KernelLand/Modules/armv7/GIC/gic.c

   1 /*
   2  * ARMv7 GIC Support
   3  * - By John Hodge (thePowersGang)
   4  *
   5  * gic.c
   6  * - GIC Core
   7  */
   8 #define DEBUG   1
   9
  10 #include <acess.h>
  11 #include <modules.h>
  12 #include "gic.h"
  13 #include <options.h>
  14
  15 #define N_IRQS  1024
  16
  17 // === IMPORTS ===
  18 extern void     *gpIRQHandler;
  19 extern tPAddr   gGIC_DistributorAddr;
  20 extern tPAddr   gGIC_InterfaceAddr;
  21
  22 // === TYPES ===
  23 typedef void (*tIRQ_Handler)(int, void*);
  24
  25 // === PROTOTYPES ===
  26  int    GIC_Install(char **Arguments);
  27 void    GIC_IRQHandler(void);
  28
  29 // === GLOBALS ===
  30 MODULE_DEFINE(0, 0x100, armv7_GIC, GIC_Install, NULL, NULL);
  31 volatile Uint32 *gpGIC_DistributorBase;
  32 volatile Uint32 *gpGIC_InterfaceBase;
  33 tIRQ_Handler    gaIRQ_Handlers[N_IRQS];
  34 void    *gaIRQ_HandlerData[N_IRQS];
  35
  36 // === CODE ===
  37 int GIC_Install(char **Arguments)
  38 {
  39         // Initialise
  40         Log_Debug("GIC", "Dist: %P, Interface: %P",
  41                 gGIC_DistributorAddr, gGIC_InterfaceAddr);
  42         gpGIC_InterfaceBase = (void*)MM_MapHWPages(gGIC_InterfaceAddr, 1);
  43         LOG("gpGIC_InterfaceBase = %p", gpGIC_InterfaceBase);
  44         gpGIC_DistributorBase = (void*)MM_MapHWPages(gGIC_DistributorAddr, 1);
  45         LOG("gpGIC_DistributorBase = %p", gpGIC_DistributorBase);
  46
  47         gpGIC_InterfaceBase[GICC_CTLR] = 0;     // Disable CPU interaface
  48         LOG("GICC_IAR = %x (CTLR=0)", gpGIC_InterfaceBase[GICC_IAR]);
  49
  50         gpGIC_InterfaceBase[GICC_PMR] = 0xFF;   // Effectively disable prioritories
  51         gpGIC_InterfaceBase[GICC_CTLR] = 1;     // Enable CPU
  52         gpGIC_DistributorBase[GICD_CTLR] = 1;   // Enable Distributor
  53
  54         gpIRQHandler = GIC_IRQHandler;
  55
  56         __asm__ __volatile__ ("cpsie if");      // Enable IRQs and FIQs
  57
  58 #if 0
  59         for( int i = 0; i < N_IRQS/32; i ++ ) {
  60                 Log_Debug("GIC", "GICD_ISENABLER%i %x = %08x",
  61                         i, GICD_ISENABLER0 + i,
  62                         gpGIC_DistributorBase[GICD_ISENABLER0+i]);
  63                 gpGIC_DistributorBase[GICD_ISENABLER0+i] = 0;
  64         }
  65 #endif
  66
  67         #if 0
  68         // Testing - First 32 actual interrupts enabled
  69         gpGIC_DistributorBase[GICD_ISENABLER0+1] = 0xFFFFFFFF;
  70         for( int i = 0; i < 32/4; i ++ )
  71                 gpGIC_DistributorBase[GICD_ITARGETSR0+8+i] = 0x01010101;
  72         #endif
  73
  74         // Clear out pending IRQs.
  75         gpGIC_InterfaceBase[GICC_EOIR] = gpGIC_InterfaceBase[GICC_IAR];
  76
  77         return MODULE_ERR_OK;
  78 }
  79
  80 void GIC_IRQHandler(void)
  81 {
  82         Uint32  num = gpGIC_InterfaceBase[GICC_IAR];
  83         if( gaIRQ_Handlers[num] ) {
  84                 gaIRQ_Handlers[num]( num, gaIRQ_HandlerData[num] );
  85         }
  86         else {
  87                 Log_Debug("GIC", "IRQ 0x%x unhandled", num);
  88         }
  89         gpGIC_InterfaceBase[GICC_EOIR] = num;
  90 }
  91
  92 int IRQ_AddHandler(int IRQ, tIRQ_Handler Handler, void *Ptr)
  93 {
  94         if( IRQ < 0 || IRQ >= N_IRQS-32 ) {
  95                 return 1;
  96         }
  97
  98         IRQ += 32;      // 32 internal IRQs
  99         // - Enable IRQ, clear pending and send to CPU 1 only
 100         gpGIC_DistributorBase[GICD_ISENABLER0+IRQ/32] = 1 << (IRQ & (32-1));
 101         ((Uint8*)&gpGIC_DistributorBase[GICD_ITARGETSR0])[IRQ] = 1;
 102         gpGIC_DistributorBase[GICD_ICPENDR0+IRQ/32] = 1 << (IRQ & (32-1));
 103
 104         // TODO: Does the GIC need to handle IRQ sharing?
 105         if( gaIRQ_Handlers[IRQ] ) {
 106                 Log_Warning("GIC", "IRQ %i already handled by %p, %p ignored",
 107                         IRQ, gaIRQ_Handlers[IRQ], Handler);
 108                 return 2;
 109         }
 110
 111         gaIRQ_Handlers[IRQ] = Handler;
 112         gaIRQ_HandlerData[IRQ] = Ptr;
 113
 114         Log_Debug("GIC", "IRQ %i handled by %p(%p)", IRQ, Handler, Ptr);
 115
 116         // DEBUG! Trip the interrupt
 117         gpGIC_DistributorBase[GICD_ISPENDR0+IRQ/32] = 1 << (IRQ & (32-1));
 118         return 0;
 119 }
 120