net: ipa: use upper_32_bits()

Use upper_32_bits() to extract the high-order 32 bits of a DMA
address.  This avoids doing a 32-position shift on a DMA address
if it happens not to be 64 bits wide.  Use lower_32_bits() to
extract the low-order 32 bits (because that's what it's for).

Suggested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ipa/gsi.c b/drivers/net/ipa/gsi.c
index 2119367..7f3e338 100644 (file)
--- a/drivers/net/ipa/gsi.c
+++ b/drivers/net/ipa/gsi.c
@@ -351,7 +351,7 @@ void *gsi_ring_virt(struct gsi_ring *ring, u32 index)
 /* Return the 32-bit DMA address associated with a ring index */
 static u32 gsi_ring_addr(struct gsi_ring *ring, u32 index)
 {
-       return (ring->addr & GENMASK(31, 0)) + index * GSI_RING_ELEMENT_SIZE;
+       return lower_32_bits(ring->addr) + index * GSI_RING_ELEMENT_SIZE;
 }
 
 /* Return the ring index of a 32-bit ring offset */
@@ -708,10 +708,9 @@ static void gsi_evt_ring_program(struct gsi *gsi, u32 evt_ring_id)
         * high-order 32 bits of the address of the event ring,
         * respectively.
         */
-       val = evt_ring->ring.addr & GENMASK(31, 0);
+       val = lower_32_bits(evt_ring->ring.addr);
        iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_2_OFFSET(evt_ring_id));
-
-       val = evt_ring->ring.addr >> 32;
+       val = upper_32_bits(evt_ring->ring.addr);
        iowrite32(val, gsi->virt + GSI_EV_CH_E_CNTXT_3_OFFSET(evt_ring_id));
 
        /* Enable interrupt moderation by setting the moderation delay */
@@ -816,10 +815,9 @@ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell)
         * high-order 32 bits of the address of the channel ring,
         * respectively.
         */
-       val = channel->tre_ring.addr & GENMASK(31, 0);
+       val = lower_32_bits(channel->tre_ring.addr);
        iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_2_OFFSET(channel_id));
-
-       val = channel->tre_ring.addr >> 32;
+       val = upper_32_bits(channel->tre_ring.addr);
        iowrite32(val, gsi->virt + GSI_CH_C_CNTXT_3_OFFSET(channel_id));
 
        /* Command channel gets low weighted round-robin priority */
@@ -1365,7 +1363,7 @@ static struct gsi_trans *gsi_event_trans(struct gsi_channel *channel,
        u32 tre_index;
 
        /* Event xfer_ptr records the TRE it's associated with */
-       tre_offset = le64_to_cpu(event->xfer_ptr) & GENMASK(31, 0);
+       tre_offset = lower_32_bits(le64_to_cpu(event->xfer_ptr));
        tre_index = gsi_ring_index(&channel->tre_ring, tre_offset);
 
        return gsi_channel_trans_mapped(channel, tre_index);