1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
4  * Module Name: utmath - Integer math support routines
14 /* Structures used only for 64-bit divide */
22 	u64 full;  member
28  * Optional support for 64-bit double-precision integer multiply and shift.
29  * This code is configurable and is implemented in order to support 32-bit
30  * kernel environments where a 64-bit double-precision math library is not
39  * PARAMETERS:  multiplicand        - 64-bit multiplicand
40  *              multiplier          - 32-bit multiplier
41  *              out_product         - Pointer to where the product is returned
56 	multiplicand_ovl.full = multiplicand;  in acpi_ut_short_multiply()
73 		*out_product = product.full;  in acpi_ut_short_multiply()
83  * PARAMETERS:  operand             - 64-bit shift operand
84  *              count               - 32-bit shift count
85  *              out_result          - Pointer to where the result is returned
97 	operand_ovl.full = operand;  in acpi_ut_short_shift_left()
102 		count = (count & 63) - 32;  in acpi_ut_short_shift_left()
110 		*out_result = operand_ovl.full;  in acpi_ut_short_shift_left()
120  * PARAMETERS:  operand             - 64-bit shift operand
121  *              count               - 32-bit shift count
122  *              out_result          - Pointer to where the result is returned
134 	operand_ovl.full = operand;  in acpi_ut_short_shift_right()
139 		count = (count & 63) - 32;  in acpi_ut_short_shift_right()
147 		*out_result = operand_ovl.full;  in acpi_ut_short_shift_right()
229  * Optional support for 64-bit double-precision integer divide. This code
230  * is configurable and is implemented in order to support 32-bit kernel
231  * environments where a 64-bit double-precision math library is not available.
233  * Support for a more normal 64-bit divide/modulo (with check for a divide-
234  * by-zero) appears after this optional section of code.
242  * PARAMETERS:  dividend            - 64-bit dividend
243  *              divisor             - 32-bit divisor
244  *              out_quotient        - Pointer to where the quotient is returned
245  *              out_remainder       - Pointer to where the remainder is returned
247  * RETURN:      Status (Checks for divide-by-zero)
250  *              divide and modulo. The result is a 64-bit quotient and a
251  *              32-bit remainder.
272 	dividend_ovl.full = dividend;  in acpi_ut_short_divide()
287 		*out_quotient = quotient.full;  in acpi_ut_short_divide()
300  * PARAMETERS:  in_dividend         - Dividend
301  *              in_divisor          - Divisor
302  *              out_quotient        - Pointer to where the quotient is returned
303  *              out_remainder       - Pointer to where the remainder is returned
305  * RETURN:      Status (Checks for divide-by-zero)
334 	divisor.full = in_divisor;  in acpi_ut_divide()
335 	dividend.full = in_dividend;  in acpi_ut_divide()
356 		 * 2) The general case where the divisor is a full 64 bits  in acpi_ut_divide()
382 		 * adjustment. The 64-bit remainder must be generated.  in acpi_ut_divide()
385 		partial2.full = (u64) quotient.part.lo * divisor.part.lo;  in acpi_ut_divide()
386 		partial3.full = (u64) partial2.part.hi + partial1;  in acpi_ut_divide()
395 						quotient.part.lo--;  in acpi_ut_divide()
396 						remainder.full -= divisor.full;  in acpi_ut_divide()
399 					quotient.part.lo--;  in acpi_ut_divide()
400 					remainder.full -= divisor.full;  in acpi_ut_divide()
404 			remainder.full = remainder.full - dividend.full;  in acpi_ut_divide()
405 			remainder.part.hi = (u32)-((s32)remainder.part.hi);  in acpi_ut_divide()
406 			remainder.part.lo = (u32)-((s32)remainder.part.lo);  in acpi_ut_divide()
409 				remainder.part.hi--;  in acpi_ut_divide()
417 		*out_quotient = quotient.full;  in acpi_ut_divide()
420 		*out_remainder = remainder.full;  in acpi_ut_divide()
435  *              1) The target is a 64-bit platform and therefore 64-bit
437  *              2) The target is a 32-bit or 16-bit platform, and the
438  *                 double-precision integer math library is available to