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/interrupt.h>
  27 #include <linux/irq.h>
  28 #include <linux/percpu.h>
  29 #include <linux/types.h>
  30 #include <linux/kallsyms.h>
  31
  32 #include <asm/io.h>
  33 #include <asm/machdep.h>
  34 #include <asm/prom.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/reg.h>
  37 #include <asm/cell-regs.h>
  38 #include <asm/cpu_has_feature.h>
  39
  40 #include "pervasive.h"
  41
  42 static void cbe_power_save(void)
  43 {
  44         unsigned long ctrl, thread_switch_control;
  45
  46         /* Ensure our interrupt state is properly tracked */
  47         if (!prep_irq_for_idle())
  48                 return;
  49
  50         ctrl = mfspr(SPRN_CTRLF);
  51
  52         /* Enable DEC and EE interrupt request */
  53         thread_switch_control  = mfspr(SPRN_TSC_CELL);
  54         thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST;
  55
  56         switch (ctrl & CTRL_CT) {
  57         case CTRL_CT0:
  58                 thread_switch_control |= TSC_CELL_DEC_ENABLE_0;
  59                 break;
  60         case CTRL_CT1:
  61                 thread_switch_control |= TSC_CELL_DEC_ENABLE_1;
  62                 break;
  63         default:
  64                 printk(KERN_WARNING "%s: unknown configuration\n",
  65                         __func__);
  66                 break;
  67         }
  68         mtspr(SPRN_TSC_CELL, thread_switch_control);
  69
  70         /*
  71          * go into low thread priority, medium priority will be
  72          * restored for us after wake-up.
  73          */
  74         HMT_low();
  75
  76         /*
  77          * atomically disable thread execution and runlatch.
  78          * External and Decrementer exceptions are still handled when the
  79          * thread is disabled but now enter in cbe_system_reset_exception()
  80          */
  81         ctrl &= ~(CTRL_RUNLATCH | CTRL_TE);
  82         mtspr(SPRN_CTRLT, ctrl);
  83
  84         /* Re-enable interrupts in MSR */
  85         __hard_irq_enable();
  86 }
  87
  88 static int cbe_system_reset_exception(struct pt_regs *regs)
  89 {
  90         switch (regs->msr & SRR1_WAKEMASK) {
  91         case SRR1_WAKEDEC:
  92                 set_dec(1);
  93         case SRR1_WAKEEE:
  94                 /*
  95                  * Handle these when interrupts get re-enabled and we take
  96                  * them as regular exceptions. We are in an NMI context
  97                  * and can't handle these here.
  98                  */
  99                 break;
 100         case SRR1_WAKEMT:
 101                 return cbe_sysreset_hack();
 102 #ifdef CONFIG_CBE_RAS
 103         case SRR1_WAKESYSERR:
 104                 cbe_system_error_exception(regs);
 105                 break;
 106         case SRR1_WAKETHERM:
 107                 cbe_thermal_exception(regs);
 108                 break;
 109 #endif /* CONFIG_CBE_RAS */
 110         default:
 111                 /* do system reset */
 112                 return 0;
 113         }
 114         /* everything handled */
 115         return 1;
 116 }
 117
 118 void __init cbe_pervasive_init(void)
 119 {
 120         int cpu;
 121
 122         if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
 123                 return;
 124
 125         for_each_possible_cpu(cpu) {
 126                 struct cbe_pmd_regs __iomem *regs = cbe_get_cpu_pmd_regs(cpu);
 127                 if (!regs)
 128                         continue;
 129
 130                  /* Enable Pause(0) control bit */
 131                 out_be64(&regs->pmcr, in_be64(&regs->pmcr) |
 132                                             CBE_PMD_PAUSE_ZERO_CONTROL);
 133         }
 134
 135         ppc_md.power_save = cbe_power_save;
 136         ppc_md.system_reset_exception = cbe_system_reset_exception;
 137 }