cxgb4: Add T5 write combining support
This patch implements a low latency Write Combining (aka Write Coalescing) work
request path. PCIE maps User Space Doorbell BAR2 region writes to the new
interface to SGE. SGE pulls a new message from PCIE new interface and if its a
coalesced write work request then pushes it for processing. This patch copies
coalesced work request to memory mapped BAR2 space.
Signed-off-by: Santosh Rastapur <santosh@chelsio.com>
Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index 3d6d23a..ce1451c 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -1327,6 +1327,8 @@
"VLANinsertions ",
"GROpackets ",
"GROmerged ",
+ "WriteCoalSuccess ",
+ "WriteCoalFail ",
};
static int get_sset_count(struct net_device *dev, int sset)
@@ -1422,11 +1424,25 @@
{
struct port_info *pi = netdev_priv(dev);
struct adapter *adapter = pi->adapter;
+ u32 val1, val2;
t4_get_port_stats(adapter, pi->tx_chan, (struct port_stats *)data);
data += sizeof(struct port_stats) / sizeof(u64);
collect_sge_port_stats(adapter, pi, (struct queue_port_stats *)data);
+ data += sizeof(struct queue_port_stats) / sizeof(u64);
+ if (!is_t4(adapter->chip)) {
+ t4_write_reg(adapter, SGE_STAT_CFG, STATSOURCE_T5(7));
+ val1 = t4_read_reg(adapter, SGE_STAT_TOTAL);
+ val2 = t4_read_reg(adapter, SGE_STAT_MATCH);
+ *data = val1 - val2;
+ data++;
+ *data = val2;
+ data++;
+ } else {
+ memset(data, 0, 2 * sizeof(u64));
+ *data += 2;
+ }
}
/*
@@ -5337,10 +5353,11 @@
#define TSO_FLAGS (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_TSO_ECN)
#define VLAN_FEAT (NETIF_F_SG | NETIF_F_IP_CSUM | TSO_FLAGS | \
NETIF_F_IPV6_CSUM | NETIF_F_HIGHDMA)
+#define SEGMENT_SIZE 128
static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
{
- int func, i, err;
+ int func, i, err, s_qpp, qpp, num_seg;
struct port_info *pi;
bool highdma = false;
struct adapter *adapter = NULL;
@@ -5420,7 +5437,34 @@
err = t4_prep_adapter(adapter);
if (err)
- goto out_unmap_bar;
+ goto out_unmap_bar0;
+
+ if (!is_t4(adapter->chip)) {
+ s_qpp = QUEUESPERPAGEPF1 * adapter->fn;
+ qpp = 1 << QUEUESPERPAGEPF0_GET(t4_read_reg(adapter,
+ SGE_EGRESS_QUEUES_PER_PAGE_PF) >> s_qpp);
+ num_seg = PAGE_SIZE / SEGMENT_SIZE;
+
+ /* Each segment size is 128B. Write coalescing is enabled only
+ * when SGE_EGRESS_QUEUES_PER_PAGE_PF reg value for the
+ * queue is less no of segments that can be accommodated in
+ * a page size.
+ */
+ if (qpp > num_seg) {
+ dev_err(&pdev->dev,
+ "Incorrect number of egress queues per page\n");
+ err = -EINVAL;
+ goto out_unmap_bar0;
+ }
+ adapter->bar2 = ioremap_wc(pci_resource_start(pdev, 2),
+ pci_resource_len(pdev, 2));
+ if (!adapter->bar2) {
+ dev_err(&pdev->dev, "cannot map device bar2 region\n");
+ err = -ENOMEM;
+ goto out_unmap_bar0;
+ }
+ }
+
setup_memwin(adapter);
err = adap_init0(adapter);
setup_memwin_rdma(adapter);
@@ -5552,6 +5596,9 @@
out_free_dev:
free_some_resources(adapter);
out_unmap_bar:
+ if (!is_t4(adapter->chip))
+ iounmap(adapter->bar2);
+ out_unmap_bar0:
iounmap(adapter->regs);
out_free_adapter:
kfree(adapter);
@@ -5602,6 +5649,8 @@
free_some_resources(adapter);
iounmap(adapter->regs);
+ if (!is_t4(adapter->chip))
+ iounmap(adapter->bar2);
kfree(adapter);
pci_disable_pcie_error_reporting(pdev);
pci_disable_device(pdev);