Flush caches on DMA memory.

* grub-core/kern/mips/cache.S (grub_arch_sync_dma_caches): New function.
	* grub-core/bus/pci.c (grub_memalign_dma32): Flush caches.
	(grub_dma_free): Likewise.
	* include/grub/cache.h (grub_arch_sync_dma_caches): New declaration.

grub-core/bus/pci.c

@@ -20,6 +20,8 @@
 #include <grub/dl.h>
 #include <grub/pci.h>
 #include <grub/mm.h>
+#include <grub/mm_private.h>
+#include <grub/cache.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -28,12 +30,19 @@ GRUB_MOD_LICENSE ("GPLv3+");
 struct grub_pci_dma_chunk *
 grub_memalign_dma32 (grub_size_t align, grub_size_t size)
 {
-  return grub_memalign (align, size);
+  void *ret = grub_memalign (align, size);
+  if (!ret)
+    return 0;
+  grub_arch_sync_dma_caches (ret, size);
+  return ret;
 }
 
+/* FIXME: evil.  */
 void
 grub_dma_free (struct grub_pci_dma_chunk *ch)
 {
+  grub_size_t size = (((struct grub_mm_header *) ch) - 1)->size * GRUB_MM_ALIGN;
+  grub_arch_sync_dma_caches (ch, size);
   grub_free (ch);
 }
 /* #endif */