Commit 37c45a4e authored by Alex Maftei (amaftei)'s avatar Alex Maftei (amaftei) Committed by David S. Miller
Browse files

sfc: move channel interrupt management code



Small code styling fixes included.

Signed-off-by: default avatarAlexandru-Mihai Maftei <amaftei@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 83975485
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+0 −316
Original line number Diff line number Diff line
@@ -96,17 +96,6 @@ static unsigned int rx_irq_mod_usec = 60;
 */
static unsigned int tx_irq_mod_usec = 150;

/* This is the requested number of CPUs to use for Receive-Side Scaling (RSS),
 * i.e. the number of CPUs among which we may distribute simultaneous
 * interrupt handling.
 *
 * Cards without MSI-X will only target one CPU via legacy or MSI interrupt.
 * The default (0) means to assign an interrupt to each core.
 */
static unsigned int rss_cpus;
module_param(rss_cpus, uint, 0444);
MODULE_PARM_DESC(rss_cpus, "Number of CPUs to use for Receive-Side Scaling");

static bool phy_flash_cfg;
module_param(phy_flash_cfg, bool, 0644);
MODULE_PARM_DESC(phy_flash_cfg, "Set PHYs into reflash mode initially");
@@ -450,311 +439,6 @@ void efx_set_default_rx_indir_table(struct efx_nic *efx,
			ethtool_rxfh_indir_default(i, efx->rss_spread);
}

static unsigned int efx_wanted_parallelism(struct efx_nic *efx)
{
	cpumask_var_t thread_mask;
	unsigned int count;
	int cpu;

	if (rss_cpus) {
		count = rss_cpus;
	} else {
		if (unlikely(!zalloc_cpumask_var(&thread_mask, GFP_KERNEL))) {
			netif_warn(efx, probe, efx->net_dev,
				   "RSS disabled due to allocation failure\n");
			return 1;
		}

		count = 0;
		for_each_online_cpu(cpu) {
			if (!cpumask_test_cpu(cpu, thread_mask)) {
				++count;
				cpumask_or(thread_mask, thread_mask,
					   topology_sibling_cpumask(cpu));
			}
		}

		free_cpumask_var(thread_mask);
	}

	if (count > EFX_MAX_RX_QUEUES) {
		netif_cond_dbg(efx, probe, efx->net_dev, !rss_cpus, warn,
			       "Reducing number of rx queues from %u to %u.\n",
			       count, EFX_MAX_RX_QUEUES);
		count = EFX_MAX_RX_QUEUES;
	}

	/* If RSS is requested for the PF *and* VFs then we can't write RSS
	 * table entries that are inaccessible to VFs
	 */
#ifdef CONFIG_SFC_SRIOV
	if (efx->type->sriov_wanted) {
		if (efx->type->sriov_wanted(efx) && efx_vf_size(efx) > 1 &&
		    count > efx_vf_size(efx)) {
			netif_warn(efx, probe, efx->net_dev,
				   "Reducing number of RSS channels from %u to %u for "
				   "VF support. Increase vf-msix-limit to use more "
				   "channels on the PF.\n",
				   count, efx_vf_size(efx));
			count = efx_vf_size(efx);
		}
	}
#endif

	return count;
}

static int efx_allocate_msix_channels(struct efx_nic *efx,
				      unsigned int max_channels,
				      unsigned int extra_channels,
				      unsigned int parallelism)
{
	unsigned int n_channels = parallelism;
	int vec_count;
	int n_xdp_tx;
	int n_xdp_ev;

	if (efx_separate_tx_channels)
		n_channels *= 2;
	n_channels += extra_channels;

	/* To allow XDP transmit to happen from arbitrary NAPI contexts
	 * we allocate a TX queue per CPU. We share event queues across
	 * multiple tx queues, assuming tx and ev queues are both
	 * maximum size.
	 */

	n_xdp_tx = num_possible_cpus();
	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, EFX_TXQ_TYPES);

	vec_count = pci_msix_vec_count(efx->pci_dev);
	if (vec_count < 0)
		return vec_count;

	max_channels = min_t(unsigned int, vec_count, max_channels);

	/* Check resources.
	 * We need a channel per event queue, plus a VI per tx queue.
	 * This may be more pessimistic than it needs to be.
	 */
	if (n_channels + n_xdp_ev > max_channels) {
		netif_err(efx, drv, efx->net_dev,
			  "Insufficient resources for %d XDP event queues (%d other channels, max %d)\n",
			  n_xdp_ev, n_channels, max_channels);
		efx->n_xdp_channels = 0;
		efx->xdp_tx_per_channel = 0;
		efx->xdp_tx_queue_count = 0;
	} else {
		efx->n_xdp_channels = n_xdp_ev;
		efx->xdp_tx_per_channel = EFX_TXQ_TYPES;
		efx->xdp_tx_queue_count = n_xdp_tx;
		n_channels += n_xdp_ev;
		netif_dbg(efx, drv, efx->net_dev,
			  "Allocating %d TX and %d event queues for XDP\n",
			  n_xdp_tx, n_xdp_ev);
	}

	if (vec_count < n_channels) {
		netif_err(efx, drv, efx->net_dev,
			  "WARNING: Insufficient MSI-X vectors available (%d < %u).\n",
			  vec_count, n_channels);
		netif_err(efx, drv, efx->net_dev,
			  "WARNING: Performance may be reduced.\n");
		n_channels = vec_count;
	}

	n_channels = min(n_channels, max_channels);

	efx->n_channels = n_channels;

	/* Ignore XDP tx channels when creating rx channels. */
	n_channels -= efx->n_xdp_channels;

	if (efx_separate_tx_channels) {
		efx->n_tx_channels =
			min(max(n_channels / 2, 1U),
			    efx->max_tx_channels);
		efx->tx_channel_offset =
			n_channels - efx->n_tx_channels;
		efx->n_rx_channels =
			max(n_channels -
			    efx->n_tx_channels, 1U);
	} else {
		efx->n_tx_channels = min(n_channels, efx->max_tx_channels);
		efx->tx_channel_offset = 0;
		efx->n_rx_channels = n_channels;
	}

	efx->n_rx_channels = min(efx->n_rx_channels, parallelism);
	efx->n_tx_channels = min(efx->n_tx_channels, parallelism);

	efx->xdp_channel_offset = n_channels;

	netif_dbg(efx, drv, efx->net_dev,
		  "Allocating %u RX channels\n",
		  efx->n_rx_channels);

	return efx->n_channels;
}

/* Probe the number and type of interrupts we are able to obtain, and
 * the resulting numbers of channels and RX queues.
 */
int efx_probe_interrupts(struct efx_nic *efx)
{
	unsigned int extra_channels = 0;
	unsigned int rss_spread;
	unsigned int i, j;
	int rc;

	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++)
		if (efx->extra_channel_type[i])
			++extra_channels;

	if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
		unsigned int parallelism = efx_wanted_parallelism(efx);
		struct msix_entry xentries[EFX_MAX_CHANNELS];
		unsigned int n_channels;

		rc = efx_allocate_msix_channels(efx, efx->max_channels,
						extra_channels, parallelism);
		if (rc >= 0) {
			n_channels = rc;
			for (i = 0; i < n_channels; i++)
				xentries[i].entry = i;
			rc = pci_enable_msix_range(efx->pci_dev, xentries, 1,
						   n_channels);
		}
		if (rc < 0) {
			/* Fall back to single channel MSI */
			netif_err(efx, drv, efx->net_dev,
				  "could not enable MSI-X\n");
			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_MSI)
				efx->interrupt_mode = EFX_INT_MODE_MSI;
			else
				return rc;
		} else if (rc < n_channels) {
			netif_err(efx, drv, efx->net_dev,
				  "WARNING: Insufficient MSI-X vectors"
				  " available (%d < %u).\n", rc, n_channels);
			netif_err(efx, drv, efx->net_dev,
				  "WARNING: Performance may be reduced.\n");
			n_channels = rc;
		}

		if (rc > 0) {
			for (i = 0; i < efx->n_channels; i++)
				efx_get_channel(efx, i)->irq =
					xentries[i].vector;
		}
	}

	/* Try single interrupt MSI */
	if (efx->interrupt_mode == EFX_INT_MODE_MSI) {
		efx->n_channels = 1;
		efx->n_rx_channels = 1;
		efx->n_tx_channels = 1;
		efx->n_xdp_channels = 0;
		efx->xdp_channel_offset = efx->n_channels;
		rc = pci_enable_msi(efx->pci_dev);
		if (rc == 0) {
			efx_get_channel(efx, 0)->irq = efx->pci_dev->irq;
		} else {
			netif_err(efx, drv, efx->net_dev,
				  "could not enable MSI\n");
			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_LEGACY)
				efx->interrupt_mode = EFX_INT_MODE_LEGACY;
			else
				return rc;
		}
	}

	/* Assume legacy interrupts */
	if (efx->interrupt_mode == EFX_INT_MODE_LEGACY) {
		efx->n_channels = 1 + (efx_separate_tx_channels ? 1 : 0);
		efx->n_rx_channels = 1;
		efx->n_tx_channels = 1;
		efx->n_xdp_channels = 0;
		efx->xdp_channel_offset = efx->n_channels;
		efx->legacy_irq = efx->pci_dev->irq;
	}

	/* Assign extra channels if possible, before XDP channels */
	efx->n_extra_tx_channels = 0;
	j = efx->xdp_channel_offset;
	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++) {
		if (!efx->extra_channel_type[i])
			continue;
		if (j <= efx->tx_channel_offset + efx->n_tx_channels) {
			efx->extra_channel_type[i]->handle_no_channel(efx);
		} else {
			--j;
			efx_get_channel(efx, j)->type =
				efx->extra_channel_type[i];
			if (efx_channel_has_tx_queues(efx_get_channel(efx, j)))
				efx->n_extra_tx_channels++;
		}
	}

	rss_spread = efx->n_rx_channels;
	/* RSS might be usable on VFs even if it is disabled on the PF */
#ifdef CONFIG_SFC_SRIOV
	if (efx->type->sriov_wanted) {
		efx->rss_spread = ((rss_spread > 1 ||
				    !efx->type->sriov_wanted(efx)) ?
				   rss_spread : efx_vf_size(efx));
		return 0;
	}
#endif
	efx->rss_spread = rss_spread;

	return 0;
}

#if defined(CONFIG_SMP)
void efx_set_interrupt_affinity(struct efx_nic *efx)
{
	struct efx_channel *channel;
	unsigned int cpu;

	efx_for_each_channel(channel, efx) {
		cpu = cpumask_local_spread(channel->channel,
					   pcibus_to_node(efx->pci_dev->bus));
		irq_set_affinity_hint(channel->irq, cpumask_of(cpu));
	}
}

void efx_clear_interrupt_affinity(struct efx_nic *efx)
{
	struct efx_channel *channel;

	efx_for_each_channel(channel, efx)
		irq_set_affinity_hint(channel->irq, NULL);
}
#else
void efx_set_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
{
}

void efx_clear_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
{
}
#endif /* CONFIG_SMP */

void efx_remove_interrupts(struct efx_nic *efx)
{
	struct efx_channel *channel;

	/* Remove MSI/MSI-X interrupts */
	efx_for_each_channel(channel, efx)
		channel->irq = 0;
	pci_disable_msi(efx->pci_dev);
	pci_disable_msix(efx->pci_dev);

	/* Remove legacy interrupt */
	efx->legacy_irq = 0;
}

static int efx_probe_nic(struct efx_nic *efx)
{
	int rc;
+322 −0
Original line number Diff line number Diff line
@@ -28,6 +28,17 @@ module_param(interrupt_mode, uint, 0444);
MODULE_PARM_DESC(interrupt_mode,
		 "Interrupt mode (0=>MSIX 1=>MSI 2=>legacy)");

/* This is the requested number of CPUs to use for Receive-Side Scaling (RSS),
 * i.e. the number of CPUs among which we may distribute simultaneous
 * interrupt handling.
 *
 * Cards without MSI-X will only target one CPU via legacy or MSI interrupt.
 * The default (0) means to assign an interrupt to each core.
 */
static unsigned int rss_cpus;
module_param(rss_cpus, uint, 0444);
MODULE_PARM_DESC(rss_cpus, "Number of CPUs to use for Receive-Side Scaling");

static unsigned int irq_adapt_low_thresh = 8000;
module_param(irq_adapt_low_thresh, uint, 0644);
MODULE_PARM_DESC(irq_adapt_low_thresh,
@@ -66,6 +77,317 @@ static const struct efx_channel_type efx_default_channel_type = {
	.want_pio		= true,
};

/*************
 * INTERRUPTS
 *************/

static unsigned int efx_wanted_parallelism(struct efx_nic *efx)
{
	cpumask_var_t thread_mask;
	unsigned int count;
	int cpu;

	if (rss_cpus) {
		count = rss_cpus;
	} else {
		if (unlikely(!zalloc_cpumask_var(&thread_mask, GFP_KERNEL))) {
			netif_warn(efx, probe, efx->net_dev,
				   "RSS disabled due to allocation failure\n");
			return 1;
		}

		count = 0;
		for_each_online_cpu(cpu) {
			if (!cpumask_test_cpu(cpu, thread_mask)) {
				++count;
				cpumask_or(thread_mask, thread_mask,
					   topology_sibling_cpumask(cpu));
			}
		}

		free_cpumask_var(thread_mask);
	}

	if (count > EFX_MAX_RX_QUEUES) {
		netif_cond_dbg(efx, probe, efx->net_dev, !rss_cpus, warn,
			       "Reducing number of rx queues from %u to %u.\n",
			       count, EFX_MAX_RX_QUEUES);
		count = EFX_MAX_RX_QUEUES;
	}

	/* If RSS is requested for the PF *and* VFs then we can't write RSS
	 * table entries that are inaccessible to VFs
	 */
#ifdef CONFIG_SFC_SRIOV
	if (efx->type->sriov_wanted) {
		if (efx->type->sriov_wanted(efx) && efx_vf_size(efx) > 1 &&
		    count > efx_vf_size(efx)) {
			netif_warn(efx, probe, efx->net_dev,
				   "Reducing number of RSS channels from %u to %u for "
				   "VF support. Increase vf-msix-limit to use more "
				   "channels on the PF.\n",
				   count, efx_vf_size(efx));
			count = efx_vf_size(efx);
		}
	}
#endif

	return count;
}

static int efx_allocate_msix_channels(struct efx_nic *efx,
				      unsigned int max_channels,
				      unsigned int extra_channels,
				      unsigned int parallelism)
{
	unsigned int n_channels = parallelism;
	int vec_count;
	int n_xdp_tx;
	int n_xdp_ev;

	if (efx_separate_tx_channels)
		n_channels *= 2;
	n_channels += extra_channels;

	/* To allow XDP transmit to happen from arbitrary NAPI contexts
	 * we allocate a TX queue per CPU. We share event queues across
	 * multiple tx queues, assuming tx and ev queues are both
	 * maximum size.
	 */

	n_xdp_tx = num_possible_cpus();
	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, EFX_TXQ_TYPES);

	vec_count = pci_msix_vec_count(efx->pci_dev);
	if (vec_count < 0)
		return vec_count;

	max_channels = min_t(unsigned int, vec_count, max_channels);

	/* Check resources.
	 * We need a channel per event queue, plus a VI per tx queue.
	 * This may be more pessimistic than it needs to be.
	 */
	if (n_channels + n_xdp_ev > max_channels) {
		netif_err(efx, drv, efx->net_dev,
			  "Insufficient resources for %d XDP event queues (%d other channels, max %d)\n",
			  n_xdp_ev, n_channels, max_channels);
		efx->n_xdp_channels = 0;
		efx->xdp_tx_per_channel = 0;
		efx->xdp_tx_queue_count = 0;
	} else {
		efx->n_xdp_channels = n_xdp_ev;
		efx->xdp_tx_per_channel = EFX_TXQ_TYPES;
		efx->xdp_tx_queue_count = n_xdp_tx;
		n_channels += n_xdp_ev;
		netif_dbg(efx, drv, efx->net_dev,
			  "Allocating %d TX and %d event queues for XDP\n",
			  n_xdp_tx, n_xdp_ev);
	}

	if (vec_count < n_channels) {
		netif_err(efx, drv, efx->net_dev,
			  "WARNING: Insufficient MSI-X vectors available (%d < %u).\n",
			  vec_count, n_channels);
		netif_err(efx, drv, efx->net_dev,
			  "WARNING: Performance may be reduced.\n");
		n_channels = vec_count;
	}

	n_channels = min(n_channels, max_channels);

	efx->n_channels = n_channels;

	/* Ignore XDP tx channels when creating rx channels. */
	n_channels -= efx->n_xdp_channels;

	if (efx_separate_tx_channels) {
		efx->n_tx_channels =
			min(max(n_channels / 2, 1U),
			    efx->max_tx_channels);
		efx->tx_channel_offset =
			n_channels - efx->n_tx_channels;
		efx->n_rx_channels =
			max(n_channels -
			    efx->n_tx_channels, 1U);
	} else {
		efx->n_tx_channels = min(n_channels, efx->max_tx_channels);
		efx->tx_channel_offset = 0;
		efx->n_rx_channels = n_channels;
	}

	efx->n_rx_channels = min(efx->n_rx_channels, parallelism);
	efx->n_tx_channels = min(efx->n_tx_channels, parallelism);

	efx->xdp_channel_offset = n_channels;

	netif_dbg(efx, drv, efx->net_dev,
		  "Allocating %u RX channels\n",
		  efx->n_rx_channels);

	return efx->n_channels;
}

/* Probe the number and type of interrupts we are able to obtain, and
 * the resulting numbers of channels and RX queues.
 */
int efx_probe_interrupts(struct efx_nic *efx)
{
	unsigned int extra_channels = 0;
	unsigned int rss_spread;
	unsigned int i, j;
	int rc;

	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++)
		if (efx->extra_channel_type[i])
			++extra_channels;

	if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
		unsigned int parallelism = efx_wanted_parallelism(efx);
		struct msix_entry xentries[EFX_MAX_CHANNELS];
		unsigned int n_channels;

		rc = efx_allocate_msix_channels(efx, efx->max_channels,
						extra_channels, parallelism);
		if (rc >= 0) {
			n_channels = rc;
			for (i = 0; i < n_channels; i++)
				xentries[i].entry = i;
			rc = pci_enable_msix_range(efx->pci_dev, xentries, 1,
						   n_channels);
		}
		if (rc < 0) {
			/* Fall back to single channel MSI */
			netif_err(efx, drv, efx->net_dev,
				  "could not enable MSI-X\n");
			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_MSI)
				efx->interrupt_mode = EFX_INT_MODE_MSI;
			else
				return rc;
		} else if (rc < n_channels) {
			netif_err(efx, drv, efx->net_dev,
				  "WARNING: Insufficient MSI-X vectors"
				  " available (%d < %u).\n", rc, n_channels);
			netif_err(efx, drv, efx->net_dev,
				  "WARNING: Performance may be reduced.\n");
			n_channels = rc;
		}

		if (rc > 0) {
			for (i = 0; i < efx->n_channels; i++)
				efx_get_channel(efx, i)->irq =
					xentries[i].vector;
		}
	}

	/* Try single interrupt MSI */
	if (efx->interrupt_mode == EFX_INT_MODE_MSI) {
		efx->n_channels = 1;
		efx->n_rx_channels = 1;
		efx->n_tx_channels = 1;
		efx->n_xdp_channels = 0;
		efx->xdp_channel_offset = efx->n_channels;
		rc = pci_enable_msi(efx->pci_dev);
		if (rc == 0) {
			efx_get_channel(efx, 0)->irq = efx->pci_dev->irq;
		} else {
			netif_err(efx, drv, efx->net_dev,
				  "could not enable MSI\n");
			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_LEGACY)
				efx->interrupt_mode = EFX_INT_MODE_LEGACY;
			else
				return rc;
		}
	}

	/* Assume legacy interrupts */
	if (efx->interrupt_mode == EFX_INT_MODE_LEGACY) {
		efx->n_channels = 1 + (efx_separate_tx_channels ? 1 : 0);
		efx->n_rx_channels = 1;
		efx->n_tx_channels = 1;
		efx->n_xdp_channels = 0;
		efx->xdp_channel_offset = efx->n_channels;
		efx->legacy_irq = efx->pci_dev->irq;
	}

	/* Assign extra channels if possible, before XDP channels */
	efx->n_extra_tx_channels = 0;
	j = efx->xdp_channel_offset;
	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++) {
		if (!efx->extra_channel_type[i])
			continue;
		if (j <= efx->tx_channel_offset + efx->n_tx_channels) {
			efx->extra_channel_type[i]->handle_no_channel(efx);
		} else {
			--j;
			efx_get_channel(efx, j)->type =
				efx->extra_channel_type[i];
			if (efx_channel_has_tx_queues(efx_get_channel(efx, j)))
				efx->n_extra_tx_channels++;
		}
	}

	rss_spread = efx->n_rx_channels;
	/* RSS might be usable on VFs even if it is disabled on the PF */
#ifdef CONFIG_SFC_SRIOV
	if (efx->type->sriov_wanted) {
		efx->rss_spread = ((rss_spread > 1 ||
				    !efx->type->sriov_wanted(efx)) ?
				   rss_spread : efx_vf_size(efx));
		return 0;
	}
#endif
	efx->rss_spread = rss_spread;

	return 0;
}

#if defined(CONFIG_SMP)
void efx_set_interrupt_affinity(struct efx_nic *efx)
{
	struct efx_channel *channel;
	unsigned int cpu;

	efx_for_each_channel(channel, efx) {
		cpu = cpumask_local_spread(channel->channel,
					   pcibus_to_node(efx->pci_dev->bus));
		irq_set_affinity_hint(channel->irq, cpumask_of(cpu));
	}
}

void efx_clear_interrupt_affinity(struct efx_nic *efx)
{
	struct efx_channel *channel;

	efx_for_each_channel(channel, efx)
		irq_set_affinity_hint(channel->irq, NULL);
}
#else
void
efx_set_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
{
}

void
efx_clear_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
{
}
#endif /* CONFIG_SMP */

void efx_remove_interrupts(struct efx_nic *efx)
{
	struct efx_channel *channel;

	/* Remove MSI/MSI-X interrupts */
	efx_for_each_channel(channel, efx)
		channel->irq = 0;
	pci_disable_msi(efx->pci_dev);
	pci_disable_msix(efx->pci_dev);

	/* Remove legacy interrupt */
	efx->legacy_irq = 0;
}

/**************************************************************************
 *
 * Channel handling