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/leonstack.h>
27#include <asm-leon/winmacros.h>
28
29/* Registers to not touch at all. */
30#define t_psr        l0 /* Set by caller */
31#define t_pc         l1 /* Set by caller */
32#define t_npc        l2 /* Set by caller */
33#define t_wim        l3 /* Set by caller */
34#define t_twinmask   l4 /* Set at beginning of this entry routine. */
35#define t_kstack     l5 /* Set right before pt_regs frame is built */
36#define t_retpc      l6 /* If you change this, change winmacro.h header file */
37#define t_systable   l7 /* Never touch this, could be the syscall table ptr. */
38#define curptr       g6 /* Set after pt_regs frame is built */
39
40	/* Number of register windows */
41	.global _nwindows_min1, _nwindows
42
43        .text
44	.align 4
45	.globl	leonbare_trapsetup
46
47leonbare_trapsetup:
48
49#ifdef 	_FLAT
50	restore
51	RW_STORE(sp)
52	save
53#endif
54
55#ifndef _SOFT_FLOAT
56	/* build a pt_regs trap frame. */
57        sub	%fp, (SF_REGS_SZ + PT_REGS_SZ + FW_REGS_SZ), %t_kstack
58	PT_STORE_ALL(t_kstack, t_psr, t_pc, t_npc, g2)
59
60	/* build a fp_regs trap frame. */
61	sethi %hi(fpustate_current), %g2
62	ld [%g2+%lo(fpustate_current)], %g3
63	st %g3,[%t_kstack + (SF_REGS_SZ + PT_REGS_SZ + FW_REGS_SZ - 4)]
64	add %t_kstack,SF_REGS_SZ + PT_REGS_SZ,%g3
65	st %g3, [%g2+%lo(fpustate_current)]
66
67#else
68	/* build a pt_regs trap frame.
69	 */
70        sub	%fp, (SF_REGS_SZ + PT_REGS_SZ), %t_kstack
71	PT_STORE_ALL(t_kstack, t_psr, t_pc, t_npc, g2)
72#endif
73
74
75#ifndef _FLAT
76        /* See if we are in the trap window. */
77	mov	1, %t_twinmask
78	sll	%t_twinmask, %t_psr, %t_twinmask ! t_twinmask = (1 << psr)
79	andcc	%t_twinmask, %t_wim, %g0
80	beq	1f		! in trap window, clean up
81	 nop
82
83                /*-------------------------------------------------*/
84                /* Spill , adjust %wim and go. */
85                srl	%t_wim, 0x1, %g2	! begin computation of new %wim
86
87		sethi %hi(_nwindows_min1), %g3
88		ld [%g3+%lo(_nwindows_min1)], %g3
89
90                sll	%t_wim, %g3, %t_wim	! NWINDOWS-1
91                or	%t_wim, %g2, %g2
92                and	%g2, 0xff, %g2
93
94                save	%g0, %g0, %g0           ! get in window to be saved
95
96        	/* Set new %wim value */
97                wr	%g2, 0x0, %wim
98
99        	/* Save the kernel window onto the corresponding stack. */
100                RW_STORE(sp)
101
102        	restore	%g0, %g0, %g0
103                /*-------------------------------------------------*/
104
1051:
106#endif
107	/* Trap from kernel with a window available.
108	 * Just do it...
109	 */
110	jmpl	%t_retpc + 0x8, %g0	! return to caller
111	 mov	%t_kstack, %sp		! jump onto new stack
112
113
114