arch/powerpc/platforms/cell/pervasive.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * CBE Pervasive Monitor and Debug
   4  *
   5  * (C) Copyright IBM Corporation 2005
   6  *
   7  * Authors: Maximino Aguilar (maguilar@us.ibm.com)
   8  *          Michael N. Day (mnday@us.ibm.com)
   9  */
  10
  11 #undef DEBUG
  12
  13 #include <linux/interrupt.h>
  14 #include <linux/irq.h>
  15 #include <linux/percpu.h>
  16 #include <linux/types.h>
  17 #include <linux/kallsyms.h>
  18
  19 #include <asm/io.h>
  20 #include <asm/machdep.h>
  21 #include <asm/prom.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/reg.h>
  24 #include <asm/cell-regs.h>
  25 #include <asm/cpu_has_feature.h>
  26
  27 #include "pervasive.h"
  28
  29 static void cbe_power_save(void)
  30 {
  31         unsigned long ctrl, thread_switch_control;
  32
  33         /* Ensure our interrupt state is properly tracked */
  34         if (!prep_irq_for_idle())
  35                 return;
  36
  37         ctrl = mfspr(SPRN_CTRLF);
  38
  39         /* Enable DEC and EE interrupt request */
  40         thread_switch_control  = mfspr(SPRN_TSC_CELL);
  41         thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST;
  42
  43         switch (ctrl & CTRL_CT) {
  44         case CTRL_CT0:
  45                 thread_switch_control |= TSC_CELL_DEC_ENABLE_0;
  46                 break;
  47         case CTRL_CT1:
  48                 thread_switch_control |= TSC_CELL_DEC_ENABLE_1;
  49                 break;
  50         default:
  51                 printk(KERN_WARNING "%s: unknown configuration\n",
  52                         __func__);
  53                 break;
  54         }
  55         mtspr(SPRN_TSC_CELL, thread_switch_control);
  56
  57         /*
  58          * go into low thread priority, medium priority will be
  59          * restored for us after wake-up.
  60          */
  61         HMT_low();
  62
  63         /*
  64          * atomically disable thread execution and runlatch.
  65          * External and Decrementer exceptions are still handled when the
  66          * thread is disabled but now enter in cbe_system_reset_exception()
  67          */
  68         ctrl &= ~(CTRL_RUNLATCH | CTRL_TE);
  69         mtspr(SPRN_CTRLT, ctrl);
  70
  71         /* Re-enable interrupts in MSR */
  72         __hard_irq_enable();
  73 }
  74
  75 static int cbe_system_reset_exception(struct pt_regs *regs)
  76 {
  77         switch (regs->msr & SRR1_WAKEMASK) {
  78         case SRR1_WAKEDEC:
  79                 set_dec(1);
  80         case SRR1_WAKEEE:
  81                 /*
  82                  * Handle these when interrupts get re-enabled and we take
  83                  * them as regular exceptions. We are in an NMI context
  84                  * and can't handle these here.
  85                  */
  86                 break;
  87         case SRR1_WAKEMT:
  88                 return cbe_sysreset_hack();
  89 #ifdef CONFIG_CBE_RAS
  90         case SRR1_WAKESYSERR:
  91                 cbe_system_error_exception(regs);
  92                 break;
  93         case SRR1_WAKETHERM:
  94                 cbe_thermal_exception(regs);
  95                 break;
  96 #endif /* CONFIG_CBE_RAS */
  97         default:
  98                 /* do system reset */
  99                 return 0;
 100         }
 101         /* everything handled */
 102         return 1;
 103 }
 104
 105 void __init cbe_pervasive_init(void)
 106 {
 107         int cpu;
 108
 109         if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
 110                 return;
 111
 112         for_each_possible_cpu(cpu) {
 113                 struct cbe_pmd_regs __iomem *regs = cbe_get_cpu_pmd_regs(cpu);
 114                 if (!regs)
 115                         continue;
 116
 117                  /* Enable Pause(0) control bit */
 118                 out_be64(&regs->pmcr, in_be64(&regs->pmcr) |
 119                                             CBE_PMD_PAUSE_ZERO_CONTROL);
 120         }
 121
 122         ppc_md.power_save = cbe_power_save;
 123         ppc_md.system_reset_exception = cbe_system_reset_exception;
 124 }