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/*  This file is part of the program psim.

    Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

    */

#ifndef _HW_OPIC_C_

#define _HW_OPIC_C_

#include "device_table.h"

#ifdef HAVE_STRING_H

#include <string.h>

#else

#ifdef HAVE_STRINGS_H

#include <strings.h>

#endif

#endif

/* DEVICE

   opic - Open Programmable Interrupt Controller (OpenPIC)

   DESCRIPTION

   This device implements the core of the OpenPIC interrupt controller

   as described in the OpenPIC specification 1.2 and other related

   documents.

   The model includes:

   o    Up to 2048 external interrupt sources

   o    The four count down timers

   o    The four interprocessor multicast interrupts

   o    multiprocessor support

   o    Full tracing to assist help debugging

   o    Support for all variations of edge/level x high/low polarity.

   PROPERTIES

   reg = <address> <size> ... (required)

   Determine where the device lives in the parents address space.  The

   first <<address>> <<size>> pair specifies the address of the

   interrupt destination unit (which might contain an interrupt source

   unit) while successive reg entries specify additional interrupt

   source units.

   Note that for an <<opic>> device attached to a <<pci>> bus, the

   first <<reg>> entry may need to be ignored it will be the address

   of the devices configuration registers.

   interrupt-ranges = <int-number> <range> ... (required)

   A list of pairs.  Each pair corresponds to a block of interrupt

   source units (the address of which being specified by the

   corresponding reg tupple).  <<int-number>> is the number of the

   first interrupt in the block while <<range>> is the number of

   interrupts in the block.

   timer-frequency = <integer>  (optional)

   If present, specifies the default value of the timer frequency

   reporting register.  By default a value of 1 HZ is used.  The value

   is arbitrary, the timers are always updated once per machine cycle.

   vendor-identification = <integer>  (optional)

   If present, specifies the value to be returned when the vendor

   identification register is read.

   EXAMPLES

   See the test suite directory:

   |  psim-test/hw-opic

   BUGS

   For an OPIC controller attached to a PCI bus, it is not clear what

   the value of the <<reg>> and <<interrupt-ranges>> properties should

   be.  In particular, the PCI firmware bindings require the first

   value of the <<reg>> property to specify the devices configuration

   address while the OpenPIC bindings require that same entry to

   specify the address of the Interrupt Delivery Unit.  This

   implementation checks for and, if present, ignores any

   configuration address (and its corresponding <<interrupt-ranges>>

   entry).

   The OpenPIC specification requires the controller to be fair when

   distributing interrupts between processors.  At present the

   algorithm used isn't fair.  It is biased towards processor zero.

   The OpenPIC specification includes a 8259 pass through mode.  This

   is not supported.

   REFERENCES

   PowerPC Multiprocessor Interrupt Controller (MPIC), January 19,

   1996. Available from IBM.

   The Open Programmable Interrupt Controller (PIC) Register Interface

   Specification Revision 1.2.  Issue Date: Opctober 1995.  Available

   somewhere on AMD's web page (http://www.amd.com/)

   PowerPC Microprocessor Common Hardware Reference Platform (CHRP)

   System bindings to: IEEE Std 1275-1994 Standard for Boot

   (Initialization, Configuration) Firmware.  Revision 1.2b (INTERIM

   DRAFT).  April 22, 1996.  Available on the Open Firmware web site

   http://playground.sun.com/p1275/.

   */

/* forward types */

typedef struct _hw_opic_device hw_opic_device;

/* bounds */

enum {

  max_nr_interrupt_sources = 2048,

  max_nr_interrupt_destinations = 32,

  max_nr_task_priorities = 16,

};

enum {

  opic_alignment = 16,

};

/* global configuration register */

enum {

  gcr0_8259_bit = 0x20000000,

  gcr0_reset_bit = 0x80000000,

};

/* offsets and sizes */

enum {

  idu_isu_base = 0x10000,

  sizeof_isu_register_block = 32,

  idu_per_processor_register_base = 0x20000,

  sizeof_idu_per_processor_register_block = 0x1000,

  idu_timer_base = 0x01100,

  sizeof_timer_register_block = 0x00040,

};

/* Interrupt sources */

enum {

  isu_mask_bit = 0x80000000,

  isu_active_bit = 0x40000000,

  isu_multicast_bit = 0x20000000,

  isu_positive_polarity_bit = 0x00800000,

  isu_level_triggered_bit = 0x00400000,

  isu_priority_shift = 16,

  isu_vector_bits = 0x000000ff,

};

typedef struct _opic_interrupt_source {

  unsigned is_masked; /* left in place */

  unsigned is_multicast; /* left in place */

  unsigned is_positive_polarity; /* left in place */

  unsigned is_level_triggered; /* left in place */

  unsigned priority;

  unsigned vector;

  /* misc */

  int nr;

  unsigned destination;

  unsigned pending;

  unsigned in_service;

} opic_interrupt_source;

/* interrupt destinations (normally processors) */

typedef struct _opic_interrupt_destination {

  int nr;

  unsigned base_priority;

  opic_interrupt_source *current_pending;

  opic_interrupt_source *current_in_service;

  unsigned bit;

  int init_port;

  int intr_port;

} opic_interrupt_destination;

/* address map descriptors */

typedef struct _opic_isu_block { /* interrupt source unit block */

  int space;

  unsigned_word address;

  unsigned size;

  unsigned_cell int_number;

  unsigned_cell range;

  int reg;

} opic_isu_block;

typedef struct _opic_idu { /* interrupt delivery unit */

  int reg;

  int space;

  unsigned_word address;

  unsigned size;

} opic_idu;

typedef enum {

  /* bad */

  invalid_opic_register,

  /* interrupt source */

  interrupt_source_N_destination_register,

  interrupt_source_N_vector_priority_register,

  /* timers */

  timer_N_destination_register,

  timer_N_vector_priority_register,

  timer_N_base_count_register,

  timer_N_current_count_register,

  timer_frequency_reporting_register,

  /* inter-processor interrupts */

  ipi_N_vector_priority_register,

  ipi_N_dispatch_register,

  /* global configuration */

  spurious_vector_register,

  processor_init_register,

  vendor_identification_register,

  global_configuration_register_N,

  feature_reporting_register_N,

  /* per processor */

  end_of_interrupt_register_N,

  interrupt_acknowledge_register_N,

  current_task_priority_register_N,

} opic_register;

static const char *

opic_register_name(opic_register type)

{

  switch (type) {

  case invalid_opic_register: return "invalid_opic_register";

  case interrupt_source_N_destination_register: return "interrupt_source_N_destination_register";

  case interrupt_source_N_vector_priority_register: return "interrupt_source_N_vector_priority_register";

  case timer_N_destination_register: return "timer_N_destination_register";

  case timer_N_vector_priority_register: return "timer_N_vector_priority_register";

  case timer_N_base_count_register: return "timer_N_base_count_register";

  case timer_N_current_count_register: return "timer_N_current_count_register";

  case timer_frequency_reporting_register: return "timer_frequency_reporting_register";

  case ipi_N_vector_priority_register: return "ipi_N_vector_priority_register";

  case ipi_N_dispatch_register: return "ipi_N_dispatch_register";

  case spurious_vector_register: return "spurious_vector_register";

  case processor_init_register: return "processor_init_register";

  case vendor_identification_register: return "vendor_identification_register";

  case global_configuration_register_N: return "global_configuration_register_N";

  case feature_reporting_register_N: return "feature_reporting_register_N";

  case end_of_interrupt_register_N: return "end_of_interrupt_register_N";

  case interrupt_acknowledge_register_N: return "interrupt_acknowledge_register_N";

  case current_task_priority_register_N: return "current_task_priority_register_N";

  }

  return NULL;

}

/* timers */

typedef struct _opic_timer {

  int nr;

  device *me; /* find my way home */

  hw_opic_device *opic; /* ditto */

  unsigned base_count;

  int inhibited;

  signed64 count; /* *ONLY* if inhibited */

  event_entry_tag timeout_event;

  opic_interrupt_source *interrupt_source;

} opic_timer;

/* the OPIC */

struct _hw_opic_device {

  /* vendor id */

  unsigned vendor_identification;

  /* interrupt destinations - processors */

  int nr_interrupt_destinations;

  opic_interrupt_destination *interrupt_destination;

  unsigned sizeof_interrupt_destination;

  /* bogus interrupts */

  int spurious_vector;

  /* interrupt sources - external interrupt source units + extra internal ones */

  int nr_interrupt_sources;

  opic_interrupt_source *interrupt_source;

  unsigned sizeof_interrupt_source;

  /* external interrupts */

  int nr_external_interrupts;

  opic_interrupt_source *external_interrupt_source;

  /* inter-processor-interrupts */

  int nr_interprocessor_interrupts;

  opic_interrupt_source *interprocessor_interrupt_source;

  /* timers */

  int nr_timer_interrupts;

  opic_timer *timer;

  unsigned sizeof_timer;

  opic_interrupt_source *timer_interrupt_source;

  unsigned timer_frequency;

  /* init register */

  unsigned32 init;

  /* address maps */

  opic_idu idu;

  int nr_isu_blocks;

  opic_isu_block *isu_block;

};

static void

hw_opic_init_data(device *me)

{

  hw_opic_device *opic = (hw_opic_device*)device_data(me);

  int isb;

  int idu_reg;

  int nr_isu_blocks;

  int i;

  /* determine the first valid reg property entry (there could be

     leading reg entries with invalid (zero) size fields) and the

     number of isu entries found in the reg property. */

  idu_reg = 0;

  nr_isu_blocks = 0;

  while (1) {

    reg_property_spec unit;

    int attach_space;

    unsigned_word attach_address;

    unsigned attach_size;

    if (!device_find_reg_array_property(me, "reg", idu_reg + nr_isu_blocks,

                                        &unit))

      break;

    if (nr_isu_blocks > 0

        || (device_address_to_attach_address(device_parent(me), &unit.address,

                                             &attach_space, &attach_address,

                                             me)

            && device_size_to_attach_size(device_parent(me), &unit.size,

                                          &attach_size,

                                          me))) {

      /* we count any thing once we've found one valid address/size pair */

      nr_isu_blocks += 1;

    }

    else {

      idu_reg += 1;

    }

  }

  /* determine the number and location of the multiple interrupt

     source units and the single interrupt delivery unit */

  if (opic->isu_block == NULL) {

    int reg_nr;

    opic->nr_isu_blocks = nr_isu_blocks;

    opic->isu_block = zalloc(sizeof(opic_isu_block) * opic->nr_isu_blocks);

    isb = 0;

    reg_nr = idu_reg;

    while (isb < opic->nr_isu_blocks) {

      reg_property_spec reg;

      if (!device_find_reg_array_property(me, "reg", reg_nr, &reg))

        device_error(me, "reg property missing entry number %d", reg_nr);

      opic->isu_block[isb].reg = reg_nr;

      if (!device_address_to_attach_address(device_parent(me), &reg.address,

                                            &opic->isu_block[isb].space,

                                            &opic->isu_block[isb].address,

                                            me)

          || !device_size_to_attach_size(device_parent(me), &reg.size,

                                         &opic->isu_block[isb].size,

                                         me)) {

        device_error(me, "reg property entry %d invalid", reg_nr);

      }

      if (!device_find_integer_array_property(me, "interrupt-ranges",

                                              reg_nr * 2,

                                              &opic->isu_block[isb].int_number)

          || !device_find_integer_array_property(me, "interrupt-ranges",

                                                 reg_nr * 2 + 1,

                                                 &opic->isu_block[isb].range))

        device_error(me, "missing or invalid interrupt-ranges property entry %d", reg_nr);

      /* first reg entry specifies the address of both the IDU and the

         first set of ISU registers, adjust things accordingly */

      if (reg_nr == idu_reg) {

        opic->idu.reg = opic->isu_block[isb].reg;

        opic->idu.space = opic->isu_block[isb].space;

        opic->idu.address = opic->isu_block[isb].address;

        opic->idu.size = opic->isu_block[isb].size;

        opic->isu_block[isb].address += idu_isu_base;

        opic->isu_block[isb].size = opic->isu_block[isb].range * (16 + 16);

      }

      /* was this a valid reg entry? */

      if (opic->isu_block[isb].range == 0) {

        opic->nr_isu_blocks -= 1;

      }

      else {

        opic->nr_external_interrupts += opic->isu_block[isb].range;

        isb++;

      }

      reg_nr++;

    }

  }

  DTRACE(opic, ("interrupt source unit block - effective number of blocks %d\n",

                (int)opic->nr_isu_blocks));

  /* the number of other interrupts */

  opic->nr_interprocessor_interrupts = 4;

  opic->nr_timer_interrupts = 4;

  /* create space for the interrupt source registers */

  if (opic->interrupt_source != NULL) {

    memset(opic->interrupt_source, 0, opic->sizeof_interrupt_source);

  }

  else {

    opic->nr_interrupt_sources = (opic->nr_external_interrupts

                                  + opic->nr_interprocessor_interrupts

                                  + opic->nr_timer_interrupts);

    if (opic->nr_interrupt_sources > max_nr_interrupt_sources)

      device_error(me, "number of interrupt sources exceeded");

    opic->sizeof_interrupt_source = (sizeof(opic_interrupt_source)

                                     * opic->nr_interrupt_sources);

    opic->interrupt_source = zalloc(opic->sizeof_interrupt_source);

    opic->external_interrupt_source = opic->interrupt_source;

    opic->interprocessor_interrupt_source = (opic->external_interrupt_source

                                             + opic->nr_external_interrupts);

    opic->timer_interrupt_source = (opic->interprocessor_interrupt_source

                                    + opic->nr_interprocessor_interrupts);

  }

  for (i = 0; i < opic->nr_interrupt_sources; i++) {

    opic_interrupt_source *source = &opic->interrupt_source[i];

    source->nr = i;

    source->is_masked = isu_mask_bit;

  }

  DTRACE(opic, ("interrupt sources - external %d, timer %d, ipi %d, total %d\n",

                opic->nr_external_interrupts,

                opic->nr_timer_interrupts,

                opic->nr_interprocessor_interrupts,

                opic->nr_interrupt_sources));

  /* timers or interprocessor interrupts */

  if (opic->timer != NULL)

    memset(opic->timer, 0, opic->sizeof_timer);

  else {

    opic->nr_timer_interrupts = 4;

    opic->sizeof_timer = sizeof(opic_timer) * opic->nr_timer_interrupts;

    opic->timer = zalloc(opic->sizeof_timer);

  }

  for (i = 0; i < opic->nr_timer_interrupts; i++) {

    opic_timer *timer = &opic->timer[i];

    timer->nr = i;

    timer->me = me;

    timer->opic = opic;

    timer->inhibited = 1;

    timer->interrupt_source = &opic->timer_interrupt_source[i];

  }

  if (device_find_property(me, "timer-frequency"))

    opic->timer_frequency = device_find_integer_property(me, "timer-frequency");

  else

    opic->timer_frequency = 1;

  /* create space for the interrupt destination registers */

  if (opic->interrupt_destination != NULL) {

    memset(opic->interrupt_destination, 0, opic->sizeof_interrupt_destination);

  }

  else {

    opic->nr_interrupt_destinations = tree_find_integer_property(me, "/openprom/options/smp");

    opic->sizeof_interrupt_destination = (sizeof(opic_interrupt_destination)

                                          * opic->nr_interrupt_destinations);

    opic->interrupt_destination = zalloc(opic->sizeof_interrupt_destination);

    if (opic->nr_interrupt_destinations > max_nr_interrupt_destinations)

      device_error(me, "number of interrupt destinations exceeded");

  }

  for (i = 0; i < opic->nr_interrupt_destinations; i++) {

    opic_interrupt_destination *dest = &opic->interrupt_destination[i];

    dest->bit = (1 << i);

    dest->nr = i;

    dest->init_port = (device_interrupt_decode(me, "init0", output_port)

                       + i);

    dest->intr_port = (device_interrupt_decode(me, "intr0", output_port)

                       + i);

    dest->base_priority = max_nr_task_priorities - 1;

  }

  DTRACE(opic, ("interrupt destinations - total %d\n",

                (int)opic->nr_interrupt_destinations));

  /* verify and print out the ISU's */

  for (isb = 0; isb < opic->nr_isu_blocks; isb++) {

    unsigned correct_size;

    if ((opic->isu_block[isb].address % opic_alignment) != 0)

      device_error(me, "interrupt source unit %d address not aligned to %d byte boundary",

                   isb, opic_alignment);

    correct_size = opic->isu_block[isb].range * sizeof_isu_register_block;

    if (opic->isu_block[isb].size != correct_size)

      device_error(me, "interrupt source unit %d (reg %d) has an incorrect size, should be 0x%x",

                   isb, opic->isu_block[isb].reg, correct_size);

    DTRACE(opic, ("interrupt source unit block %ld - address %d:0x%lx, size 0x%lx, int-number %ld, range %ld\n",

                  (long)isb,

                  (int)opic->isu_block[isb].space,

                  (unsigned long)opic->isu_block[isb].address,

                  (unsigned long)opic->isu_block[isb].size,

                  (long)opic->isu_block[isb].int_number,

                  (long)opic->isu_block[isb].range));

  }

  /* verify and print out the IDU */

  {

    unsigned correct_size;

    unsigned alternate_size;

    if ((opic->idu.address % opic_alignment) != 0)

      device_error(me, "interrupt delivery unit not aligned to %d byte boundary",

                   opic_alignment);

    correct_size = (idu_per_processor_register_base

                    + (sizeof_idu_per_processor_register_block

                       * opic->nr_interrupt_destinations));

    alternate_size = (idu_per_processor_register_base

                      + (sizeof_idu_per_processor_register_block

                         * max_nr_interrupt_destinations));

    if (opic->idu.size != correct_size

        && opic->idu.size != alternate_size)

      device_error(me, "interrupt delivery unit has incorrect size, should be 0x%x or 0x%x",

                   correct_size, alternate_size);

    DTRACE(opic, ("interrupt delivery unit - address %d:0x%lx, size 0x%lx\n",

                  (int)opic->idu.space,

                  (unsigned long)opic->idu.address,

                  (unsigned long)opic->idu.size));

  }

  /* initialize the init interrupts */

  opic->init = 0;

  /* vendor ident */

  if (device_find_property(me, "vendor-identification") != NULL)

    opic->vendor_identification = device_find_integer_property(me, "vendor-identification");

  else

    opic->vendor_identification = 0;

  /* misc registers */

  opic->spurious_vector = 0xff;

}

/* interrupt related actions */

static void

assert_interrupt(device *me,

                 hw_opic_device *opic,

                 opic_interrupt_destination *dest)

{

  ASSERT(dest >= opic->interrupt_destination);

  ASSERT(dest < opic->interrupt_destination + opic->nr_interrupt_destinations);

  DTRACE(opic, ("assert interrupt - intr port %d\n", dest->intr_port));

  device_interrupt_event(me, dest->intr_port, 1, NULL, 0);

}

static void

negate_interrupt(device *me,

                 hw_opic_device *opic,

                 opic_interrupt_destination *dest)

{

  ASSERT(dest >= opic->interrupt_destination);

  ASSERT(dest < opic->interrupt_destination + opic->nr_interrupt_destinations);

  DTRACE(opic, ("negate interrupt - intr port %d\n", dest->intr_port));

  device_interrupt_event(me, dest->intr_port, 0, NULL, 0);

}

static int

can_deliver(device *me,

            opic_interrupt_source *source,

            opic_interrupt_destination *dest)

{

  return (source != NULL && dest != NULL

          && source->priority > dest->base_priority

          && (dest->current_in_service == NULL

              || source->priority > dest->current_in_service->priority));

}

static unsigned

deliver_pending(device *me,

                hw_opic_device *opic,

                opic_interrupt_destination *dest)

{

  ASSERT(can_deliver(me, dest->current_pending, dest));

  dest->current_in_service = dest->current_pending;

  dest->current_in_service->in_service |= dest->bit;

  if (!dest->current_pending->is_level_triggered) {

    if (dest->current_pending->is_multicast)

      dest->current_pending->pending &= ~dest->bit;

    else

      dest->current_pending->pending = 0;

  }

  dest->current_pending = NULL;

  negate_interrupt(me, opic, dest);

  return dest->current_in_service->vector;

}

typedef enum {

  pending_interrupt,

  in_service_interrupt,

} interrupt_class;

static opic_interrupt_source *

find_interrupt_for_dest(device *me,

                        hw_opic_device *opic,

                        opic_interrupt_destination *dest,

                        interrupt_class class)

{

  int i;

  opic_interrupt_source *pending = NULL;

  for (i = 0; i < opic->nr_interrupt_sources; i++) {

    opic_interrupt_source *src = &opic->interrupt_source[i];

    /* is this a potential hit? */

    switch (class) {

    case in_service_interrupt:

      if ((src->in_service & dest->bit) == 0)

        continue;

      break;

    case pending_interrupt:

      if ((src->pending & dest->bit) == 0)

        continue;

      break;

    }

    /* see if it is the highest priority */

    if (pending == NULL)

      pending = src;

    else if (src->priority > pending->priority)

      pending = src;

  }

  return pending;

}

static opic_interrupt_destination *

find_lowest_dest(device *me,

                 hw_opic_device *opic,

                 opic_interrupt_source *src)

{

  int i;

  opic_interrupt_destination *lowest = NULL;

  for (i = 0; i < opic->nr_interrupt_destinations; i++) {

    opic_interrupt_destination *dest = &opic->interrupt_destination[i];

    if (src->destination & dest->bit) {

      if (dest->base_priority < src->priority) {