arch/blackfin/mach-bf561/smp.c

   1 /*
   2  * Copyright 2007-2009 Analog Devices Inc.
   3  *               Philippe Gerum <rpm@xenomai.org>
   4  *
   5  * Licensed under the GPL-2 or later.
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/delay.h>
  12 #include <asm/smp.h>
  13 #include <asm/dma.h>
  14 #include <asm/time.h>
  15
  16 static DEFINE_SPINLOCK(boot_lock);
  17
  18 /*
  19  * platform_init_cpus() - Tell the world about how many cores we
  20  * have. This is called while setting up the architecture support
  21  * (setup_arch()), so don't be too demanding here with respect to
  22  * available kernel services.
  23  */
  24
  25 void __init platform_init_cpus(void)
  26 {
  27         struct cpumask mask;
  28
  29         cpumask_set_cpu(0, &mask); /* CoreA */
  30         cpumask_set_cpu(1, &mask); /* CoreB */
  31         init_cpu_possible(&mask);
  32 }
  33
  34 void __init platform_prepare_cpus(unsigned int max_cpus)
  35 {
  36         struct cpumask mask;
  37
  38         bfin_relocate_coreb_l1_mem();
  39
  40         /* Both cores ought to be present on a bf561! */
  41         cpumask_set_cpu(0, &mask); /* CoreA */
  42         cpumask_set_cpu(1, &mask); /* CoreB */
  43         init_cpu_present(&mask);
  44 }
  45
  46 int __init setup_profiling_timer(unsigned int multiplier) /* not supported */
  47 {
  48         return -EINVAL;
  49 }
  50
  51 void __cpuinit platform_secondary_init(unsigned int cpu)
  52 {
  53         /* Clone setup for peripheral interrupt sources from CoreA. */
  54         bfin_write_SICB_IMASK0(bfin_read_SIC_IMASK0());
  55         bfin_write_SICB_IMASK1(bfin_read_SIC_IMASK1());
  56         SSYNC();
  57
  58         /* Clone setup for IARs from CoreA. */
  59         bfin_write_SICB_IAR0(bfin_read_SIC_IAR0());
  60         bfin_write_SICB_IAR1(bfin_read_SIC_IAR1());
  61         bfin_write_SICB_IAR2(bfin_read_SIC_IAR2());
  62         bfin_write_SICB_IAR3(bfin_read_SIC_IAR3());
  63         bfin_write_SICB_IAR4(bfin_read_SIC_IAR4());
  64         bfin_write_SICB_IAR5(bfin_read_SIC_IAR5());
  65         bfin_write_SICB_IAR6(bfin_read_SIC_IAR6());
  66         bfin_write_SICB_IAR7(bfin_read_SIC_IAR7());
  67         bfin_write_SICB_IWR0(IWR_DISABLE_ALL);
  68         bfin_write_SICB_IWR1(IWR_DISABLE_ALL);
  69         SSYNC();
  70
  71         /* We are done with local CPU inits, unblock the boot CPU. */
  72         set_cpu_online(cpu, true);
  73         spin_lock(&boot_lock);
  74         spin_unlock(&boot_lock);
  75 }
  76
  77 int __cpuinit platform_boot_secondary(unsigned int cpu, struct task_struct *idle)
  78 {
  79         unsigned long timeout;
  80
  81         printk(KERN_INFO "Booting Core B.\n");
  82
  83         spin_lock(&boot_lock);
  84
  85         if ((bfin_read_SYSCR() & COREB_SRAM_INIT) == 0) {
  86                 /* CoreB already running, sending ipi to wakeup it */
  87                 platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);
  88         } else {
  89                 /* Kick CoreB, which should start execution from CORE_SRAM_BASE. */
  90                 bfin_write_SYSCR(bfin_read_SYSCR() & ~COREB_SRAM_INIT);
  91                 SSYNC();
  92         }
  93
  94         timeout = jiffies + 1 * HZ;
  95         while (time_before(jiffies, timeout)) {
  96                 if (cpu_online(cpu))
  97                         break;
  98                 udelay(100);
  99                 barrier();
 100         }
 101
 102         if (cpu_online(cpu)) {
 103                 /* release the lock and let coreb run */
 104                 spin_unlock(&boot_lock);
 105                 return 0;
 106         } else
 107                 panic("CPU%u: processor failed to boot\n", cpu);
 108 }
 109
 110 static const char supple0[] = "IRQ_SUPPLE_0";
 111 static const char supple1[] = "IRQ_SUPPLE_1";
 112 void __init platform_request_ipi(int irq, void *handler)
 113 {
 114         int ret;
 115         const char *name = (irq == IRQ_SUPPLE_0) ? supple0 : supple1;
 116
 117         ret = request_irq(irq, handler, IRQF_PERCPU, name, handler);
 118         if (ret)
 119                 panic("Cannot request %s for IPI service", name);
 120 }
 121
 122 void platform_send_ipi(cpumask_t callmap, int irq)
 123 {
 124         unsigned int cpu;
 125         int offset = (irq == IRQ_SUPPLE_0) ? 6 : 8;
 126
 127         for_each_cpu_mask(cpu, callmap) {
 128                 BUG_ON(cpu >= 2);
 129                 SSYNC();
 130                 bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (offset + cpu)));
 131                 SSYNC();
 132         }
 133 }
 134
 135 void platform_send_ipi_cpu(unsigned int cpu, int irq)
 136 {
 137         int offset = (irq == IRQ_SUPPLE_0) ? 6 : 8;
 138         BUG_ON(cpu >= 2);
 139         SSYNC();
 140         bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (offset + cpu)));
 141         SSYNC();
 142 }
 143
 144 void platform_clear_ipi(unsigned int cpu, int irq)
 145 {
 146         int offset = (irq == IRQ_SUPPLE_0) ? 10 : 12;
 147         BUG_ON(cpu >= 2);
 148         SSYNC();
 149         bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (offset + cpu)));
 150         SSYNC();
 151 }
 152
 153 /*
 154  * Setup core B's local core timer.
 155  * In SMP, core timer is used for clock event device.
 156  */
 157 void __cpuinit bfin_local_timer_setup(void)
 158 {
 159 #if defined(CONFIG_TICKSOURCE_CORETMR)
 160         struct irq_data *data = irq_get_irq_data(IRQ_CORETMR);
 161         struct irq_chip *chip = irq_data_get_irq_chip(data);
 162
 163         bfin_coretmr_init();
 164         bfin_coretmr_clockevent_init();
 165
 166         chip->irq_unmask(data);
 167 #else
 168         /* Power down the core timer, just to play safe. */
 169         bfin_write_TCNTL(0);
 170 #endif
 171
 172 }