arch/powerpc/platforms/cell/pervasive.c

   1 /*
   2  * CBE Pervasive Monitor and Debug
   3  *
   4  * (C) Copyright IBM Corporation 2005
   5  *
   6  * Authors: Maximino Aguilar (maguilar@us.ibm.com)
   7  *          Michael N. Day (mnday@us.ibm.com)
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2, or (at your option)
  12  * any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #undef DEBUG
  25
  26 #include <linux/config.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/irq.h>
  29 #include <linux/percpu.h>
  30 #include <linux/types.h>
  31 #include <linux/kallsyms.h>
  32
  33 #include <asm/io.h>
  34 #include <asm/machdep.h>
  35 #include <asm/prom.h>
  36 #include <asm/pgtable.h>
  37 #include <asm/reg.h>
  38
  39 #include "pervasive.h"
  40
  41 static DEFINE_SPINLOCK(cbe_pervasive_lock);
  42 struct cbe_pervasive {
  43         struct pmd_regs __iomem *regs;
  44         unsigned int thread;
  45 };
  46
  47 /* can't use per_cpu from setup_arch */
  48 static struct cbe_pervasive cbe_pervasive[NR_CPUS];
  49
  50 static void __init cbe_enable_pause_zero(void)
  51 {
  52         unsigned long thread_switch_control;
  53         unsigned long temp_register;
  54         struct cbe_pervasive *p;
  55         int thread;
  56
  57         spin_lock_irq(&cbe_pervasive_lock);
  58         p = &cbe_pervasive[smp_processor_id()];
  59
  60         if (!cbe_pervasive->regs)
  61                 goto out;
  62
  63         pr_debug("Power Management: CPU %d\n", smp_processor_id());
  64
  65          /* Enable Pause(0) control bit */
  66         temp_register = in_be64(&p->regs->pm_control);
  67
  68         out_be64(&p->regs->pm_control,
  69                  temp_register|PMD_PAUSE_ZERO_CONTROL);
  70
  71         /* Enable DEC and EE interrupt request */
  72         thread_switch_control  = mfspr(SPRN_TSC_CELL);
  73         thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST;
  74
  75         switch ((mfspr(SPRN_CTRLF) & CTRL_CT)) {
  76         case CTRL_CT0:
  77                 thread_switch_control |= TSC_CELL_DEC_ENABLE_0;
  78                 thread = 0;
  79                 break;
  80         case CTRL_CT1:
  81                 thread_switch_control |= TSC_CELL_DEC_ENABLE_1;
  82                 thread = 1;
  83                 break;
  84         default:
  85                 printk(KERN_WARNING "%s: unknown configuration\n",
  86                         __FUNCTION__);
  87                 thread = -1;
  88                 break;
  89         }
  90
  91         if (p->thread != thread)
  92                 printk(KERN_WARNING "%s: device tree inconsistant, "
  93                                      "cpu %i: %d/%d\n", __FUNCTION__,
  94                                      smp_processor_id(),
  95                                      p->thread, thread);
  96
  97         mtspr(SPRN_TSC_CELL, thread_switch_control);
  98
  99 out:
 100         spin_unlock_irq(&cbe_pervasive_lock);
 101 }
 102
 103 static void cbe_idle(void)
 104 {
 105         unsigned long ctrl;
 106
 107         cbe_enable_pause_zero();
 108
 109         while (1) {
 110                 if (!need_resched()) {
 111                         local_irq_disable();
 112                         while (!need_resched()) {
 113                                 /* go into low thread priority */
 114                                 HMT_low();
 115
 116                                 /*
 117                                  * atomically disable thread execution
 118                                  * and runlatch.
 119                                  * External and Decrementer exceptions
 120                                  * are still handled when the thread
 121                                  * is disabled but now enter in
 122                                  * cbe_system_reset_exception()
 123                                  */
 124                                 ctrl = mfspr(SPRN_CTRLF);
 125                                 ctrl &= ~(CTRL_RUNLATCH | CTRL_TE);
 126                                 mtspr(SPRN_CTRLT, ctrl);
 127                         }
 128                         /* restore thread prio */
 129                         HMT_medium();
 130                         local_irq_enable();
 131                 }
 132
 133                 /*
 134                  * turn runlatch on again before scheduling the
 135                  * process we just woke up
 136                  */
 137                 ppc64_runlatch_on();
 138
 139                 preempt_enable_no_resched();
 140                 schedule();
 141                 preempt_disable();
 142         }
 143 }
 144
 145 static int cbe_system_reset_exception(struct pt_regs *regs)
 146 {
 147         switch (regs->msr & SRR1_WAKEMASK) {
 148         case SRR1_WAKEEE:
 149                 do_IRQ(regs);
 150                 break;
 151         case SRR1_WAKEDEC:
 152                 timer_interrupt(regs);
 153                 break;
 154         case SRR1_WAKEMT:
 155                 /* no action required */
 156                 break;
 157         default:
 158                 /* do system reset */
 159                 return 0;
 160         }
 161         /* everything handled */
 162         return 1;
 163 }
 164
 165 static int __init cbe_find_pmd_mmio(int cpu, struct cbe_pervasive *p)
 166 {
 167         struct device_node *node;
 168         unsigned int *int_servers;
 169         char *addr;
 170         unsigned long real_address;
 171         unsigned int size;
 172
 173         struct pmd_regs __iomem *pmd_mmio_area;
 174         int hardid, thread;
 175         int proplen;
 176
 177         pmd_mmio_area = NULL;
 178         hardid = get_hard_smp_processor_id(cpu);
 179         for (node = NULL; (node = of_find_node_by_type(node, "cpu"));) {
 180                 int_servers = (void *) get_property(node,
 181                                 "ibm,ppc-interrupt-server#s", &proplen);
 182                 if (!int_servers) {
 183                         printk(KERN_WARNING "%s misses "
 184                                 "ibm,ppc-interrupt-server#s property",
 185                                 node->full_name);
 186                         continue;
 187                 }
 188                 for (thread = 0; thread < proplen / sizeof (int); thread++) {
 189                         if (hardid == int_servers[thread]) {
 190                                 addr = get_property(node, "pervasive", NULL);
 191                                 goto found;
 192                         }
 193                 }
 194         }
 195
 196         printk(KERN_WARNING "%s: CPU %d not found\n", __FUNCTION__, cpu);
 197         return -EINVAL;
 198
 199 found:
 200         real_address = *(unsigned long*) addr;
 201         addr += sizeof (unsigned long);
 202         size = *(unsigned int*) addr;
 203
 204         pr_debug("pervasive area for CPU %d at %lx, size %x\n",
 205                         cpu, real_address, size);
 206         p->regs = ioremap(real_address, size);
 207         p->thread = thread;
 208         return 0;
 209 }
 210
 211 void __init cell_pervasive_init(void)
 212 {
 213         struct cbe_pervasive *p;
 214         int cpu;
 215         int ret;
 216
 217         if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
 218                 return;
 219
 220         for_each_possible_cpu(cpu) {
 221                 p = &cbe_pervasive[cpu];
 222                 ret = cbe_find_pmd_mmio(cpu, p);
 223                 if (ret)
 224                         return;
 225         }
 226
 227         ppc_md.idle_loop = cbe_idle;
 228         ppc_md.system_reset_exception = cbe_system_reset_exception;
 229 }