/* mpi-internal.h  -  Internal to the Multi Precision Integers
   *	Copyright (C) 1994, 1996 Free Software Foundation, Inc.
   *	Copyright (C) 1998, 2000 Free Software Foundation, Inc.
   *
   * This file is part of GnuPG.
   *
   * GnuPG is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * GnuPG is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
   *
   * Note: This code is heavily based on the GNU MP Library.
   *	 Actually it's the same code with only minor changes in the
   *	 way the data is stored; this is to support the abstraction
   *	 of an optional secure memory allocation which may be used
   *	 to avoid revealing of sensitive data due to paging etc.
   *	 The GNU MP Library itself is published under the LGPL;
   *	 however I decided to publish this code under the plain GPL.
   */
  
  #ifndef G10_MPI_INTERNAL_H
  #define G10_MPI_INTERNAL_H
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/string.h>
  #include <linux/mpi.h>
  #include <linux/errno.h>
  
  #define log_debug printk
  #define log_bug printk
  
  #define assert(x) \
  	do { \
  		if (!x) \
  			log_bug("failed assertion
  "); \
  	} while (0);
  
  /* If KARATSUBA_THRESHOLD is not already defined, define it to a
   * value which is good on most machines.  */
  
  /* tested 4, 16, 32 and 64, where 16 gave the best performance when
   * checking a 768 and a 1024 bit ElGamal signature.
   * (wk 22.12.97) */
  #ifndef KARATSUBA_THRESHOLD
  #define KARATSUBA_THRESHOLD 16
  #endif
  
  /* The code can't handle KARATSUBA_THRESHOLD smaller than 2.  */
  #if KARATSUBA_THRESHOLD < 2
  #undef KARATSUBA_THRESHOLD
  #define KARATSUBA_THRESHOLD 2
  #endif
  
  typedef mpi_limb_t *mpi_ptr_t;	/* pointer to a limb */
  typedef int mpi_size_t;		/* (must be a signed type) */
  
  static inline int RESIZE_IF_NEEDED(MPI a, unsigned b)
  {
  	if (a->alloced < b)
  		return mpi_resize(a, b);
  	return 0;
  }
  
  /* Copy N limbs from S to D.  */
  #define MPN_COPY(d, s, n) \
  	do {					\
  		mpi_size_t _i;			\
  		for (_i = 0; _i < (n); _i++)	\
  			(d)[_i] = (s)[_i];	\
  	} while (0)
  
  #define MPN_COPY_INCR(d, s, n) \
  	do {					\
  		mpi_size_t _i;			\
  		for (_i = 0; _i < (n); _i++)	\
  			(d)[_i] = (d)[_i];	\
  	} while (0)
  
  #define MPN_COPY_DECR(d, s, n) \
  	do {					\
  		mpi_size_t _i;			\
  		for (_i = (n)-1; _i >= 0; _i--) \
  			(d)[_i] = (s)[_i];	\
  	} while (0)
  
  /* Zero N limbs at D */
  #define MPN_ZERO(d, n) \
  	do {					\
  		int  _i;			\
  		for (_i = 0; _i < (n); _i++)	\
  			(d)[_i] = 0;		\
  	} while (0)
  
  #define MPN_NORMALIZE(d, n)  \
  	do {					\
  		while ((n) > 0) {		\
  			if ((d)[(n)-1])		\
  				break;		\
  			(n)--;			\
  		}				\
  	} while (0)
  
  #define MPN_NORMALIZE_NOT_ZERO(d, n) \
  	do {				\
  		for (;;) {		\
  			if ((d)[(n)-1])	\
  				break;	\
  			(n)--;		\
  		}			\
  	} while (0)
  
  #define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
  	do {							\
  		if ((size) < KARATSUBA_THRESHOLD)		\
  			mul_n_basecase(prodp, up, vp, size);	\
  		else						\
  			mul_n(prodp, up, vp, size, tspace);	\
  	} while (0);
  
  /* Divide the two-limb number in (NH,,NL) by D, with DI being the largest
   * limb not larger than (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB).
   * If this would yield overflow, DI should be the largest possible number
   * (i.e., only ones).  For correct operation, the most significant bit of D
   * has to be set.  Put the quotient in Q and the remainder in R.
   */
  #define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \
  	do {								\
  		mpi_limb_t _q, _ql, _r;					\
  		mpi_limb_t _xh, _xl;					\
  		umul_ppmm(_q, _ql, (nh), (di));				\
  		_q += (nh);	/* DI is 2**BITS_PER_MPI_LIMB too small */ \
  		umul_ppmm(_xh, _xl, _q, (d));				\
  		sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl);		\
  		if (_xh) {						\
  			sub_ddmmss(_xh, _r, _xh, _r, 0, (d));		\
  			_q++;						\
  			if (_xh) {					\
  				sub_ddmmss(_xh, _r, _xh, _r, 0, (d));	\
  				_q++;					\
  			}						\
  		}							\
  		if (_r >= (d)) {					\
  			_r -= (d);					\
  			_q++;						\
  		}							\
  		(r) = _r;						\
  		(q) = _q;						\
  	} while (0)
  
  /*-- mpiutil.c --*/
  mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
  void mpi_free_limb_space(mpi_ptr_t a);
  void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);
  
  /*-- mpi-bit.c --*/
  void mpi_rshift_limbs(MPI a, unsigned int count);
  int mpi_lshift_limbs(MPI a, unsigned int count);
  
  /*-- mpihelp-add.c --*/
  mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  			 mpi_size_t s1_size, mpi_limb_t s2_limb);
  mpi_limb_t mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  			 mpi_ptr_t s2_ptr, mpi_size_t size);
  mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
  		       mpi_ptr_t s2_ptr, mpi_size_t s2_size);
  
  /*-- mpihelp-sub.c --*/
  mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  			 mpi_size_t s1_size, mpi_limb_t s2_limb);
  mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  			 mpi_ptr_t s2_ptr, mpi_size_t size);
  mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
  		       mpi_ptr_t s2_ptr, mpi_size_t s2_size);
  
  /*-- mpihelp-cmp.c --*/
  int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);
  
  /*-- mpihelp-mul.c --*/
  
  struct karatsuba_ctx {
  	struct karatsuba_ctx *next;
  	mpi_ptr_t tspace;
  	mpi_size_t tspace_size;
  	mpi_ptr_t tp;
  	mpi_size_t tp_size;
  };
  
  void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx);
  
  mpi_limb_t mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  			    mpi_size_t s1_size, mpi_limb_t s2_limb);
  mpi_limb_t mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  			    mpi_size_t s1_size, mpi_limb_t s2_limb);
  int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
  int mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
  		mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result);
  void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
  void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
  		mpi_ptr_t tspace);
  
  int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
  			       mpi_ptr_t up, mpi_size_t usize,
  			       mpi_ptr_t vp, mpi_size_t vsize,
  			       struct karatsuba_ctx *ctx);
  
  /*-- mpihelp-mul_1.c (or xxx/cpu/ *.S) --*/
  mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
  			 mpi_size_t s1_size, mpi_limb_t s2_limb);
  
  /*-- mpihelp-div.c --*/
  mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
  			 mpi_limb_t divisor_limb);
  mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
  			  mpi_ptr_t np, mpi_size_t nsize,
  			  mpi_ptr_t dp, mpi_size_t dsize);
  mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr,
  			    mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
  			    mpi_limb_t divisor_limb);
  
  /*-- mpihelp-shift.c --*/
  mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
  			  unsigned cnt);
  mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
  			  unsigned cnt);
  
  /* Define stuff for longlong.h.  */
  #define W_TYPE_SIZE BITS_PER_MPI_LIMB
  typedef mpi_limb_t UWtype;
  typedef unsigned int UHWtype;
  #if defined(__GNUC__)
  typedef unsigned int UQItype __attribute__ ((mode(QI)));
  typedef int SItype __attribute__ ((mode(SI)));
  typedef unsigned int USItype __attribute__ ((mode(SI)));
  typedef int DItype __attribute__ ((mode(DI)));
  typedef unsigned int UDItype __attribute__ ((mode(DI)));
  #else
  typedef unsigned char UQItype;
  typedef long SItype;
  typedef unsigned long USItype;
  #endif
  
  #ifdef __GNUC__
  #include "mpi-inline.h"
  #endif
  
  #endif /*G10_MPI_INTERNAL_H */