1 /*
2 * Copyright (C) 2007 MIPS Technologies, Inc.
3 * All rights reserved.
4
5 * This program is free software; you can distribute it and/or modify it
6 * under the terms of the GNU General Public License (Version 2) as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
17 *
18 * Arbitrary Monitor interface
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/smp.h>
24
25 #include <asm/addrspace.h>
26 #include <asm/mips-boards/launch.h>
27 #include <asm/mipsmtregs.h>
28
amon_cpu_avail(int cpu)29 int amon_cpu_avail(int cpu)
30 {
31 struct cpulaunch *launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
32
33 if (cpu < 0 || cpu >= NCPULAUNCH) {
34 pr_debug("avail: cpu%d is out of range\n", cpu);
35 return 0;
36 }
37
38 launch += cpu;
39 if (!(launch->flags & LAUNCH_FREADY)) {
40 pr_debug("avail: cpu%d is not ready\n", cpu);
41 return 0;
42 }
43 if (launch->flags & (LAUNCH_FGO|LAUNCH_FGONE)) {
44 pr_debug("avail: too late.. cpu%d is already gone\n", cpu);
45 return 0;
46 }
47
48 return 1;
49 }
50
amon_cpu_start(int cpu,unsigned long pc,unsigned long sp,unsigned long gp,unsigned long a0)51 void amon_cpu_start(int cpu,
52 unsigned long pc, unsigned long sp,
53 unsigned long gp, unsigned long a0)
54 {
55 volatile struct cpulaunch *launch =
56 (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
57
58 if (!amon_cpu_avail(cpu))
59 return;
60 if (cpu == smp_processor_id()) {
61 pr_debug("launch: I am cpu%d!\n", cpu);
62 return;
63 }
64 launch += cpu;
65
66 pr_debug("launch: starting cpu%d\n", cpu);
67
68 launch->pc = pc;
69 launch->gp = gp;
70 launch->sp = sp;
71 launch->a0 = a0;
72
73 smp_wmb(); /* Target must see parameters before go */
74 launch->flags |= LAUNCH_FGO;
75 smp_wmb(); /* Target must see go before we poll */
76
77 while ((launch->flags & LAUNCH_FGONE) == 0)
78 ;
79 smp_rmb(); /* Target will be updating flags soon */
80 pr_debug("launch: cpu%d gone!\n", cpu);
81 }
82