arch/arm/mach-shmobile/smp-emev2.c

   1 /*
   2  * SMP support for Emma Mobile EV2
   3  *
   4  * Copyright (C) 2012  Renesas Solutions Corp.
   5  * Copyright (C) 2012  Magnus Damm
   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; version 2 of the License.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/smp.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/io.h>
  25 #include <linux/delay.h>
  26 #include <mach/common.h>
  27 #include <mach/emev2.h>
  28 #include <asm/smp_plat.h>
  29 #include <asm/smp_scu.h>
  30 #include <asm/hardware/gic.h>
  31 #include <asm/cacheflush.h>
  32
  33 #define EMEV2_SCU_BASE 0x1e000000
  34
  35 static DEFINE_SPINLOCK(scu_lock);
  36 static void __iomem *scu_base;
  37
  38 static void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
  39 {
  40         unsigned long tmp;
  41
  42         /* we assume this code is running on a different cpu
  43          * than the one that is changing coherency setting */
  44         spin_lock(&scu_lock);
  45         tmp = readl(scu_base + 8);
  46         tmp &= ~clr;
  47         tmp |= set;
  48         writel(tmp, scu_base + 8);
  49         spin_unlock(&scu_lock);
  50
  51 }
  52
  53 unsigned int __init emev2_get_core_count(void)
  54 {
  55         if (!scu_base) {
  56                 scu_base = ioremap(EMEV2_SCU_BASE, PAGE_SIZE);
  57                 emev2_clock_init(); /* need ioremapped SMU */
  58         }
  59
  60         WARN_ON_ONCE(!scu_base);
  61
  62         return scu_base ? scu_get_core_count(scu_base) : 1;
  63 }
  64
  65 int emev2_platform_cpu_kill(unsigned int cpu)
  66 {
  67         return 0; /* not supported yet */
  68 }
  69
  70 void __cpuinit emev2_secondary_init(unsigned int cpu)
  71 {
  72         gic_secondary_init(0);
  73 }
  74
  75 int __cpuinit emev2_boot_secondary(unsigned int cpu)
  76 {
  77         cpu = cpu_logical_map(cpu);
  78
  79         /* enable cache coherency */
  80         modify_scu_cpu_psr(0, 3 << (cpu * 8));
  81
  82         /* Tell ROM loader about our vector (in headsmp.S) */
  83         emev2_set_boot_vector(__pa(shmobile_secondary_vector));
  84
  85         gic_raise_softirq(cpumask_of(cpu), 1);
  86         return 0;
  87 }
  88
  89 void __init emev2_smp_prepare_cpus(void)
  90 {
  91         int cpu = cpu_logical_map(0);
  92
  93         scu_enable(scu_base);
  94
  95         /* enable cache coherency on CPU0 */
  96         modify_scu_cpu_psr(0, 3 << (cpu * 8));
  97 }