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myri10ge: DCA update (resubmit)

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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: Andrew Gallatin <gallatin@myri.com>
Signed-off-by: Loic Prylli <loic@myri.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Andrew Gallatin 2010-09-28 08:13:12 +00:00 committed by David S. Miller
parent 8681dc3abd
commit ef09aadf7b
1 changed files with 30 additions and 4 deletions
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34
drivers/net/myri10ge/myri10ge.c
View file

@ -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);
}