xref: /openbmc/linux/arch/mips/sibyte/bcm1480/smp.c (revision 293d5b43)
1 /*
2  * Copyright (C) 2001,2002,2004 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17  */
18 
19 #include <linux/init.h>
20 #include <linux/delay.h>
21 #include <linux/smp.h>
22 #include <linux/kernel_stat.h>
23 #include <linux/sched.h>
24 
25 #include <asm/mmu_context.h>
26 #include <asm/io.h>
27 #include <asm/fw/cfe/cfe_api.h>
28 #include <asm/sibyte/sb1250.h>
29 #include <asm/sibyte/bcm1480_regs.h>
30 #include <asm/sibyte/bcm1480_int.h>
31 
32 /*
33  * These are routines for dealing with the bcm1480 smp capabilities
34  * independent of board/firmware
35  */
36 
37 static void *mailbox_0_set_regs[] = {
38 	IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
39 	IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
40 	IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
41 	IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
42 };
43 
44 static void *mailbox_0_clear_regs[] = {
45 	IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
46 	IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
47 	IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
48 	IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
49 };
50 
51 static void *mailbox_0_regs[] = {
52 	IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
53 	IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
54 	IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
55 	IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
56 };
57 
58 /*
59  * SMP init and finish on secondary CPUs
60  */
61 void bcm1480_smp_init(void)
62 {
63 	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
64 		STATUSF_IP1 | STATUSF_IP0;
65 
66 	/* Set interrupt mask, but don't enable */
67 	change_c0_status(ST0_IM, imask);
68 }
69 
70 /*
71  * These are routines for dealing with the sb1250 smp capabilities
72  * independent of board/firmware
73  */
74 
75 /*
76  * Simple enough; everything is set up, so just poke the appropriate mailbox
77  * register, and we should be set
78  */
79 static void bcm1480_send_ipi_single(int cpu, unsigned int action)
80 {
81 	__raw_writeq((((u64)action)<< 48), mailbox_0_set_regs[cpu]);
82 }
83 
84 static void bcm1480_send_ipi_mask(const struct cpumask *mask,
85 				  unsigned int action)
86 {
87 	unsigned int i;
88 
89 	for_each_cpu(i, mask)
90 		bcm1480_send_ipi_single(i, action);
91 }
92 
93 /*
94  * Code to run on secondary just after probing the CPU
95  */
96 static void bcm1480_init_secondary(void)
97 {
98 	extern void bcm1480_smp_init(void);
99 
100 	bcm1480_smp_init();
101 }
102 
103 /*
104  * Do any tidying up before marking online and running the idle
105  * loop
106  */
107 static void bcm1480_smp_finish(void)
108 {
109 	extern void sb1480_clockevent_init(void);
110 
111 	sb1480_clockevent_init();
112 	local_irq_enable();
113 }
114 
115 /*
116  * Setup the PC, SP, and GP of a secondary processor and start it
117  * running!
118  */
119 static void bcm1480_boot_secondary(int cpu, struct task_struct *idle)
120 {
121 	int retval;
122 
123 	retval = cfe_cpu_start(cpu_logical_map(cpu), &smp_bootstrap,
124 			       __KSTK_TOS(idle),
125 			       (unsigned long)task_thread_info(idle), 0);
126 	if (retval != 0)
127 		printk("cfe_start_cpu(%i) returned %i\n" , cpu, retval);
128 }
129 
130 /*
131  * Use CFE to find out how many CPUs are available, setting up
132  * cpu_possible_mask and the logical/physical mappings.
133  * XXXKW will the boot CPU ever not be physical 0?
134  *
135  * Common setup before any secondaries are started
136  */
137 static void __init bcm1480_smp_setup(void)
138 {
139 	int i, num;
140 
141 	init_cpu_possible(cpumask_of(0));
142 	__cpu_number_map[0] = 0;
143 	__cpu_logical_map[0] = 0;
144 
145 	for (i = 1, num = 0; i < NR_CPUS; i++) {
146 		if (cfe_cpu_stop(i) == 0) {
147 			set_cpu_possible(i, true);
148 			__cpu_number_map[i] = ++num;
149 			__cpu_logical_map[num] = i;
150 		}
151 	}
152 	printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
153 }
154 
155 static void __init bcm1480_prepare_cpus(unsigned int max_cpus)
156 {
157 }
158 
159 struct plat_smp_ops bcm1480_smp_ops = {
160 	.send_ipi_single	= bcm1480_send_ipi_single,
161 	.send_ipi_mask		= bcm1480_send_ipi_mask,
162 	.init_secondary		= bcm1480_init_secondary,
163 	.smp_finish		= bcm1480_smp_finish,
164 	.boot_secondary		= bcm1480_boot_secondary,
165 	.smp_setup		= bcm1480_smp_setup,
166 	.prepare_cpus		= bcm1480_prepare_cpus,
167 };
168 
169 void bcm1480_mailbox_interrupt(void)
170 {
171 	int cpu = smp_processor_id();
172 	int irq = K_BCM1480_INT_MBOX_0_0;
173 	unsigned int action;
174 
175 	kstat_incr_irq_this_cpu(irq);
176 	/* Load the mailbox register to figure out what we're supposed to do */
177 	action = (__raw_readq(mailbox_0_regs[cpu]) >> 48) & 0xffff;
178 
179 	/* Clear the mailbox to clear the interrupt */
180 	__raw_writeq(((u64)action)<<48, mailbox_0_clear_regs[cpu]);
181 
182 	if (action & SMP_RESCHEDULE_YOURSELF)
183 		scheduler_ipi();
184 
185 	if (action & SMP_CALL_FUNCTION) {
186 		irq_enter();
187 		generic_smp_call_function_interrupt();
188 		irq_exit();
189 	}
190 }
191