1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
4 * Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
5 * Copyright (C) 2002 ARM Ltd.
9 #include <linux/delay.h>
11 #include <linux/of_address.h>
13 #include <asm/cacheflush.h>
15 #include <asm/smp_plat.h>
16 #include <asm/smp_scu.h>
18 extern void ox820_secondary_startup(void);
20 static void __iomem
*cpu_ctrl
;
21 static void __iomem
*gic_cpu_ctrl
;
23 #define HOLDINGPEN_CPU_OFFSET 0xc8
24 #define HOLDINGPEN_LOCATION_OFFSET 0xc4
26 #define GIC_NCPU_OFFSET(cpu) (0x100 + (cpu)*0x100)
27 #define GIC_CPU_CTRL 0x00
28 #define GIC_CPU_CTRL_ENABLE 1
30 int __init
ox820_boot_secondary(unsigned int cpu
, struct task_struct
*idle
)
33 * Write the address of secondary startup into the
34 * system-wide flags register. The BootMonitor waits
35 * until it receives a soft interrupt, and then the
36 * secondary CPU branches to this address.
38 writel(virt_to_phys(ox820_secondary_startup
),
39 cpu_ctrl
+ HOLDINGPEN_LOCATION_OFFSET
);
41 writel(cpu
, cpu_ctrl
+ HOLDINGPEN_CPU_OFFSET
);
44 * Enable GIC cpu interface in CPU Interface Control Register
46 writel(GIC_CPU_CTRL_ENABLE
,
47 gic_cpu_ctrl
+ GIC_NCPU_OFFSET(cpu
) + GIC_CPU_CTRL
);
50 * Send the secondary CPU a soft interrupt, thereby causing
51 * the boot monitor to read the system wide flags register,
52 * and branch to the address found there.
54 arch_send_wakeup_ipi_mask(cpumask_of(cpu
));
59 static void __init
ox820_smp_prepare_cpus(unsigned int max_cpus
)
61 struct device_node
*np
;
62 void __iomem
*scu_base
;
64 np
= of_find_compatible_node(NULL
, NULL
, "arm,arm11mp-scu");
65 scu_base
= of_iomap(np
, 0);
70 /* Remap CPU Interrupt Interface Registers */
71 np
= of_find_compatible_node(NULL
, NULL
, "arm,arm11mp-gic");
72 gic_cpu_ctrl
= of_iomap(np
, 1);
77 np
= of_find_compatible_node(NULL
, NULL
, "oxsemi,ox820-sys-ctrl");
78 cpu_ctrl
= of_iomap(np
, 0);
90 static const struct smp_operations ox820_smp_ops __initconst
= {
91 .smp_prepare_cpus
= ox820_smp_prepare_cpus
,
92 .smp_boot_secondary
= ox820_boot_secondary
,
95 CPU_METHOD_OF_DECLARE(ox820_smp
, "oxsemi,ox820-smp", &ox820_smp_ops
);