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   1 /*
   2  * File:         arch/blackfin/mach-bf561/smp.c
   3  * Author:       Philippe Gerum <rpm@xenomai.org>
   4  *
   5  *               Copyright 2007 Analog Devices Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see the file COPYING, or write
  19  * to the Free Software Foundation, Inc.,
  20  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21  */
  22
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/delay.h>
  27 #include <asm/smp.h>
  28 #include <asm/dma.h>
  29
  30 static DEFINE_SPINLOCK(boot_lock);
  31
  32 static cpumask_t cpu_callin_map;
  33
  34 /*
  35  * platform_init_cpus() - Tell the world about how many cores we
  36  * have. This is called while setting up the architecture support
  37  * (setup_arch()), so don't be too demanding here with respect to
  38  * available kernel services.
  39  */
  40
  41 void __init platform_init_cpus(void)
  42 {
  43         cpu_set(0, cpu_possible_map); /* CoreA */
  44         cpu_set(1, cpu_possible_map); /* CoreB */
  45 }
  46
  47 void __init platform_prepare_cpus(unsigned int max_cpus)
  48 {
  49         int len;
  50
  51         len = &coreb_trampoline_end - &coreb_trampoline_start + 1;
  52         BUG_ON(len > L1_CODE_LENGTH);
  53
  54         dma_memcpy((void *)COREB_L1_CODE_START, &coreb_trampoline_start, len);
  55
  56         /* Both cores ought to be present on a bf561! */
  57         cpu_set(0, cpu_present_map); /* CoreA */
  58         cpu_set(1, cpu_present_map); /* CoreB */
  59
  60         printk(KERN_INFO "CoreB bootstrap code to SRAM %p via DMA.\n", (void *)COREB_L1_CODE_START);
  61 }
  62
  63 int __init setup_profiling_timer(unsigned int multiplier) /* not supported */
  64 {
  65         return -EINVAL;
  66 }
  67
  68 void __cpuinit platform_secondary_init(unsigned int cpu)
  69 {
  70         local_irq_disable();
  71
  72         /* Clone setup for peripheral interrupt sources from CoreA. */
  73         bfin_write_SICB_IMASK0(bfin_read_SICA_IMASK0());
  74         bfin_write_SICB_IMASK1(bfin_read_SICA_IMASK1());
  75         SSYNC();
  76
  77         /* Clone setup for IARs from CoreA. */
  78         bfin_write_SICB_IAR0(bfin_read_SICA_IAR0());
  79         bfin_write_SICB_IAR1(bfin_read_SICA_IAR1());
  80         bfin_write_SICB_IAR2(bfin_read_SICA_IAR2());
  81         bfin_write_SICB_IAR3(bfin_read_SICA_IAR3());
  82         bfin_write_SICB_IAR4(bfin_read_SICA_IAR4());
  83         bfin_write_SICB_IAR5(bfin_read_SICA_IAR5());
  84         bfin_write_SICB_IAR6(bfin_read_SICA_IAR6());
  85         bfin_write_SICB_IAR7(bfin_read_SICA_IAR7());
  86         SSYNC();
  87
  88         local_irq_enable();
  89
  90         /* Calibrate loops per jiffy value. */
  91         calibrate_delay();
  92
  93         /* Store CPU-private information to the cpu_data array. */
  94         bfin_setup_cpudata(cpu);
  95
  96         /* We are done with local CPU inits, unblock the boot CPU. */
  97         cpu_set(cpu, cpu_callin_map);
  98         spin_lock(&boot_lock);
  99         spin_unlock(&boot_lock);
 100 }
 101
 102 int __cpuinit platform_boot_secondary(unsigned int cpu, struct task_struct *idle)
 103 {
 104         unsigned long timeout;
 105
 106         /* CoreB already running?! */
 107         BUG_ON((bfin_read_SICA_SYSCR() & COREB_SRAM_INIT) == 0);
 108
 109         printk(KERN_INFO "Booting Core B.\n");
 110
 111         spin_lock(&boot_lock);
 112
 113         /* Kick CoreB, which should start execution from CORE_SRAM_BASE. */
 114         SSYNC();
 115         bfin_write_SICA_SYSCR(bfin_read_SICA_SYSCR() & ~COREB_SRAM_INIT);
 116         SSYNC();
 117
 118         timeout = jiffies + 1 * HZ;
 119         while (time_before(jiffies, timeout)) {
 120                 if (cpu_isset(cpu, cpu_callin_map))
 121                         break;
 122                 udelay(100);
 123                 barrier();
 124         }
 125
 126         spin_unlock(&boot_lock);
 127
 128         return cpu_isset(cpu, cpu_callin_map) ? 0 : -ENOSYS;
 129 }
 130
 131 void __init platform_request_ipi(irq_handler_t handler)
 132 {
 133         int ret;
 134
 135         ret = request_irq(IRQ_SUPPLE_0, handler, IRQF_DISABLED,
 136                           "SMP interrupt", handler);
 137         if (ret)
 138                 panic("Cannot request supplemental interrupt 0 for IPI service\n");
 139 }
 140
 141 void platform_send_ipi(cpumask_t callmap)
 142 {
 143         unsigned int cpu;
 144
 145         for_each_cpu_mask(cpu, callmap) {
 146                 BUG_ON(cpu >= 2);
 147                 SSYNC();
 148                 bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (6 + cpu)));
 149                 SSYNC();
 150         }
 151 }
 152
 153 void platform_send_ipi_cpu(unsigned int cpu)
 154 {
 155         BUG_ON(cpu >= 2);
 156         SSYNC();
 157         bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (6 + cpu)));
 158         SSYNC();
 159 }
 160
 161 void platform_clear_ipi(unsigned int cpu)
 162 {
 163         BUG_ON(cpu >= 2);
 164         SSYNC();
 165         bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (10 + cpu)));
 166         SSYNC();
 167 }