1 /* linux/arch/arm/mach-exynos4/platsmp.c
3 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
4 * http://www.samsung.com
6 * Cloned from linux/arch/arm/mach-vexpress/platsmp.c
8 * Copyright (C) 2002 ARM Ltd.
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
16 #include <linux/init.h>
17 #include <linux/errno.h>
18 #include <linux/delay.h>
19 #include <linux/device.h>
20 #include <linux/jiffies.h>
21 #include <linux/smp.h>
23 #include <linux/of_address.h>
25 #include <asm/cacheflush.h>
26 #include <asm/smp_plat.h>
27 #include <asm/smp_scu.h>
28 #include <asm/firmware.h>
35 extern void exynos4_secondary_startup(void);
37 static void __iomem
*sysram_base_addr
;
38 void __iomem
*sysram_ns_base_addr
;
40 static void __init
exynos_smp_prepare_sysram(void)
42 struct device_node
*node
;
44 for_each_compatible_node(node
, NULL
, "samsung,exynos4210-sysram") {
45 if (!of_device_is_available(node
))
47 sysram_base_addr
= of_iomap(node
, 0);
51 for_each_compatible_node(node
, NULL
, "samsung,exynos4210-sysram-ns") {
52 if (!of_device_is_available(node
))
54 sysram_ns_base_addr
= of_iomap(node
, 0);
59 static inline void __iomem
*cpu_boot_reg_base(void)
61 if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1
)
63 return sysram_base_addr
;
66 static inline void __iomem
*cpu_boot_reg(int cpu
)
68 void __iomem
*boot_reg
;
70 boot_reg
= cpu_boot_reg_base();
72 return ERR_PTR(-ENODEV
);
73 if (soc_is_exynos4412())
75 else if (soc_is_exynos5420())
81 * Write pen_release in a way that is guaranteed to be visible to all
82 * observers, irrespective of whether they're taking part in coherency
83 * or not. This is necessary for the hotplug code to work reliably.
85 static void write_pen_release(int val
)
89 sync_cache_w(&pen_release
);
92 static void __iomem
*scu_base_addr(void)
94 return (void __iomem
*)(S5P_VA_SCU
);
97 static DEFINE_SPINLOCK(boot_lock
);
99 static void exynos_secondary_init(unsigned int cpu
)
102 * let the primary processor know we're out of the
103 * pen, then head off into the C entry point
105 write_pen_release(-1);
108 * Synchronise with the boot thread.
110 spin_lock(&boot_lock
);
111 spin_unlock(&boot_lock
);
114 static int exynos_boot_secondary(unsigned int cpu
, struct task_struct
*idle
)
116 unsigned long timeout
;
117 unsigned long phys_cpu
= cpu_logical_map(cpu
);
121 * Set synchronisation state between this boot processor
122 * and the secondary one
124 spin_lock(&boot_lock
);
127 * The secondary processor is waiting to be released from
128 * the holding pen - release it, then wait for it to flag
129 * that it has been released by resetting pen_release.
131 * Note that "pen_release" is the hardware CPU ID, whereas
132 * "cpu" is Linux's internal ID.
134 write_pen_release(phys_cpu
);
136 if (!(__raw_readl(S5P_ARM_CORE1_STATUS
) & S5P_CORE_LOCAL_PWR_EN
)) {
137 __raw_writel(S5P_CORE_LOCAL_PWR_EN
,
138 S5P_ARM_CORE1_CONFIGURATION
);
142 /* wait max 10 ms until cpu1 is on */
143 while ((__raw_readl(S5P_ARM_CORE1_STATUS
)
144 & S5P_CORE_LOCAL_PWR_EN
) != S5P_CORE_LOCAL_PWR_EN
) {
152 printk(KERN_ERR
"cpu1 power enable failed");
153 spin_unlock(&boot_lock
);
158 * Send the secondary CPU a soft interrupt, thereby causing
159 * the boot monitor to read the system wide flags register,
160 * and branch to the address found there.
163 timeout
= jiffies
+ (1 * HZ
);
164 while (time_before(jiffies
, timeout
)) {
165 unsigned long boot_addr
;
169 boot_addr
= virt_to_phys(exynos4_secondary_startup
);
172 * Try to set boot address using firmware first
173 * and fall back to boot register if it fails.
175 ret
= call_firmware_op(set_cpu_boot_addr
, phys_cpu
, boot_addr
);
176 if (ret
&& ret
!= -ENOSYS
)
178 if (ret
== -ENOSYS
) {
179 void __iomem
*boot_reg
= cpu_boot_reg(phys_cpu
);
181 if (IS_ERR(boot_reg
)) {
182 ret
= PTR_ERR(boot_reg
);
185 __raw_writel(boot_addr
, cpu_boot_reg(phys_cpu
));
188 call_firmware_op(cpu_boot
, phys_cpu
);
190 arch_send_wakeup_ipi_mask(cpumask_of(cpu
));
192 if (pen_release
== -1)
199 * now the secondary core is starting up let it run its
200 * calibrations, then wait for it to finish
203 spin_unlock(&boot_lock
);
205 return pen_release
!= -1 ? ret
: 0;
209 * Initialise the CPU possible map early - this describes the CPUs
210 * which may be present or become present in the system.
213 static void __init
exynos_smp_init_cpus(void)
215 void __iomem
*scu_base
= scu_base_addr();
216 unsigned int i
, ncores
;
218 if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9
)
219 ncores
= scu_base
? scu_get_core_count(scu_base
) : 1;
222 * CPU Nodes are passed thru DT and set_cpu_possible
223 * is set by "arm_dt_init_cpu_maps".
228 if (ncores
> nr_cpu_ids
) {
229 pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
234 for (i
= 0; i
< ncores
; i
++)
235 set_cpu_possible(i
, true);
238 static void __init
exynos_smp_prepare_cpus(unsigned int max_cpus
)
242 if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A9
)
243 scu_enable(scu_base_addr());
245 exynos_smp_prepare_sysram();
248 * Write the address of secondary startup into the
249 * system-wide flags register. The boot monitor waits
250 * until it receives a soft interrupt, and then the
251 * secondary CPU branches to this address.
253 * Try using firmware operation first and fall back to
254 * boot register if it fails.
256 for (i
= 1; i
< max_cpus
; ++i
) {
257 unsigned long phys_cpu
;
258 unsigned long boot_addr
;
261 phys_cpu
= cpu_logical_map(i
);
262 boot_addr
= virt_to_phys(exynos4_secondary_startup
);
264 ret
= call_firmware_op(set_cpu_boot_addr
, phys_cpu
, boot_addr
);
265 if (ret
&& ret
!= -ENOSYS
)
267 if (ret
== -ENOSYS
) {
268 void __iomem
*boot_reg
= cpu_boot_reg(phys_cpu
);
270 if (IS_ERR(boot_reg
))
272 __raw_writel(boot_addr
, cpu_boot_reg(phys_cpu
));
277 struct smp_operations exynos_smp_ops __initdata
= {
278 .smp_init_cpus
= exynos_smp_init_cpus
,
279 .smp_prepare_cpus
= exynos_smp_prepare_cpus
,
280 .smp_secondary_init
= exynos_secondary_init
,
281 .smp_boot_secondary
= exynos_boot_secondary
,
282 #ifdef CONFIG_HOTPLUG_CPU
283 .cpu_die
= exynos_cpu_die
,