupt: the interrupt number
286 *
287 * This function signals the end of processing for the the specified
288 * interrupt, which must be the interrupt currently in service. By
289 * definition, this is also the highest-priority interrupt.
290 *
291 * Returns 0 for success, or an error code.
292 */
ev_int_eoi(unsigned int interrupt)293 static inline unsigned int ev_int_eoi(unsigned int interrupt)
294 {
295 register uintptr_t r11 __asm__("r11");
296 register uintptr_t r3 __asm__("r3");
297
298 r11 = EV_HCALL_TOKEN(EV_INT_EOI);
299 r3 = interrupt;
300
301 __asm__ __volatile__ ("sc 1"
302 : "+r" (r11), "+r" (r3)
303 : : EV_HCALL_CLOBBERS1
304 );
305
306 return r3;
307 }
308
309 /**
310 * ev_byte_channel_send - send characters to a byte stream
311 * @handle: byte stream handle
312 * @count: (input) num of chars to send, (output) num chars sent
313 * @buffer: pointer to a 16-byte buffer
314 *
315 * @buffer must be at least 16 bytes long, because all 16 bytes will be
316 * read from memory into registers, even if count < 16.
317 *
318 * Returns 0 for success, or an error code.
319 */
ev_byte_channel_send(unsigned int handle,unsigned int * count,const char buffer[EV_BYTE_CHANNEL_MAX_BYTES])320 static inline unsigned int ev_byte_channel_send(unsigned int handle,
321 unsigned int *count, const char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
322 {
323 register uintptr_t r11 __asm__("r11");
324 register uintptr_t r3 __asm__("r3");
325 register uintptr_t r4 __asm__("r4");
326 register uintptr_t r5 __asm__("r5");
327 register uintptr_t r6 __asm__("r6");
328 register uintptr_t r7 __asm__("r7");
329 register uintptr_t r8 __asm__("r8");
330 const uint32_t *p = (const uint32_t *) buffer;
331
332 r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_SEND);
333 r3 = handle;
334 r4 = *count;
335 r5 = be32_to_cpu(p[0]);
336 r6 = be32_to_cpu(p[1]);
337 r7 = be32_to_cpu(p[2]);
338 r8 = be32_to_cpu(p[3]);
339
340 __asm__ __volatile__ ("sc 1"
341 : "+r" (r11), "+r" (r3),
342 "+r" (r4), "+r" (r5), "+r" (r6), "+r" (r7), "+r" (r8)
343 : : EV_HCALL_CLOBBERS6
344 );
345
346 *count = r4;
347
348 return r3;
349 }
350
351 /**
352 * ev_byte_channel_receive - fetch characters from a byte channel
353 * @handle: byte channel handle
354 * @count: (input) max num of chars to receive, (output) num chars received
355 * @buffer: pointer to a 16-byte buffer
356 *
357 * The size of @buffer must be at least 16 bytes, even if you request fewer
358 * than 16 characters, because we always write 16 bytes to @buffer. This is
359 * for performance reasons.
360 *
361 * Returns 0 for success, or an error code.
362 */
ev_byte_channel_receive(unsigned int handle,unsigned int * count,char buffer[EV_BYTE_CHANNEL_MAX_BYTES])363 static inline unsigned int ev_byte_channel_receive(unsigned int handle,
364 unsigned int *count, char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
365 {
366 register uintptr_t r11 __asm__("r11");
367 register uintptr_t r3 __asm__("r3");
368 register uintptr_t r4 __asm__("r4");
369 register uintptr_t r5 __asm__("r5");
370 register uintptr_t r6 __asm__("r6");
371 register uintptr_t r7 __asm__("r7");
372 register uintptr_t r8 __asm__("r8");
373 uint32_t *p = (uint32_t *) buffer;
374
375 r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_RECEIVE);
376 r3 = handle;
377 r4 = *count;
378
379 __asm__ __volatile__ ("sc 1"
380 : "+r" (r11), "+r" (r3), "+r" (r4),
381 "=r" (r5), "=r" (r6), "=r" (r7), "=r" (r8)
382 : : EV_HCALL_CLOBBERS6
383 );
384
385 *count = r4;
386 p[0] = cpu_to_be32(r5);
387 p[1] = cpu_to_be32(r6);
388 p[2] = cpu_to_be32(r7);
389 p[3] = cpu_to_be32(r8);
390
391 return r3;
392 }
393
394 /**
395 * ev_byte_channel_poll - returns the status of the byte channel buffers
396 * @handle: byte channel handle
397 * @rx_count: returned count of bytes in receive queue
398 * @tx_count: returned count of free space in transmit queue
399 *
400 * This function reports the amount of data in the receive queue (i.e. the
401 * number of bytes you can read), and the amount of free space in the transmit
402 * queue (i.e. the number of bytes you can write).
403 *
404 * Returns 0 for success, or an error code.
405 */
ev_byte_channel_poll(unsigned int handle,unsigned int * rx_count,unsigned int * tx_count)406 static inline unsigned int ev_byte_channel_poll(unsigned int handle,
407 unsigned int *rx_count, unsigned int *tx_count)
408 {
409 register uintptr_t r11 __asm__("r11");
410 register uintptr_t r3 __asm__("r3");
411 register uintptr_t r4 __asm__("r4");
412 register uintptr_t r5 __asm__("r5");
413
414 r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_POLL);
415 r3 = handle;
416
417 __asm__ __volatile__ ("sc 1"
418 : "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5)
419 : : EV_HCALL_CLOBBERS3
420 );
421
422 *rx_count = r4;
423 *tx_count = r5;
424
425 return r3;
426 }
427
428 /**
429 * ev_int_iack - acknowledge an interrupt
430 * @handle: handle to the target interrupt controller
431 * @vector: returned interrupt vector
432 *
433 * If handle is zero, the function returns the next interrupt source
434 * number to be handled irrespective of the hierarchy or cascading
435 * of interrupt controllers. If non-zero, specifies a handle to the
436 * interrupt controller that is the target of the acknowledge.
437 *
438 * Returns 0 for success, or an error code.
439 */
ev_int_iack(unsigned int handle,unsigned int * vector)440 static inline unsigned int ev_int_iack(unsigned int handle,
441 unsigned int *vector)
442 {
443 register uintptr_t r11 __asm__("r11");
444 register uintptr_t r3 __asm__("r3");
445 register uintptr_t r4 __asm__("r4");
446
447 r11 = EV_HCALL_TOKEN(EV_INT_IACK);
448 r3 = handle;
449
450 __asm__ __volatile__ ("sc 1"
451 : "+r" (r11), "+r" (r3), "=r" (r4)
452 : : EV_HCALL_CLOBBERS2
453 );
454
455 *vector = r4;
456
457 return r3;
458 }
459
460 /**
461 * ev_doorbell_send - send a doorbell to another partition
462 * @handle: doorbell send handle
463 *
464 * Returns 0 for success, or an error code.
465 */
ev_doorbell_send(unsigned int handle)466 static inline unsigned int ev_doorbell_send(unsigned int handle)
467 {
468 register uintptr_t r11 __asm__("r11");
469 register uintptr_t r3 __asm__("r3");
470
471 r11 = EV_HCALL_TOKEN(EV_DOORBELL_SEND);
472 r3 = handle;
473
474 __asm__ __volatile__ ("sc 1"
475 : "+r" (r11), "+r" (r3)
476 : : EV_HCALL_CLOBBERS1
477 );
478
479 return r3;
480 }
481
482 /**
483 * ev_idle -- wait for next interrupt on this core
484 *
485 * Returns 0 for success, or an error code.
486 */
ev_idle(void)487 static inline unsigned int ev_idle(void)
488 {
489 register uintptr_t r11 __asm__("r11");
490 register uintptr_t r3 __asm__("r3");
491
492 r11 = EV_HCALL_TOKEN(EV_IDLE);
493
494 __asm__ __volatile__ ("sc 1"
495 : "+r" (r11), "=r" (r3)
496 : : EV_HCALL_CLOBBERS1
497 );
498
499 return r3;
500 }
501
502 #endif
503