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 - 2012, 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 *****************************************************************************/ 115 116 117 #define __UTMATH_C__ 118 119 #include "acpi.h" 120 #include "accommon.h" 121 122 123 #define _COMPONENT ACPI_UTILITIES 124 ACPI_MODULE_NAME ("utmath") 125 126 /* 127 * Optional support for 64-bit double-precision integer divide. This code 128 * is configurable and is implemented in order to support 32-bit kernel 129 * environments where a 64-bit double-precision math library is not available. 130 * 131 * Support for a more normal 64-bit divide/modulo (with check for a divide- 132 * by-zero) appears after this optional section of code. 133 */ 134 #ifndef ACPI_USE_NATIVE_DIVIDE 135 136 /* Structures used only for 64-bit divide */ 137 138 typedef struct uint64_struct 139 { 140 UINT32 Lo; 141 UINT32 Hi; 142 143 } UINT64_STRUCT; 144 145 typedef union uint64_overlay 146 { 147 UINT64 Full; 148 UINT64_STRUCT Part; 149 150 } UINT64_OVERLAY; 151 152 153 /******************************************************************************* 154 * 155 * FUNCTION: AcpiUtShortDivide 156 * 157 * PARAMETERS: Dividend - 64-bit dividend 158 * Divisor - 32-bit divisor 159 * OutQuotient - Pointer to where the quotient is returned 160 * OutRemainder - Pointer to where the remainder is returned 161 * 162 * RETURN: Status (Checks for divide-by-zero) 163 * 164 * DESCRIPTION: Perform a short (maximum 64 bits divided by 32 bits) 165 * divide and modulo. The result is a 64-bit quotient and a 166 * 32-bit remainder. 167 * 168 ******************************************************************************/ 169 170 ACPI_STATUS 171 AcpiUtShortDivide ( 172 UINT64 Dividend, 173 UINT32 Divisor, 174 UINT64 *OutQuotient, 175 UINT32 *OutRemainder) 176 { 177 UINT64_OVERLAY DividendOvl; 178 UINT64_OVERLAY Quotient; 179 UINT32 Remainder32; 180 181 182 ACPI_FUNCTION_TRACE (UtShortDivide); 183 184 185 /* Always check for a zero divisor */ 186 187 if (Divisor == 0) 188 { 189 ACPI_ERROR ((AE_INFO, "Divide by zero")); 190 return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); 191 } 192 193 DividendOvl.Full = Dividend; 194 195 /* 196 * The quotient is 64 bits, the remainder is always 32 bits, 197 * and is generated by the second divide. 198 */ 199 ACPI_DIV_64_BY_32 (0, DividendOvl.Part.Hi, Divisor, 200 Quotient.Part.Hi, Remainder32); 201 ACPI_DIV_64_BY_32 (Remainder32, DividendOvl.Part.Lo, Divisor, 202 Quotient.Part.Lo, Remainder32); 203 204 /* Return only what was requested */ 205 206 if (OutQuotient) 207 { 208 *OutQuotient = Quotient.Full; 209 } 210 if (OutRemainder) 211 { 212 *OutRemainder = Remainder32; 213 } 214 215 return_ACPI_STATUS (AE_OK); 216 } 217 218 219 /******************************************************************************* 220 * 221 * FUNCTION: AcpiUtDivide 222 * 223 * PARAMETERS: InDividend - Dividend 224 * InDivisor - Divisor 225 * OutQuotient - Pointer to where the quotient is returned 226 * OutRemainder - Pointer to where the remainder is returned 227 * 228 * RETURN: Status (Checks for divide-by-zero) 229 * 230 * DESCRIPTION: Perform a divide and modulo. 231 * 232 ******************************************************************************/ 233 234 ACPI_STATUS 235 AcpiUtDivide ( 236 UINT64 InDividend, 237 UINT64 InDivisor, 238 UINT64 *OutQuotient, 239 UINT64 *OutRemainder) 240 { 241 UINT64_OVERLAY Dividend; 242 UINT64_OVERLAY Divisor; 243 UINT64_OVERLAY Quotient; 244 UINT64_OVERLAY Remainder; 245 UINT64_OVERLAY NormalizedDividend; 246 UINT64_OVERLAY NormalizedDivisor; 247 UINT32 Partial1; 248 UINT64_OVERLAY Partial2; 249 UINT64_OVERLAY Partial3; 250 251 252 ACPI_FUNCTION_TRACE (UtDivide); 253 254 255 /* Always check for a zero divisor */ 256 257 if (InDivisor == 0) 258 { 259 ACPI_ERROR ((AE_INFO, "Divide by zero")); 260 return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); 261 } 262 263 Divisor.Full = InDivisor; 264 Dividend.Full = InDividend; 265 if (Divisor.Part.Hi == 0) 266 { 267 /* 268 * 1) Simplest case is where the divisor is 32 bits, we can 269 * just do two divides 270 */ 271 Remainder.Part.Hi = 0; 272 273 /* 274 * The quotient is 64 bits, the remainder is always 32 bits, 275 * and is generated by the second divide. 276 */ 277 ACPI_DIV_64_BY_32 (0, Dividend.Part.Hi, Divisor.Part.Lo, 278 Quotient.Part.Hi, Partial1); 279 ACPI_DIV_64_BY_32 (Partial1, Dividend.Part.Lo, Divisor.Part.Lo, 280 Quotient.Part.Lo, Remainder.Part.Lo); 281 } 282 283 else 284 { 285 /* 286 * 2) The general case where the divisor is a full 64 bits 287 * is more difficult 288 */ 289 Quotient.Part.Hi = 0; 290 NormalizedDividend = Dividend; 291 NormalizedDivisor = Divisor; 292 293 /* Normalize the operands (shift until the divisor is < 32 bits) */ 294 295 do 296 { 297 ACPI_SHIFT_RIGHT_64 (NormalizedDivisor.Part.Hi, 298 NormalizedDivisor.Part.Lo); 299 ACPI_SHIFT_RIGHT_64 (NormalizedDividend.Part.Hi, 300 NormalizedDividend.Part.Lo); 301 302 } while (NormalizedDivisor.Part.Hi != 0); 303 304 /* Partial divide */ 305 306 ACPI_DIV_64_BY_32 (NormalizedDividend.Part.Hi, 307 NormalizedDividend.Part.Lo, 308 NormalizedDivisor.Part.Lo, 309 Quotient.Part.Lo, Partial1); 310 311 /* 312 * The quotient is always 32 bits, and simply requires adjustment. 313 * The 64-bit remainder must be generated. 314 */ 315 Partial1 = Quotient.Part.Lo * Divisor.Part.Hi; 316 Partial2.Full = (UINT64) Quotient.Part.Lo * Divisor.Part.Lo; 317 Partial3.Full = (UINT64) Partial2.Part.Hi + Partial1; 318 319 Remainder.Part.Hi = Partial3.Part.Lo; 320 Remainder.Part.Lo = Partial2.Part.Lo; 321 322 if (Partial3.Part.Hi == 0) 323 { 324 if (Partial3.Part.Lo >= Dividend.Part.Hi) 325 { 326 if (Partial3.Part.Lo == Dividend.Part.Hi) 327 { 328 if (Partial2.Part.Lo > Dividend.Part.Lo) 329 { 330 Quotient.Part.Lo--; 331 Remainder.Full -= Divisor.Full; 332 } 333 } 334 else 335 { 336 Quotient.Part.Lo--; 337 Remainder.Full -= Divisor.Full; 338 } 339 } 340 341 Remainder.Full = Remainder.Full - Dividend.Full; 342 Remainder.Part.Hi = (UINT32) -((INT32) Remainder.Part.Hi); 343 Remainder.Part.Lo = (UINT32) -((INT32) Remainder.Part.Lo); 344 345 if (Remainder.Part.Lo) 346 { 347 Remainder.Part.Hi--; 348 } 349 } 350 } 351 352 /* Return only what was requested */ 353 354 if (OutQuotient) 355 { 356 *OutQuotient = Quotient.Full; 357 } 358 if (OutRemainder) 359 { 360 *OutRemainder = Remainder.Full; 361 } 362 363 return_ACPI_STATUS (AE_OK); 364 } 365 366 #else 367 368 /******************************************************************************* 369 * 370 * FUNCTION: AcpiUtShortDivide, AcpiUtDivide 371 * 372 * PARAMETERS: See function headers above 373 * 374 * DESCRIPTION: Native versions of the UtDivide functions. Use these if either 375 * 1) The target is a 64-bit platform and therefore 64-bit 376 * integer math is supported directly by the machine. 377 * 2) The target is a 32-bit or 16-bit platform, and the 378 * double-precision integer math library is available to 379 * perform the divide. 380 * 381 ******************************************************************************/ 382 383 ACPI_STATUS 384 AcpiUtShortDivide ( 385 UINT64 InDividend, 386 UINT32 Divisor, 387 UINT64 *OutQuotient, 388 UINT32 *OutRemainder) 389 { 390 391 ACPI_FUNCTION_TRACE (UtShortDivide); 392 393 394 /* Always check for a zero divisor */ 395 396 if (Divisor == 0) 397 { 398 ACPI_ERROR ((AE_INFO, "Divide by zero")); 399 return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); 400 } 401 402 /* Return only what was requested */ 403 404 if (OutQuotient) 405 { 406 *OutQuotient = InDividend / Divisor; 407 } 408 if (OutRemainder) 409 { 410 *OutRemainder = (UINT32) (InDividend % Divisor); 411 } 412 413 return_ACPI_STATUS (AE_OK); 414 } 415 416 ACPI_STATUS 417 AcpiUtDivide ( 418 UINT64 InDividend, 419 UINT64 InDivisor, 420 UINT64 *OutQuotient, 421 UINT64 *OutRemainder) 422 { 423 ACPI_FUNCTION_TRACE (UtDivide); 424 425 426 /* Always check for a zero divisor */ 427 428 if (InDivisor == 0) 429 { 430 ACPI_ERROR ((AE_INFO, "Divide by zero")); 431 return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO); 432 } 433 434 435 /* Return only what was requested */ 436 437 if (OutQuotient) 438 { 439 *OutQuotient = InDividend / InDivisor; 440 } 441 if (OutRemainder) 442 { 443 *OutRemainder = InDividend % InDivisor; 444 } 445 446 return_ACPI_STATUS (AE_OK); 447 } 448 449 #endif 450 451 452