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sfc: Move CPU counting for RSS into a separate function, efx_wanted_rx_queues()

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Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Ben Hutchings 2008-09-01 12:47:33 +01:00 committed by Jeff Garzik
parent 4a5b504d0c
commit 46123d043d
1 changed files with 35 additions and 25 deletions
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60
drivers/net/sfc/efx.c
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@ -819,38 +819,48 @@ static void efx_fini_io(struct efx_nic *efx)
pci_disable_device(efx->pci_dev);
}
/* Probe the number and type of interrupts we are able to obtain. */
/* Get number of RX queues wanted. Return number of online CPU
* packages in the expectation that an IRQ balancer will spread
* interrupts across them. */
static int efx_wanted_rx_queues(void)
{
cpumask_t core_mask;
int count;
int cpu;
cpus_clear(core_mask);
count = 0;
for_each_online_cpu(cpu) {
if (!cpu_isset(cpu, core_mask)) {
++count;
cpus_or(core_mask, core_mask,
topology_core_siblings(cpu));
}
}
return count;
}
/* Probe the number and type of interrupts we are able to obtain, and
* the resulting numbers of channels and RX queues.
*/
static void efx_probe_interrupts(struct efx_nic *efx)
{
int max_channel = efx->type->phys_addr_channels - 1;
struct msix_entry xentries[EFX_MAX_CHANNELS];
int max_channels =
min_t(int, efx->type->phys_addr_channels, EFX_MAX_CHANNELS);
int rc, i;
if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
BUG_ON(!pci_find_capability(efx->pci_dev, PCI_CAP_ID_MSIX));
struct msix_entry xentries[EFX_MAX_CHANNELS];
int wanted_ints;
if (rss_cpus == 0) {
cpumask_t core_mask;
int cpu;
/* We want one RX queue and interrupt per CPU package
* (or as specified by the rss_cpus module parameter).
* We will need one channel per interrupt.
*/
wanted_ints = rss_cpus ? rss_cpus : efx_wanted_rx_queues();
efx->rss_queues = min(wanted_ints, max_channels);
cpus_clear(core_mask);
efx->rss_queues = 0;
for_each_online_cpu(cpu) {
if (!cpu_isset(cpu, core_mask)) {
++efx->rss_queues;
cpus_or(core_mask, core_mask,
topology_core_siblings(cpu));
}
}
} else {
efx->rss_queues = rss_cpus;
}
efx->rss_queues = min(efx->rss_queues, max_channel + 1);
efx->rss_queues = min(efx->rss_queues, EFX_MAX_CHANNELS);
/* Request maximum number of MSI interrupts, and fill out
* the channel interrupt information the allowed allocation */
for (i = 0; i < efx->rss_queues; i++)
xentries[i].entry = i;
rc = pci_enable_msix(efx->pci_dev, xentries, efx->rss_queues);