Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /* mpih-rshift.c  -  MPI helper functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Copyright (C) 1994, 1996, 1998, 1999,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *               2000, 2001 Free Software Foundation, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * This file is part of GNUPG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * Note: This code is heavily based on the GNU MP Library.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  *	 Actually it's the same code with only minor changes in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  *	 way the data is stored; this is to support the abstraction
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  *	 of an optional secure memory allocation which may be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  *	 to avoid revealing of sensitive data due to paging etc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  *	 The GNU MP Library itself is published under the LGPL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  *	 however I decided to publish this code under the plain GPL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include "mpi-internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) /* Shift U (pointed to by UP and USIZE limbs long) CNT bits to the right
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  * and store the USIZE least significant limbs of the result at WP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  * The bits shifted out to the right are returned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)  * Argument constraints:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * 1. 0 < CNT < BITS_PER_MP_LIMB
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * 2. If the result is to be written over the input, WP must be <= UP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) mpi_limb_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned cnt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	mpi_limb_t high_limb, low_limb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	unsigned sh_1, sh_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	mpi_size_t i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	mpi_limb_t retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	sh_1 = cnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	wp -= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	sh_2 = BITS_PER_MPI_LIMB - sh_1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	high_limb = up[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	retval = high_limb << sh_2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	low_limb = high_limb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	for (i = 1; i < usize; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 		high_limb = up[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 		wp[i] = (low_limb >> sh_1) | (high_limb << sh_2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 		low_limb = high_limb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	wp[i] = low_limb >> sh_1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) }