1 /*
2 * Copyright (c) 2011 Aeroflex Gaisler
3 *
4 * BSD license:
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25
26 #include <asm-leon/leon.h>
27 #include <asm-leon/leonstack.h>
28 #include <asm-leon/asmmacro.h>
29
30 extern volatile unsigned int __window_overflow_rettseq[3];
31 extern volatile unsigned int __window_overflow_slow1[2];
32
33 static unsigned int installed = 0;
34 static unsigned int save__window_overflow_rettseq[3];
35
36 int
install_winoverflow_hook(void (* func)(void))37 install_winoverflow_hook (void (*func) (void))
38 {
39 if (installed)
40 {
41 return 0;
42 }
43 if (!installed)
44 {
45 /*
46 a7 50 00 00 rd %wim, %l3
47 ae 10 00 01 mov %g1, %l7
48 83 34 e0 01 srl %l3, 1, %g1
49
50 81 c4 40 00 jmp %l1
51 81 cc 80 00 rett %l2 */
52 save__window_overflow_rettseq[0] = __window_overflow_rettseq[0];
53 save__window_overflow_rettseq[1] = __window_overflow_rettseq[1];
54 save__window_overflow_rettseq[2] = __window_overflow_rettseq[2];
55
56 /*29 10 00 31 sethi %hi(0x4000c400), %l4
57 81 c5 22 48 jmp %l4 + 0x248
58 01 00 00 00 nop */
59
60 __window_overflow_rettseq[0] = ((((unsigned int) func) >> 10) & 0x3fffff) | 0x29000000; /* upper 22 */
61 __window_overflow_rettseq[1] = ((((unsigned int) func)) & 0x03ff) | 0x81c52000; /* lower 10 */
62 __window_overflow_rettseq[2] = 0x01000000; /* nop */
63
64 sparc_leon23_icache_flush ();
65 installed = 1;
66 }
67 return 0;
68 }
69
70 void
uninstall_winoverflow_hook()71 uninstall_winoverflow_hook ()
72 {
73 if (installed)
74 {
75 __window_overflow_rettseq[0] = save__window_overflow_rettseq[0];
76 __window_overflow_rettseq[1] = save__window_overflow_rettseq[1];
77 __window_overflow_rettseq[2] = save__window_overflow_rettseq[2];
78
79 sparc_leon23_icache_flush ();
80 installed = 0;
81 }
82 }
83