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Commit | Line | Data |
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19fe0475 AB |
1 | /* |
2 | * SMP support for BPA machines. | |
3 | * | |
4 | * Dave Engebretsen, Peter Bergner, and | |
5 | * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com | |
6 | * | |
7 | * Plus various changes from other IBM teams... | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | */ | |
14 | ||
15 | #undef DEBUG | |
16 | ||
19fe0475 | 17 | #include <linux/kernel.h> |
19fe0475 AB |
18 | #include <linux/sched.h> |
19 | #include <linux/smp.h> | |
20 | #include <linux/interrupt.h> | |
21 | #include <linux/delay.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/spinlock.h> | |
24 | #include <linux/cache.h> | |
25 | #include <linux/err.h> | |
edbaa603 | 26 | #include <linux/device.h> |
19fe0475 AB |
27 | #include <linux/cpu.h> |
28 | ||
29 | #include <asm/ptrace.h> | |
60063497 | 30 | #include <linux/atomic.h> |
19fe0475 AB |
31 | #include <asm/irq.h> |
32 | #include <asm/page.h> | |
33 | #include <asm/pgtable.h> | |
34 | #include <asm/io.h> | |
35 | #include <asm/prom.h> | |
36 | #include <asm/smp.h> | |
37 | #include <asm/paca.h> | |
19fe0475 AB |
38 | #include <asm/machdep.h> |
39 | #include <asm/cputable.h> | |
40 | #include <asm/firmware.h> | |
19fe0475 | 41 | #include <asm/rtas.h> |
8d089085 | 42 | #include <asm/cputhreads.h> |
2751b628 | 43 | #include <asm/code-patching.h> |
19fe0475 AB |
44 | |
45 | #include "interrupt.h" | |
aa39be09 | 46 | #include <asm/udbg.h> |
19fe0475 AB |
47 | |
48 | #ifdef DEBUG | |
49 | #define DBG(fmt...) udbg_printf(fmt) | |
50 | #else | |
51 | #define DBG(fmt...) | |
52 | #endif | |
53 | ||
54 | /* | |
6a75a6b8 MM |
55 | * The Primary thread of each non-boot processor was started from the OF client |
56 | * interface by prom_hold_cpus and is spinning on secondary_hold_spinloop. | |
19fe0475 AB |
57 | */ |
58 | static cpumask_t of_spin_map; | |
59 | ||
19fe0475 AB |
60 | /** |
61 | * smp_startup_cpu() - start the given cpu | |
62 | * | |
63 | * At boot time, there is nothing to do for primary threads which were | |
64 | * started from Open Firmware. For anything else, call RTAS with the | |
65 | * appropriate start location. | |
66 | * | |
67 | * Returns: | |
68 | * 0 - failure | |
69 | * 1 - success | |
70 | */ | |
cad5cef6 | 71 | static inline int smp_startup_cpu(unsigned int lcpu) |
19fe0475 AB |
72 | { |
73 | int status; | |
2751b628 AB |
74 | unsigned long start_here = |
75 | __pa(ppc_function_entry(generic_secondary_smp_init)); | |
19fe0475 AB |
76 | unsigned int pcpu; |
77 | int start_cpu; | |
78 | ||
104699c0 | 79 | if (cpumask_test_cpu(lcpu, &of_spin_map)) |
19fe0475 AB |
80 | /* Already started by OF and sitting in spin loop */ |
81 | return 1; | |
82 | ||
83 | pcpu = get_hard_smp_processor_id(lcpu); | |
84 | ||
85 | /* Fixup atomic count: it exited inside IRQ handler. */ | |
b5e2fc1c | 86 | task_thread_info(paca[lcpu].__current)->preempt_count = 0; |
19fe0475 AB |
87 | |
88 | /* | |
89 | * If the RTAS start-cpu token does not exist then presume the | |
90 | * cpu is already spinning. | |
91 | */ | |
92 | start_cpu = rtas_token("start-cpu"); | |
93 | if (start_cpu == RTAS_UNKNOWN_SERVICE) | |
94 | return 1; | |
95 | ||
96 | status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, lcpu); | |
97 | if (status != 0) { | |
98 | printk(KERN_ERR "start-cpu failed: %i\n", status); | |
99 | return 0; | |
100 | } | |
101 | ||
102 | return 1; | |
103 | } | |
104 | ||
cad5cef6 | 105 | static void smp_cell_setup_cpu(int cpu) |
19fe0475 AB |
106 | { |
107 | if (cpu != boot_cpuid) | |
108 | iic_setup_cpu(); | |
960cedb4 AB |
109 | |
110 | /* | |
111 | * change default DABRX to allow user watchpoints | |
112 | */ | |
113 | mtspr(SPRN_DABRX, DABRX_KERNEL | DABRX_USER); | |
19fe0475 AB |
114 | } |
115 | ||
cad5cef6 | 116 | static int smp_cell_kick_cpu(int nr) |
19fe0475 | 117 | { |
c642af9c | 118 | if (nr < 0 || nr >= nr_cpu_ids) |
f8d0d5dc | 119 | return -EINVAL; |
19fe0475 AB |
120 | |
121 | if (!smp_startup_cpu(nr)) | |
de300974 | 122 | return -ENOENT; |
19fe0475 AB |
123 | |
124 | /* | |
125 | * The processor is currently spinning, waiting for the | |
126 | * cpu_start field to become non-zero After we set cpu_start, | |
127 | * the processor will continue on to secondary_start | |
128 | */ | |
129 | paca[nr].cpu_start = 1; | |
de300974 ME |
130 | |
131 | return 0; | |
19fe0475 AB |
132 | } |
133 | ||
19fe0475 | 134 | static struct smp_ops_t bpa_iic_smp_ops = { |
d5a1c193 | 135 | .message_pass = iic_message_pass, |
a7f4ee1f | 136 | .probe = iic_request_IPIs, |
19fe0475 | 137 | .kick_cpu = smp_cell_kick_cpu, |
960cedb4 | 138 | .setup_cpu = smp_cell_setup_cpu, |
39fd4027 | 139 | .cpu_bootable = smp_generic_cpu_bootable, |
19fe0475 AB |
140 | }; |
141 | ||
142 | /* This is called very early */ | |
143 | void __init smp_init_cell(void) | |
144 | { | |
145 | int i; | |
146 | ||
147 | DBG(" -> smp_init_cell()\n"); | |
148 | ||
149 | smp_ops = &bpa_iic_smp_ops; | |
150 | ||
151 | /* Mark threads which are still spinning in hold loops. */ | |
152 | if (cpu_has_feature(CPU_FTR_SMT)) { | |
153 | for_each_present_cpu(i) { | |
6a75a6b8 | 154 | if (cpu_thread_in_core(i) == 0) |
104699c0 | 155 | cpumask_set_cpu(i, &of_spin_map); |
19fe0475 | 156 | } |
104699c0 KM |
157 | } else |
158 | cpumask_copy(&of_spin_map, cpu_present_mask); | |
19fe0475 | 159 | |
104699c0 | 160 | cpumask_clear_cpu(boot_cpuid, &of_spin_map); |
19fe0475 AB |
161 | |
162 | /* Non-lpar has additional take/give timebase */ | |
163 | if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { | |
c4007a2f BH |
164 | smp_ops->give_timebase = rtas_give_timebase; |
165 | smp_ops->take_timebase = rtas_take_timebase; | |
19fe0475 AB |
166 | } |
167 | ||
168 | DBG(" <- smp_init_cell()\n"); | |
169 | } |