myri10ge: add Direct Cache Access support

Add I/O AT DCA (Direct Cache Access) support.

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Andrew Gallatin <gallatin@myri.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 145 insertions, 1 deletions

diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index eddcee326f06..93007d38df57 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -49,6 +49,7 @@
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>
 #include <linux/inet_lro.h>
+#include <linux/dca.h>
 #include <linux/ip.h>
 #include <linux/inet.h>
 #include <linux/in.h>
@@ -185,6 +186,11 @@ struct myri10ge_slice_state {
         dma_addr_t fw_stats_bus;
         int watchdog_tx_done;
         int watchdog_tx_req;
+#ifdef CONFIG_DCA
+        int cached_dca_tag;
+        int cpu;
+        __be32 __iomem *dca_tag;
+#endif
         char irq_desc[32];
 };
 
@@ -212,6 +218,9 @@ struct myri10ge_priv {
         int msi_enabled;
         int msix_enabled;
         struct msix_entry *msix_vectors;
+#ifdef CONFIG_DCA
+        int dca_enabled;
+#endif
         u32 link_state;
         unsigned int rdma_tags_available;
         int intr_coal_delay;
@@ -335,6 +344,10 @@ static int myri10ge_rss_hash = MXGEFW_RSS_HASH_TYPE_SRC_PORT;
 module_param(myri10ge_rss_hash, int, S_IRUGO);
 MODULE_PARM_DESC(myri10ge_rss_hash, "Type of RSS hashing to do");
 
+static int myri10ge_dca = 1;
+module_param(myri10ge_dca, int, S_IRUGO);
+MODULE_PARM_DESC(myri10ge_dca, "Enable DCA if possible");
+
 #define MYRI10GE_FW_OFFSET 1024*1024
 #define MYRI10GE_HIGHPART_TO_U32(X) \
 (sizeof (X) == 8) ? ((u32)((u64)(X) >> 32)) : (0)
@@ -878,6 +891,9 @@ static int myri10ge_reset(struct myri10ge_priv *mgp)
         struct myri10ge_slice_state *ss;
         int i, status;
         size_t bytes;
+#ifdef CONFIG_DCA
+        unsigned long dca_tag_off;
+#endif
 
         /* try to send a reset command to the card to see if it
          * is alive */
@@ -970,6 +986,20 @@ static int myri10ge_reset(struct myri10ge_priv *mgp)
         }
         put_be32(htonl(mgp->intr_coal_delay), mgp->intr_coal_delay_ptr);
 
+#ifdef CONFIG_DCA
+        status = myri10ge_send_cmd(mgp, MXGEFW_CMD_GET_DCA_OFFSET, &cmd, 0);
+        dca_tag_off = cmd.data0;
+        for (i = 0; i < mgp->num_slices; i++) {
+                ss = &mgp->ss[i];
+                if (status == 0) {
+                        ss->dca_tag = (__iomem __be32 *)
+                            (mgp->sram + dca_tag_off + 4 * i);
+                } else {
+                        ss->dca_tag = NULL;
+                }
+        }
+#endif                          /* CONFIG_DCA */
+
         /* reset mcp/driver shared state back to 0 */
 
         mgp->link_changes = 0;
@@ -995,6 +1025,77 @@ static int myri10ge_reset(struct myri10ge_priv *mgp)
         return status;
 }
 
+#ifdef CONFIG_DCA
+static void
+myri10ge_write_dca(struct myri10ge_slice_state *ss, int cpu, int tag)
+{
+        ss->cpu = cpu;
+        ss->cached_dca_tag = tag;
+        put_be32(htonl(tag), ss->dca_tag);
+}
+
+static inline void myri10ge_update_dca(struct myri10ge_slice_state *ss)
+{
+        int cpu = get_cpu();
+        int tag;
+
+        if (cpu != ss->cpu) {
+                tag = dca_get_tag(cpu);
+                if (ss->cached_dca_tag != tag)
+                        myri10ge_write_dca(ss, cpu, tag);
+        }
+        put_cpu();
+}
+
+static void myri10ge_setup_dca(struct myri10ge_priv *mgp)
+{
+        int err, i;
+        struct pci_dev *pdev = mgp->pdev;
+
+        if (mgp->ss[0].dca_tag == NULL || mgp->dca_enabled)
+                return;
+        if (!myri10ge_dca) {
+                dev_err(&pdev->dev, "dca disabled by administrator\n");
+                return;
+        }
+        err = dca_add_requester(&pdev->dev);
+        if (err) {
+                dev_err(&pdev->dev,
+                        "dca_add_requester() failed, err=%d\n", err);
+                return;
+        }
+        mgp->dca_enabled = 1;
+        for (i = 0; i < mgp->num_slices; i++)
+                myri10ge_write_dca(&mgp->ss[i], -1, 0);
+}
+
+static void myri10ge_teardown_dca(struct myri10ge_priv *mgp)
+{
+        struct pci_dev *pdev = mgp->pdev;
+        int err;
+
+        if (!mgp->dca_enabled)
+                return;
+        mgp->dca_enabled = 0;
+        err = dca_remove_requester(&pdev->dev);
+}
+
+static int myri10ge_notify_dca_device(struct device *dev, void *data)
+{
+        struct myri10ge_priv *mgp;
+        unsigned long event;
+
+        mgp = dev_get_drvdata(dev);
+        event = *(unsigned long *)data;
+
+        if (event == DCA_PROVIDER_ADD)
+                myri10ge_setup_dca(mgp);
+        else if (event == DCA_PROVIDER_REMOVE)
+                myri10ge_teardown_dca(mgp);
+        return 0;
+}
+#endif                          /* CONFIG_DCA */
+
 static inline void
 myri10ge_submit_8rx(struct mcp_kreq_ether_recv __iomem * dst,
                     struct mcp_kreq_ether_recv *src)
@@ -1362,6 +1463,11 @@ static int myri10ge_poll(struct napi_struct *napi, int budget)
         struct net_device *netdev = ss->mgp->dev;
         int work_done;
 
+#ifdef CONFIG_DCA
+        if (ss->mgp->dca_enabled)
+                myri10ge_update_dca(ss);
+#endif
+
         /* process as many rx events as NAPI will allow */
         work_done = myri10ge_clean_rx_done(ss, budget);
 
@@ -1586,6 +1692,9 @@ static const char myri10ge_gstrings_main_stats[][ETH_GSTRING_LEN] = {
         "tx_boundary", "WC", "irq", "MSI", "MSIX",
         "read_dma_bw_MBs", "write_dma_bw_MBs", "read_write_dma_bw_MBs",
         "serial_number", "watchdog_resets",
+#ifdef CONFIG_DCA
+        "dca_capable", "dca_enabled",
+#endif
         "link_changes", "link_up", "dropped_link_overflow",
         "dropped_link_error_or_filtered",
         "dropped_pause", "dropped_bad_phy", "dropped_bad_crc32",
@@ -1662,6 +1771,10 @@ myri10ge_get_ethtool_stats(struct net_device *netdev,
         data[i++] = (unsigned int)mgp->read_write_dma;
         data[i++] = (unsigned int)mgp->serial_number;
         data[i++] = (unsigned int)mgp->watchdog_resets;
+#ifdef CONFIG_DCA
+        data[i++] = (unsigned int)(mgp->ss[0].dca_tag != NULL);
+        data[i++] = (unsigned int)(mgp->dca_enabled);
+#endif
         data[i++] = (unsigned int)mgp->link_changes;
 
         /* firmware stats are useful only in the first slice */
@@ -3687,7 +3800,9 @@ static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
                 dev_err(&pdev->dev, "failed reset\n");
                 goto abort_with_slices;
         }
-
+#ifdef CONFIG_DCA
+        myri10ge_setup_dca(mgp);
+#endif
         pci_set_drvdata(pdev, mgp);
         if ((myri10ge_initial_mtu + ETH_HLEN) > MYRI10GE_MAX_ETHER_MTU)
                 myri10ge_initial_mtu = MYRI10GE_MAX_ETHER_MTU - ETH_HLEN;
@@ -3788,6 +3903,9 @@ static void myri10ge_remove(struct pci_dev *pdev)
         netdev = mgp->dev;
         unregister_netdev(netdev);
 
+#ifdef CONFIG_DCA
+        myri10ge_teardown_dca(mgp);
+#endif
         myri10ge_dummy_rdma(mgp, 0);
 
         /* avoid a memory leak */
@@ -3830,6 +3948,26 @@ static struct pci_driver myri10ge_driver = {
 #endif
 };
 
+#ifdef CONFIG_DCA
+static int
+myri10ge_notify_dca(struct notifier_block *nb, unsigned long event, void *p)
+{
+        int err = driver_for_each_device(&myri10ge_driver.driver,
+                                         NULL, &event,
+                                         myri10ge_notify_dca_device);
+
+        if (err)
+                return NOTIFY_BAD;
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block myri10ge_dca_notifier = {
+        .notifier_call = myri10ge_notify_dca,
+        .next = NULL,
+        .priority = 0,
+};
+#endif                          /* CONFIG_DCA */
+
 static __init int myri10ge_init_module(void)
 {
         printk(KERN_INFO "%s: Version %s\n", myri10ge_driver.name,
@@ -3842,6 +3980,9 @@ static __init int myri10ge_init_module(void)
                        myri10ge_driver.name, myri10ge_rss_hash);
                 myri10ge_rss_hash = MXGEFW_RSS_HASH_TYPE_SRC_PORT;
         }
+#ifdef CONFIG_DCA
+        dca_register_notify(&myri10ge_dca_notifier);
+#endif
 
         return pci_register_driver(&myri10ge_driver);
 }
@@ -3850,6 +3991,9 @@ module_init(myri10ge_init_module);
 
 static __exit void myri10ge_cleanup_module(void)
 {
+#ifdef CONFIG_DCA
+        dca_unregister_notify(&myri10ge_dca_notifier);
+#endif
         pci_unregister_driver(&myri10ge_driver);
 }