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 - 2018, 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 /* Structures used only for 64-bit divide */
160 
161 typedef struct uint64_struct
162 {
163     UINT32                          Lo;
164     UINT32                          Hi;
165 
166 } UINT64_STRUCT;
167 
168 typedef union uint64_overlay
169 {
170     UINT64                          Full;
171     UINT64_STRUCT                   Part;
172 
173 } UINT64_OVERLAY;
174 
175 /*
176  * Optional support for 64-bit double-precision integer multiply and shift.
177  * This code is configurable and is implemented in order to support 32-bit
178  * kernel environments where a 64-bit double-precision math library is not
179  * available.
180  */
181 #ifndef ACPI_USE_NATIVE_MATH64
182 
183 /*******************************************************************************
184  *
185  * FUNCTION:    AcpiUtShortMultiply
186  *
187  * PARAMETERS:  Multiplicand        - 64-bit multiplicand
188  *              Multiplier          - 32-bit multiplier
189  *              OutProduct          - Pointer to where the product is returned
190  *
191  * DESCRIPTION: Perform a short multiply.
192  *
193  ******************************************************************************/
194 
195 ACPI_STATUS
AcpiUtShortMultiply(UINT64 Multiplicand,UINT32 Multiplier,UINT64 * OutProduct)196 AcpiUtShortMultiply (
197     UINT64                  Multiplicand,
198     UINT32                  Multiplier,
199     UINT64                  *OutProduct)
200 {
201     UINT64_OVERLAY          MultiplicandOvl;
202     UINT64_OVERLAY          Product;
203     UINT32                  Carry32;
204 
205 
206     ACPI_FUNCTION_TRACE (UtShortMultiply);
207 
208 
209     MultiplicandOvl.Full = Multiplicand;
210 
211     /*
212      * The Product is 64 bits, the carry is always 32 bits,
213      * and is generated by the second multiply.
214      */
215     ACPI_MUL_64_BY_32 (0, MultiplicandOvl.Part.Hi, Multiplier,
216         Product.Part.Hi, Carry32);
217 
218     ACPI_MUL_64_BY_32 (0, MultiplicandOvl.Part.Lo, Multiplier,
219         Product.Part.Lo, Carry32);
220 
221     Product.Part.Hi += Carry32;
222 
223     /* Return only what was requested */
224 
225     if (OutProduct)
226     {
227         *OutProduct = Product.Full;
228     }
229 
230     return_ACPI_STATUS (AE_OK);
231 }
232 
233 
234 /*******************************************************************************
235  *
236  * FUNCTION:    AcpiUtShortShiftLeft
237  *
238  * PARAMETERS:  Operand             - 64-bit shift operand
239  *              Count               - 32-bit shift count
240  *              OutResult           - Pointer to where the result is returned
241  *
242  * DESCRIPTION: Perform a short left shift.
243  *
244  ******************************************************************************/
245 
246 ACPI_STATUS
AcpiUtShortShiftLeft(UINT64 Operand,UINT32 Count,UINT64 * OutResult)247 AcpiUtShortShiftLeft (
248     UINT64                  Operand,
249     UINT32                  Count,
250     UINT64                  *OutResult)
251 {
252     UINT64_OVERLAY          OperandOvl;
253 
254 
255     ACPI_FUNCTION_TRACE (UtShortShiftLeft);
256 
257 
258     OperandOvl.Full = Operand;
259 
260     if ((Count & 63) >= 32)
261     {
262         OperandOvl.Part.Hi = OperandOvl.Part.Lo;
263         OperandOvl.Part.Lo = 0;
264         Count = (Count & 63) - 32;
265     }
266     ACPI_SHIFT_LEFT_64_BY_32 (OperandOvl.Part.Hi,
267         OperandOvl.Part.Lo, Count);
268 
269     /* Return only what was requested */
270 
271     if (OutResult)
272     {
273         *OutResult = OperandOvl.Full;
274     }
275 
276     return_ACPI_STATUS (AE_OK);
277 }
278 
279 /*******************************************************************************
280  *
281  * FUNCTION:    AcpiUtShortShiftRight
282  *
283  * PARAMETERS:  Operand             - 64-bit shift operand
284  *              Count               - 32-bit shift count
285  *              OutResult           - Pointer to where the result is returned
286  *
287  * DESCRIPTION: Perform a short right shift.
288  *
289  ******************************************************************************/
290 
291 ACPI_STATUS
AcpiUtShortShiftRight(UINT64 Operand,UINT32 Count,UINT64 * OutResult)292 AcpiUtShortShiftRight (
293     UINT64                  Operand,
294     UINT32                  Count,
295     UINT64                  *OutResult)
296 {
297     UINT64_OVERLAY          OperandOvl;
298 
299 
300     ACPI_FUNCTION_TRACE (UtShortShiftRight);
301 
302 
303     OperandOvl.Full = Operand;
304 
305     if ((Count & 63) >= 32)
306     {
307         OperandOvl.Part.Lo = OperandOvl.Part.Hi;
308         OperandOvl.Part.Hi = 0;
309         Count = (Count & 63) - 32;
310     }
311     ACPI_SHIFT_RIGHT_64_BY_32 (OperandOvl.Part.Hi,
312         OperandOvl.Part.Lo, Count);
313 
314     /* Return only what was requested */
315 
316     if (OutResult)
317     {
318         *OutResult = OperandOvl.Full;
319     }
320 
321     return_ACPI_STATUS (AE_OK);
322 }
323 #else
324 
325 /*******************************************************************************
326  *
327  * FUNCTION:    AcpiUtShortMultiply
328  *
329  * PARAMETERS:  See function headers above
330  *
331  * DESCRIPTION: Native version of the UtShortMultiply function.
332  *
333  ******************************************************************************/
334 
335 ACPI_STATUS
AcpiUtShortMultiply(UINT64 Multiplicand,UINT32 Multiplier,UINT64 * OutProduct)336 AcpiUtShortMultiply (
337     UINT64                  Multiplicand,
338     UINT32                  Multiplier,
339     UINT64                  *OutProduct)
340 {
341 
342     ACPI_FUNCTION_TRACE (UtShortMultiply);
343 
344 
345     /* Return only what was requested */
346 
347     if (OutProduct)
348     {
349         *OutProduct = Multiplicand * Multiplier;
350     }
351 
352     return_ACPI_STATUS (AE_OK);
353 }
354 
355 /*******************************************************************************
356  *
357  * FUNCTION:    AcpiUtShortShiftLeft
358  *
359  * PARAMETERS:  See function headers above
360  *
361  * DESCRIPTION: Native version of the UtShortShiftLeft function.
362  *
363  ******************************************************************************/
364 
365 ACPI_STATUS
AcpiUtShortShiftLeft(UINT64 Operand,UINT32 Count,UINT64 * OutResult)366 AcpiUtShortShiftLeft (
367     UINT64                  Operand,
368     UINT32                  Count,
369     UINT64                  *OutResult)
370 {
371 
372     ACPI_FUNCTION_TRACE (UtShortShiftLeft);
373 
374 
375     /* Return only what was requested */
376 
377     if (OutResult)
378     {
379         *OutResult = Operand << Count;
380     }
381 
382     return_ACPI_STATUS (AE_OK);
383 }
384 
385 /*******************************************************************************
386  *
387  * FUNCTION:    AcpiUtShortShiftRight
388  *
389  * PARAMETERS:  See function headers above
390  *
391  * DESCRIPTION: Native version of the UtShortShiftRight function.
392  *
393  ******************************************************************************/
394 
395 ACPI_STATUS
AcpiUtShortShiftRight(UINT64 Operand,UINT32 Count,UINT64 * OutResult)396 AcpiUtShortShiftRight (
397     UINT64                  Operand,
398     UINT32                  Count,
399     UINT64                  *OutResult)
400 {
401 
402     ACPI_FUNCTION_TRACE (UtShortShiftRight);
403 
404 
405     /* Return only what was requested */
406 
407     if (OutResult)
408     {
409         *OutResult = Operand >> Count;
410     }
411 
412     return_ACPI_STATUS (AE_OK);
413 }
414 #endif
415 
416 /*
417  * Optional support for 64-bit double-precision integer divide. This code
418  * is configurable and is implemented in order to support 32-bit kernel
419  * environments where a 64-bit double-precision math library is not available.
420  *
421  * Support for a more normal 64-bit divide/modulo (with check for a divide-
422  * by-zero) appears after this optional section of code.
423  */
424 #ifndef ACPI_USE_NATIVE_DIVIDE
425 
426 
427 /*******************************************************************************
428  *
429  * FUNCTION:    AcpiUtShortDivide
430  *
431  * PARAMETERS:  Dividend            - 64-bit dividend
432  *              Divisor             - 32-bit divisor
433  *              OutQuotient         - Pointer to where the quotient is returned
434  *              OutRemainder        - Pointer to where the remainder is returned
435  *
436  * RETURN:      Status (Checks for divide-by-zero)
437  *
438  * DESCRIPTION: Perform a short (maximum 64 bits divided by 32 bits)
439  *              divide and modulo. The result is a 64-bit quotient and a
440  *              32-bit remainder.
441  *
442  ******************************************************************************/
443 
444 ACPI_STATUS
AcpiUtShortDivide(UINT64 Dividend,UINT32 Divisor,UINT64 * OutQuotient,UINT32 * OutRemainder)445 AcpiUtShortDivide (
446     UINT64                  Dividend,
447     UINT32                  Divisor,
448     UINT64                  *OutQuotient,
449     UINT32                  *OutRemainder)
450 {
451     UINT64_OVERLAY          DividendOvl;
452     UINT64_OVERLAY          Quotient;
453     UINT32                  Remainder32;
454 
455 
456     ACPI_FUNCTION_TRACE (UtShortDivide);
457 
458 
459     /* Always check for a zero divisor */
460 
461     if (Divisor == 0)
462     {
463         ACPI_ERROR ((AE_INFO, "Divide by zero"));
464         return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
465     }
466 
467     DividendOvl.Full = Dividend;
468 
469     /*
470      * The quotient is 64 bits, the remainder is always 32 bits,
471      * and is generated by the second divide.
472      */
473     ACPI_DIV_64_BY_32 (0, DividendOvl.Part.Hi, Divisor,
474         Quotient.Part.Hi, Remainder32);
475 
476     ACPI_DIV_64_BY_32 (Remainder32, DividendOvl.Part.Lo, Divisor,
477         Quotient.Part.Lo, Remainder32);
478 
479     /* Return only what was requested */
480 
481     if (OutQuotient)
482     {
483         *OutQuotient = Quotient.Full;
484     }
485     if (OutRemainder)
486     {
487         *OutRemainder = Remainder32;
488     }
489 
490     return_ACPI_STATUS (AE_OK);
491 }
492 
493 
494 /*******************************************************************************
495  *
496  * FUNCTION:    AcpiUtDivide
497  *
498  * PARAMETERS:  InDividend          - Dividend
499  *              InDivisor           - Divisor
500  *              OutQuotient         - Pointer to where the quotient is returned
501  *              OutRemainder        - Pointer to where the remainder is returned
502  *
503  * RETURN:      Status (Checks for divide-by-zero)
504  *
505  * DESCRIPTION: Perform a divide and modulo.
506  *
507  ******************************************************************************/
508 
509 ACPI_STATUS
AcpiUtDivide(UINT64 InDividend,UINT64 InDivisor,UINT64 * OutQuotient,UINT64 * OutRemainder)510 AcpiUtDivide (
511     UINT64                  InDividend,
512     UINT64                  InDivisor,
513     UINT64                  *OutQuotient,
514     UINT64                  *OutRemainder)
515 {
516     UINT64_OVERLAY          Dividend;
517     UINT64_OVERLAY          Divisor;
518     UINT64_OVERLAY          Quotient;
519     UINT64_OVERLAY          Remainder;
520     UINT64_OVERLAY          NormalizedDividend;
521     UINT64_OVERLAY          NormalizedDivisor;
522     UINT32                  Partial1;
523     UINT64_OVERLAY          Partial2;
524     UINT64_OVERLAY          Partial3;
525 
526 
527     ACPI_FUNCTION_TRACE (UtDivide);
528 
529 
530     /* Always check for a zero divisor */
531 
532     if (InDivisor == 0)
533     {
534         ACPI_ERROR ((AE_INFO, "Divide by zero"));
535         return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
536     }
537 
538     Divisor.Full  = InDivisor;
539     Dividend.Full = InDividend;
540     if (Divisor.Part.Hi == 0)
541     {
542         /*
543          * 1) Simplest case is where the divisor is 32 bits, we can
544          * just do two divides
545          */
546         Remainder.Part.Hi = 0;
547 
548         /*
549          * The quotient is 64 bits, the remainder is always 32 bits,
550          * and is generated by the second divide.
551          */
552         ACPI_DIV_64_BY_32 (0, Dividend.Part.Hi, Divisor.Part.Lo,
553             Quotient.Part.Hi, Partial1);
554 
555         ACPI_DIV_64_BY_32 (Partial1, Dividend.Part.Lo, Divisor.Part.Lo,
556             Quotient.Part.Lo, Remainder.Part.Lo);
557     }
558 
559     else
560     {
561         /*
562          * 2) The general case where the divisor is a full 64 bits
563          * is more difficult
564          */
565         Quotient.Part.Hi   = 0;
566         NormalizedDividend = Dividend;
567         NormalizedDivisor  = Divisor;
568 
569         /* Normalize the operands (shift until the divisor is < 32 bits) */
570 
571         do
572         {
573             ACPI_SHIFT_RIGHT_64 (
574                 NormalizedDivisor.Part.Hi, NormalizedDivisor.Part.Lo);
575             ACPI_SHIFT_RIGHT_64 (
576                 NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo);
577 
578         } while (NormalizedDivisor.Part.Hi != 0);
579 
580         /* Partial divide */
581 
582         ACPI_DIV_64_BY_32 (
583             NormalizedDividend.Part.Hi, NormalizedDividend.Part.Lo,
584             NormalizedDivisor.Part.Lo, Quotient.Part.Lo, Partial1);
585 
586         /*
587          * The quotient is always 32 bits, and simply requires
588          * adjustment. The 64-bit remainder must be generated.
589          */
590         Partial1 = Quotient.Part.Lo * Divisor.Part.Hi;
591         Partial2.Full = (UINT64) Quotient.Part.Lo * Divisor.Part.Lo;
592         Partial3.Full = (UINT64) Partial2.Part.Hi + Partial1;
593 
594         Remainder.Part.Hi = Partial3.Part.Lo;
595         Remainder.Part.Lo = Partial2.Part.Lo;
596 
597         if (Partial3.Part.Hi == 0)
598         {
599             if (Partial3.Part.Lo >= Dividend.Part.Hi)
600             {
601                 if (Partial3.Part.Lo == Dividend.Part.Hi)
602                 {
603                     if (Partial2.Part.Lo > Dividend.Part.Lo)
604                     {
605                         Quotient.Part.Lo--;
606                         Remainder.Full -= Divisor.Full;
607                     }
608                 }
609                 else
610                 {
611                     Quotient.Part.Lo--;
612                     Remainder.Full -= Divisor.Full;
613                 }
614             }
615 
616             Remainder.Full = Remainder.Full - Dividend.Full;
617             Remainder.Part.Hi = (UINT32) -((INT32) Remainder.Part.Hi);
618             Remainder.Part.Lo = (UINT32) -((INT32) Remainder.Part.Lo);
619 
620             if (Remainder.Part.Lo)
621             {
622                 Remainder.Part.Hi--;
623             }
624         }
625     }
626 
627     /* Return only what was requested */
628 
629     if (OutQuotient)
630     {
631         *OutQuotient = Quotient.Full;
632     }
633     if (OutRemainder)
634     {
635         *OutRemainder = Remainder.Full;
636     }
637 
638     return_ACPI_STATUS (AE_OK);
639 }
640 
641 #else
642 
643 /*******************************************************************************
644  *
645  * FUNCTION:    AcpiUtShortDivide, AcpiUtDivide
646  *
647  * PARAMETERS:  See function headers above
648  *
649  * DESCRIPTION: Native versions of the UtDivide functions. Use these if either
650  *              1) The target is a 64-bit platform and therefore 64-bit
651  *                 integer math is supported directly by the machine.
652  *              2) The target is a 32-bit or 16-bit platform, and the
653  *                 double-precision integer math library is available to
654  *                 perform the divide.
655  *
656  ******************************************************************************/
657 
658 ACPI_STATUS
AcpiUtShortDivide(UINT64 InDividend,UINT32 Divisor,UINT64 * OutQuotient,UINT32 * OutRemainder)659 AcpiUtShortDivide (
660     UINT64                  InDividend,
661     UINT32                  Divisor,
662     UINT64                  *OutQuotient,
663     UINT32                  *OutRemainder)
664 {
665 
666     ACPI_FUNCTION_TRACE (UtShortDivide);
667 
668 
669     /* Always check for a zero divisor */
670 
671     if (Divisor == 0)
672     {
673         ACPI_ERROR ((AE_INFO, "Divide by zero"));
674         return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
675     }
676 
677     /* Return only what was requested */
678 
679     if (OutQuotient)
680     {
681         *OutQuotient = InDividend / Divisor;
682     }
683     if (OutRemainder)
684     {
685         *OutRemainder = (UINT32) (InDividend % Divisor);
686     }
687 
688     return_ACPI_STATUS (AE_OK);
689 }
690 
691 ACPI_STATUS
AcpiUtDivide(UINT64 InDividend,UINT64 InDivisor,UINT64 * OutQuotient,UINT64 * OutRemainder)692 AcpiUtDivide (
693     UINT64                  InDividend,
694     UINT64                  InDivisor,
695     UINT64                  *OutQuotient,
696     UINT64                  *OutRemainder)
697 {
698     ACPI_FUNCTION_TRACE (UtDivide);
699 
700 
701     /* Always check for a zero divisor */
702 
703     if (InDivisor == 0)
704     {
705         ACPI_ERROR ((AE_INFO, "Divide by zero"));
706         return_ACPI_STATUS (AE_AML_DIVIDE_BY_ZERO);
707     }
708 
709 
710     /* Return only what was requested */
711 
712     if (OutQuotient)
713     {
714         *OutQuotient = InDividend / InDivisor;
715     }
716     if (OutRemainder)
717     {
718         *OutRemainder = InDividend % InDivisor;
719     }
720 
721     return_ACPI_STATUS (AE_OK);
722 }
723 
724 #endif
725