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Commit ef09aadf authored by Andrew Gallatin's avatar Andrew Gallatin Committed by David S. Miller
Browse files

myri10ge: DCA update (resubmit) 



This patch contains the following DCA improvements to myri10ge:

1) Finally move myri10ge to use dca3 API

2) Disable PCIe relaxed ordering when enabling DCA on
     myri10ge.  This provides a performance boost on Nehalem
     based Xeons

3) Make sure to properly initialize NIC's DCA state when it is enabled,
     rather than giving the NIC a bogus tag (0) and waiting for
     the first received packet to trigger an update.  Not using a
     real tag can cause hardware exceptions on some motherboards
     when a CPU socket is empty.

3) Always update the cached CPU when our interrupt affinity changes
     so as to avoid excessive calls to dca3_get_tag()

Signed-off-by: default avatarAndrew Gallatin <gallatin@myri.com>
Signed-off-by: default avatarLoic Prylli <loic@myri.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8681dc3a

drivers/net/myri10ge/myri10ge.c

+30 −4
Original line number Diff line number Diff line
@@ -225,6 +225,7 @@ struct myri10ge_priv { 
	struct msix_entry *msix_vectors;

#ifdef CONFIG_MYRI10GE_DCA

	int dca_enabled;

	int relaxed_order;

#endif

	u32 link_state;

	unsigned int rdma_tags_available;
@@ -1074,10 +1075,28 @@ static int myri10ge_reset(struct myri10ge_priv *mgp) 
}



#ifdef CONFIG_MYRI10GE_DCA

static int myri10ge_toggle_relaxed(struct pci_dev *pdev, int on)

{

	int ret, cap, err;

	u16 ctl;



	cap = pci_find_capability(pdev, PCI_CAP_ID_EXP);

	if (!cap)

		return 0;



	err = pci_read_config_word(pdev, cap + PCI_EXP_DEVCTL, &ctl);

	ret = (ctl & PCI_EXP_DEVCTL_RELAX_EN) >> 4;

	if (ret != on) {

		ctl &= ~PCI_EXP_DEVCTL_RELAX_EN;

		ctl |= (on << 4);

		pci_write_config_word(pdev, cap + PCI_EXP_DEVCTL, ctl);

	}

	return ret;

}



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);

}
@@ -1088,9 +1107,10 @@ static inline void myri10ge_update_dca(struct myri10ge_slice_state *ss) 
	int tag;



	if (cpu != ss->cpu) {

		tag = dca_get_tag(cpu);

		tag = dca3_get_tag(&ss->mgp->pdev->dev, cpu);

		if (ss->cached_dca_tag != tag)

			myri10ge_write_dca(ss, cpu, tag);

		ss->cpu = cpu;

	}

	put_cpu();

}
@@ -1113,9 +1133,13 @@ static void myri10ge_setup_dca(struct myri10ge_priv *mgp) 
				"dca_add_requester() failed, err=%d\n", err);

		return;

	}

	mgp->relaxed_order = myri10ge_toggle_relaxed(pdev, 0);

	mgp->dca_enabled = 1;

	for (i = 0; i < mgp->num_slices; i++)

		myri10ge_write_dca(&mgp->ss[i], -1, 0);

	for (i = 0; i < mgp->num_slices; i++) {

		mgp->ss[i].cpu = -1;

		mgp->ss[i].cached_dca_tag = -1;

		myri10ge_update_dca(&mgp->ss[i]);

	 }

}



static void myri10ge_teardown_dca(struct myri10ge_priv *mgp)
@@ -1126,6 +1150,8 @@ static void myri10ge_teardown_dca(struct myri10ge_priv *mgp) 
	if (!mgp->dca_enabled)

		return;

	mgp->dca_enabled = 0;

	if (mgp->relaxed_order)

		myri10ge_toggle_relaxed(pdev, 1);

	err = dca_remove_requester(&pdev->dev);

}