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 * The "memory" clobber is only necessary for hcalls where the Hypervisor 139 * will read or write guest memory. However, we add it to all hcalls because 140 * the impact is minimal, and we want to ensure that it's present for the 141 * hcalls that need it. 142 */ 143 144 /* List of common clobbered registers. Do not use this macro. */ 145 #define EV_HCALL_CLOBBERS "r0", "r12", "xer", "ctr", "lr", "cc", "memory" 146 147 #define EV_HCALL_CLOBBERS8 EV_HCALL_CLOBBERS 148 #define EV_HCALL_CLOBBERS7 EV_HCALL_CLOBBERS8, "r10" 149 #define EV_HCALL_CLOBBERS6 EV_HCALL_CLOBBERS7, "r9" 150 #define EV_HCALL_CLOBBERS5 EV_HCALL_CLOBBERS6, "r8" 151 #define EV_HCALL_CLOBBERS4 EV_HCALL_CLOBBERS5, "r7" 152 #define EV_HCALL_CLOBBERS3 EV_HCALL_CLOBBERS4, "r6" 153 #define EV_HCALL_CLOBBERS2 EV_HCALL_CLOBBERS3, "r5" 154 #define EV_HCALL_CLOBBERS1 EV_HCALL_CLOBBERS2, "r4" 155 156 157 /* 158 * We use "uintptr_t" to define a register because it's guaranteed to be a 159 * 32-bit integer on a 32-bit platform, and a 64-bit integer on a 64-bit 160 * platform. 161 * 162 * All registers are either input/output or output only. Registers that are 163 * initialized before making the hypercall are input/output. All 164 * input/output registers are represented with "+r". Output-only registers 165 * are represented with "=r". Do not specify any unused registers. The 166 * clobber list will tell the compiler that the hypercall modifies those 167 * registers, which is good enough. 168 */ 169 170 /** 171 * ev_int_set_config - configure the specified interrupt 172 * @interrupt: the interrupt number 173 * @config: configuration for this interrupt 174 * @priority: interrupt priority 175 * @destination: destination CPU number 176 * 177 * Returns 0 for success, or an error code. 178 */ 179 static inline unsigned int ev_int_set_config(unsigned int interrupt, 180 uint32_t config, unsigned int priority, uint32_t destination) 181 { 182 register uintptr_t r11 __asm__("r11"); 183 register uintptr_t r3 __asm__("r3"); 184 register uintptr_t r4 __asm__("r4"); 185 register uintptr_t r5 __asm__("r5"); 186 register uintptr_t r6 __asm__("r6"); 187 188 r11 = EV_HCALL_TOKEN(EV_INT_SET_CONFIG); 189 r3 = interrupt; 190 r4 = config; 191 r5 = priority; 192 r6 = destination; 193 194 __asm__ __volatile__ ("sc 1" 195 : "+r" (r11), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6) 196 : : EV_HCALL_CLOBBERS4 197 ); 198 199 return r3; 200 } 201 202 /** 203 * ev_int_get_config - return the config of the specified interrupt 204 * @interrupt: the interrupt number 205 * @config: returned configuration for this interrupt 206 * @priority: returned interrupt priority 207 * @destination: returned destination CPU number 208 * 209 * Returns 0 for success, or an error code. 210 */ 211 static inline unsigned int ev_int_get_config(unsigned int interrupt, 212 uint32_t *config, unsigned int *priority, uint32_t *destination) 213 { 214 register uintptr_t r11 __asm__("r11"); 215 register uintptr_t r3 __asm__("r3"); 216 register uintptr_t r4 __asm__("r4"); 217 register uintptr_t r5 __asm__("r5"); 218 register uintptr_t r6 __asm__("r6"); 219 220 r11 = EV_HCALL_TOKEN(EV_INT_GET_CONFIG); 221 r3 = interrupt; 222 223 __asm__ __volatile__ ("sc 1" 224 : "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5), "=r" (r6) 225 : : EV_HCALL_CLOBBERS4 226 ); 227 228 *config = r4; 229 *priority = r5; 230 *destination = r6; 231 232 return r3; 233 } 234 235 /** 236 * ev_int_set_mask - sets the mask for the specified interrupt source 237 * @interrupt: the interrupt number 238 * @mask: 0=enable interrupts, 1=disable interrupts 239 * 240 * Returns 0 for success, or an error code. 241 */ 242 static inline unsigned int ev_int_set_mask(unsigned int interrupt, 243 unsigned int mask) 244 { 245 register uintptr_t r11 __asm__("r11"); 246 register uintptr_t r3 __asm__("r3"); 247 register uintptr_t r4 __asm__("r4"); 248 249 r11 = EV_HCALL_TOKEN(EV_INT_SET_MASK); 250 r3 = interrupt; 251 r4 = mask; 252 253 __asm__ __volatile__ ("sc 1" 254 : "+r" (r11), "+r" (r3), "+r" (r4) 255 : : EV_HCALL_CLOBBERS2 256 ); 257 258 return r3; 259 } 260 261 /** 262 * ev_int_get_mask - returns the mask for the specified interrupt source 263 * @interrupt: the interrupt number 264 * @mask: returned mask for this interrupt (0=enabled, 1=disabled) 265 * 266 * Returns 0 for success, or an error code. 267 */ 268 static inline unsigned int ev_int_get_mask(unsigned int interrupt, 269 unsigned int *mask) 270 { 271 register uintptr_t r11 __asm__("r11"); 272 register uintptr_t r3 __asm__("r3"); 273 register uintptr_t r4 __asm__("r4"); 274 275 r11 = EV_HCALL_TOKEN(EV_INT_GET_MASK); 276 r3 = interrupt; 277 278 __asm__ __volatile__ ("sc 1" 279 : "+r" (r11), "+r" (r3), "=r" (r4) 280 : : EV_HCALL_CLOBBERS2 281 ); 282 283 *mask = r4; 284 285 return r3; 286 } 287 288 /** 289 * ev_int_eoi - signal the end of interrupt processing 290 * @interrupt: the interrupt number 291 * 292 * This function signals the end of processing for the the specified 293 * interrupt, which must be the interrupt currently in service. By 294 * definition, this is also the highest-priority interrupt. 295 * 296 * Returns 0 for success, or an error code. 297 */ 298 static inline unsigned int ev_int_eoi(unsigned int interrupt) 299 { 300 register uintptr_t r11 __asm__("r11"); 301 register uintptr_t r3 __asm__("r3"); 302 303 r11 = EV_HCALL_TOKEN(EV_INT_EOI); 304 r3 = interrupt; 305 306 __asm__ __volatile__ ("sc 1" 307 : "+r" (r11), "+r" (r3) 308 : : EV_HCALL_CLOBBERS1 309 ); 310 311 return r3; 312 } 313 314 /** 315 * ev_byte_channel_send - send characters to a byte stream 316 * @handle: byte stream handle 317 * @count: (input) num of chars to send, (output) num chars sent 318 * @buffer: pointer to a 16-byte buffer 319 * 320 * @buffer must be at least 16 bytes long, because all 16 bytes will be 321 * read from memory into registers, even if count < 16. 322 * 323 * Returns 0 for success, or an error code. 324 */ 325 static inline unsigned int ev_byte_channel_send(unsigned int handle, 326 unsigned int *count, const char buffer[EV_BYTE_CHANNEL_MAX_BYTES]) 327 { 328 register uintptr_t r11 __asm__("r11"); 329 register uintptr_t r3 __asm__("r3"); 330 register uintptr_t r4 __asm__("r4"); 331 register uintptr_t r5 __asm__("r5"); 332 register uintptr_t r6 __asm__("r6"); 333 register uintptr_t r7 __asm__("r7"); 334 register uintptr_t r8 __asm__("r8"); 335 const uint32_t *p = (const uint32_t *) buffer; 336 337 r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_SEND); 338 r3 = handle; 339 r4 = *count; 340 r5 = be32_to_cpu(p[0]); 341 r6 = be32_to_cpu(p[1]); 342 r7 = be32_to_cpu(p[2]); 343 r8 = be32_to_cpu(p[3]); 344 345 __asm__ __volatile__ ("sc 1" 346 : "+r" (r11), "+r" (r3), 347 "+r" (r4), "+r" (r5), "+r" (r6), "+r" (r7), "+r" (r8) 348 : : EV_HCALL_CLOBBERS6 349 ); 350 351 *count = r4; 352 353 return r3; 354 } 355 356 /** 357 * ev_byte_channel_receive - fetch characters from a byte channel 358 * @handle: byte channel handle 359 * @count: (input) max num of chars to receive, (output) num chars received 360 * @buffer: pointer to a 16-byte buffer 361 * 362 * The size of @buffer must be at least 16 bytes, even if you request fewer 363 * than 16 characters, because we always write 16 bytes to @buffer. This is 364 * for performance reasons. 365 * 366 * Returns 0 for success, or an error code. 367 */ 368 static inline unsigned int ev_byte_channel_receive(unsigned int handle, 369 unsigned int *count, char buffer[EV_BYTE_CHANNEL_MAX_BYTES]) 370 { 371 register uintptr_t r11 __asm__("r11"); 372 register uintptr_t r3 __asm__("r3"); 373 register uintptr_t r4 __asm__("r4"); 374 register uintptr_t r5 __asm__("r5"); 375 register uintptr_t r6 __asm__("r6"); 376 register uintptr_t r7 __asm__("r7"); 377 register uintptr_t r8 __asm__("r8"); 378 uint32_t *p = (uint32_t *) buffer; 379 380 r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_RECEIVE); 381 r3 = handle; 382 r4 = *count; 383 384 __asm__ __volatile__ ("sc 1" 385 : "+r" (r11), "+r" (r3), "+r" (r4), 386 "=r" (r5), "=r" (r6), "=r" (r7), "=r" (r8) 387 : : EV_HCALL_CLOBBERS6 388 ); 389 390 *count = r4; 391 p[0] = cpu_to_be32(r5); 392 p[1] = cpu_to_be32(r6); 393 p[2] = cpu_to_be32(r7); 394 p[3] = cpu_to_be32(r8); 395 396 return r3; 397 } 398 399 /** 400 * ev_byte_channel_poll - returns the status of the byte channel buffers 401 * @handle: byte channel handle 402 * @rx_count: returned count of bytes in receive queue 403 * @tx_count: returned count of free space in transmit queue 404 * 405 * This function reports the amount of data in the receive queue (i.e. the 406 * number of bytes you can read), and the amount of free space in the transmit 407 * queue (i.e. the number of bytes you can write). 408 * 409 * Returns 0 for success, or an error code. 410 */ 411 static inline unsigned int ev_byte_channel_poll(unsigned int handle, 412 unsigned int *rx_count, unsigned int *tx_count) 413 { 414 register uintptr_t r11 __asm__("r11"); 415 register uintptr_t r3 __asm__("r3"); 416 register uintptr_t r4 __asm__("r4"); 417 register uintptr_t r5 __asm__("r5"); 418 419 r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_POLL); 420 r3 = handle; 421 422 __asm__ __volatile__ ("sc 1" 423 : "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5) 424 : : EV_HCALL_CLOBBERS3 425 ); 426 427 *rx_count = r4; 428 *tx_count = r5; 429 430 return r3; 431 } 432 433 /** 434 * ev_int_iack - acknowledge an interrupt 435 * @handle: handle to the target interrupt controller 436 * @vector: returned interrupt vector 437 * 438 * If handle is zero, the function returns the next interrupt source 439 * number to be handled irrespective of the hierarchy or cascading 440 * of interrupt controllers. If non-zero, specifies a handle to the 441 * interrupt controller that is the target of the acknowledge. 442 * 443 * Returns 0 for success, or an error code. 444 */ 445 static inline unsigned int ev_int_iack(unsigned int handle, 446 unsigned int *vector) 447 { 448 register uintptr_t r11 __asm__("r11"); 449 register uintptr_t r3 __asm__("r3"); 450 register uintptr_t r4 __asm__("r4"); 451 452 r11 = EV_HCALL_TOKEN(EV_INT_IACK); 453 r3 = handle; 454 455 __asm__ __volatile__ ("sc 1" 456 : "+r" (r11), "+r" (r3), "=r" (r4) 457 : : EV_HCALL_CLOBBERS2 458 ); 459 460 *vector = r4; 461 462 return r3; 463 } 464 465 /** 466 * ev_doorbell_send - send a doorbell to another partition 467 * @handle: doorbell send handle 468 * 469 * Returns 0 for success, or an error code. 470 */ 471 static inline unsigned int ev_doorbell_send(unsigned int handle) 472 { 473 register uintptr_t r11 __asm__("r11"); 474 register uintptr_t r3 __asm__("r3"); 475 476 r11 = EV_HCALL_TOKEN(EV_DOORBELL_SEND); 477 r3 = handle; 478 479 __asm__ __volatile__ ("sc 1" 480 : "+r" (r11), "+r" (r3) 481 : : EV_HCALL_CLOBBERS1 482 ); 483 484 return r3; 485 } 486 487 /** 488 * ev_idle -- wait for next interrupt on this core 489 * 490 * Returns 0 for success, or an error code. 491 */ 492 static inline unsigned int ev_idle(void) 493 { 494 register uintptr_t r11 __asm__("r11"); 495 register uintptr_t r3 __asm__("r3"); 496 497 r11 = EV_HCALL_TOKEN(EV_IDLE); 498 499 __asm__ __volatile__ ("sc 1" 500 : "+r" (r11), "=r" (r3) 501 : : EV_HCALL_CLOBBERS1 502 ); 503 504 return r3; 505 } 506 507 #endif 508