driver/net: enic: Try DMA 64 first, then failover to DMA

In servers with more than 1.1 TB of RAM, the existing 40/32 bit DMA
could cause failure as the DMA-able address could go outside the range
addressable using 40/32 bits.

The following patch first tried 64 bit DMA if possible, failover to 32
bit.

Signed-off-by: Sujith Sankar <ssujith@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: Govindarajulu Varadarajan <govindarajulu90@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index 93898baa25dbe43b46678023487424f62b549092..7b756cf9474a90497de9987591c57cabfcc09f2d 100644 (file)
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -2080,11 +2080,11 @@ static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
        pci_set_master(pdev);
 
        /* Query PCI controller on system for DMA addressing
-        * limitation for the device.  Try 40-bit first, and
+        * limitation for the device.  Try 64-bit first, and
         * fail to 32-bit.
         */
 
-       err = pci_set_dma_mask(pdev, DMA_BIT_MASK(40));
+       err = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
        if (err) {
                err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
                if (err) {
@@ -2098,10 +2098,10 @@ static int enic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
                        goto err_out_release_regions;
                }
        } else {
-               err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(40));
+               err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
                if (err) {
                        dev_err(dev, "Unable to obtain %u-bit DMA "
-                               "for consistent allocations, aborting\n", 40);
+                               "for consistent allocations, aborting\n", 64);
                        goto err_out_release_regions;
                }
                using_dac = 1;