xref: /openbmc/linux/arch/mips/sibyte/bcm1480/smp.c (revision ae213c44)
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 #include <linux/sched/task_stack.h>
25 
26 #include <asm/mmu_context.h>
27 #include <asm/io.h>
28 #include <asm/fw/cfe/cfe_api.h>
29 #include <asm/sibyte/sb1250.h>
30 #include <asm/sibyte/bcm1480_regs.h>
31 #include <asm/sibyte/bcm1480_int.h>
32 
33 /*
34  * These are routines for dealing with the bcm1480 smp capabilities
35  * independent of board/firmware
36  */
37 
38 static void *mailbox_0_set_regs[] = {
39 	IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
40 	IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
41 	IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
42 	IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_SET_CPU),
43 };
44 
45 static void *mailbox_0_clear_regs[] = {
46 	IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
47 	IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
48 	IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
49 	IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_CLR_CPU),
50 };
51 
52 static void *mailbox_0_regs[] = {
53 	IOADDR(A_BCM1480_IMR_CPU0_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
54 	IOADDR(A_BCM1480_IMR_CPU1_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
55 	IOADDR(A_BCM1480_IMR_CPU2_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
56 	IOADDR(A_BCM1480_IMR_CPU3_BASE + R_BCM1480_IMR_MAILBOX_0_CPU),
57 };
58 
59 /*
60  * SMP init and finish on secondary CPUs
61  */
62 void bcm1480_smp_init(void)
63 {
64 	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
65 		STATUSF_IP1 | STATUSF_IP0;
66 
67 	/* Set interrupt mask, but don't enable */
68 	change_c0_status(ST0_IM, imask);
69 }
70 
71 /*
72  * These are routines for dealing with the sb1250 smp capabilities
73  * independent of board/firmware
74  */
75 
76 /*
77  * Simple enough; everything is set up, so just poke the appropriate mailbox
78  * register, and we should be set
79  */
80 static void bcm1480_send_ipi_single(int cpu, unsigned int action)
81 {
82 	__raw_writeq((((u64)action)<< 48), mailbox_0_set_regs[cpu]);
83 }
84 
85 static void bcm1480_send_ipi_mask(const struct cpumask *mask,
86 				  unsigned int action)
87 {
88 	unsigned int i;
89 
90 	for_each_cpu(i, mask)
91 		bcm1480_send_ipi_single(i, action);
92 }
93 
94 /*
95  * Code to run on secondary just after probing the CPU
96  */
97 static void bcm1480_init_secondary(void)
98 {
99 	extern void bcm1480_smp_init(void);
100 
101 	bcm1480_smp_init();
102 }
103 
104 /*
105  * Do any tidying up before marking online and running the idle
106  * loop
107  */
108 static void bcm1480_smp_finish(void)
109 {
110 	extern void sb1480_clockevent_init(void);
111 
112 	sb1480_clockevent_init();
113 	local_irq_enable();
114 }
115 
116 /*
117  * Setup the PC, SP, and GP of a secondary processor and start it
118  * running!
119  */
120 static int bcm1480_boot_secondary(int cpu, struct task_struct *idle)
121 {
122 	int retval;
123 
124 	retval = cfe_cpu_start(cpu_logical_map(cpu), &smp_bootstrap,
125 			       __KSTK_TOS(idle),
126 			       (unsigned long)task_thread_info(idle), 0);
127 	if (retval != 0)
128 		printk("cfe_start_cpu(%i) returned %i\n" , cpu, retval);
129 	return retval;
130 }
131 
132 /*
133  * Use CFE to find out how many CPUs are available, setting up
134  * cpu_possible_mask and the logical/physical mappings.
135  * XXXKW will the boot CPU ever not be physical 0?
136  *
137  * Common setup before any secondaries are started
138  */
139 static void __init bcm1480_smp_setup(void)
140 {
141 	int i, num;
142 
143 	init_cpu_possible(cpumask_of(0));
144 	__cpu_number_map[0] = 0;
145 	__cpu_logical_map[0] = 0;
146 
147 	for (i = 1, num = 0; i < NR_CPUS; i++) {
148 		if (cfe_cpu_stop(i) == 0) {
149 			set_cpu_possible(i, true);
150 			__cpu_number_map[i] = ++num;
151 			__cpu_logical_map[num] = i;
152 		}
153 	}
154 	printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
155 }
156 
157 static void __init bcm1480_prepare_cpus(unsigned int max_cpus)
158 {
159 }
160 
161 const struct plat_smp_ops bcm1480_smp_ops = {
162 	.send_ipi_single	= bcm1480_send_ipi_single,
163 	.send_ipi_mask		= bcm1480_send_ipi_mask,
164 	.init_secondary		= bcm1480_init_secondary,
165 	.smp_finish		= bcm1480_smp_finish,
166 	.boot_secondary		= bcm1480_boot_secondary,
167 	.smp_setup		= bcm1480_smp_setup,
168 	.prepare_cpus		= bcm1480_prepare_cpus,
169 };
170 
171 void bcm1480_mailbox_interrupt(void)
172 {
173 	int cpu = smp_processor_id();
174 	int irq = K_BCM1480_INT_MBOX_0_0;
175 	unsigned int action;
176 
177 	kstat_incr_irq_this_cpu(irq);
178 	/* Load the mailbox register to figure out what we're supposed to do */
179 	action = (__raw_readq(mailbox_0_regs[cpu]) >> 48) & 0xffff;
180 
181 	/* Clear the mailbox to clear the interrupt */
182 	__raw_writeq(((u64)action)<<48, mailbox_0_clear_regs[cpu]);
183 
184 	if (action & SMP_RESCHEDULE_YOURSELF)
185 		scheduler_ipi();
186 
187 	if (action & SMP_CALL_FUNCTION) {
188 		irq_enter();
189 		generic_smp_call_function_interrupt();
190 		irq_exit();
191 	}
192 }
193