Change FIOC_MMAP into file operation call

- Add mmap into file_operations and remove it from ioctl definitions.
- Add mm_map structure definitions to support future unmapping
- Modify all drivers to initialize the operations struct accordingly

Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>

fs/mmap/README.txt

@@ -14,7 +14,7 @@ conditions where mmap() can be supported:
 1. mmap can be used to support eXecute In Place (XIP) on random access media
    under the following very restrictive conditions:
 
-   a. The filesystem supports the FIOC_MMAP ioctl command.  Any file
+   a. The filesystem implements the mmap file operation.  Any file
       system that maps files contiguously on the media should support
       this ioctl. (vs. file system that scatter files over the media
       in non-contiguous sectors).  As of this writing, ROMFS is the

fs/mmap/fs_mmap.c

@@ -23,6 +23,7 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+#include <nuttx/mm/map.h>
 
 #include <sys/types.h>
 #include <sys/mman.h>
@@ -49,7 +50,6 @@ static int file_mmap_(FAR struct file *filep, FAR void *start,
                       size_t length, int prot, int flags,
                       off_t offset, bool kernel, FAR void **mapped)
 {
-  FAR void *addr;
   int ret;
 
   /* Since only a tiny subset of mmap() functionality, we have to verify many
@@ -135,14 +135,33 @@ static int file_mmap_(FAR struct file *filep, FAR void *start,
 #endif
     }
 
-  /* Perform the ioctl to get the base address of the file in 'mapped'
-   * in memory. (casting to uintptr_t first eliminates complaints on some
-   * architectures where the sizeof long is different from the size of
-   * a pointer).
+  /* Call driver's mmap to get the base address of the file in 'mapped'
+   * in memory.
    */
 
-  ret = file_ioctl(filep, FIOC_MMAP, (unsigned long)((uintptr_t)&addr));
-  if (ret < 0)
+  if (filep->f_inode && filep->f_inode->u.i_ops->mmap != NULL)
+    {
+      /* Pass the information about the mapping in mm_map_entry_s structure.
+       * The driver may alter the structure, and if it supports unmap, it
+       * will also add it to the kernel maintained list of mappings.
+       */
+
+      struct mm_map_entry_s map =
+        {
+         NULL, /* sq_entry_t */
+         start, length, offset,
+         prot, flags,
+         NULL, /* priv */
+         NULL  /* munmap */
+        };
+
+      ret = filep->f_inode->u.i_ops->mmap(filep, &map);
+      if (ret == OK)
+        {
+          *mapped = (void *)map.vaddr;
+        }
+    }
+  else
     {
       /* Not directly mappable, probably because the underlying media does
        * not support random access.
@@ -155,15 +174,14 @@ static int file_mmap_(FAR struct file *filep, FAR void *start,
 
       return rammap(filep, length, offset, kernel, mapped);
 #else
-      ferr("ERROR: file_ioctl(FIOC_MMAP) failed: %d\n", ret);
-      return ret;
+      ferr("ERROR: mmap not supported \n");
+      return -ENOSYS;
 #endif
     }
 
-  /* Return the offset address */
+  /* Return */
 
-  *mapped = (FAR void *)(((FAR uint8_t *)addr) + offset);
-  return OK;
+  return ret;
 }
 
 /****************************************************************************
@@ -197,7 +215,7 @@ int file_mmap(FAR struct file *filep, FAR void *start, size_t length,
  *   1. mmap() is the API that is used to support direct access to random
  *     access media under the following very restrictive conditions:
  *
- *     a. The filesystem supports the FIOC_MMAP ioctl command.  Any file
+ *     a. The filesystem implements the mmap file operation.  Any file
  *        system that maps files contiguously on the media should support
  *        this ioctl. (vs. file system that scatter files over the media
  *        in non-contiguous sectors).  As of this writing, ROMFS is the

fs/mmap/fs_munmap.c

@@ -196,7 +196,7 @@ int file_munmap(FAR void *start, size_t length)
  *   1. mmap() is the API that is used to support direct access to random
  *     access media under the following very restrictive conditions:
  *
- *     a. The filesystem supports the FIOC_MMAP ioctl command.  Any file
+ *     a. The filesystem impelements the mmap file operation.  Any file
  *        system that maps files contiguously on the media should support
  *        this ioctl. (vs. file system that scatter files over the media
  *        in non-contiguous sectors).  As of this writing, ROMFS is the