ethtool: add infrastructure for centralized checking of coalescing parameters

Linux supports 22 different interrupt coalescing parameters.
No driver implements them all. Some drivers just ignore the
ones they don't support, while others have to carry a long
list of checks to reject unsupported settings.

To simplify the drivers add the ability to specify inside
ethtool_ops which parameters are supported and let the core
reject attempts to set any other one.

This commit makes the mechanism an opt-in, only drivers which
set ethtool_opts->coalesce_types to a non-zero value will have
the checks enforced.

The same mask is used for global and per queue settings.

v3: - move the (temporary) check if driver defines types
      earlier (Michal)
    - rename used_types -> nonzero_params, and
      coalesce_types -> supported_coalesce_params (Alex)
    - use EOPNOTSUPP instead of EINVAL (Andrew, Michal)

Leaving the long series of ifs for now, it seems nice to
be able to grep for the field and flag names. This will
probably have to be revisited once netlink support lands.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 66 insertions, 0 deletions

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index f2fe8e5896dc..b2684ffa26de 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1544,6 +1544,64 @@ static noinline_for_stack int ethtool_get_coalesce(struct net_device *dev,
 	return 0;
 }
 
+static bool
+ethtool_set_coalesce_supported(struct net_device *dev,
+			       struct ethtool_coalesce *coalesce)
+{
+	u32 supported_params = dev->ethtool_ops->supported_coalesce_params;
+	u32 nonzero_params = 0;
+
+	if (!supported_params)
+		return true;
+
+	if (coalesce->rx_coalesce_usecs)
+		nonzero_params |= ETHTOOL_COALESCE_RX_USECS;
+	if (coalesce->rx_max_coalesced_frames)
+		nonzero_params |= ETHTOOL_COALESCE_RX_MAX_FRAMES;
+	if (coalesce->rx_coalesce_usecs_irq)
+		nonzero_params |= ETHTOOL_COALESCE_RX_USECS_IRQ;
+	if (coalesce->rx_max_coalesced_frames_irq)
+		nonzero_params |= ETHTOOL_COALESCE_RX_MAX_FRAMES_IRQ;
+	if (coalesce->tx_coalesce_usecs)
+		nonzero_params |= ETHTOOL_COALESCE_TX_USECS;
+	if (coalesce->tx_max_coalesced_frames)
+		nonzero_params |= ETHTOOL_COALESCE_TX_MAX_FRAMES;
+	if (coalesce->tx_coalesce_usecs_irq)
+		nonzero_params |= ETHTOOL_COALESCE_TX_USECS_IRQ;
+	if (coalesce->tx_max_coalesced_frames_irq)
+		nonzero_params |= ETHTOOL_COALESCE_TX_MAX_FRAMES_IRQ;
+	if (coalesce->stats_block_coalesce_usecs)
+		nonzero_params |= ETHTOOL_COALESCE_STATS_BLOCK_USECS;
+	if (coalesce->use_adaptive_rx_coalesce)
+		nonzero_params |= ETHTOOL_COALESCE_USE_ADAPTIVE_RX;
+	if (coalesce->use_adaptive_tx_coalesce)
+		nonzero_params |= ETHTOOL_COALESCE_USE_ADAPTIVE_TX;
+	if (coalesce->pkt_rate_low)
+		nonzero_params |= ETHTOOL_COALESCE_PKT_RATE_LOW;
+	if (coalesce->rx_coalesce_usecs_low)
+		nonzero_params |= ETHTOOL_COALESCE_RX_USECS_LOW;
+	if (coalesce->rx_max_coalesced_frames_low)
+		nonzero_params |= ETHTOOL_COALESCE_RX_MAX_FRAMES_LOW;
+	if (coalesce->tx_coalesce_usecs_low)
+		nonzero_params |= ETHTOOL_COALESCE_TX_USECS_LOW;
+	if (coalesce->tx_max_coalesced_frames_low)
+		nonzero_params |= ETHTOOL_COALESCE_TX_MAX_FRAMES_LOW;
+	if (coalesce->pkt_rate_high)
+		nonzero_params |= ETHTOOL_COALESCE_PKT_RATE_HIGH;
+	if (coalesce->rx_coalesce_usecs_high)
+		nonzero_params |= ETHTOOL_COALESCE_RX_USECS_HIGH;
+	if (coalesce->rx_max_coalesced_frames_high)
+		nonzero_params |= ETHTOOL_COALESCE_RX_MAX_FRAMES_HIGH;
+	if (coalesce->tx_coalesce_usecs_high)
+		nonzero_params |= ETHTOOL_COALESCE_TX_USECS_HIGH;
+	if (coalesce->tx_max_coalesced_frames_high)
+		nonzero_params |= ETHTOOL_COALESCE_TX_MAX_FRAMES_HIGH;
+	if (coalesce->rate_sample_interval)
+		nonzero_params |= ETHTOOL_COALESCE_RATE_SAMPLE_INTERVAL;
+
+	return (supported_params & nonzero_params) == nonzero_params;
+}
+
 static noinline_for_stack int ethtool_set_coalesce(struct net_device *dev,
 						   void __user *useraddr)
 {
@@ -1555,6 +1613,9 @@ static noinline_for_stack int ethtool_set_coalesce(struct net_device *dev,
 	if (copy_from_user(&coalesce, useraddr, sizeof(coalesce)))
 		return -EFAULT;
 
+	if (!ethtool_set_coalesce_supported(dev, &coalesce))
+		return -EOPNOTSUPP;
+
 	return dev->ethtool_ops->set_coalesce(dev, &coalesce);
 }
 
@@ -2336,6 +2397,11 @@ ethtool_set_per_queue_coalesce(struct net_device *dev,
 			goto roll_back;
 		}
 
+		if (!ethtool_set_coalesce_supported(dev, &coalesce)) {
+			ret = -EOPNOTSUPP;
+			goto roll_back;
+		}
+
 		ret = dev->ethtool_ops->set_per_queue_coalesce(dev, bit, &coalesce);
 		if (ret != 0)
 			goto roll_back;