[Intel-wired-lan] [next PATCH S21 09/14] i40e: use priv flags to control packet split
Joshua Hay
joshua.a.hay at intel.com
Fri Nov 6 23:26:07 UTC 2015
From: Jesse Brandeburg <jesse.brandeburg at intel.com>
Ethtool priv flags implementation to enable or disable packet split, which
is a hardware feature that inspects headers and will put headers in a
separate DMA buffer from the payload data. The driver was automatically
choosing to enable packet split in some cases and this gives the user the
ability to turn it off/on explicitly.
to query state:
ethtool --show-priv-flags ethx
to enable:
ethtool --set-priv-flags ethx packet-split on
to disable:
ethtool --set-priv-flags ethx packet-split off
Why would anyone want this?
Because some environments benefit from header/data split in the receive
buffer, and the driver defaults to one or the other depending on
environment/kernel parameters.
Why didn't you implement a generic ethtool control for this feature?
Because Intel hardware is the only hardware that supports header/data
split.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg at intel.com>
Change-ID: I803121e1eecc9ccb2884031fd85dd1110b3af66d
---
drivers/net/ethernet/intel/i40e/i40e.h | 1 +
drivers/net/ethernet/intel/i40e/i40e_ethtool.c | 27 ++++++++++++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 768a19b..050fc0f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -104,6 +104,7 @@
#define I40E_PRIV_FLAGS_LINKPOLL_FLAG BIT(1)
#define I40E_PRIV_FLAGS_FD_ATR BIT(2)
#define I40E_PRIV_FLAGS_VEB_STATS BIT(3)
+#define I40E_PRIV_FLAGS_PS BIT(4)
#define I40E_NVM_VERSION_LO_SHIFT 0
#define I40E_NVM_VERSION_LO_MASK (0xff << I40E_NVM_VERSION_LO_SHIFT)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
index b52c509..d686041 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
@@ -231,6 +231,7 @@ static const char i40e_priv_flags_strings[][ETH_GSTRING_LEN] = {
"LinkPolling",
"flow-director-atr",
"veb-stats",
+ "packet-split",
};
#define I40E_PRIV_FLAGS_STR_LEN ARRAY_SIZE(i40e_priv_flags_strings)
@@ -2709,6 +2710,8 @@ static u32 i40e_get_priv_flags(struct net_device *dev)
I40E_PRIV_FLAGS_FD_ATR : 0;
ret_flags |= pf->flags & I40E_FLAG_VEB_STATS_ENABLED ?
I40E_PRIV_FLAGS_VEB_STATS : 0;
+ ret_flags |= pf->flags & I40E_FLAG_RX_PS_ENABLED ?
+ I40E_PRIV_FLAGS_PS : 0;
return ret_flags;
}
@@ -2723,6 +2726,26 @@ static int i40e_set_priv_flags(struct net_device *dev, u32 flags)
struct i40e_netdev_priv *np = netdev_priv(dev);
struct i40e_vsi *vsi = np->vsi;
struct i40e_pf *pf = vsi->back;
+ bool reset_required = false;
+
+ /* NOTE: MFP is not settable */
+
+ /* allow the user to control the method of receive
+ * buffer dma, whether the packet is split at header
+ * boundaries into two separate buffers. In some cases
+ * one routine or the other will perform better.
+ */
+ if ((flags & I40E_PRIV_FLAGS_PS) &&
+ !(pf->flags & I40E_FLAG_RX_PS_ENABLED)) {
+ pf->flags |= I40E_FLAG_RX_PS_ENABLED;
+ pf->flags &= ~I40E_FLAG_RX_1BUF_ENABLED;
+ reset_required = true;
+ } else if (!(flags & I40E_PRIV_FLAGS_PS) &&
+ (pf->flags & I40E_FLAG_RX_PS_ENABLED)) {
+ pf->flags &= ~I40E_FLAG_RX_PS_ENABLED;
+ pf->flags |= I40E_FLAG_RX_1BUF_ENABLED;
+ reset_required = true;
+ }
if (flags & I40E_PRIV_FLAGS_LINKPOLL_FLAG)
pf->flags |= I40E_FLAG_LINK_POLLING_ENABLED;
@@ -2745,6 +2768,10 @@ static int i40e_set_priv_flags(struct net_device *dev, u32 flags)
else
pf->flags &= ~I40E_FLAG_VEB_STATS_ENABLED;
+ /* if needed, issue reset to cause things to take effect */
+ if (reset_required)
+ i40e_do_reset(pf, BIT(__I40E_PF_RESET_REQUESTED));
+
return 0;
}
--
2.1.0
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