This commit adds a new function arch_invalidate_dcache_by_addr(). It takes the same parameters as arch_invalidate_dcache(), but performs invalidation of only the lines in cache that need to be invalidated. This new function could be used as a a direct replacement for arch_invalidate_dcache().

The user of this invalidation are mmcsd_sdio currently.  The mmcsd_sdio driver makes calls for dcache invalidation through the chip specific architecture function SDIO_DMARECVSETUP(). I changed the arch/arm/stm32f7 chips to use arch_invalidate_dcache_by_addr() instead of arch_invalidate_dcache().

This commit includes additional changes to mmcsd_sdio.c.  I created SDIO_DMADELYDINVLDT() (DMA delayed invalidate) to invalidate store-into mode dcaches after the DMA transfer.  I have been using SDIO_DMADELYDINVLDT() for several weeks now and it has fixed the problems that I previously reported regarding non-cache aligned buffer invalidation errors (for my store-through dcache). However, it does not permit use of unaligned DMA buffers for store-into mode dcaches.

SDIO_DMADELYDINVLDT() is a NoOp unless the chip specific Kconfig file selects CONFIG_ARCH_HAVE_SDIO_DELAYED_INVLDT. I have modified all the stm32f7 chips to select it.

drivers/mmcsd/mmcsd_sdio.c

@@ -3,6 +3,7 @@
  *
  *   Copyright (C) 2009-2013, 2016-2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *           Bob Feretich <bob.fereich@rafresearch.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -1408,6 +1409,9 @@ static ssize_t mmcsd_readsingle(FAR struct mmcsd_state_s *priv,
 
   ret = mmcsd_eventwait(priv, SDIOWAIT_TIMEOUT | SDIOWAIT_ERROR,
                         MMCSD_BLOCK_RDATADELAY);
+#ifdef CONFIG_SDIO_DMA
+  SDIO_DMADELYDINVLDT(priv->dev, buffer, priv->blocksize);
+#endif
   if (ret != OK)
     {
       ferr("ERROR: CMD17 transfer failed: %d\n", ret);
@@ -1550,6 +1554,10 @@ static ssize_t mmcsd_readmultiple(FAR struct mmcsd_state_s *priv,
   /* Send STOP_TRANSMISSION */
 
   ret = mmcsd_stoptransmission(priv);
+#ifdef CONFIG_SDIO_DMA
+  SDIO_DMADELYDINVLDT(priv->dev, buffer, priv->blocksize * nblocks);
+#endif
+
   if (ret != OK)
     {
       ferr("ERROR: mmcsd_stoptransmission failed: %d\n", ret);
@@ -1794,6 +1802,8 @@ static ssize_t mmcsd_writesingle(FAR struct mmcsd_state_s *priv,
  *
  * Description:
  *   Write multiple, contiguous blocks of data to the physical device.
+ *   This function expects that the data to be written is contained in
+ *   one large buffer that is pointed to by buffer.
  *
  ****************************************************************************/