xref: /OK3568_Linux_fs/kernel/drivers/watchdog/octeon-wdt-nmi.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/*
2*4882a593Smuzhiyun * This file is subject to the terms and conditions of the GNU General Public
3*4882a593Smuzhiyun * License.  See the file "COPYING" in the main directory of this archive
4*4882a593Smuzhiyun * for more details.
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * Copyright (C) 2007-2017 Cavium, Inc.
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun#include <asm/asm.h>
9*4882a593Smuzhiyun#include <asm/regdef.h>
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun#define CVMSEG_BASE	-32768
12*4882a593Smuzhiyun#define CVMSEG_SIZE	6912
13*4882a593Smuzhiyun#define SAVE_REG(r)	sd $r, CVMSEG_BASE + CVMSEG_SIZE - ((32 - r) * 8)($0)
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun        NESTED(octeon_wdt_nmi_stage2, 0, sp)
16*4882a593Smuzhiyun	.set 	push
17*4882a593Smuzhiyun	.set 	noreorder
18*4882a593Smuzhiyun	.set 	noat
19*4882a593Smuzhiyun	/* Clear Dcache so cvmseg works right. */
20*4882a593Smuzhiyun	cache	1,0($0)
21*4882a593Smuzhiyun	/* Use K0 to do a read/modify/write of CVMMEMCTL */
22*4882a593Smuzhiyun	dmfc0	k0, $11, 7
23*4882a593Smuzhiyun	/* Clear out the size of CVMSEG	*/
24*4882a593Smuzhiyun	dins	k0, $0, 0, 6
25*4882a593Smuzhiyun	/* Set CVMSEG to its largest value */
26*4882a593Smuzhiyun	ori	k0, k0, 0x1c0 | 54
27*4882a593Smuzhiyun	/* Store the CVMMEMCTL value */
28*4882a593Smuzhiyun	dmtc0	k0, $11, 7
29*4882a593Smuzhiyun	/*
30*4882a593Smuzhiyun	 * Restore K0 from the debug scratch register, it was saved in
31*4882a593Smuzhiyun	 * the boot-vector code.
32*4882a593Smuzhiyun	 */
33*4882a593Smuzhiyun	dmfc0	k0, $31
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun	/*
36*4882a593Smuzhiyun	 * Save all registers to the top CVMSEG. This shouldn't
37*4882a593Smuzhiyun	 * corrupt any state used by the kernel. Also all registers
38*4882a593Smuzhiyun	 * should have the value right before the NMI.
39*4882a593Smuzhiyun	 */
40*4882a593Smuzhiyun	SAVE_REG(0)
41*4882a593Smuzhiyun	SAVE_REG(1)
42*4882a593Smuzhiyun	SAVE_REG(2)
43*4882a593Smuzhiyun	SAVE_REG(3)
44*4882a593Smuzhiyun	SAVE_REG(4)
45*4882a593Smuzhiyun	SAVE_REG(5)
46*4882a593Smuzhiyun	SAVE_REG(6)
47*4882a593Smuzhiyun	SAVE_REG(7)
48*4882a593Smuzhiyun	SAVE_REG(8)
49*4882a593Smuzhiyun	SAVE_REG(9)
50*4882a593Smuzhiyun	SAVE_REG(10)
51*4882a593Smuzhiyun	SAVE_REG(11)
52*4882a593Smuzhiyun	SAVE_REG(12)
53*4882a593Smuzhiyun	SAVE_REG(13)
54*4882a593Smuzhiyun	SAVE_REG(14)
55*4882a593Smuzhiyun	SAVE_REG(15)
56*4882a593Smuzhiyun	SAVE_REG(16)
57*4882a593Smuzhiyun	SAVE_REG(17)
58*4882a593Smuzhiyun	SAVE_REG(18)
59*4882a593Smuzhiyun	SAVE_REG(19)
60*4882a593Smuzhiyun	SAVE_REG(20)
61*4882a593Smuzhiyun	SAVE_REG(21)
62*4882a593Smuzhiyun	SAVE_REG(22)
63*4882a593Smuzhiyun	SAVE_REG(23)
64*4882a593Smuzhiyun	SAVE_REG(24)
65*4882a593Smuzhiyun	SAVE_REG(25)
66*4882a593Smuzhiyun	SAVE_REG(26)
67*4882a593Smuzhiyun	SAVE_REG(27)
68*4882a593Smuzhiyun	SAVE_REG(28)
69*4882a593Smuzhiyun	SAVE_REG(29)
70*4882a593Smuzhiyun	SAVE_REG(30)
71*4882a593Smuzhiyun	SAVE_REG(31)
72*4882a593Smuzhiyun	/* Write zero to all CVMSEG locations per Core-15169 */
73*4882a593Smuzhiyun	dli	a0, CVMSEG_SIZE - (33 * 8)
74*4882a593Smuzhiyun1:	sd	zero, CVMSEG_BASE(a0)
75*4882a593Smuzhiyun	daddiu	a0, a0, -8
76*4882a593Smuzhiyun	bgez	a0, 1b
77*4882a593Smuzhiyun	nop
78*4882a593Smuzhiyun	/* Set the stack to begin right below the registers */
79*4882a593Smuzhiyun	dli	sp, CVMSEG_BASE + CVMSEG_SIZE - (32 * 8)
80*4882a593Smuzhiyun	/* Load the address of the third stage handler */
81*4882a593Smuzhiyun	dla	$25, octeon_wdt_nmi_stage3
82*4882a593Smuzhiyun	/* Call the third stage handler */
83*4882a593Smuzhiyun	jal	$25
84*4882a593Smuzhiyun	/* a0 is the address of the saved registers */
85*4882a593Smuzhiyun	 move	a0, sp
86*4882a593Smuzhiyun	/* Loop forvever if we get here. */
87*4882a593Smuzhiyun2:	b	2b
88*4882a593Smuzhiyun	nop
89*4882a593Smuzhiyun	.set pop
90*4882a593Smuzhiyun	END(octeon_wdt_nmi_stage2)
91