1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * ip30-smp.c: SMP on IP30 architecture. |
4 | * Based off of the original IP30 SMP code, with inspiration from ip27-smp.c |
5 | * and smp-bmips.c. |
6 | * |
7 | * Copyright (C) 2005-2007 Stanislaw Skowronek <skylark@unaligned.org> |
8 | * 2006-2007, 2014-2015 Joshua Kinard <kumba@gentoo.org> |
9 | * 2009 Johannes Dickgreber <tanzy@gmx.de> |
10 | */ |
11 | |
12 | #include <linux/init.h> |
13 | #include <linux/sched.h> |
14 | #include <linux/sched/task_stack.h> |
15 | |
16 | #include <asm/time.h> |
17 | #include <asm/sgi/heart.h> |
18 | |
19 | #include "ip30-common.h" |
20 | |
21 | #define MPCONF_MAGIC 0xbaddeed2 |
22 | #define MPCONF_ADDR 0xa800000000000600L |
23 | #define MPCONF_SIZE 0x80 |
24 | #define MPCONF(x) (MPCONF_ADDR + (x) * MPCONF_SIZE) |
25 | |
26 | /* HEART can theoretically do 4 CPUs, but only 2 are physically possible */ |
27 | #define MP_NCPU 2 |
28 | |
29 | struct mpconf { |
30 | u32 magic; |
31 | u32 prid; |
32 | u32 physid; |
33 | u32 virtid; |
34 | u32 scachesz; |
35 | u16 fanloads; |
36 | u16 res; |
37 | void *launch; |
38 | void *rendezvous; |
39 | u64 res2[3]; |
40 | void *stackaddr; |
41 | void *lnch_parm; |
42 | void *rndv_parm; |
43 | u32 idleflag; |
44 | }; |
45 | |
46 | static void ip30_smp_send_ipi_single(int cpu, u32 action) |
47 | { |
48 | int irq; |
49 | |
50 | switch (action) { |
51 | case SMP_RESCHEDULE_YOURSELF: |
52 | irq = HEART_L2_INT_RESCHED_CPU_0; |
53 | break; |
54 | case SMP_CALL_FUNCTION: |
55 | irq = HEART_L2_INT_CALL_CPU_0; |
56 | break; |
57 | default: |
58 | panic(fmt: "IP30: Unknown action value in %s!\n" , __func__); |
59 | } |
60 | |
61 | irq += cpu; |
62 | |
63 | /* Poke the other CPU -- it's got mail! */ |
64 | heart_write(BIT_ULL(irq), &heart_regs->set_isr); |
65 | } |
66 | |
67 | static void ip30_smp_send_ipi_mask(const struct cpumask *mask, u32 action) |
68 | { |
69 | u32 i; |
70 | |
71 | for_each_cpu(i, mask) |
72 | ip30_smp_send_ipi_single(cpu: i, action); |
73 | } |
74 | |
75 | static void __init ip30_smp_setup(void) |
76 | { |
77 | int i; |
78 | int ncpu = 0; |
79 | struct mpconf *mpc; |
80 | |
81 | init_cpu_possible(cpumask_of(0)); |
82 | |
83 | /* Scan the MPCONF structure and enumerate available CPUs. */ |
84 | for (i = 0; i < MP_NCPU; i++) { |
85 | mpc = (struct mpconf *)MPCONF(i); |
86 | if (mpc->magic == MPCONF_MAGIC) { |
87 | set_cpu_possible(cpu: i, possible: true); |
88 | __cpu_number_map[i] = ++ncpu; |
89 | __cpu_logical_map[ncpu] = i; |
90 | pr_info("IP30: Slot: %d, PrID: %.8x, PhyID: %d, VirtID: %d\n" , |
91 | i, mpc->prid, mpc->physid, mpc->virtid); |
92 | } |
93 | } |
94 | pr_info("IP30: Detected %d CPU(s) present.\n" , ncpu); |
95 | |
96 | /* |
97 | * Set the coherency algorithm to '5' (cacheable coherent |
98 | * exclusive on write). This is needed on IP30 SMP, especially |
99 | * for R14000 CPUs, otherwise, instruction bus errors will |
100 | * occur upon reaching userland. |
101 | */ |
102 | change_c0_config(CONF_CM_CMASK, CONF_CM_CACHABLE_COW); |
103 | } |
104 | |
105 | static void __init ip30_smp_prepare_cpus(unsigned int max_cpus) |
106 | { |
107 | /* nothing to do here */ |
108 | } |
109 | |
110 | static int __init ip30_smp_boot_secondary(int cpu, struct task_struct *idle) |
111 | { |
112 | struct mpconf *mpc = (struct mpconf *)MPCONF(cpu); |
113 | |
114 | /* Stack pointer (sp). */ |
115 | mpc->stackaddr = (void *)__KSTK_TOS(idle); |
116 | |
117 | /* Global pointer (gp). */ |
118 | mpc->lnch_parm = task_thread_info(idle); |
119 | |
120 | mb(); /* make sure stack and lparm are written */ |
121 | |
122 | /* Boot CPUx. */ |
123 | mpc->launch = smp_bootstrap; |
124 | |
125 | /* CPUx now executes smp_bootstrap, then ip30_smp_finish */ |
126 | return 0; |
127 | } |
128 | |
129 | static void __init ip30_smp_init_cpu(void) |
130 | { |
131 | ip30_per_cpu_init(); |
132 | } |
133 | |
134 | static void __init ip30_smp_finish(void) |
135 | { |
136 | enable_percpu_irq(get_c0_compare_int(), IRQ_TYPE_NONE); |
137 | local_irq_enable(); |
138 | } |
139 | |
140 | struct plat_smp_ops __read_mostly ip30_smp_ops = { |
141 | .send_ipi_single = ip30_smp_send_ipi_single, |
142 | .send_ipi_mask = ip30_smp_send_ipi_mask, |
143 | .smp_setup = ip30_smp_setup, |
144 | .prepare_cpus = ip30_smp_prepare_cpus, |
145 | .boot_secondary = ip30_smp_boot_secondary, |
146 | .init_secondary = ip30_smp_init_cpu, |
147 | .smp_finish = ip30_smp_finish, |
148 | .prepare_boot_cpu = ip30_smp_init_cpu, |
149 | }; |
150 | |