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 #include <linux/pgtable.h>
  19
  20 #include <asm/io.h>
  21 #include <asm/machdep.h>
  22 #include <asm/prom.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 #include "ras.h"
  29
  30 static void cbe_power_save(void)
  31 {
  32         unsigned long ctrl, thread_switch_control;
  33
  34         /* Ensure our interrupt state is properly tracked */
  35         if (!prep_irq_for_idle())
  36                 return;
  37
  38         ctrl = mfspr(SPRN_CTRLF);
  39
  40         /* Enable DEC and EE interrupt request */
  41         thread_switch_control  = mfspr(SPRN_TSC_CELL);
  42         thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST;
  43
  44         switch (ctrl & CTRL_CT) {
  45         case CTRL_CT0:
  46                 thread_switch_control |= TSC_CELL_DEC_ENABLE_0;
  47                 break;
  48         case CTRL_CT1:
  49                 thread_switch_control |= TSC_CELL_DEC_ENABLE_1;
  50                 break;
  51         default:
  52                 printk(KERN_WARNING "%s: unknown configuration\n",
  53                         __func__);
  54                 break;
  55         }
  56         mtspr(SPRN_TSC_CELL, thread_switch_control);
  57
  58         /*
  59          * go into low thread priority, medium priority will be
  60          * restored for us after wake-up.
  61          */
  62         HMT_low();
  63
  64         /*
  65          * atomically disable thread execution and runlatch.
  66          * External and Decrementer exceptions are still handled when the
  67          * thread is disabled but now enter in cbe_system_reset_exception()
  68          */
  69         ctrl &= ~(CTRL_RUNLATCH | CTRL_TE);
  70         mtspr(SPRN_CTRLT, ctrl);
  71
  72         /* Re-enable interrupts in MSR */
  73         __hard_irq_enable();
  74 }
  75
  76 static int cbe_system_reset_exception(struct pt_regs *regs)
  77 {
  78         switch (regs->msr & SRR1_WAKEMASK) {
  79         case SRR1_WAKEDEC:
  80                 set_dec(1);
  81                 break;
  82         case SRR1_WAKEEE:
  83                 /*
  84                  * Handle these when interrupts get re-enabled and we take
  85                  * them as regular exceptions. We are in an NMI context
  86                  * and can't handle these here.
  87                  */
  88                 break;
  89         case SRR1_WAKEMT:
  90                 return cbe_sysreset_hack();
  91 #ifdef CONFIG_CBE_RAS
  92         case SRR1_WAKESYSERR:
  93                 cbe_system_error_exception(regs);
  94                 break;
  95         case SRR1_WAKETHERM:
  96                 cbe_thermal_exception(regs);
  97                 break;
  98 #endif /* CONFIG_CBE_RAS */
  99         default:
 100                 /* do system reset */
 101                 return 0;
 102         }
 103         /* everything handled */
 104         return 1;
 105 }
 106
 107 void __init cbe_pervasive_init(void)
 108 {
 109         int cpu;
 110
 111         if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO))
 112                 return;
 113
 114         for_each_possible_cpu(cpu) {
 115                 struct cbe_pmd_regs __iomem *regs = cbe_get_cpu_pmd_regs(cpu);
 116                 if (!regs)
 117                         continue;
 118
 119                  /* Enable Pause(0) control bit */
 120                 out_be64(&regs->pmcr, in_be64(&regs->pmcr) |
 121                                             CBE_PMD_PAUSE_ZERO_CONTROL);
 122         }
 123
 124         ppc_md.power_save = cbe_power_save;
 125         ppc_md.system_reset_exception = cbe_system_reset_exception;
 126 }