path: root/devio/dev.c

/* Mach devices.

   Copyright (C) 1995 Free Software Foundation, Inc.

   Written by Miles Bader <miles@gnu.ai.mit.edu>

   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, 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., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include <hurd.h>
#include <device/device.h>
#include <assert.h>
#include <hurd/pager.h>

#include "dev.h"
#include "iostate.h"

#ifdef MSG
#include <ctype.h>
#endif
#ifdef FAKE
#include <stdio.h>
#include <sys/stat.h>
#include <errno.h>
#include <sys/fcntl.h>
#endif

/* ---------------------------------------------------------------- */

/* Returns a pointer to a new device structure in DEV for the kernel device
   NAME, with the given FLAGS.  If BLOCK_SIZE is non-zero, it should be the
   desired block size, and must be a multiple of the device block size.
   If an error occurs, the error code is returned, otherwise 0.  */
error_t
dev_open(char *name, int flags, int block_size, struct dev **dev)
{
  error_t err = 0;
  static mach_port_t device_master = MACH_PORT_NULL;

  *dev = malloc(sizeof (struct dev));

  if (!(flags & DEV_SERIAL))
    flags |= DEV_SEEKABLE;

  if (*dev == NULL)
    return ENOMEM;

  (*dev)->port = MACH_PORT_NULL;

  if (device_master == MACH_PORT_NULL)
    err = get_privileged_ports(NULL, &device_master);

#ifdef FAKE
  (*dev)->port = (mach_port_t)
    open(name, ((flags & DEV_READONLY) ? O_RDONLY : O_RDWR));
  err = ((int)(*dev)->port == -1 ? errno : 0);
  if (!err)
    {
      struct stat stat;
      if (fstat((int)(*dev)->port, &stat) == 0)
	{
	  (*dev)->size = stat.st_size;
	  (*dev)->dev_block_size = stat.st_blksize;
	}
      else
	err = errno;
    }
#else
  if (!err)
    err = device_open(device_master,
		      D_READ | (flags & DEV_READONLY ? D_WRITE : 0),
		      name, &(*dev)->port);

  if (!err)
    {
      int count = DEV_GET_SIZE_COUNT;
      int sizes[DEV_GET_SIZE_COUNT];

      /* Get info about the device: total size (in bytes) and block size (in
	 bytes).  Block size is unit in which device addressing is done.  */
      err = device_get_status((*dev)->port, DEV_GET_SIZE, sizes, &count);
      if (!err)
	{
	  (*dev)->size = sizes[DEV_GET_SIZE_DEVICE_SIZE];
	  (*dev)->dev_block_size = sizes[DEV_GET_SIZE_RECORD_SIZE];
	}
    }
#endif
#ifdef MSG
  if (debug)
    {
      mutex_lock(&debug_lock);
      fprintf(debug, "dev_open(`%s', 0x%x, %d) => %s\n",
	      name, flags, block_size, err ? strerror(err) : "OK");
      if (!err)
	fprintf(debug, "  size = %d, dev_block_size = %d\n",
		(*dev)->size, (*dev)->dev_block_size);
      mutex_unlock(&debug_lock);
    }
#endif

  if (!err)
    {
      if (block_size > 0)
	if (block_size > (*dev)->dev_block_size
	    && block_size % (*dev)->dev_block_size == 0)
	  (*dev)->block_size = block_size;
	else
	  err = EINVAL;
      else
	(*dev)->block_size = (*dev)->dev_block_size;

      if ((*dev)->dev_block_size == 1)
	flags |= DEV_SERIAL;

      (*dev)->flags = flags;
      (*dev)->owner = 0;
    }

  if (!err)
    err = io_state_init(&(*dev)->io_state, *dev);

  if (err)
    {
      if ((*dev)->port != MACH_PORT_NULL)
	mach_port_deallocate(mach_task_self(), (*dev)->port);
      free(*dev);
    }

  return err;
}

/* Free DEV and any resources it consumes.  */
void 
dev_close(struct dev *dev)
{
  if (!dev_is(dev, DEV_READONLY))
    {
      if (dev->pager != NULL)
	pager_shutdown(dev->pager);
      io_state_sync(&dev->io_state, dev);
    }

  device_close(dev->port);
  io_state_finalize(&dev->io_state);

  free(dev);
}

/* ---------------------------------------------------------------- */

/* Try and write out any pending writes to DEV.  If WAIT is true, will wait
   for any paging activity to cease.  */
error_t
dev_sync(struct dev *dev, int wait)
{
  error_t err = 0;

  if (!dev_is(dev, DEV_READONLY))
    {
      struct io_state *ios = &dev->io_state;

      io_state_lock(ios);

      /* Sync any paged backing store.  */
      if (dev->pager != NULL)
	pager_sync(dev->pager, wait);

      /* Write out any stuff buffered in our io_state.  */
      err = io_state_sync(ios, dev);

      io_state_unlock(ios);
    }

  return err;
}

/* ---------------------------------------------------------------- */

#ifdef MSG
char *
brep(vm_address_t buf, vm_size_t len)
{
  static char rep[200];
  char *prep(char *buf, char *str, int len)
    {
      *buf++ = '`';
      while (len-- > 0)
	{
	  int ch = *str++;
	  if (isprint(ch) && ch != '\'' && ch != '\\')
	    *buf++ = ch;
	  else
	    {
	      *buf++ = '\\';
	      switch (ch)
		{
		case '\n': *buf++ = 'n'; break;
		case '\t': *buf++ = 't'; break;
		case '\b': *buf++ = 'b'; break;
		case '\f': *buf++ = 'f'; break;
		default:   sprintf(buf, "%03o", ch); buf += 3; break;
		}
	    }
	}
      *buf++ = '\'';
      *buf = '\0';
      return buf;
    }

  if (len < 40)
    prep(rep, (char *)buf, (int)len);
  else
    {
      char *end = prep(rep, (char *)buf, 20);
      *end++ = '.'; *end++ = '.'; *end++ = '.';
      prep(end, (char *)buf + len - 20, 20);
    }

  return rep;
}
#endif

/* Writes AMOUNT bytes from the buffer pointed to by BUF to the device DEV.
   *OFFS is incremented to reflect the amount read/written.  Both AMOUNT and
   *OFFS must be multiples of DEV's block size, and either BUF must be
   page-aligned, or dev_write_valid() must return true for these arguments.
   If an error occurs, the error code is returned, otherwise 0.  */
error_t
dev_write(struct dev *dev,
	  vm_address_t buf, vm_size_t amount, vm_offset_t *offs)
{
  int bsize = dev->dev_block_size;
  vm_offset_t written = 0;
  vm_offset_t block = (bsize == 1 ? *offs : *offs / bsize);
  error_t err;

  assert(dev_write_valid(dev, buf, amount, *offs));
  assert(*offs % bsize == 0);
  assert(amount % bsize == 0);

  if (amount < IO_INBAND_MAX)
    {
#ifdef FAKE
      if (*offs != dev->io_state.location)
	{
	  err = lseek((int)dev->port, SEEK_SET, *offs);
	  if (err == -1)
	    err = errno;
	  else
	    dev->io_state.location = *offs;
	}
      written = write((int)dev->port, (char *)buf, amount);
      err = (written < 1 ?  errno : 0);
      if (!err)
	dev->io_state.location += written;
#else
      err =
	device_write_inband(dev->port, 0, block,
			    (io_buf_ptr_t)buf, amount, &written);
#endif
#ifdef MSG
      if (debug)
	{
	  mutex_lock(&debug_lock);
	  fprintf(debug, "device_write_inband(%d, %s, %d) => %s, %d\n",
		  block, brep(buf, amount), amount, err ? strerror(err) : "OK", written);
	  fprintf(debug, "  offset = %d => %d\n", *offs, *offs + written);
#endif
	  mutex_unlock(&debug_lock);
	}
    }
  else
    {
#ifdef FAKE
    if (*offs != dev->io_state.location)
      {
	err = lseek((int)dev->port, SEEK_SET, *offs);
	if (err == -1)
	  err = errno;
	else
	  dev->io_state.location = *offs;
      }
    written = write((int)dev->port, (char *)buf, amount);
    err = (written < 1 ?  errno : 0);
    if (!err)
      dev->io_state.location += written;
#else
    err =
      device_write(dev->port, 0, block, (io_buf_ptr_t)buf, amount, &written);
#endif
#ifdef MSG
    if (debug)
      {
	mutex_lock(&debug_lock);
	fprintf(debug, "device_write(%d, %s, %d) => %s, %d\n",
		block, brep(buf, amount), amount,
		err ? strerror(err) : "OK", written);
	fprintf(debug, "  offset = %d => %d\n", *offs, *offs + written);
	mutex_unlock(&debug_lock);
      }
#endif
  }

  if (!err)
    *offs += written;

  return err;
}

/* Reads AMOUNT bytes from DEV and returns it in BUF and BUF_LEN (using the
   standard mach out-array convention).  *OFFS is incremented to reflect the
   amount read/written.  Both LEN and *OFFS must be multiples of DEV's block
   size.  If an error occurs, the error code is returned, otherwise 0.  */
error_t
dev_read(struct dev *dev,
	 vm_address_t *buf, vm_size_t *buf_len, vm_size_t amount,
	 vm_offset_t *offs)
{
  error_t err = 0;
  int bsize = dev->dev_block_size;
  vm_offset_t read = 0;
  vm_offset_t block = (bsize == 1 ? *offs : *offs / bsize);

  assert(*offs % bsize == 0);
  assert(amount % bsize == 0);

  if (amount < IO_INBAND_MAX)
    {
      if (*buf_len < amount)
	err = vm_allocate(mach_task_self(), buf, amount, 1);
#ifdef FAKE
      if (*offs != dev->io_state.location)
	{
	  err = lseek((int)dev->port, SEEK_SET, *offs);
	  if (err == -1)
	    err = errno;
	  else
	    dev->io_state.location = *offs;
	}
      err = vm_allocate(mach_task_self(), buf, amount, 1);
      if (!err)
	{
	  read = __read((int)dev->port, (char *)*buf, amount);
	  err = (read == -1 ? errno : 0);
	  if (!err)
	    dev->io_state.location += read;
	}
#else
      if (!err)
	err =
	  device_read_inband(dev->port, 0, block,
			     amount, (io_buf_ptr_t)*buf, &read);
#endif
#ifdef MSG
      if (debug)
	{
	  mutex_lock(&debug_lock);
	  fprintf(debug, "device_read_inband(%d, %d) => %s, %s, %d\n",
		  block, amount,
		  err ? strerror(err) : "OK", err ? "-" : brep(*buf, read),
		  read);
	  if (!err)
	    fprintf(debug, "  offset = %d => %d\n", *offs, *offs + read);
	  mutex_unlock(&debug_lock);
	}
#endif
    }
  else
    {
#ifdef FAKE
      if (*offs != dev->io_state.location)
	{
	  err = lseek((int)dev->port, SEEK_SET, *offs);
	  if (err == -1)
	    err = errno;
	  else
	    dev->io_state.location = *offs;
	}
      err = vm_allocate(mach_task_self(), buf, amount, 1);
      if (!err)
	{
	  read = __read((int)dev->port, (char *)*buf, amount);
	  err = (read == -1 ? errno : 0);
	  if (!err)
	    dev->io_state.location += read;
	}
#else
      err =
	device_read(dev->port, 0, block, amount, (io_buf_ptr_t *)buf, &read);
#endif
#ifdef MSG
      if (debug)
	{
	  mutex_lock(&debug_lock);
	  fprintf(debug, "device_read(%d, %d) => %s, %s, %d\n",
		  block, amount,
		  err ? strerror(err) : "OK", err ? "-" : brep(*buf, read),
		  read);
	  if (!err)
	    fprintf(debug, "  offset = %d => %d\n", *offs, *offs + read);
	  mutex_unlock(&debug_lock);
	}
#endif
    }

  if (!err)
    {
      *offs += read;
      *buf_len = read;
    }

  return err;
}