V4L/DVB (5592): DMA: Correctly free resources on error, sync PCI streamed data

I added saa7146_vmalloc_destroy_pgtable() which frees the resources
allocated by saa7146_vmalloc_build_pgtable() and updated the callers in
budget-core.c and av7110.c. I have also been through the updated
functions and updated the error paths to ensure they free all allocated
resources on error.
I also realised that there are other callers to saa7146_pgtable_free()
which did not have any sg DMA mapped so it seems wrong to add the
pci_unmap_sg() into that function. Instead I created
saa7146_vmalloc_destroy_pgtable() to do this.
Also included in this patch are the previous fixes for pci_unmap_sg()
and syncing the PCI streamed data to work with a SWIOTLB and match the
requirements documented in DMA-API.txt.

Signed-off-by: Jon Burgess <jburgess777@googlemail.com>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/media/saa7146.h b/include/media/saa7146.h
index 796bcf151a3a..d3f4f5a38214 100644
--- a/include/media/saa7146.h
+++ b/include/media/saa7146.h
@@ -58,6 +58,7 @@ struct saa7146_pgtable {
         unsigned long   offset;
         /* used for custom pagetables (used for example by budget dvb cards) */
         struct scatterlist *slist;
+        int             nents;
 };
 
 struct saa7146_pci_extension_data {
@@ -157,6 +158,7 @@ int saa7146_pgtable_alloc(struct pci_dev *pci, struct saa7146_pgtable *pt);
 void saa7146_pgtable_free(struct pci_dev *pci, struct saa7146_pgtable *pt);
 int saa7146_pgtable_build_single(struct pci_dev *pci, struct saa7146_pgtable *pt, struct scatterlist *list, int length );
 char *saa7146_vmalloc_build_pgtable(struct pci_dev *pci, long length, struct saa7146_pgtable *pt);
+void saa7146_vfree_destroy_pgtable(struct pci_dev *pci, char *mem, struct saa7146_pgtable *pt);
 void saa7146_setgpio(struct saa7146_dev *dev, int port, u32 data);
 int saa7146_wait_for_debi_done(struct saa7146_dev *dev, int nobusyloop);