reactos/drivers/bus/acpi/acpica/utilities/utmath.c

   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 - 2015, 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 #include "acpi.h"
 117 #include "accommon.h"
 118
 119
 120 #define _COMPONENT          ACPI_UTILITIES
 121         ACPI_MODULE_NAME    ("utmath")
 122
 123 /*
 124  * Optional support for 64-bit double-precision integer divide. This code
 125  * is configurable and is implemented in order to support 32-bit kernel
 126  * environments where a 64-bit double-precision math library is not available.
 127  *
 128  * Support for a more normal 64-bit divide/modulo (with check for a divide-
 129  * by-zero) appears after this optional section of code.
 130  */
 131 #ifndef ACPI_USE_NATIVE_DIVIDE
 132
 133 /* Structures used only for 64-bit divide */
 134
 135 typedef struct uint64_struct
 136 {
 137     UINT32                          Lo;
 138     UINT32                          Hi;
 139
 140 } UINT64_STRUCT;
 141
 142 typedef union uint64_overlay
 143 {
 144     UINT64                          Full;
 145     UINT64_STRUCT                   Part;
 146
 147 } UINT64_OVERLAY;
 148
 149
 150 /*******************************************************************************
 151  *
 152  * FUNCTION:    AcpiUtShortDivide
 153  *
 154  * PARAMETERS:  Dividend            - 64-bit dividend
 155  *              Divisor             - 32-bit divisor
 156  *              OutQuotient         - Pointer to where the quotient is returned
 157  *              OutRemainder        - Pointer to where the remainder is returned
 158  *
 159  * RETURN:      Status (Checks for divide-by-zero)
 160  *
 161  * DESCRIPTION: Perform a short (maximum 64 bits divided by 32 bits)
 162  *              divide and modulo. The result is a 64-bit quotient and a
 163  *              32-bit remainder.
 164  *
 165  ******************************************************************************/
 166
 167 ACPI_STATUS
 168 AcpiUtShortDivide (
 169     UINT64                  Dividend,
 170     UINT32                  Divisor,
 171     UINT64                  *OutQuotient,
 172     UINT32                  *OutRemainder)
 173 {
 174     UINT64_OVERLAY          DividendOvl;
 175     UINT64_OVERLAY          Quotient;
 176     UINT32                  Remainder32;
 177
 178
 179     ACPI_FUNCTION_TRACE (UtShortDivide);
 180
 181
 182     /* Always check for a zero divisor */
 183
 184     if (Divisor == 0)
 185     {
 186         ACPI_ERROR ((AE_INFO, "Divide by zero"));
 187         return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
 188     }
 189
 190     DividendOvl.Full = Dividend;
 191
 192     /*
 193      * The quotient is 64 bits, the remainder is always 32 bits,
 194      * and is generated by the second divide.
 195      */
 196     ACPI_DIV_64_BY_32 (0, DividendOvl.Part.Hi, Divisor,
 197         Quotient.Part.Hi, Remainder32);
 198
 199     ACPI_DIV_64_BY_32 (Remainder32, DividendOvl.Part.Lo, Divisor,
 200         Quotient.Part.Lo, Remainder32);
 201
 202     /* Return only what was requested */
 203
 204     if (OutQuotient)
 205     {
 206         *OutQuotient = Quotient.Full;
 207     }
 208     if (OutRemainder)
 209     {
 210         *OutRemainder = Remainder32;
 211     }
 212
 213     return_ACPI_STATUS (AE_OK);
 214 }
 215
 216
 217 /*******************************************************************************
 218  *
 219  * FUNCTION:    AcpiUtDivide
 220  *
 221  * PARAMETERS:  InDividend          - Dividend
 222  *              InDivisor           - Divisor
 223  *              OutQuotient         - Pointer to where the quotient is returned
 224  *              OutRemainder        - Pointer to where the remainder is returned
 225  *
 226  * RETURN:      Status (Checks for divide-by-zero)
 227  *
 228  * DESCRIPTION: Perform a divide and modulo.
 229  *
 230  ******************************************************************************/
 231
 232 ACPI_STATUS
 233 AcpiUtDivide (
 234     UINT64                  InDividend,
 235     UINT64                  InDivisor,
 236     UINT64                  *OutQuotient,
 237     UINT64                  *OutRemainder)
 238 {
 239     UINT64_OVERLAY          Dividend;
 240     UINT64_OVERLAY          Divisor;
 241     UINT64_OVERLAY          Quotient;
 242     UINT64_OVERLAY          Remainder;
 243     UINT64_OVERLAY          NormalizedDividend;
 244     UINT64_OVERLAY          NormalizedDivisor;
 245     UINT32                  Partial1;
 246     UINT64_OVERLAY          Partial2;
 247     UINT64_OVERLAY          Partial3;
 248
 249
 250     ACPI_FUNCTION_TRACE (UtDivide);
 251
 252
 253     /* Always check for a zero divisor */
 254
 255     if (InDivisor == 0)
 256     {
 257         ACPI_ERROR ((AE_INFO, "Divide by zero"));
 258         return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
 259     }
 260
 261     Divisor.Full  = InDivisor;
 262     Dividend.Full = InDividend;
 263     if (Divisor.Part.Hi == 0)
 264     {
 265         /*
 266          * 1) Simplest case is where the divisor is 32 bits, we can
 267          * just do two divides
 268          */
 269         Remainder.Part.Hi = 0;
 270
 271         /*
 272          * The quotient is 64 bits, the remainder is always 32 bits,
 273          * and is generated by the second divide.
 274          */
 275         ACPI_DIV_64_BY_32 (0, Dividend.Part.Hi, Divisor.Part.Lo,
 276             Quotient.Part.Hi, Partial1);
 277
 278         ACPI_DIV_64_BY_32 (Partial1, Dividend.Part.Lo, Divisor.Part.Lo,
 279             Quotient.Part.Lo, Remainder.Part.Lo);
 280     }
 281
 282     else
 283     {
 284         /*
 285          * 2) The general case where the divisor is a full 64 bits
 286          * is more difficult
 287          */
 288         Quotient.Part.Hi   = 0;
 289         NormalizedDividend = Dividend;
 290         NormalizedDivisor  = Divisor;
 291
 292         /* Normalize the operands (shift until the divisor is < 32 bits) */
 293
 294         do
 295         {
 296             ACPI_SHIFT_RIGHT_64 (
 297                 NormalizedDivisor.Part.Hi, NormalizedDivisor.Part.Lo);
 298             ACPI_SHIFT_RIGHT_64 (
 299                 NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo);
 300
 301         } while (NormalizedDivisor.Part.Hi != 0);
 302
 303         /* Partial divide */
 304
 305         ACPI_DIV_64_BY_32 (
 306             NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo,
 307             NormalizedDivisor.Part.Lo, Quotient.Part.Lo, Partial1);
 308
 309         /*
 310          * The quotient is always 32 bits, and simply requires
 311          * adjustment. The 64-bit remainder must be generated.
 312          */
 313         Partial1 = Quotient.Part.Lo * Divisor.Part.Hi;
 314         Partial2.Full = (UINT64) Quotient.Part.Lo * Divisor.Part.Lo;
 315         Partial3.Full = (UINT64) Partial2.Part.Hi + Partial1;
 316
 317         Remainder.Part.Hi = Partial3.Part.Lo;
 318         Remainder.Part.Lo = Partial2.Part.Lo;
 319
 320         if (Partial3.Part.Hi == 0)
 321         {
 322             if (Partial3.Part.Lo >= Dividend.Part.Hi)
 323             {
 324                 if (Partial3.Part.Lo == Dividend.Part.Hi)
 325                 {
 326                     if (Partial2.Part.Lo > Dividend.Part.Lo)
 327                     {
 328                         Quotient.Part.Lo--;
 329                         Remainder.Full -= Divisor.Full;
 330                     }
 331                 }
 332                 else
 333                 {
 334                     Quotient.Part.Lo--;
 335                     Remainder.Full -= Divisor.Full;
 336                 }
 337             }
 338
 339             Remainder.Full = Remainder.Full - Dividend.Full;
 340             Remainder.Part.Hi = (UINT32) -((INT32) Remainder.Part.Hi);
 341             Remainder.Part.Lo = (UINT32) -((INT32) Remainder.Part.Lo);
 342
 343             if (Remainder.Part.Lo)
 344             {
 345                 Remainder.Part.Hi--;
 346             }
 347         }
 348     }
 349
 350     /* Return only what was requested */
 351
 352     if (OutQuotient)
 353     {
 354         *OutQuotient = Quotient.Full;
 355     }
 356     if (OutRemainder)
 357     {
 358         *OutRemainder = Remainder.Full;
 359     }
 360
 361     return_ACPI_STATUS (AE_OK);
 362 }
 363
 364 #else
 365
 366 /*******************************************************************************
 367  *
 368  * FUNCTION:    AcpiUtShortDivide, AcpiUtDivide
 369  *
 370  * PARAMETERS:  See function headers above
 371  *
 372  * DESCRIPTION: Native versions of the UtDivide functions. Use these if either
 373  *              1) The target is a 64-bit platform and therefore 64-bit
 374  *                 integer math is supported directly by the machine.
 375  *              2) The target is a 32-bit or 16-bit platform, and the
 376  *                 double-precision integer math library is available to
 377  *                 perform the divide.
 378  *
 379  ******************************************************************************/
 380
 381 ACPI_STATUS
 382 AcpiUtShortDivide (
 383     UINT64                  InDividend,
 384     UINT32                  Divisor,
 385     UINT64                  *OutQuotient,
 386     UINT32                  *OutRemainder)
 387 {
 388
 389     ACPI_FUNCTION_TRACE (UtShortDivide);
 390
 391
 392     /* Always check for a zero divisor */
 393
 394     if (Divisor == 0)
 395     {
 396         ACPI_ERROR ((AE_INFO, "Divide by zero"));
 397         return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
 398     }
 399
 400     /* Return only what was requested */
 401
 402     if (OutQuotient)
 403     {
 404         *OutQuotient = InDividend / Divisor;
 405     }
 406     if (OutRemainder)
 407     {
 408         *OutRemainder = (UINT32) (InDividend % Divisor);
 409     }
 410
 411     return_ACPI_STATUS (AE_OK);
 412 }
 413
 414 ACPI_STATUS
 415 AcpiUtDivide (
 416     UINT64                  InDividend,
 417     UINT64                  InDivisor,
 418     UINT64                  *OutQuotient,
 419     UINT64                  *OutRemainder)
 420 {
 421     ACPI_FUNCTION_TRACE (UtDivide);
 422
 423
 424     /* Always check for a zero divisor */
 425
 426     if (InDivisor == 0)
 427     {
 428         ACPI_ERROR ((AE_INFO, "Divide by zero"));
 429         return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
 430     }
 431
 432
 433     /* Return only what was requested */
 434
 435     if (OutQuotient)
 436     {
 437         *OutQuotient = InDividend / InDivisor;
 438     }
 439     if (OutRemainder)
 440     {
 441         *OutRemainder = InDividend % InDivisor;
 442     }
 443
 444     return_ACPI_STATUS (AE_OK);
 445 }
 446
 447 #endif