1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright © 2019 Keith Packard
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 *
18 * 3. Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33 * OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include <picotls.h>
37 #include <string.h>
38 #include <stdint.h>
39 #include "arm_tls.h"
40
41 /* This needs to be global so that __aeabi_read_tp can
42 * refer to it in an asm statement
43 */
44 #ifndef ARM_TLS_CP15
45 void *__tls;
46 #endif
47
48 /* The size of the thread control block.
49 * TLS relocations are generated relative to
50 * a location this far *before* the first thread
51 * variable (!)
52 * NB: The actual size before tp also includes padding
53 * to align up to the alignment of .tdata/.tbss.
54 */
55 #define TCB_SIZE 8
56 extern char __arm32_tls_tcb_offset;
57 #define TP_OFFSET ((size_t)&__arm32_tls_tcb_offset)
58
59 void
_set_tls(void * tls)60 _set_tls(void *tls)
61 {
62 #ifdef ARM_TLS_CP15
63 __asm__("mcr p15, 0, %0, cr13, cr0, 3" : : "r" (tls - TP_OFFSET));
64 #else
65 __tls = (uint8_t *) tls - TP_OFFSET;
66 #endif
67 }
68
