vmxnet3: add support for get_coalesce, set_coalesce ethtool operations

The emulation supports a variety of coalescing modes viz. disabled
(no coalescing), adaptive, static (number of packets to batch before
raising an interrupt), rate based (number of interrupts per second).

This patch implements get_coalesce and set_coalesce methods to allow
querying and configuring different coalescing modes.

Signed-off-by: Keyong Sun <sunk@vmware.com>
Signed-off-by: Manoj Tammali <tammalim@vmware.com>
Signed-off-by: Shrikrishna Khare <skhare@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 253 insertions, 1 deletions

diff --git a/drivers/net/vmxnet3/vmxnet3_defs.h b/drivers/net/vmxnet3/vmxnet3_defs.h
index f3b31c2d8abc..274e145ab72a 100644
--- a/drivers/net/vmxnet3/vmxnet3_defs.h
+++ b/drivers/net/vmxnet3/vmxnet3_defs.h
@@ -80,6 +80,7 @@ enum {
         VMXNET3_CMD_LOAD_PLUGIN,
         VMXNET3_CMD_RESERVED2,
         VMXNET3_CMD_RESERVED3,
+        VMXNET3_CMD_SET_COALESCE,
 
         VMXNET3_CMD_FIRST_GET = 0xF00D0000,
         VMXNET3_CMD_GET_QUEUE_STATUS = VMXNET3_CMD_FIRST_GET,
@@ -92,7 +93,8 @@ enum {
         VMXNET3_CMD_GET_DEV_EXTRA_INFO,
         VMXNET3_CMD_GET_CONF_INTR,
         VMXNET3_CMD_GET_RESERVED1,
-        VMXNET3_CMD_GET_TXDATA_DESC_SIZE
+        VMXNET3_CMD_GET_TXDATA_DESC_SIZE,
+        VMXNET3_CMD_GET_COALESCE,
 };
 
 /*
@@ -637,6 +639,35 @@ struct Vmxnet3_SetPolling {
         u8                                      enablePolling;
 };
 
+#define VMXNET3_COAL_STATIC_MAX_DEPTH           128
+#define VMXNET3_COAL_RBC_MIN_RATE               100
+#define VMXNET3_COAL_RBC_MAX_RATE               100000
+
+enum Vmxnet3_CoalesceMode {
+        VMXNET3_COALESCE_DISABLED   = 0,
+        VMXNET3_COALESCE_ADAPT      = 1,
+        VMXNET3_COALESCE_STATIC     = 2,
+        VMXNET3_COALESCE_RBC        = 3
+};
+
+struct Vmxnet3_CoalesceRbc {
+        u32                                     rbc_rate;
+};
+
+struct Vmxnet3_CoalesceStatic {
+        u32                                     tx_depth;
+        u32                                     tx_comp_depth;
+        u32                                     rx_depth;
+};
+
+struct Vmxnet3_CoalesceScheme {
+        enum Vmxnet3_CoalesceMode               coalMode;
+        union {
+                struct Vmxnet3_CoalesceRbc      coalRbc;
+                struct Vmxnet3_CoalesceStatic   coalStatic;
+        } coalPara;
+};
+
 /* If the command data <= 16 bytes, use the shared memory directly.
  * otherwise, use variable length configuration descriptor.
  */
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 6449d2e6d94f..d0bcc1d97e80 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -2491,6 +2491,32 @@ vmxnet3_setup_driver_shared(struct vmxnet3_adapter *adapter)
         /* the rest are already zeroed */
 }
 
+static void
+vmxnet3_init_coalesce(struct vmxnet3_adapter *adapter)
+{
+        struct Vmxnet3_DriverShared *shared = adapter->shared;
+        union Vmxnet3_CmdInfo *cmdInfo = &shared->cu.cmdInfo;
+        unsigned long flags;
+
+        if (!VMXNET3_VERSION_GE_3(adapter))
+                return;
+
+        spin_lock_irqsave(&adapter->cmd_lock, flags);
+        cmdInfo->varConf.confVer = 1;
+        cmdInfo->varConf.confLen =
+                cpu_to_le32(sizeof(*adapter->coal_conf));
+        cmdInfo->varConf.confPA  = cpu_to_le64(adapter->coal_conf_pa);
+
+        if (adapter->default_coal_mode) {
+                VMXNET3_WRITE_BAR1_REG(adapter, VMXNET3_REG_CMD,
+                                       VMXNET3_CMD_GET_COALESCE);
+        } else {
+                VMXNET3_WRITE_BAR1_REG(adapter, VMXNET3_REG_CMD,
+                                       VMXNET3_CMD_SET_COALESCE);
+        }
+
+        spin_unlock_irqrestore(&adapter->cmd_lock, flags);
+}
 
 int
 vmxnet3_activate_dev(struct vmxnet3_adapter *adapter)
@@ -2540,6 +2566,8 @@ vmxnet3_activate_dev(struct vmxnet3_adapter *adapter)
                 goto activate_err;
         }
 
+        vmxnet3_init_coalesce(adapter);
+
         for (i = 0; i < adapter->num_rx_queues; i++) {
                 VMXNET3_WRITE_BAR0_REG(adapter,
                                 VMXNET3_REG_RXPROD + i * VMXNET3_REG_ALIGN,
@@ -3345,6 +3373,22 @@ vmxnet3_probe_device(struct pci_dev *pdev,
                 goto err_ver;
         }
 
+        if (VMXNET3_VERSION_GE_3(adapter)) {
+                adapter->coal_conf =
+                        dma_alloc_coherent(&adapter->pdev->dev,
+                                           sizeof(struct Vmxnet3_CoalesceScheme)
+                                           ,
+                                           &adapter->coal_conf_pa,
+                                           GFP_KERNEL);
+                if (!adapter->coal_conf) {
+                        err = -ENOMEM;
+                        goto err_ver;
+                }
+                memset(adapter->coal_conf, 0, sizeof(*adapter->coal_conf));
+                adapter->coal_conf->coalMode = VMXNET3_COALESCE_DISABLED;
+                adapter->default_coal_mode = true;
+        }
+
         SET_NETDEV_DEV(netdev, &pdev->dev);
         vmxnet3_declare_features(adapter, dma64);
 
@@ -3407,6 +3451,11 @@ vmxnet3_probe_device(struct pci_dev *pdev,
         return 0;
 
 err_register:
+        if (VMXNET3_VERSION_GE_3(adapter)) {
+                dma_free_coherent(&adapter->pdev->dev,
+                                  sizeof(struct Vmxnet3_CoalesceScheme),
+                                  adapter->coal_conf, adapter->coal_conf_pa);
+        }
         vmxnet3_free_intr_resources(adapter);
 err_ver:
         vmxnet3_free_pci_resources(adapter);
@@ -3457,6 +3506,11 @@ vmxnet3_remove_device(struct pci_dev *pdev)
 
         vmxnet3_free_intr_resources(adapter);
         vmxnet3_free_pci_resources(adapter);
+        if (VMXNET3_VERSION_GE_3(adapter)) {
+                dma_free_coherent(&adapter->pdev->dev,
+                                  sizeof(struct Vmxnet3_CoalesceScheme),
+                                  adapter->coal_conf, adapter->coal_conf_pa);
+        }
 #ifdef VMXNET3_RSS
         dma_free_coherent(&adapter->pdev->dev, sizeof(struct UPT1_RSSConf),
                           adapter->rss_conf, adapter->rss_conf_pa);
diff --git a/drivers/net/vmxnet3/vmxnet3_ethtool.c b/drivers/net/vmxnet3/vmxnet3_ethtool.c
index 38f7c7975e1f..aabc6ef366b4 100644
--- a/drivers/net/vmxnet3/vmxnet3_ethtool.c
+++ b/drivers/net/vmxnet3/vmxnet3_ethtool.c
@@ -725,6 +725,162 @@ vmxnet3_set_rss(struct net_device *netdev, const u32 *p, const u8 *key,
 }
 #endif
 
+static int
+vmxnet3_get_coalesce(struct net_device *netdev, struct ethtool_coalesce *ec)
+{
+        struct vmxnet3_adapter *adapter = netdev_priv(netdev);
+
+        if (!VMXNET3_VERSION_GE_3(adapter))
+                return -EOPNOTSUPP;
+
+        switch (adapter->coal_conf->coalMode) {
+        case VMXNET3_COALESCE_DISABLED:
+                /* struct ethtool_coalesce is already initialized to 0 */
+                break;
+        case VMXNET3_COALESCE_ADAPT:
+                ec->use_adaptive_rx_coalesce = true;
+                break;
+        case VMXNET3_COALESCE_STATIC:
+                ec->tx_max_coalesced_frames =
+                        adapter->coal_conf->coalPara.coalStatic.tx_comp_depth;
+                ec->rx_max_coalesced_frames =
+                        adapter->coal_conf->coalPara.coalStatic.rx_depth;
+                break;
+        case VMXNET3_COALESCE_RBC: {
+                u32 rbc_rate;
+
+                rbc_rate = adapter->coal_conf->coalPara.coalRbc.rbc_rate;
+                ec->rx_coalesce_usecs = VMXNET3_COAL_RBC_USECS(rbc_rate);
+        }
+                break;
+        default:
+                return -EOPNOTSUPP;
+        }
+
+        return 0;
+}
+
+static int
+vmxnet3_set_coalesce(struct net_device *netdev, struct ethtool_coalesce *ec)
+{
+        struct vmxnet3_adapter *adapter = netdev_priv(netdev);
+        struct Vmxnet3_DriverShared *shared = adapter->shared;
+        union Vmxnet3_CmdInfo *cmdInfo = &shared->cu.cmdInfo;
+        unsigned long flags;
+
+        if (!VMXNET3_VERSION_GE_3(adapter))
+                return -EOPNOTSUPP;
+
+        if (ec->rx_coalesce_usecs_irq ||
+            ec->rx_max_coalesced_frames_irq ||
+            ec->tx_coalesce_usecs ||
+            ec->tx_coalesce_usecs_irq ||
+            ec->tx_max_coalesced_frames_irq ||
+            ec->stats_block_coalesce_usecs ||
+            ec->use_adaptive_tx_coalesce ||
+            ec->pkt_rate_low ||
+            ec->rx_coalesce_usecs_low ||
+            ec->rx_max_coalesced_frames_low ||
+            ec->tx_coalesce_usecs_low ||
+            ec->tx_max_coalesced_frames_low ||
+            ec->pkt_rate_high ||
+            ec->rx_coalesce_usecs_high ||
+            ec->rx_max_coalesced_frames_high ||
+            ec->tx_coalesce_usecs_high ||
+            ec->tx_max_coalesced_frames_high ||
+            ec->rate_sample_interval) {
+                return -EINVAL;
+        }
+
+        if ((ec->rx_coalesce_usecs == 0) &&
+            (ec->use_adaptive_rx_coalesce == 0) &&
+            (ec->tx_max_coalesced_frames == 0) &&
+            (ec->rx_max_coalesced_frames == 0)) {
+                memset(adapter->coal_conf, 0, sizeof(*adapter->coal_conf));
+                adapter->coal_conf->coalMode = VMXNET3_COALESCE_DISABLED;
+                goto done;
+        }
+
+        if (ec->rx_coalesce_usecs != 0) {
+                u32 rbc_rate;
+
+                if ((ec->use_adaptive_rx_coalesce != 0) ||
+                    (ec->tx_max_coalesced_frames != 0) ||
+                    (ec->rx_max_coalesced_frames != 0)) {
+                        return -EINVAL;
+                }
+
+                rbc_rate = VMXNET3_COAL_RBC_RATE(ec->rx_coalesce_usecs);
+                if (rbc_rate < VMXNET3_COAL_RBC_MIN_RATE ||
+                    rbc_rate > VMXNET3_COAL_RBC_MAX_RATE) {
+                        return -EINVAL;
+                }
+
+                memset(adapter->coal_conf, 0, sizeof(*adapter->coal_conf));
+                adapter->coal_conf->coalMode = VMXNET3_COALESCE_RBC;
+                adapter->coal_conf->coalPara.coalRbc.rbc_rate = rbc_rate;
+                goto done;
+        }
+
+        if (ec->use_adaptive_rx_coalesce != 0) {
+                if ((ec->rx_coalesce_usecs != 0) ||
+                    (ec->tx_max_coalesced_frames != 0) ||
+                    (ec->rx_max_coalesced_frames != 0)) {
+                        return -EINVAL;
+                }
+                memset(adapter->coal_conf, 0, sizeof(*adapter->coal_conf));
+                adapter->coal_conf->coalMode = VMXNET3_COALESCE_ADAPT;
+                goto done;
+        }
+
+        if ((ec->tx_max_coalesced_frames != 0) ||
+            (ec->rx_max_coalesced_frames != 0)) {
+                if ((ec->rx_coalesce_usecs != 0) ||
+                    (ec->use_adaptive_rx_coalesce != 0)) {
+                        return -EINVAL;
+                }
+
+                if ((ec->tx_max_coalesced_frames >
+                    VMXNET3_COAL_STATIC_MAX_DEPTH) ||
+                    (ec->rx_max_coalesced_frames >
+                     VMXNET3_COAL_STATIC_MAX_DEPTH)) {
+                        return -EINVAL;
+                }
+
+                memset(adapter->coal_conf, 0, sizeof(*adapter->coal_conf));
+                adapter->coal_conf->coalMode = VMXNET3_COALESCE_STATIC;
+
+                adapter->coal_conf->coalPara.coalStatic.tx_comp_depth =
+                        (ec->tx_max_coalesced_frames ?
+                         ec->tx_max_coalesced_frames :
+                         VMXNET3_COAL_STATIC_DEFAULT_DEPTH);
+
+                adapter->coal_conf->coalPara.coalStatic.rx_depth =
+                        (ec->rx_max_coalesced_frames ?
+                         ec->rx_max_coalesced_frames :
+                         VMXNET3_COAL_STATIC_DEFAULT_DEPTH);
+
+                adapter->coal_conf->coalPara.coalStatic.tx_depth =
+                         VMXNET3_COAL_STATIC_DEFAULT_DEPTH;
+                goto done;
+        }
+
+done:
+        adapter->default_coal_mode = false;
+        if (netif_running(netdev)) {
+                spin_lock_irqsave(&adapter->cmd_lock, flags);
+                cmdInfo->varConf.confVer = 1;
+                cmdInfo->varConf.confLen =
+                        cpu_to_le32(sizeof(*adapter->coal_conf));
+                cmdInfo->varConf.confPA  = cpu_to_le64(adapter->coal_conf_pa);
+                VMXNET3_WRITE_BAR1_REG(adapter, VMXNET3_REG_CMD,
+                                       VMXNET3_CMD_SET_COALESCE);
+                spin_unlock_irqrestore(&adapter->cmd_lock, flags);
+        }
+
+        return 0;
+}
+
 static const struct ethtool_ops vmxnet3_ethtool_ops = {
         .get_settings      = vmxnet3_get_settings,
         .get_drvinfo       = vmxnet3_get_drvinfo,
@@ -733,6 +889,8 @@ static const struct ethtool_ops vmxnet3_ethtool_ops = {
         .get_wol           = vmxnet3_get_wol,
         .set_wol           = vmxnet3_set_wol,
         .get_link          = ethtool_op_get_link,
+        .get_coalesce      = vmxnet3_get_coalesce,
+        .set_coalesce      = vmxnet3_set_coalesce,
         .get_strings       = vmxnet3_get_strings,
         .get_sset_count    = vmxnet3_get_sset_count,
         .get_ethtool_stats = vmxnet3_get_ethtool_stats,
diff --git a/drivers/net/vmxnet3/vmxnet3_int.h b/drivers/net/vmxnet3/vmxnet3_int.h
index c46bf09ade5a..63df4f2a743d 100644
--- a/drivers/net/vmxnet3/vmxnet3_int.h
+++ b/drivers/net/vmxnet3/vmxnet3_int.h
@@ -358,6 +358,7 @@ struct vmxnet3_adapter {
         int             rx_buf_per_pkt;  /* only apply to the 1st ring */
         dma_addr_t                      shared_pa;
         dma_addr_t queue_desc_pa;
+        dma_addr_t coal_conf_pa;
 
         /* Wake-on-LAN */
         u32     wol;
@@ -384,6 +385,9 @@ struct vmxnet3_adapter {
 
         int share_intr;
 
+        struct Vmxnet3_CoalesceScheme *coal_conf;
+        bool   default_coal_mode;
+
         dma_addr_t adapter_pa;
         dma_addr_t pm_conf_pa;
         dma_addr_t rss_conf_pa;
@@ -429,6 +433,11 @@ struct vmxnet3_adapter {
         (rqID >= 2 * adapter->num_rx_queues &&          \
         rqID < 3 * adapter->num_rx_queues)              \
 
+#define VMXNET3_COAL_STATIC_DEFAULT_DEPTH       64
+
+#define VMXNET3_COAL_RBC_RATE(usecs) (1000000 / usecs)
+#define VMXNET3_COAL_RBC_USECS(rbc_rate) (1000000 / rbc_rate)
+
 int
 vmxnet3_quiesce_dev(struct vmxnet3_adapter *adapter);