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smp.c
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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>
30 #include <asm/sibyte/bcm1480_int.h>
31 
32 extern void smp_call_function_interrupt(void);
33 
34 /*
35  * These are routines for dealing with the bcm1480 smp capabilities
36  * independent of board/firmware
37  */
38 
39 static void *mailbox_0_set_regs[] = {
44 };
45 
46 static void *mailbox_0_clear_regs[] = {
51 };
52 
53 static void *mailbox_0_regs[] = {
58 };
59 
60 /*
61  * SMP init and finish on secondary CPUs
62  */
64 {
65  unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
67 
68  /* Set interrupt mask, but don't enable */
69  change_c0_status(ST0_IM, imask);
70 }
71 
72 /*
73  * These are routines for dealing with the sb1250 smp capabilities
74  * independent of board/firmware
75  */
76 
77 /*
78  * Simple enough; everything is set up, so just poke the appropriate mailbox
79  * register, and we should be set
80  */
81 static void bcm1480_send_ipi_single(int cpu, unsigned int action)
82 {
83  __raw_writeq((((u64)action)<< 48), mailbox_0_set_regs[cpu]);
84 }
85 
86 static void bcm1480_send_ipi_mask(const struct cpumask *mask,
87  unsigned int action)
88 {
89  unsigned int i;
90 
91  for_each_cpu(i, mask)
92  bcm1480_send_ipi_single(i, action);
93 }
94 
95 /*
96  * Code to run on secondary just after probing the CPU
97  */
98 static void __cpuinit bcm1480_init_secondary(void)
99 {
100  extern void bcm1480_smp_init(void);
101 
103 }
104 
105 /*
106  * Do any tidying up before marking online and running the idle
107  * loop
108  */
109 static void __cpuinit bcm1480_smp_finish(void)
110 {
111  extern void sb1480_clockevent_init(void);
112 
115 }
116 
117 /*
118  * Final cleanup after all secondaries booted
119  */
120 static void bcm1480_cpus_done(void)
121 {
122 }
123 
124 /*
125  * Setup the PC, SP, and GP of a secondary processor and start it
126  * running!
127  */
128 static void __cpuinit bcm1480_boot_secondary(int cpu, struct task_struct *idle)
129 {
130  int retval;
131 
133  __KSTK_TOS(idle),
134  (unsigned long)task_thread_info(idle), 0);
135  if (retval != 0)
136  printk("cfe_start_cpu(%i) returned %i\n" , cpu, retval);
137 }
138 
139 /*
140  * Use CFE to find out how many CPUs are available, setting up
141  * cpu_possible_mask and the logical/physical mappings.
142  * XXXKW will the boot CPU ever not be physical 0?
143  *
144  * Common setup before any secondaries are started
145  */
146 static void __init bcm1480_smp_setup(void)
147 {
148  int i, num;
149 
151  __cpu_number_map[0] = 0;
152  __cpu_logical_map[0] = 0;
153 
154  for (i = 1, num = 0; i < NR_CPUS; i++) {
155  if (cfe_cpu_stop(i) == 0) {
156  set_cpu_possible(i, true);
157  __cpu_number_map[i] = ++num;
158  __cpu_logical_map[num] = i;
159  }
160  }
161  printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
162 }
163 
164 static void __init bcm1480_prepare_cpus(unsigned int max_cpus)
165 {
166 }
167 
169  .send_ipi_single = bcm1480_send_ipi_single,
170  .send_ipi_mask = bcm1480_send_ipi_mask,
171  .init_secondary = bcm1480_init_secondary,
172  .smp_finish = bcm1480_smp_finish,
173  .cpus_done = bcm1480_cpus_done,
174  .boot_secondary = bcm1480_boot_secondary,
175  .smp_setup = bcm1480_smp_setup,
176  .prepare_cpus = bcm1480_prepare_cpus,
177 };
178 
180 {
181  int cpu = smp_processor_id();
183  unsigned int action;
184 
185  kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
186  /* Load the mailbox register to figure out what we're supposed to do */
187  action = (__raw_readq(mailbox_0_regs[cpu]) >> 48) & 0xffff;
188 
189  /* Clear the mailbox to clear the interrupt */
190  __raw_writeq(((u64)action)<<48, mailbox_0_clear_regs[cpu]);
191 
192  if (action & SMP_RESCHEDULE_YOURSELF)
193  scheduler_ipi();
194 
195  if (action & SMP_CALL_FUNCTION)
197 }