tg3: Allow DMAs to cross cacheline boundaries

By default, the 5717 (and future chips) break up PCIe DMA packets across
cacheline boundaries.  This isn't necessary on x86.  This patch
selectively loosens the restriction.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 16 insertions, 7 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 2d58406deb00..1c1cf68baa94 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -7294,9 +7294,12 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
         if (err)
                 return err;
 
-        if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5784 &&
-            GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5761 &&
-            GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5717) {
+        if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5717) {
+                val = tr32(TG3PCI_DMA_RW_CTRL) &
+                      ~DMA_RWCTRL_DIS_CACHE_ALIGNMENT;
+                tw32(TG3PCI_DMA_RW_CTRL, val | tp->dma_rwctrl);
+        } else if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5784 &&
+                   GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5761) {
                 /* This value is determined during the probe time DMA
                  * engine test, tg3_test_dma.
                  */
@@ -13329,6 +13332,11 @@ static u32 __devinit tg3_calc_dma_bndry(struct tg3 *tp, u32 val)
 #endif
 #endif
 
+        if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5717) {
+                val = goal ? 0 : DMA_RWCTRL_DIS_CACHE_ALIGNMENT;
+                goto out;
+        }
+
         if (!goal)
                 goto out;
 
@@ -13523,7 +13531,7 @@ static int __devinit tg3_test_dma(struct tg3 *tp)
 {
         dma_addr_t buf_dma;
         u32 *buf, saved_dma_rwctrl;
-        int ret;
+        int ret = 0;
 
         buf = pci_alloc_consistent(tp->pdev, TEST_BUFFER_SIZE, &buf_dma);
         if (!buf) {
@@ -13536,6 +13544,9 @@ static int __devinit tg3_test_dma(struct tg3 *tp)
 
         tp->dma_rwctrl = tg3_calc_dma_bndry(tp, tp->dma_rwctrl);
 
+        if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5717)
+                goto out;
+
         if (tp->tg3_flags2 & TG3_FLG2_PCI_EXPRESS) {
                 /* DMA read watermark not used on PCIE */
                 tp->dma_rwctrl |= 0x00180000;
@@ -13608,7 +13619,6 @@ static int __devinit tg3_test_dma(struct tg3 *tp)
         tg3_switch_clocks(tp);
 #endif
 
-        ret = 0;
         if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5700 &&
             GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5701)
                 goto out;
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index e7916bdafab5..42fefa11c052 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -142,8 +142,7 @@
 #define   METAL_REV_B1                   0x01
 #define   METAL_REV_B2                   0x02
 #define TG3PCI_DMA_RW_CTRL              0x0000006c
-#define  DMA_RWCTRL_MIN_DMA              0x000000ff
-#define  DMA_RWCTRL_MIN_DMA_SHIFT        0
+#define  DMA_RWCTRL_DIS_CACHE_ALIGNMENT  0x00000001
 #define  DMA_RWCTRL_READ_BNDRY_MASK      0x00000700
 #define  DMA_RWCTRL_READ_BNDRY_DISAB     0x00000000
 #define  DMA_RWCTRL_READ_BNDRY_16        0x00000100