/*
   Copyright (C) 2017 Free Software Foundation, Inc.

   This file is part of the GNU Hurd.

   The GNU Hurd 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, or (at
   your option) any later version.

   The GNU Hurd 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 the GNU Hurd.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
 * Per-function files implementation.
 *
 * Implementation of all files repeated for each function.
 */

#include "func_files.h"

#include <assert.h>
#include <sys/io.h>

/* Read or write a block of data from/to the configuration space */
static error_t
config_block_op (struct pci_device *dev, off_t offset, size_t * len,
		 void *data, pci_io_op_t op)
{
  error_t err;
  size_t pendent = *len;
  pciaddr_t actual = 0;

  while (pendent >= 4)
    {
      err = op (dev, data, offset, 4, &actual);
      if (err)
	return err;

      offset += 4;
      data += 4;
      pendent -= 4;
    }

  if (pendent >= 2)
    {
      err = op (dev, data, offset, 2, &actual);
      if (err)
	return err;

      offset += 2;
      data += 2;
      pendent -= 2;
    }

  if (pendent)
    {
      err = op (dev, data, offset, 1, &actual);
      if (err)
	return err;

      offset++;
      data++;
      pendent--;
    }

  *len -= pendent;

  return 0;
}

/* Read or write from/to the config file */
error_t
io_config_file (struct pci_device * dev, off_t offset, size_t * len,
		void *data, pci_io_op_t op)
{
  error_t err;

  /* This should never happen */
  assert_backtrace (dev != 0);

  /* Don't exceed the config space size */
  if (offset > PCI_CONFIG_SIZE)
    return EINVAL;
  if ((offset + *len) > PCI_CONFIG_SIZE)
    *len = PCI_CONFIG_SIZE - offset;

  pthread_mutex_lock (&fs->pci_conf_lock);
  err = config_block_op (dev, offset, len, data, op);
  pthread_mutex_unlock (&fs->pci_conf_lock);

  return err;
}

/* Read the mapped ROM */
error_t
read_rom_file (struct pci_device * dev, off_t offset, size_t * len,
	       void *data)
{
  void *fullrom;

  /* This should never happen */
  assert_backtrace (dev != 0);

  /* Don't exceed the ROM size */
  if (offset > dev->rom_size)
    return EINVAL;
  if ((offset + *len) > dev->rom_size)
    *len = dev->rom_size - offset;

  /* Grab the full rom first */
  fullrom = calloc(1, dev->rom_size);
  pci_device_read_rom(dev, fullrom);

  /* Return the requested amount */
  memcpy (data, fullrom + offset, *len);

  free(fullrom);
  return 0;
}

/* Read or write from/to a memory region by using I/O ports */
static error_t
region_block_ioport_op (uint16_t port, off_t offset, size_t * len,
			void *data, int read)
{
  size_t pending = *len;

  while (pending >= 4)
    {
      /* read == true: read; else: write */
      if (read)
	*((unsigned int *) data) = inl (port + offset);
      else
	outl (*((unsigned int *) data), port + offset);

      offset += 4;
      data += 4;
      pending -= 4;
    }

  if (pending >= 2)
    {
      if (read)
	*((unsigned short *) data) = inw (port + offset);
      else
	outw (*((unsigned short *) data), port + offset);

      offset += 2;
      data += 2;
      pending -= 2;
    }

  if (pending)
    {
      if (read)
	*((unsigned char *) data) = inb (port + offset);
      else
	outb (*((unsigned char *) data), port + offset);

      offset++;
      data++;
      pending--;
    }

  *len -= pending;

  return 0;
}

/* Read or write from/to a region file */
error_t
io_region_file (struct pcifs_dirent * e, off_t offset, size_t * len,
		void *data, int read)
{
  size_t reg_num;
  struct pci_mem_region *region;

  /* This should never happen */
  assert_backtrace (e->device != 0);

  /* Get the region */
  reg_num = strtol (&e->name[strlen (e->name) - 1], 0, 16);
  region = &e->device->regions[reg_num];

  /* Don't exceed the region size */
  if (offset > region->size)
    return EINVAL;
  if ((offset + *len) > region->size)
    *len = region->size - offset;

  if (region->is_IO)
    region_block_ioport_op (region->base_addr, offset, len, data, read);
  else if (read)
    memcpy (data, region->memory + offset, *len);
  else
    memcpy (region->memory + offset, data, *len);

  return 0;
}