LXR linux/arch/hexagon/mm/copy_to

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * User memory copying routines for the Hexagon Kernel
   4 *
   5 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
   6 */
   7
   8/* The right way to do this involves valignb
   9 * The easy way to do this is only speed up src/dest similar alignment.
  10 */
  11
  12/*
  13 * Copy to/from user are the same, except that for packets with a load and
  14 * a store, I don't know how to tell which kind of exception we got.
  15 * Therefore, we duplicate the function, and handle faulting addresses
  16 * differently for each function
  17 */
  18
  19/*
  20 * copy to user: stores can fault
  21 */
  22#define src_sav r13
  23#define dst_sav r12
  24#define src_dst_sav r13:12
  25#define d_dbuf r15:14
  26#define w_dbuf r15
  27
  28#define dst r0
  29#define src r1
  30#define bytes r2
  31#define loopcount r5
  32
  33#define FUNCNAME raw_copy_to_user
  34#include "copy_user_template.S"
  35
  36        /* STORE FAULTS from COPY_TO_USER */
  37        .falign
  381109:
  392109:
  404109:
  41        /* Alignment loop.  r2 has been updated.  Return it. */
  42        {
  43                r0 = r2
  44                jumpr r31
  45        }
  46        /* Normal copy loops.  Use dst-dst_sav to compute distance */
  47        /* dst holds best write, no need to unwind any loops */
  48        /* X - (A - B) == X + B - A */
  49        .falign
  508189:
  518199:
  524189:
  534199:
  542189:
  552199:
  561189:
  571199:
  58        {
  59                r2 += sub(dst_sav,dst)
  60        }
  61        {
  62                r0 = r2
  63                jumpr r31
  64        }
  65
  66        /* COPY TO USER: only stores can fail */
  67        .section __ex_table,"a"
  68        .long 1100b,1109b
  69        .long 2100b,2109b
  70        .long 4100b,4109b
  71        .long 8180b,8189b
  72        .long 8190b,8199b
  73        .long 4180b,4189b
  74        .long 4190b,4199b
  75        .long 2180b,2189b
  76        .long 2190b,2199b
  77        .long 1180b,1189b
  78        .long 1190b,1199b
  79        .previous
  80