1 /******************************************************************************* 2 * 3 * Module Name: utmath - Integer math support routines 4 * 5 ******************************************************************************/ 6 7 /****************************************************************************** 8 * 9 * 1. Copyright Notice 10 * 11 * Some or all of this work - Copyright (c) 1999 - 2017, Intel Corp. 12 * All rights reserved. 13 * 14 * 2. License 15 * 16 * 2.1. This is your license from Intel Corp. under its intellectual property 17 * rights. You may have additional license terms from the party that provided 18 * you this software, covering your right to use that party's intellectual 19 * property rights. 20 * 21 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 22 * copy of the source code appearing in this file ("Covered Code") an 23 * irrevocable, perpetual, worldwide license under Intel's copyrights in the 24 * base code distributed originally by Intel ("Original Intel Code") to copy, 25 * make derivatives, distribute, use and display any portion of the Covered 26 * Code in any form, with the right to sublicense such rights; and 27 * 28 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 29 * license (with the right to sublicense), under only those claims of Intel 30 * patents that are infringed by the Original Intel Code, to make, use, sell, 31 * offer to sell, and import the Covered Code and derivative works thereof 32 * solely to the minimum extent necessary to exercise the above copyright 33 * license, and in no event shall the patent license extend to any additions 34 * to or modifications of the Original Intel Code. No other license or right 35 * is granted directly or by implication, estoppel or otherwise; 36 * 37 * The above copyright and patent license is granted only if the following 38 * conditions are met: 39 * 40 * 3. Conditions 41 * 42 * 3.1. Redistribution of Source with Rights to Further Distribute Source. 43 * Redistribution of source code of any substantial portion of the Covered 44 * Code or modification with rights to further distribute source must include 45 * the above Copyright Notice, the above License, this list of Conditions, 46 * and the following Disclaimer and Export Compliance provision. In addition, 47 * Licensee must cause all Covered Code to which Licensee contributes to 48 * contain a file documenting the changes Licensee made to create that Covered 49 * Code and the date of any change. Licensee must include in that file the 50 * documentation of any changes made by any predecessor Licensee. Licensee 51 * must include a prominent statement that the modification is derived, 52 * directly or indirectly, from Original Intel Code. 53 * 54 * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 55 * Redistribution of source code of any substantial portion of the Covered 56 * Code or modification without rights to further distribute source must 57 * include the following Disclaimer and Export Compliance provision in the 58 * documentation and/or other materials provided with distribution. In 59 * addition, Licensee may not authorize further sublicense of source of any 60 * portion of the Covered Code, and must include terms to the effect that the 61 * license from Licensee to its licensee is limited to the intellectual 62 * property embodied in the software Licensee provides to its licensee, and 63 * not to intellectual property embodied in modifications its licensee may 64 * make. 65 * 66 * 3.3. Redistribution of Executable. Redistribution in executable form of any 67 * substantial portion of the Covered Code or modification must reproduce the 68 * above Copyright Notice, and the following Disclaimer and Export Compliance 69 * provision in the documentation and/or other materials provided with the 70 * distribution. 71 * 72 * 3.4. Intel retains all right, title, and interest in and to the Original 73 * Intel Code. 74 * 75 * 3.5. Neither the name Intel nor any other trademark owned or controlled by 76 * Intel shall be used in advertising or otherwise to promote the sale, use or 77 * other dealings in products derived from or relating to the Covered Code 78 * without prior written authorization from Intel. 79 * 80 * 4. Disclaimer and Export Compliance 81 * 82 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 83 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 84 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 85 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 86 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 87 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 88 * PARTICULAR PURPOSE. 89 * 90 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 91 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 92 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 93 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 94 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 95 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 96 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 97 * LIMITED REMEDY. 98 * 99 * 4.3. Licensee shall not export, either directly or indirectly, any of this 100 * software or system incorporating such software without first obtaining any 101 * required license or other approval from the U. S. Department of Commerce or 102 * any other agency or department of the United States Government. In the 103 * event Licensee exports any such software from the United States or 104 * re-exports any such software from a foreign destination, Licensee shall 105 * ensure that the distribution and export/re-export of the software is in 106 * compliance with all laws, regulations, orders, or other restrictions of the 107 * U.S. Export Administration Regulations. Licensee agrees that neither it nor 108 * any of its subsidiaries will export/re-export any technical data, process, 109 * software, or service, directly or indirectly, to any country for which the 110 * United States government or any agency thereof requires an export license, 111 * other governmental approval, or letter of assurance, without first obtaining 112 * such license, approval or letter. 113 * 114 ***************************************************************************** 115 * 116 * Alternatively, you may choose to be licensed under the terms of the 117 * following license: 118 * 119 * Redistribution and use in source and binary forms, with or without 120 * modification, are permitted provided that the following conditions 121 * are met: 122 * 1. Redistributions of source code must retain the above copyright 123 * notice, this list of conditions, and the following disclaimer, 124 * without modification. 125 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 126 * substantially similar to the "NO WARRANTY" disclaimer below 127 * ("Disclaimer") and any redistribution must be conditioned upon 128 * including a substantially similar Disclaimer requirement for further 129 * binary redistribution. 130 * 3. Neither the names of the above-listed copyright holders nor the names 131 * of any contributors may be used to endorse or promote products derived 132 * from this software without specific prior written permission. 133 * 134 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 135 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 136 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 137 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 138 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 139 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 140 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 141 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 142 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 143 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 144 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 145 * 146 * Alternatively, you may choose to be licensed under the terms of the 147 * GNU General Public License ("GPL") version 2 as published by the Free 148 * Software Foundation. 149 * 150 *****************************************************************************/ 151 152 #include "acpi.h" 153 #include "accommon.h" 154 155 156 #define _COMPONENT ACPI_UTILITIES 157 ACPI_MODULE_NAME ("utmath") 158 159 /* 160 * Optional support for 64-bit double-precision integer divide. This code 161 * is configurable and is implemented in order to support 32-bit kernel 162 * environments where a 64-bit double-precision math library is not available. 163 * 164 * Support for a more normal 64-bit divide/modulo (with check for a divide- 165 * by-zero) appears after this optional section of code. 166 */ 167 #ifndef ACPI_USE_NATIVE_DIVIDE 168 169 /* Structures used only for 64-bit divide */ 170 171 typedef struct uint64_struct 172 { 173 UINT32 Lo; 174 UINT32 Hi; 175 176 } UINT64_STRUCT; 177 178 typedef union uint64_overlay 179 { 180 UINT64 Full; 181 UINT64_STRUCT Part; 182 183 } UINT64_OVERLAY; 184 185 186 /******************************************************************************* 187 * 188 * FUNCTION: AcpiUtShortDivide 189 * 190 * PARAMETERS: Dividend - 64-bit dividend 191 * Divisor - 32-bit divisor 192 * OutQuotient - Pointer to where the quotient is returned 193 * OutRemainder - Pointer to where the remainder is returned 194 * 195 * RETURN: Status (Checks for divide-by-zero) 196 * 197 * DESCRIPTION: Perform a short (maximum 64 bits divided by 32 bits) 198 * divide and modulo. The result is a 64-bit quotient and a 199 * 32-bit remainder. 200 * 201 ******************************************************************************/ 202 203 ACPI_STATUS 204 AcpiUtShortDivide ( 205 UINT64 Dividend, 206 UINT32 Divisor, 207 UINT64 *OutQuotient, 208 UINT32 *OutRemainder) 209 { 210 UINT64_OVERLAY DividendOvl; 211 UINT64_OVERLAY Quotient; 212 UINT32 Remainder32; 213 214 215 ACPI_FUNCTION_TRACE (UtShortDivide); 216 217 218 /* Always check for a zero divisor */ 219 220 if (Divisor == 0) 221 { 222 ACPI_ERROR ((AE_INFO, "Divide by zero")); 223 return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); 224 } 225 226 DividendOvl.Full = Dividend; 227 228 /* 229 * The quotient is 64 bits, the remainder is always 32 bits, 230 * and is generated by the second divide. 231 */ 232 ACPI_DIV_64_BY_32 (0, DividendOvl.Part.Hi, Divisor, 233 Quotient.Part.Hi, Remainder32); 234 235 ACPI_DIV_64_BY_32 (Remainder32, DividendOvl.Part.Lo, Divisor, 236 Quotient.Part.Lo, Remainder32); 237 238 /* Return only what was requested */ 239 240 if (OutQuotient) 241 { 242 *OutQuotient = Quotient.Full; 243 } 244 if (OutRemainder) 245 { 246 *OutRemainder = Remainder32; 247 } 248 249 return_ACPI_STATUS (AE_OK); 250 } 251 252 253 /******************************************************************************* 254 * 255 * FUNCTION: AcpiUtDivide 256 * 257 * PARAMETERS: InDividend - Dividend 258 * InDivisor - Divisor 259 * OutQuotient - Pointer to where the quotient is returned 260 * OutRemainder - Pointer to where the remainder is returned 261 * 262 * RETURN: Status (Checks for divide-by-zero) 263 * 264 * DESCRIPTION: Perform a divide and modulo. 265 * 266 ******************************************************************************/ 267 268 ACPI_STATUS 269 AcpiUtDivide ( 270 UINT64 InDividend, 271 UINT64 InDivisor, 272 UINT64 *OutQuotient, 273 UINT64 *OutRemainder) 274 { 275 UINT64_OVERLAY Dividend; 276 UINT64_OVERLAY Divisor; 277 UINT64_OVERLAY Quotient; 278 UINT64_OVERLAY Remainder; 279 UINT64_OVERLAY NormalizedDividend; 280 UINT64_OVERLAY NormalizedDivisor; 281 UINT32 Partial1; 282 UINT64_OVERLAY Partial2; 283 UINT64_OVERLAY Partial3; 284 285 286 ACPI_FUNCTION_TRACE (UtDivide); 287 288 289 /* Always check for a zero divisor */ 290 291 if (InDivisor == 0) 292 { 293 ACPI_ERROR ((AE_INFO, "Divide by zero")); 294 return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); 295 } 296 297 Divisor.Full = InDivisor; 298 Dividend.Full = InDividend; 299 if (Divisor.Part.Hi == 0) 300 { 301 /* 302 * 1) Simplest case is where the divisor is 32 bits, we can 303 * just do two divides 304 */ 305 Remainder.Part.Hi = 0; 306 307 /* 308 * The quotient is 64 bits, the remainder is always 32 bits, 309 * and is generated by the second divide. 310 */ 311 ACPI_DIV_64_BY_32 (0, Dividend.Part.Hi, Divisor.Part.Lo, 312 Quotient.Part.Hi, Partial1); 313 314 ACPI_DIV_64_BY_32 (Partial1, Dividend.Part.Lo, Divisor.Part.Lo, 315 Quotient.Part.Lo, Remainder.Part.Lo); 316 } 317 318 else 319 { 320 /* 321 * 2) The general case where the divisor is a full 64 bits 322 * is more difficult 323 */ 324 Quotient.Part.Hi = 0; 325 NormalizedDividend = Dividend; 326 NormalizedDivisor = Divisor; 327 328 /* Normalize the operands (shift until the divisor is < 32 bits) */ 329 330 do 331 { 332 ACPI_SHIFT_RIGHT_64 ( 333 NormalizedDivisor.Part.Hi, NormalizedDivisor.Part.Lo); 334 ACPI_SHIFT_RIGHT_64 ( 335 NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo); 336 337 } while (NormalizedDivisor.Part.Hi != 0); 338 339 /* Partial divide */ 340 341 ACPI_DIV_64_BY_32 ( 342 NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo, 343 NormalizedDivisor.Part.Lo, Quotient.Part.Lo, Partial1); 344 345 /* 346 * The quotient is always 32 bits, and simply requires 347 * adjustment. The 64-bit remainder must be generated. 348 */ 349 Partial1 = Quotient.Part.Lo * Divisor.Part.Hi; 350 Partial2.Full = (UINT64) Quotient.Part.Lo * Divisor.Part.Lo; 351 Partial3.Full = (UINT64) Partial2.Part.Hi + Partial1; 352 353 Remainder.Part.Hi = Partial3.Part.Lo; 354 Remainder.Part.Lo = Partial2.Part.Lo; 355 356 if (Partial3.Part.Hi == 0) 357 { 358 if (Partial3.Part.Lo >= Dividend.Part.Hi) 359 { 360 if (Partial3.Part.Lo == Dividend.Part.Hi) 361 { 362 if (Partial2.Part.Lo > Dividend.Part.Lo) 363 { 364 Quotient.Part.Lo--; 365 Remainder.Full -= Divisor.Full; 366 } 367 } 368 else 369 { 370 Quotient.Part.Lo--; 371 Remainder.Full -= Divisor.Full; 372 } 373 } 374 375 Remainder.Full = Remainder.Full - Dividend.Full; 376 Remainder.Part.Hi = (UINT32) -((INT32) Remainder.Part.Hi); 377 Remainder.Part.Lo = (UINT32) -((INT32) Remainder.Part.Lo); 378 379 if (Remainder.Part.Lo) 380 { 381 Remainder.Part.Hi--; 382 } 383 } 384 } 385 386 /* Return only what was requested */ 387 388 if (OutQuotient) 389 { 390 *OutQuotient = Quotient.Full; 391 } 392 if (OutRemainder) 393 { 394 *OutRemainder = Remainder.Full; 395 } 396 397 return_ACPI_STATUS (AE_OK); 398 } 399 400 #else 401 402 /******************************************************************************* 403 * 404 * FUNCTION: AcpiUtShortDivide, AcpiUtDivide 405 * 406 * PARAMETERS: See function headers above 407 * 408 * DESCRIPTION: Native versions of the UtDivide functions. Use these if either 409 * 1) The target is a 64-bit platform and therefore 64-bit 410 * integer math is supported directly by the machine. 411 * 2) The target is a 32-bit or 16-bit platform, and the 412 * double-precision integer math library is available to 413 * perform the divide. 414 * 415 ******************************************************************************/ 416 417 ACPI_STATUS 418 AcpiUtShortDivide ( 419 UINT64 InDividend, 420 UINT32 Divisor, 421 UINT64 *OutQuotient, 422 UINT32 *OutRemainder) 423 { 424 425 ACPI_FUNCTION_TRACE (UtShortDivide); 426 427 428 /* Always check for a zero divisor */ 429 430 if (Divisor == 0) 431 { 432 ACPI_ERROR ((AE_INFO, "Divide by zero")); 433 return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); 434 } 435 436 /* Return only what was requested */ 437 438 if (OutQuotient) 439 { 440 *OutQuotient = InDividend / Divisor; 441 } 442 if (OutRemainder) 443 { 444 *OutRemainder = (UINT32) (InDividend % Divisor); 445 } 446 447 return_ACPI_STATUS (AE_OK); 448 } 449 450 ACPI_STATUS 451 AcpiUtDivide ( 452 UINT64 InDividend, 453 UINT64 InDivisor, 454 UINT64 *OutQuotient, 455 UINT64 *OutRemainder) 456 { 457 ACPI_FUNCTION_TRACE (UtDivide); 458 459 460 /* Always check for a zero divisor */ 461 462 if (InDivisor == 0) 463 { 464 ACPI_ERROR ((AE_INFO, "Divide by zero")); 465 return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); 466 } 467 468 469 /* Return only what was requested */ 470 471 if (OutQuotient) 472 { 473 *OutQuotient = InDividend / InDivisor; 474 } 475 if (OutRemainder) 476 { 477 *OutRemainder = InDividend % InDivisor; 478 } 479 480 return_ACPI_STATUS (AE_OK); 481 } 482 483 #endif 484