termios: Use IMFS nodes for new Termios devices

This makes the new Termios devices independent of device major/minor
numbers.  It enables BSP independent Termios device drivers which may
reside in the cpukit domain.  These drivers require an IMFS and do not
work with the device file system.  However, the device file system
should go away in the future.

2 files changed, 281 insertions, 235 deletions

diff --git a/cpukit/libcsupport/include/rtems/termiostypes.h b/cpukit/libcsupport/include/rtems/termiostypes.h
index 71be95fc06..80251a22d2 100644
--- a/cpukit/libcsupport/include/rtems/termiostypes.h
+++ b/cpukit/libcsupport/include/rtems/termiostypes.h
@@ -344,10 +344,9 @@ typedef struct rtems_termios_tty {
 /**
  * @brief Installs a Termios device.
  *
- * @param[in] device_file If not @c NULL, then a device file for the specified
- *   major and minor number will be created.
- * @param[in] major The device major number of the corresponding device driver.
- * @param[in] minor The device minor number of the corresponding device driver.
+ * The installed Termios device may be removed via unlink().
+ *
+ * @param[in] device_file The device file path.
  * @param[in] handler The device handler.  It must be persistent throughout the
  *   installed time of the device.
  * @param[in] flow The device flow control handler.  The device flow control
@@ -359,65 +358,18 @@ typedef struct rtems_termios_tty {
  * @retval RTEMS_SUCCESSFUL Successful operation.
  * @retval RTEMS_NO_MEMORY Not enough memory to create a device node.
  * @retval RTEMS_UNSATISFIED Creation of the device file failed.
- * @retval RTEMS_RESOURCE_IN_USE There exists a device node for this major and
- *   minor number pair.
  * @retval RTEMS_INCORRECT_STATE Termios is not initialized.
  *
- * @see rtems_termios_device_remove(), rtems_termios_device_open(),
- *   rtems_termios_device_close() and rtems_termios_get_device_context().
+ * @see rtems_termios_get_device_context().
  */
 rtems_status_code rtems_termios_device_install(
   const char                         *device_file,
-  rtems_device_major_number           major,
-  rtems_device_minor_number           minor,
   const rtems_termios_device_handler *handler,
   const rtems_termios_device_flow    *flow,
   rtems_termios_device_context       *context
 );
 
 /**
- * @brief Removes a Termios device.
- *
- * @param[in] device_file If not @c NULL, then the device file to remove.
- * @param[in] major The device major number of the corresponding device driver.
- * @param[in] minor The device minor number of the corresponding device driver.
- *
- * @retval RTEMS_SUCCESSFUL Successful operation.
- * @retval RTEMS_INVALID_ID There is no device installed with this major and
- * minor number pair.
- * @retval RTEMS_RESOURCE_IN_USE This device is currently in use.
- * @retval RTEMS_UNSATISFIED Removal of the device file failed.
- * @retval RTEMS_INCORRECT_STATE Termios is not initialized.
- *
- * @see rtems_termios_device_install().
- */
-rtems_status_code rtems_termios_device_remove(
-  const char                *device_file,
-  rtems_device_major_number  major,
-  rtems_device_minor_number  minor
-);
-
-/**
- * @brief Opens an installed Termios device.
- *
- * @see rtems_termios_device_install().
- */
-rtems_status_code rtems_termios_device_open(
-  rtems_device_major_number  major,
-  rtems_device_minor_number  minor,
-  void                      *arg
-);
-
-/**
- * @brief Closes an installed Termios device.
- *
- * @retval RTEMS_SUCCESSFUL Successful operation.
- *
- * @see rtems_termios_device_install().
- */
-rtems_status_code rtems_termios_device_close(void *arg);
-
-/**
  * @brief Returns the device context of an installed Termios device.
  *
  * @param[in] tty The Termios control.
diff --git a/cpukit/libcsupport/src/termios.c b/cpukit/libcsupport/src/termios.c
index d9886f4c01..3a6a3897f4 100644
--- a/cpukit/libcsupport/src/termios.c
+++ b/cpukit/libcsupport/src/termios.c
@@ -22,6 +22,8 @@
 
 #include <rtems.h>
 #include <rtems/libio.h>
+#include <rtems/imfs.h>
+#include <rtems/score/assert.h>
 #include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
@@ -85,6 +87,8 @@ static size_t rtems_termios_cbufsize = 256;
 static size_t rtems_termios_raw_input_size = 128;
 static size_t rtems_termios_raw_output_size = 64;
 
+static const IMFS_node_control rtems_termios_imfs_node_control;
+
 static struct rtems_termios_tty *rtems_termios_ttyHead;
 static struct rtems_termios_tty *rtems_termios_ttyTail;
 
@@ -108,126 +112,55 @@ static rtems_task rtems_termios_txdaemon(rtems_task_argument argument);
 #define TERMIOS_RX_PROC_EVENT      RTEMS_EVENT_1
 #define TERMIOS_RX_TERMINATE_EVENT RTEMS_EVENT_0
 
-static rtems_termios_device_node *
-rtems_termios_find_device_node(
-  rtems_device_major_number major,
-  rtems_device_minor_number minor
-)
+static rtems_status_code
+rtems_termios_obtain (void)
 {
-  rtems_chain_node *tail = rtems_chain_tail(&rtems_termios_devices);
-  rtems_chain_node *current = rtems_chain_first(&rtems_termios_devices);
-
-  while (current != tail) {
-    rtems_termios_device_node *device_node =
-      (rtems_termios_device_node *) current;
-
-    if (device_node->major == major && device_node->minor == minor) {
-      return device_node;
-    }
+  return rtems_semaphore_obtain (rtems_termios_ttyMutex, RTEMS_WAIT,
+    RTEMS_NO_TIMEOUT);
+}
 
-    current = rtems_chain_next(current);
-  }
+static void
+rtems_termios_release (void)
+{
+  rtems_status_code sc;
 
-  return NULL;
+  sc = rtems_semaphore_release (rtems_termios_ttyMutex);
+  _Assert (sc == RTEMS_SUCCESSFUL);
+  (void) sc;
 }
 
 rtems_status_code rtems_termios_device_install(
   const char                         *device_file,
-  rtems_device_major_number           major,
-  rtems_device_minor_number           minor,
   const rtems_termios_device_handler *handler,
   const rtems_termios_device_flow    *flow,
   rtems_termios_device_context       *context
 )
 {
-  rtems_status_code          sc;
   rtems_termios_device_node *new_device_node;
-  rtems_termios_device_node *existing_device_node;
+  int rv;
 
-  new_device_node = malloc(sizeof(*new_device_node));
+  new_device_node = calloc (1, sizeof(*new_device_node));
   if (new_device_node == NULL) {
     return RTEMS_NO_MEMORY;
   }
 
-  rtems_chain_initialize_node(&new_device_node->node);
-  new_device_node->major = major;
-  new_device_node->minor = minor;
+  rtems_chain_initialize_node (&new_device_node->node);
   new_device_node->handler = handler;
   new_device_node->flow = flow;
   new_device_node->context = context;
   new_device_node->tty = NULL;
 
-  sc = rtems_semaphore_obtain(
-    rtems_termios_ttyMutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
-  if (sc != RTEMS_SUCCESSFUL) {
-    free(new_device_node);
-    return RTEMS_INCORRECT_STATE;
-  }
-
-  existing_device_node = rtems_termios_find_device_node (major, minor);
-  if (existing_device_node != NULL) {
-    free(new_device_node);
-    rtems_semaphore_release (rtems_termios_ttyMutex);
-    return RTEMS_RESOURCE_IN_USE;
-  }
-
-  if (device_file != NULL) {
-    sc = rtems_io_register_name (device_file, major, minor);
-    if (sc != RTEMS_SUCCESSFUL) {
-      free(new_device_node);
-      rtems_semaphore_release (rtems_termios_ttyMutex);
-      return RTEMS_UNSATISFIED;
-    }
-  }
-
-  rtems_chain_append_unprotected(
-    &rtems_termios_devices, &new_device_node->node);
-
-  rtems_semaphore_release (rtems_termios_ttyMutex);
-
-  return RTEMS_SUCCESSFUL;
-}
-
-rtems_status_code rtems_termios_device_remove(
-  const char                *device_file,
-  rtems_device_major_number  major,
-  rtems_device_minor_number  minor
-)
-{
-  rtems_status_code          sc;
-  rtems_termios_device_node *device_node;
-
-  sc = rtems_semaphore_obtain(
-    rtems_termios_ttyMutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
-  if (sc != RTEMS_SUCCESSFUL) {
-    return RTEMS_INCORRECT_STATE;
-  }
-
-  device_node = rtems_termios_find_device_node (major, minor);
-  if (device_node == NULL) {
-    rtems_semaphore_release (rtems_termios_ttyMutex);
-    return RTEMS_INVALID_ID;
-  }
-
-  if (device_node->tty != NULL) {
-    rtems_semaphore_release (rtems_termios_ttyMutex);
-    return RTEMS_RESOURCE_IN_USE;
-  }
-
-  if (device_file != NULL) {
-    int rv = unlink (device_file);
-
-    if (rv != 0) {
-      rtems_semaphore_release (rtems_termios_ttyMutex);
-      return RTEMS_UNSATISFIED;
-    }
+  rv = IMFS_make_generic_node(
+    device_file,
+    S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO,
+    &rtems_termios_imfs_node_control,
+    new_device_node
+  );
+  if (rv != 0) {
+    free (new_device_node);
+    return RTEMS_UNSATISFIED;
   }
 
-  rtems_chain_extract_unprotected (&device_node->node);
-  free (device_node);
-
-  rtems_semaphore_release (rtems_termios_ttyMutex);
-
   return RTEMS_SUCCESSFUL;
 }
 
@@ -629,40 +562,6 @@ rtems_termios_open_tty(
   return tty;
 }
 
-rtems_status_code
-rtems_termios_device_open(
-  rtems_device_major_number  major,
-  rtems_device_minor_number  minor,
-  void                      *arg
-)
-{
-  rtems_status_code          sc;
-  rtems_termios_device_node *device_node;
-  struct rtems_termios_tty  *tty;
-
-  sc = rtems_semaphore_obtain(
-    rtems_termios_ttyMutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
-  if (sc != RTEMS_SUCCESSFUL)
-    return sc;
-
-  device_node = rtems_termios_find_device_node (major, minor);
-  if (device_node == NULL) {
-    rtems_semaphore_release (rtems_termios_ttyMutex);
-    return RTEMS_INVALID_ID;
-  }
-
-  tty = rtems_termios_open_tty(
-    major, minor, arg, device_node->tty, device_node, NULL);
-  if (tty == NULL) {
-    rtems_semaphore_release (rtems_termios_ttyMutex);
-    return RTEMS_NO_MEMORY;
-  }
-
-  rtems_semaphore_release (rtems_termios_ttyMutex);
-
-  return RTEMS_SUCCESSFUL;
-}
-
 /*
  * Open a termios device
  */
@@ -680,8 +579,7 @@ rtems_termios_open (
   /*
    * See if the device has already been opened
    */
-  sc = rtems_semaphore_obtain(
-    rtems_termios_ttyMutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+  sc = rtems_termios_obtain ();
   if (sc != RTEMS_SUCCESSFUL)
     return sc;
 
@@ -693,7 +591,7 @@ rtems_termios_open (
   tty = rtems_termios_open_tty(
     major, minor, arg, tty, NULL, callbacks);
   if (tty == NULL) {
-    rtems_semaphore_release (rtems_termios_ttyMutex);
+    rtems_termios_release ();
     return RTEMS_NO_MEMORY;
   }
 
@@ -710,7 +608,7 @@ rtems_termios_open (
       rtems_termios_ttyTail = tty;
   }
 
-  rtems_semaphore_release (rtems_termios_ttyMutex);
+  rtems_termios_release ();
 
   return RTEMS_SUCCESSFUL;
 }
@@ -755,8 +653,7 @@ rtems_termios_close (void *arg)
   rtems_libio_open_close_args_t *args = arg;
   struct rtems_termios_tty *tty = args->iop->data1;
 
-  sc = rtems_semaphore_obtain(
-    rtems_termios_ttyMutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+  sc = rtems_termios_obtain ();
   if (sc != RTEMS_SUCCESSFUL)
     rtems_fatal_error_occurred (sc);
 
@@ -782,26 +679,7 @@ rtems_termios_close (void *arg)
 
   rtems_termios_close_tty (tty, arg);
 
-  rtems_semaphore_release (rtems_termios_ttyMutex);
-
-  return RTEMS_SUCCESSFUL;
-}
-
-rtems_status_code
-rtems_termios_device_close (void *arg)
-{
-  rtems_status_code sc;
-  rtems_libio_open_close_args_t *args = arg;
-  struct rtems_termios_tty *tty = args->iop->data1;
-
-  sc = rtems_semaphore_obtain(
-    rtems_termios_ttyMutex, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
-  if (sc != RTEMS_SUCCESSFUL)
-    rtems_fatal_error_occurred (sc);
-
-  rtems_termios_close_tty (tty, arg);
-
-  rtems_semaphore_release (rtems_termios_ttyMutex);
+  rtems_termios_release ();
 
   return RTEMS_SUCCESSFUL;
 }
@@ -1193,6 +1071,25 @@ oproc (unsigned char c, struct rtems_termios_tty *tty)
   rtems_termios_puts (&c, 1, tty);
 }
 
+static uint32_t
+rtems_termios_write_tty (struct rtems_termios_tty *tty, const char *buffer,
+  uint32_t initial_count)
+{
+
+  if (tty->termios.c_oflag & OPOST) {
+    uint32_t count;
+
+    count = initial_count;
+
+    while (count--)
+      oproc (*buffer++, tty);
+  } else {
+    rtems_termios_puts (buffer, initial_count, tty);
+  }
+
+  return initial_count;
+}
+
 rtems_status_code
 rtems_termios_write (void *arg)
 {
@@ -1208,16 +1105,7 @@ rtems_termios_write (void *arg)
     rtems_semaphore_release (tty->osem);
     return sc;
   }
-  if (tty->termios.c_oflag & OPOST) {
-    uint32_t   count = args->count;
-    char      *buffer = args->buffer;
-    while (count--)
-      oproc (*buffer++, tty);
-    args->bytes_moved = args->count;
-  } else {
-    rtems_termios_puts (args->buffer, args->count, tty);
-    args->bytes_moved = args->count;
-  }
+  args->bytes_moved = rtems_termios_write_tty (tty, args->buffer, args->count);
   rtems_semaphore_release (tty->osem);
   return sc;
 }
@@ -1521,27 +1409,17 @@ fillBufferQueue (struct rtems_termios_tty *tty)
   return RTEMS_SUCCESSFUL;
 }
 
-rtems_status_code
-rtems_termios_read (void *arg)
+static uint32_t
+rtems_termios_read_tty (struct rtems_termios_tty *tty, char *buffer,
+  uint32_t initial_count)
 {
-  rtems_libio_rw_args_t *args = arg;
-  struct rtems_termios_tty *tty = args->iop->data1;
-  uint32_t   count = args->count;
-  char      *buffer = args->buffer;
-  rtems_status_code sc;
-
-  sc = rtems_semaphore_obtain (tty->isem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
-  if (sc != RTEMS_SUCCESSFUL)
-    return sc;
+  uint32_t count;
 
-  if (rtems_termios_linesw[tty->t_line].l_read != NULL) {
-    sc = rtems_termios_linesw[tty->t_line].l_read(tty,args);
-    tty->tty_rcvwakeup = 0;
-    rtems_semaphore_release (tty->isem);
-    return sc;
-  }
+  count = initial_count;
 
   if (tty->cindex == tty->ccount) {
+    rtems_status_code sc;
+
     tty->cindex = tty->ccount = 0;
     tty->read_start_column = tty->column;
     if (tty->handler.poll_read != NULL && tty->handler.mode == TERMIOS_POLLED)
@@ -1556,8 +1434,29 @@ rtems_termios_read (void *arg)
     *buffer++ = tty->cbuf[tty->cindex++];
     count--;
   }
-  args->bytes_moved = args->count - count;
   tty->tty_rcvwakeup = 0;
+  return initial_count - count;
+}
+
+rtems_status_code
+rtems_termios_read (void *arg)
+{
+  rtems_libio_rw_args_t *args = arg;
+  struct rtems_termios_tty *tty = args->iop->data1;
+  rtems_status_code sc;
+
+  sc = rtems_semaphore_obtain (tty->isem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+  if (sc != RTEMS_SUCCESSFUL)
+    return sc;
+
+  if (rtems_termios_linesw[tty->t_line].l_read != NULL) {
+    sc = rtems_termios_linesw[tty->t_line].l_read(tty,args);
+    tty->tty_rcvwakeup = 0;
+    rtems_semaphore_release (tty->isem);
+    return sc;
+  }
+
+  args->bytes_moved = rtems_termios_read_tty (tty, args->buffer, args->count);
   rtems_semaphore_release (tty->isem);
   return sc;
 }
@@ -1928,3 +1827,198 @@ static rtems_task rtems_termios_rxdaemon(rtems_task_argument argument)
     }
   }
 }
+
+static int
+rtems_termios_imfs_open (rtems_libio_t *iop,
+  const char *path, int oflag, mode_t mode)
+{
+  rtems_termios_device_node *device_node;
+  rtems_status_code sc;
+  rtems_libio_open_close_args_t args;
+  struct rtems_termios_tty *tty;
+
+  device_node = IMFS_generic_get_context_by_iop (iop);
+
+  memset (&args, 0, sizeof (args));
+  args.iop = iop;
+  args.flags = iop->flags;
+  args.mode = mode;
+
+  sc = rtems_termios_obtain ();
+  if (sc != RTEMS_SUCCESSFUL) {
+    rtems_set_errno_and_return_minus_one (ENXIO);
+  }
+
+  tty = rtems_termios_open_tty (device_node->major, device_node->minor, &args,
+      device_node->tty, device_node, NULL);
+  if (tty == NULL) {
+    rtems_termios_release ();
+    rtems_set_errno_and_return_minus_one (ENOMEM);
+  }
+
+  rtems_termios_release ();
+  return 0;
+}
+
+static int
+rtems_termios_imfs_close (rtems_libio_t *iop)
+{
+  rtems_status_code sc;
+  rtems_libio_open_close_args_t args;
+  struct rtems_termios_tty *tty;
+
+  memset (&args, 0, sizeof (args));
+  args.iop = iop;
+
+  tty = iop->data1;
+
+  sc = rtems_termios_obtain ();
+  _Assert (sc == RTEMS_SUCCESSFUL);
+  (void) sc;
+
+  rtems_termios_close_tty (tty, &args);
+  rtems_termios_release ();
+  return 0;
+}
+
+static ssize_t
+rtems_termios_imfs_read (rtems_libio_t *iop, void *buffer, size_t count)
+{
+  struct rtems_termios_tty *tty;
+  rtems_status_code sc;
+  uint32_t bytes_moved;
+
+  tty = iop->data1;
+
+  sc = rtems_semaphore_obtain (tty->isem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+  _Assert (sc == RTEMS_SUCCESSFUL);
+
+  if (rtems_termios_linesw[tty->t_line].l_read != NULL) {
+    rtems_libio_rw_args_t args;
+
+    memset (&args, 0, sizeof (args));
+    args.iop = iop;
+    args.buffer = buffer;
+    args.count = count;
+    args.flags = iop->flags;
+
+    sc = rtems_termios_linesw[tty->t_line].l_read (tty, &args);
+    tty->tty_rcvwakeup = 0;
+    rtems_semaphore_release (tty->isem);
+
+    if (sc != RTEMS_SUCCESSFUL) {
+      return rtems_status_code_to_errno (sc);
+    }
+
+    return (ssize_t) args.bytes_moved;
+  }
+
+  bytes_moved = rtems_termios_read_tty (tty, buffer, count);
+  rtems_semaphore_release (tty->isem);
+  return (ssize_t) bytes_moved;
+}
+
+static ssize_t
+rtems_termios_imfs_write (rtems_libio_t *iop, const void *buffer, size_t count)
+{
+  struct rtems_termios_tty *tty;
+  rtems_status_code sc;
+  uint32_t bytes_moved;
+
+  tty = iop->data1;
+
+  sc = rtems_semaphore_obtain (tty->osem, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+  _Assert (sc == RTEMS_SUCCESSFUL);
+
+  if (rtems_termios_linesw[tty->t_line].l_write != NULL) {
+    rtems_libio_rw_args_t args;
+
+    memset (&args, 0, sizeof (args));
+    args.iop = iop;
+    args.buffer = RTEMS_DECONST (void *, buffer);
+    args.count = count;
+    args.flags = iop->flags;
+
+    sc = rtems_termios_linesw[tty->t_line].l_write (tty, &args);
+    rtems_semaphore_release (tty->osem);
+
+    if (sc != RTEMS_SUCCESSFUL) {
+      return rtems_status_code_to_errno (sc);
+    }
+
+    return (ssize_t) args.bytes_moved;
+  }
+
+  bytes_moved = rtems_termios_write_tty (tty, buffer, count);
+  rtems_semaphore_release (tty->osem);
+  return (ssize_t) bytes_moved;
+}
+
+static int
+rtems_termios_imfs_ioctl (rtems_libio_t *iop, uint32_t request, void *buffer)
+{
+  rtems_status_code sc;
+  rtems_libio_ioctl_args_t args;
+
+  memset (&args, 0, sizeof (args));
+  args.iop = iop;
+  args.command = request;
+  args.buffer = buffer;
+
+  sc = rtems_termios_ioctl (&args);
+  if ( sc == RTEMS_SUCCESSFUL ) {
+    return args.ioctl_return;
+  } else {
+    return rtems_status_code_to_errno (sc);
+  }
+}
+
+static const rtems_filesystem_file_handlers_r rtems_termios_imfs_handler = {
+  .open_h = rtems_termios_imfs_open,
+  .close_h = rtems_termios_imfs_close,
+  .read_h = rtems_termios_imfs_read,
+  .write_h = rtems_termios_imfs_write,
+  .ioctl_h = rtems_termios_imfs_ioctl,
+  .lseek_h = rtems_filesystem_default_lseek,
+  .fstat_h = IMFS_stat,
+  .ftruncate_h = rtems_filesystem_default_ftruncate,
+  .fsync_h = rtems_filesystem_default_fsync_or_fdatasync,
+  .fdatasync_h = rtems_filesystem_default_fsync_or_fdatasync,
+  .fcntl_h = rtems_filesystem_default_fcntl,
+  .kqfilter_h = rtems_filesystem_default_kqfilter,
+  .poll_h = rtems_filesystem_default_poll,
+  .readv_h = rtems_filesystem_default_readv,
+  .writev_h = rtems_filesystem_default_writev
+};
+
+static IMFS_jnode_t *
+rtems_termios_imfs_node_initialize (IMFS_jnode_t *node, void *arg)
+{
+  rtems_termios_device_node *device_node;
+  dev_t dev;
+
+  node = IMFS_node_initialize_generic (node, arg);
+  device_node = IMFS_generic_get_context_by_node (node);
+  dev = IMFS_generic_get_device_identifier_by_node (node);
+  device_node->major = rtems_filesystem_dev_major_t (dev);
+  device_node->minor = rtems_filesystem_dev_minor_t (dev);
+
+  return node;
+}
+
+static void
+rtems_termios_imfs_node_destroy (IMFS_jnode_t *node)
+{
+  rtems_termios_device_node *device_node;
+
+  device_node = IMFS_generic_get_context_by_node (node);
+  free (device_node);
+  IMFS_node_destroy_default (node);
+}
+
+static const IMFS_node_control rtems_termios_imfs_node_control =
+  IMFS_GENERIC_INITIALIZER(
+    &rtems_termios_imfs_handler,
+    rtems_termios_imfs_node_initialize,
+    rtems_termios_imfs_node_destroy
+  );