shared/exceptions/ppc_exc_alignment.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /*
0004  * Copyright (c) 2011 embedded brains GmbH & Co. KG
0005  *
0006  * Redistribution and use in source and binary forms, with or without
0007  * modification, are permitted provided that the following conditions
0008  * are met:
0009  * 1. Redistributions of source code must retain the above copyright
0010  *    notice, this list of conditions and the following disclaimer.
0011  * 2. Redistributions in binary form must reproduce the above copyright
0012  *    notice, this list of conditions and the following disclaimer in the
0013  *    documentation and/or other materials provided with the distribution.
0014  *
0015  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0016  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0017  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0018  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0019  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0020  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0021  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0022  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0023  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0024  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0025  * POSSIBILITY OF SUCH DAMAGE.
0026  */
0027
0028 #include <rtems.h>
0029 #include <bsp/vectors.h>
0030
0031 int ppc_exc_alignment_handler(BSP_Exception_frame *frame, unsigned excNum)
0032 {
0033   unsigned opcode = *(unsigned *) frame->EXC_SRR0;
0034
0035   /* Do we have a dcbz instruction? */
0036   if ((opcode & 0xffe007ff) == 0x7c0007ec) {
0037     unsigned clsz = rtems_cache_get_data_line_size();
0038     unsigned a = (opcode >> 16) & 0x1f;
0039     unsigned b = (opcode >> 11) & 0x1f;
0040     PPC_GPR_TYPE *regs = &frame->GPR0;
0041     unsigned *current = (unsigned *)
0042       (((a == 0 ? 0 : (unsigned) regs[a]) + (unsigned) regs[b]) & (clsz - 1));
0043     unsigned *end = current + clsz / sizeof(*current);
0044
0045     while (current != end) {
0046       *current = 0;
0047       ++current;
0048     }
0049
0050     frame->EXC_SRR0 += 4;
0051
0052     return 0;
0053   } else {
0054     return -1;
0055   }
0056 }