cpukit/flashdev: Clarify interface and update consumers

This clarifies the flashdev out of band read and write interfaces and
updates any consumers of those interfaces. This was partially refactored
at one point and the refactoring didn't extend to the consumers as it
should have.

Closes #5652

bsps/shared/dev/flash/flash_sim_flashdev.c

@@ -282,9 +282,7 @@ static int flash_sim_oob_read(
   uint64_t start_time = rtems_clock_get_uptime_nanoseconds();
   struct nand_priv_data *flash_driver = (struct nand_priv_data *) flash->driver;
   struct flash_sim_flashdev_attributes *attr = &flash_driver->attr;
-  uint32_t page_index = offset / attr->page_size_bytes;
-  uint32_t oob_offset = page_index * attr->page_oob_bytes;
-  unsigned char *chunk = &flash_driver->oob[ oob_offset ];
+  unsigned char *chunk = &flash_driver->oob[ offset ];
 
   memcpy( buffer, chunk, size_of_buffer );
 
@@ -303,9 +301,7 @@ static int flash_sim_oob_write(
   uint64_t start_time = rtems_clock_get_uptime_nanoseconds();
   struct nand_priv_data *flash_driver = (struct nand_priv_data *) flash->driver;
   struct flash_sim_flashdev_attributes *attr = &flash_driver->attr;
-  uint32_t page_index = offset / attr->page_size_bytes;
-  uint32_t oob_offset = page_index * attr->page_oob_bytes;
-  unsigned char *chunk = &flash_driver->oob[ oob_offset ];
+  unsigned char *chunk = &flash_driver->oob[ offset ];
   const uint8_t *cbuff = buffer;
   size_t i;
 

bsps/shared/dev/flash/jffs2_flashdev.c

@@ -141,6 +141,36 @@ static int do_block_mark_bad(
   return ioctl(fd, RTEMS_FLASHDEV_IOCTL_REGION_SECTOR_MARK_BAD, &o_offset);
 }
 
+static uint32_t do_get_oob_size(
+  rtems_jffs2_flash_control *super
+)
+{
+  int rv;
+  int fd = fileno(get_flash_control( super )->handle);
+  size_t bytes_per_page = 0;
+
+  rv = ioctl(fd, RTEMS_FLASHDEV_IOCTL_OOB_BYTES_PER_PAGE, &bytes_per_page);
+
+  if (rv != 0) {
+    return 0;
+  }
+
+  return bytes_per_page;
+}
+
+static uint32_t page_offset_to_oob_offset(
+  rtems_jffs2_flash_control *super,
+  uint32_t page_offset
+)
+{
+  uint32_t page_size = super->write_size;
+  uint32_t oob_bytes_per_page = do_get_oob_size(super);
+  uint32_t page_index = page_offset / page_size;
+
+  /* JFFS2 only makes these requests on even page boundaries */
+  return page_index * oob_bytes_per_page;
+}
+
 static int do_read_oob(
   rtems_jffs2_flash_control *super,
   uint32_t offset,
@@ -151,7 +181,7 @@ static int do_read_oob(
   int fd = fileno(get_flash_control( super )->handle);
   rtems_flashdev_ioctl_oob_rw_info args;
 
-  args.offset = offset;
+  args.offset = page_offset_to_oob_offset(super, offset);
   args.count = ooblen;
   args.buffer = oobbuf;
 
@@ -168,30 +198,13 @@ static int do_write_oob(
   int fd = fileno(get_flash_control( super )->handle);
   rtems_flashdev_ioctl_oob_rw_info args;
 
-  args.offset = offset;
+  args.offset = page_offset_to_oob_offset(super, offset);
   args.count = ooblen;
   args.buffer = oobbuf;
 
   return ioctl(fd, RTEMS_FLASHDEV_IOCTL_REGION_OOB_WRITE, &args);
 }
 
-static uint32_t do_get_oob_size(
-  rtems_jffs2_flash_control *super
-)
-{
-  int rv;
-  int fd = fileno(get_flash_control( super )->handle);
-  size_t bytes_per_page = 0;
-
-  rv = ioctl(fd, RTEMS_FLASHDEV_IOCTL_OOB_BYTES_PER_PAGE, &bytes_per_page);
-
-  if (rv != 0) {
-    return 0;
-  }
-
-  return bytes_per_page;
-}
-
 static void do_destroy( rtems_jffs2_flash_control *super )
 {
   flash_control *self = get_flash_control( super );

bsps/shared/dev/flash/xnandpsu_flashdev.c

@@ -331,8 +331,8 @@ static int xnandpsu_oob_read(
     return -EIO;
   }
 
-  /* Get page index */
-  uint32_t PageIndex = offset / nandpsu->Geometry.BytesPerPage;
+  /* Get page index, offset is in oob-space */
+  uint32_t PageIndex = offset / nandpsu->Geometry.SpareBytesPerPage;
 
   spare_bytes = rtems_malloc( SpareBytesPerPage );
   if ( spare_bytes == NULL ) {
@@ -402,8 +402,8 @@ static int xnandpsu_oob_write(
     memcpy( buffer, oobbuf, ooblen );
   }
 
-  /* Get page index */
-  uint32_t PageIndex = offset / nandpsu->Geometry.BytesPerPage;
+  /* Get page index, offset is in oob-space */
+  uint32_t PageIndex = offset / nandpsu->Geometry.SpareBytesPerPage;
 
   sc = XNandPsu_WriteSpareBytes( nandpsu, PageIndex, buffer );
   free( spare_bytes );

cpukit/dev/flash/flashdev.c

@@ -1100,6 +1100,10 @@ static int get_region_first_page_index(
   return 0;
 }
 
+/*
+ * This converts a region-relative OOB space offset to a device-global OOB
+ * space offset
+ */
 static int rtems_flashdev_get_region_oob_addr(
   rtems_flashdev *flash,
   rtems_libio_t *iop,

cpukit/include/dev/flash/flashdev.h

@@ -337,7 +337,7 @@ typedef struct rtems_flashdev_ioctl_sector_health {
  */
 typedef struct rtems_flashdev_ioctl_oob_rw_info {
   /**
-   * @brief Offset at which to operate.
+   * @brief Offset into contiguous OOB space at which to operate.
    */
   off_t offset;
 
@@ -552,6 +552,9 @@ struct rtems_flashdev {
    * @brief Call to the device driver to read the out of band space of the flash
    * device.
    *
+   * The offset specified is relative to a contiguous out of band space, not to
+   * normal data space.
+   *
    * @param[in] flash Pointer to flash device.
    * @param[in] offset Address to read from.
    * @param[in] count Number of bytes to read.
@@ -571,6 +574,9 @@ struct rtems_flashdev {
    * @brief Call to the device driver to write to the out of band space of the
    * flash device.
    *
+   * The offset specified is relative to a contiguous out of band space, not to
+   * normal data space.
+   *
    * @param[in] flash Pointer to flash device.
    * @param[in] offset Address to write to.
    * @param[in] count Number of bytes to read.