gve: fix dma sync bug where not all pages synced

The previous commit had a bug where the last page in the memory range
could not be synced. This change fixes the behavior so that all the
required pages are synced.

Fixes: 9cfeeb576d49 ("gve: Fixes DMA synchronization")
Signed-off-by: Adi Suresh <adisuresh@google.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c
index 0a9a7ee..f488943 100644 (file)
--- a/drivers/net/ethernet/google/gve/gve_tx.c
+++ b/drivers/net/ethernet/google/gve/gve_tx.c
@@ -393,12 +393,13 @@ static void gve_tx_fill_seg_desc(union gve_tx_desc *seg_desc,
 static void gve_dma_sync_for_device(struct device *dev, dma_addr_t *page_buses,
                                    u64 iov_offset, u64 iov_len)
 {
+       u64 last_page = (iov_offset + iov_len - 1) / PAGE_SIZE;
+       u64 first_page = iov_offset / PAGE_SIZE;
        dma_addr_t dma;
-       u64 addr;
+       u64 page;
 
-       for (addr = iov_offset; addr < iov_offset + iov_len;
-            addr += PAGE_SIZE) {
-               dma = page_buses[addr / PAGE_SIZE];
+       for (page = first_page; page <= last_page; page++) {
+               dma = page_buses[page];
                dma_sync_single_for_device(dev, dma, PAGE_SIZE, DMA_TO_DEVICE);
        }
 }