1 /*
2  * Copyright (C) 2002 Momentum Computer, Inc.
3  * Author: Matthew Dharm, mdharm@momenco.com
4  *
5  * Based on work by:
6  *   Copyright (C) 2000 RidgeRun, Inc.
7  *   Author: RidgeRun, Inc.
8  *   glonnon@ridgerun.com, skranz@ridgerun.com, stevej@ridgerun.com
9  *
10  *   Copyright 2001 MontaVista Software Inc.
11  *   Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
12  *
13  *   Copyright (C) 2000, 2001 Ralf Baechle (ralf@gnu.org)
14  *
15  *  This program is free software; you can redistribute  it and/or modify it
16  *  under  the terms of  the GNU General  Public License as published by the
17  *  Free Software Foundation;  either version 2 of the  License, or (at your
18  *  option) any later version.
19  *
20  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
21  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
22  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
23  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
24  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
26  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
27  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
28  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  *  You should have received a copy of the  GNU General Public License along
32  *  with this program; if not, write  to the Free Software Foundation, Inc.,
33  *  675 Mass Ave, Cambridge, MA 02139, USA.
34  */
35 #include <linux/errno.h>
36 #include <linux/init.h>
37 #include <linux/kernel_stat.h>
38 #include <linux/module.h>
39 #include <linux/signal.h>
40 #include <linux/sched.h>
41 #include <linux/types.h>
42 #include <linux/interrupt.h>
43 #include <linux/ioport.h>
44 #include <linux/timex.h>
45 #include <linux/slab.h>
46 #include <linux/random.h>
47 #include <asm/bitops.h>
48 #include <asm/bootinfo.h>
49 #include <asm/io.h>
50 #include <asm/irq.h>
51 #include <asm/mipsregs.h>
52 #include <asm/system.h>
53 
54 #define read_32bit_cp0_set1_register(source)                    \
55 ({ int __res;                                                   \
56         __asm__ __volatile__(                                   \
57 	".set\tpush\n\t"					\
58 	".set\treorder\n\t"					\
59         "cfc0\t%0,"STR(source)"\n\t"                            \
60 	".set\tpop"						\
61         : "=r" (__res));                                        \
62         __res;})
63 
64 #define write_32bit_cp0_set1_register(register,value)           \
65         __asm__ __volatile__(                                   \
66         "ctc0\t%0,"STR(register)"\n\t"				\
67 	"nop"							\
68         : : "r" (value));
69 
70 static spinlock_t irq_lock = SPIN_LOCK_UNLOCKED;
71 
72 /* Function for careful CP0 interrupt mask access */
modify_cp0_intmask(unsigned clr_mask_in,unsigned set_mask_in)73 static inline void modify_cp0_intmask(unsigned clr_mask_in, unsigned set_mask_in)
74 {
75 	unsigned long status;
76 	unsigned clr_mask;
77 	unsigned set_mask;
78 
79 	/* do the low 8 bits first */
80 	clr_mask = 0xff & clr_mask_in;
81 	set_mask = 0xff & set_mask_in;
82 	status = read_c0_status();
83 	status &= ~((clr_mask & 0xFF) << 8);
84 	status |= (set_mask & 0xFF) << 8;
85 	write_c0_status(status);
86 
87 	/* do the high 8 bits */
88 	clr_mask = 0xff & (clr_mask_in >> 8);
89 	set_mask = 0xff & (set_mask_in >> 8);
90 	status = read_32bit_cp0_set1_register(CP0_S1_INTCONTROL);
91 	status &= ~((clr_mask & 0xFF) << 8);
92 	status |= (set_mask & 0xFF) << 8;
93 	write_32bit_cp0_set1_register(CP0_S1_INTCONTROL, status);
94 }
95 
mask_irq(unsigned int irq)96 static inline void mask_irq(unsigned int irq)
97 {
98 	modify_cp0_intmask(irq, 0);
99 }
100 
unmask_irq(unsigned int irq)101 static inline void unmask_irq(unsigned int irq)
102 {
103 	modify_cp0_intmask(0, irq);
104 }
105 
enable_rm9000_irq(unsigned int irq)106 static void enable_rm9000_irq(unsigned int irq)
107 {
108 	unsigned long flags;
109 
110 	spin_lock_irqsave(&irq_lock, flags);
111 	unmask_irq(1 << (irq-1));
112 	spin_unlock_irqrestore(&irq_lock, flags);
113 }
114 
startup_rm9000_irq(unsigned int irq)115 static unsigned int startup_rm9000_irq(unsigned int irq)
116 {
117 	enable_rm9000_irq(irq);
118 
119 	return 0;				/* never anything pending */
120 }
121 
disable_rm9000_irq(unsigned int irq)122 static void disable_rm9000_irq(unsigned int irq)
123 {
124 	unsigned long flags;
125 
126 	spin_lock_irqsave(&irq_lock, flags);
127 	mask_irq(1 << (irq-1));
128 	spin_unlock_irqrestore(&irq_lock, flags);
129 }
130 
131 #define shutdown_rm9000_irq disable_rm9000_irq
132 
mask_and_ack_rm9000_irq(unsigned int irq)133 static void mask_and_ack_rm9000_irq(unsigned int irq)
134 {
135 	mask_irq(1 << (irq-1));
136 }
137 
end_rm9000_irq(unsigned int irq)138 static void end_rm9000_irq(unsigned int irq)
139 {
140 	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
141 		unmask_irq(1 << (irq-1));
142 }
143 
144 static struct hw_interrupt_type rm9000_hpcdma_irq_type = {
145 	"RM9000",
146 	startup_rm9000_irq,
147 	shutdown_rm9000_irq,
148 	enable_rm9000_irq,
149 	disable_rm9000_irq,
150 	mask_and_ack_rm9000_irq,
151 	end_rm9000_irq,
152 	NULL
153 };
154 
155 extern void wired_reset(void);
156 extern void PMON_v2_setup(void);
157 extern asmlinkage void jaguar_handle_int(void);
158 extern void mv64340_irq_init(void);
159 
160 static struct irqaction cascade_mv64340 =
161 	{ no_action, SA_INTERRUPT, 0, "cascade via MV64340", NULL, NULL };
162 static struct irqaction unused_irq =
163 	{ no_action, SA_INTERRUPT, 0, "unused", NULL, NULL };
164 
init_IRQ(void)165 void __init init_IRQ(void)
166 {
167 	int i;
168 
169 	/*
170 	 * Clear all of the interrupts while we change the able around a bit.
171 	 * int-handler is not on bootstrap
172 	 */
173 	clear_c0_status(ST0_IM | ST0_BEV);
174 	__cli();
175 
176 	/* Sets the first-level interrupt dispatcher. */
177 	set_except_vector(0, jaguar_handle_int);
178 	init_generic_irq();
179 
180 	/* set up handler for first 12 IRQs as the CPU */
181 	for (i = 0; i < 13; i++) {
182 		irq_desc[i].status	= IRQ_DISABLED;
183 		irq_desc[i].action	= 0;
184 		irq_desc[i].depth	= 1;
185 		irq_desc[i].handler	= &rm9000_hpcdma_irq_type;
186 	}
187 
188 	/* set up the cascading interrupts */
189 	setup_irq(9, &cascade_mv64340);
190 
191 	/* mark unconnected IRQs as unconnected */
192 	setup_irq(10, &unused_irq);
193 
194 	/* mark un-used IRQ numbers as unconnected */
195 	setup_irq(13, &unused_irq);
196 	setup_irq(14, &unused_irq);
197 	setup_irq(15, &unused_irq);
198 
199 	mv64340_irq_init();
200 
201 #ifdef CONFIG_REMOTE_DEBUG
202 	printk("start kgdb ...\n");
203 	set_debug_traps();
204 	breakpoint();	/* you may move this line to whereever you want :-) */
205 #endif
206 #ifdef CONFIG_GDB_CONSOLE
207 	register_gdb_console();
208 #endif
209 
210 }
211