147d11326SKuninori Morimoto // SPDX-License-Identifier: GPL-2.0
2b4214e41SRich Felker /*
3b4214e41SRich Felker * SMP support for J2 processor
4b4214e41SRich Felker *
5b4214e41SRich Felker * Copyright (C) 2015-2016 Smart Energy Instruments, Inc.
6b4214e41SRich Felker */
7b4214e41SRich Felker
8b4214e41SRich Felker #include <linux/smp.h>
9b4214e41SRich Felker #include <linux/interrupt.h>
10b4214e41SRich Felker #include <linux/io.h>
11b4214e41SRich Felker #include <linux/of_address.h>
12b4214e41SRich Felker #include <linux/of_irq.h>
13b4214e41SRich Felker #include <asm/cmpxchg.h>
14b4214e41SRich Felker
15b4214e41SRich Felker DEFINE_PER_CPU(unsigned, j2_ipi_messages);
16b4214e41SRich Felker
17b4214e41SRich Felker extern u32 *sh2_cpuid_addr;
18b4214e41SRich Felker static u32 *j2_ipi_trigger;
19b4214e41SRich Felker static int j2_ipi_irq;
20b4214e41SRich Felker
j2_ipi_interrupt_handler(int irq,void * arg)21b4214e41SRich Felker static irqreturn_t j2_ipi_interrupt_handler(int irq, void *arg)
22b4214e41SRich Felker {
23b4214e41SRich Felker unsigned cpu = hard_smp_processor_id();
24b4214e41SRich Felker volatile unsigned *pmsg = &per_cpu(j2_ipi_messages, cpu);
25b4214e41SRich Felker unsigned messages, i;
26b4214e41SRich Felker
27b4214e41SRich Felker do messages = *pmsg;
28b4214e41SRich Felker while (cmpxchg(pmsg, messages, 0) != messages);
29b4214e41SRich Felker
30b4214e41SRich Felker if (!messages) return IRQ_NONE;
31b4214e41SRich Felker
32b4214e41SRich Felker for (i=0; i<SMP_MSG_NR; i++)
33b4214e41SRich Felker if (messages & (1U<<i))
34b4214e41SRich Felker smp_message_recv(i);
35b4214e41SRich Felker
36b4214e41SRich Felker return IRQ_HANDLED;
37b4214e41SRich Felker }
38b4214e41SRich Felker
j2_smp_setup(void)39b4214e41SRich Felker static void j2_smp_setup(void)
40b4214e41SRich Felker {
41b4214e41SRich Felker }
42b4214e41SRich Felker
j2_prepare_cpus(unsigned int max_cpus)43b4214e41SRich Felker static void j2_prepare_cpus(unsigned int max_cpus)
44b4214e41SRich Felker {
45b4214e41SRich Felker struct device_node *np;
46b4214e41SRich Felker unsigned i, max = 1;
47b4214e41SRich Felker
48b4214e41SRich Felker np = of_find_compatible_node(NULL, NULL, "jcore,ipi-controller");
49b4214e41SRich Felker if (!np)
50b4214e41SRich Felker goto out;
51b4214e41SRich Felker
52b4214e41SRich Felker j2_ipi_irq = irq_of_parse_and_map(np, 0);
53b4214e41SRich Felker j2_ipi_trigger = of_iomap(np, 0);
54b4214e41SRich Felker if (!j2_ipi_irq || !j2_ipi_trigger)
55b4214e41SRich Felker goto out;
56b4214e41SRich Felker
57b4214e41SRich Felker np = of_find_compatible_node(NULL, NULL, "jcore,cpuid-mmio");
58b4214e41SRich Felker if (!np)
59b4214e41SRich Felker goto out;
60b4214e41SRich Felker
61b4214e41SRich Felker sh2_cpuid_addr = of_iomap(np, 0);
62b4214e41SRich Felker if (!sh2_cpuid_addr)
63b4214e41SRich Felker goto out;
64b4214e41SRich Felker
65b4214e41SRich Felker if (request_irq(j2_ipi_irq, j2_ipi_interrupt_handler, IRQF_PERCPU,
66b4214e41SRich Felker "ipi", (void *)j2_ipi_interrupt_handler) != 0)
67b4214e41SRich Felker goto out;
68b4214e41SRich Felker
69b4214e41SRich Felker max = max_cpus;
70b4214e41SRich Felker out:
71b4214e41SRich Felker /* Disable any cpus past max_cpus, or all secondaries if we didn't
72b4214e41SRich Felker * get the necessary resources to support SMP. */
73b4214e41SRich Felker for (i=max; i<NR_CPUS; i++) {
74b4214e41SRich Felker set_cpu_possible(i, false);
75b4214e41SRich Felker set_cpu_present(i, false);
76b4214e41SRich Felker }
77b4214e41SRich Felker }
78b4214e41SRich Felker
j2_start_cpu(unsigned int cpu,unsigned long entry_point)79b4214e41SRich Felker static void j2_start_cpu(unsigned int cpu, unsigned long entry_point)
80b4214e41SRich Felker {
81b4214e41SRich Felker struct device_node *np;
82b4214e41SRich Felker u32 regs[2];
83b4214e41SRich Felker void __iomem *release, *initpc;
84b4214e41SRich Felker
85b4214e41SRich Felker if (!cpu) return;
86b4214e41SRich Felker
87b4214e41SRich Felker np = of_get_cpu_node(cpu, NULL);
88b4214e41SRich Felker if (!np) return;
89b4214e41SRich Felker
90b4214e41SRich Felker if (of_property_read_u32_array(np, "cpu-release-addr", regs, 2)) return;
91*4bdc0d67SChristoph Hellwig release = ioremap(regs[0], sizeof(u32));
92*4bdc0d67SChristoph Hellwig initpc = ioremap(regs[1], sizeof(u32));
93b4214e41SRich Felker
94b4214e41SRich Felker __raw_writel(entry_point, initpc);
95b4214e41SRich Felker __raw_writel(1, release);
96b4214e41SRich Felker
97b4214e41SRich Felker iounmap(initpc);
98b4214e41SRich Felker iounmap(release);
99b4214e41SRich Felker
100b4214e41SRich Felker pr_info("J2 SMP: requested start of cpu %u\n", cpu);
101b4214e41SRich Felker }
102b4214e41SRich Felker
j2_smp_processor_id(void)103b4214e41SRich Felker static unsigned int j2_smp_processor_id(void)
104b4214e41SRich Felker {
105b4214e41SRich Felker return __raw_readl(sh2_cpuid_addr);
106b4214e41SRich Felker }
107b4214e41SRich Felker
j2_send_ipi(unsigned int cpu,unsigned int message)108b4214e41SRich Felker static void j2_send_ipi(unsigned int cpu, unsigned int message)
109b4214e41SRich Felker {
110b4214e41SRich Felker volatile unsigned *pmsg;
111b4214e41SRich Felker unsigned old;
112b4214e41SRich Felker unsigned long val;
113b4214e41SRich Felker
114b4214e41SRich Felker /* There is only one IPI interrupt shared by all messages, so
115b4214e41SRich Felker * we keep a separate interrupt flag per message type in sw. */
116b4214e41SRich Felker pmsg = &per_cpu(j2_ipi_messages, cpu);
117b4214e41SRich Felker do old = *pmsg;
118b4214e41SRich Felker while (cmpxchg(pmsg, old, old|(1U<<message)) != old);
119b4214e41SRich Felker
120b4214e41SRich Felker /* Generate the actual interrupt by writing to CCRn bit 28. */
121b4214e41SRich Felker val = __raw_readl(j2_ipi_trigger + cpu);
122b4214e41SRich Felker __raw_writel(val | (1U<<28), j2_ipi_trigger + cpu);
123b4214e41SRich Felker }
124b4214e41SRich Felker
125b4214e41SRich Felker static struct plat_smp_ops j2_smp_ops = {
126b4214e41SRich Felker .smp_setup = j2_smp_setup,
127b4214e41SRich Felker .prepare_cpus = j2_prepare_cpus,
128b4214e41SRich Felker .start_cpu = j2_start_cpu,
129b4214e41SRich Felker .smp_processor_id = j2_smp_processor_id,
130b4214e41SRich Felker .send_ipi = j2_send_ipi,
131b4214e41SRich Felker .cpu_die = native_cpu_die,
132b4214e41SRich Felker .cpu_disable = native_cpu_disable,
133b4214e41SRich Felker .play_dead = native_play_dead,
134b4214e41SRich Felker };
135b4214e41SRich Felker
136b4214e41SRich Felker CPU_METHOD_OF_DECLARE(j2_cpu_method, "jcore,spin-table", &j2_smp_ops);
137