summaryrefslogtreecommitdiff
path: root/drivers/net/ethernet/sfc
diff options
context:
space:
mode:
authorBen Hutchings <bhutchings@solarflare.com>2012-10-06 02:35:41 +0400
committerBen Hutchings <bhutchings@solarflare.com>2013-08-21 22:47:23 +0400
commitd829118705f8213ffeffa4fefa8931dea6b7f016 (patch)
treea6e8f3cb560c2e113af0574363cb197b1b938345 /drivers/net/ethernet/sfc
parent514bedbc3a07e466b040f76319b8f2a4c7b0c7a4 (diff)
downloadlinux-d829118705f8213ffeffa4fefa8931dea6b7f016.tar.xz
sfc: Rework IRQ enable/disable
There are many problems with the current efx_stop_interrupts() and efx_start_interrupts(): 1. On Siena, it is unsafe to disable the master IRQ enable bit (DRV_INT_EN_KER) while any IRQ sources are enabled. 2. On EF10 there is no master IRQ enable bit, so we cannot expect to defer IRQs without tearing down event queues. (Though I don't think we will need to keep any event queues around while the device is down, as we do for VFDI on Siena.) 3. synchronize_irq() only waits for a running IRQ handler to finish, not for any propagation through IRQ controllers. Therefore an IRQ may still be received and handled after efx_stop_interrupts() returns. IRQ handlers can then race with channel reallocation. To fix this: a. Introduce a software IRQ enable flag. So long as this is clear, IRQ handlers will only acknowledge IRQs and not touch the channel structures. b. Define a new struct efx_msi_context as the context for MSIs. This is never reallocated and is sufficient to find the software enable flag and the channel structure. It also includes the channel/IRQ name, which was previously separated out as it must also not be reallocated. c. Split efx_{start,stop}_interrupts() into efx_{,soft_}_{enable,disable}_interrupts(). The 'soft' functions don't touch the hardware master enable flag (if it exists) and don't reinitialise or tear down channels with the keep_eventq flag set. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Diffstat (limited to 'drivers/net/ethernet/sfc')
-rw-r--r--drivers/net/ethernet/sfc/efx.c91
-rw-r--r--drivers/net/ethernet/sfc/falcon.c3
-rw-r--r--drivers/net/ethernet/sfc/net_driver.h24
-rw-r--r--drivers/net/ethernet/sfc/nic.c53
4 files changed, 112 insertions, 59 deletions
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 2b2dba1a0676..a7818d1c2415 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -191,8 +191,8 @@ MODULE_PARM_DESC(debug, "Bitmapped debugging message enable value");
*
*************************************************************************/
-static void efx_start_interrupts(struct efx_nic *efx, bool may_keep_eventq);
-static void efx_stop_interrupts(struct efx_nic *efx, bool may_keep_eventq);
+static void efx_soft_enable_interrupts(struct efx_nic *efx);
+static void efx_soft_disable_interrupts(struct efx_nic *efx);
static void efx_remove_channel(struct efx_channel *channel);
static void efx_remove_channels(struct efx_nic *efx);
static const struct efx_channel_type efx_default_channel_type;
@@ -520,8 +520,8 @@ static void efx_set_channel_names(struct efx_nic *efx)
efx_for_each_channel(channel, efx)
channel->type->get_name(channel,
- efx->channel_name[channel->channel],
- sizeof(efx->channel_name[0]));
+ efx->msi_context[channel->channel].name,
+ sizeof(efx->msi_context[0].name));
}
static int efx_probe_channels(struct efx_nic *efx)
@@ -746,7 +746,7 @@ efx_realloc_channels(struct efx_nic *efx, u32 rxq_entries, u32 txq_entries)
efx_device_detach_sync(efx);
efx_stop_all(efx);
- efx_stop_interrupts(efx, true);
+ efx_soft_disable_interrupts(efx);
/* Clone channels (where possible) */
memset(other_channel, 0, sizeof(other_channel));
@@ -796,7 +796,7 @@ out:
}
}
- efx_start_interrupts(efx, true);
+ efx_soft_enable_interrupts(efx);
efx_start_all(efx);
netif_device_attach(efx->net_dev);
return rc;
@@ -1329,23 +1329,17 @@ static int efx_probe_interrupts(struct efx_nic *efx)
return 0;
}
-/* Enable interrupts, then probe and start the event queues */
-static void efx_start_interrupts(struct efx_nic *efx, bool may_keep_eventq)
+static void efx_soft_enable_interrupts(struct efx_nic *efx)
{
struct efx_channel *channel;
BUG_ON(efx->state == STATE_DISABLED);
- if (efx->eeh_disabled_legacy_irq) {
- enable_irq(efx->legacy_irq);
- efx->eeh_disabled_legacy_irq = false;
- }
- if (efx->legacy_irq)
- efx->legacy_irq_enabled = true;
- efx_nic_enable_interrupts(efx);
+ efx->irq_soft_enabled = true;
+ smp_wmb();
efx_for_each_channel(channel, efx) {
- if (!channel->type->keep_eventq || !may_keep_eventq)
+ if (!channel->type->keep_eventq)
efx_init_eventq(channel);
efx_start_eventq(channel);
}
@@ -1353,7 +1347,7 @@ static void efx_start_interrupts(struct efx_nic *efx, bool may_keep_eventq)
efx_mcdi_mode_event(efx);
}
-static void efx_stop_interrupts(struct efx_nic *efx, bool may_keep_eventq)
+static void efx_soft_disable_interrupts(struct efx_nic *efx)
{
struct efx_channel *channel;
@@ -1362,22 +1356,57 @@ static void efx_stop_interrupts(struct efx_nic *efx, bool may_keep_eventq)
efx_mcdi_mode_poll(efx);
- efx_nic_disable_interrupts(efx);
- if (efx->legacy_irq) {
+ efx->irq_soft_enabled = false;
+ smp_wmb();
+
+ if (efx->legacy_irq)
synchronize_irq(efx->legacy_irq);
- efx->legacy_irq_enabled = false;
- }
efx_for_each_channel(channel, efx) {
if (channel->irq)
synchronize_irq(channel->irq);
efx_stop_eventq(channel);
- if (!channel->type->keep_eventq || !may_keep_eventq)
+ if (!channel->type->keep_eventq)
efx_fini_eventq(channel);
}
}
+static void efx_enable_interrupts(struct efx_nic *efx)
+{
+ struct efx_channel *channel;
+
+ BUG_ON(efx->state == STATE_DISABLED);
+
+ if (efx->eeh_disabled_legacy_irq) {
+ enable_irq(efx->legacy_irq);
+ efx->eeh_disabled_legacy_irq = false;
+ }
+
+ efx_nic_enable_interrupts(efx);
+
+ efx_for_each_channel(channel, efx) {
+ if (channel->type->keep_eventq)
+ efx_init_eventq(channel);
+ }
+
+ efx_soft_enable_interrupts(efx);
+}
+
+static void efx_disable_interrupts(struct efx_nic *efx)
+{
+ struct efx_channel *channel;
+
+ efx_soft_disable_interrupts(efx);
+
+ efx_for_each_channel(channel, efx) {
+ if (channel->type->keep_eventq)
+ efx_fini_eventq(channel);
+ }
+
+ efx_nic_disable_interrupts(efx);
+}
+
static void efx_remove_interrupts(struct efx_nic *efx)
{
struct efx_channel *channel;
@@ -2160,7 +2189,7 @@ void efx_reset_down(struct efx_nic *efx, enum reset_type method)
EFX_ASSERT_RESET_SERIALISED(efx);
efx_stop_all(efx);
- efx_stop_interrupts(efx, false);
+ efx_disable_interrupts(efx);
mutex_lock(&efx->mac_lock);
if (efx->port_initialized && method != RESET_TYPE_INVISIBLE)
@@ -2199,7 +2228,7 @@ int efx_reset_up(struct efx_nic *efx, enum reset_type method, bool ok)
efx->type->reconfigure_mac(efx);
- efx_start_interrupts(efx, false);
+ efx_enable_interrupts(efx);
efx_restore_filters(efx);
efx_sriov_reset(efx);
@@ -2464,6 +2493,8 @@ static int efx_init_struct(struct efx_nic *efx,
efx->channel[i] = efx_alloc_channel(efx, i, NULL);
if (!efx->channel[i])
goto fail;
+ efx->msi_context[i].efx = efx;
+ efx->msi_context[i].index = i;
}
EFX_BUG_ON_PARANOID(efx->type->phys_addr_channels > EFX_MAX_CHANNELS);
@@ -2516,7 +2547,7 @@ static void efx_pci_remove_main(struct efx_nic *efx)
BUG_ON(efx->state == STATE_READY);
cancel_work_sync(&efx->reset_work);
- efx_stop_interrupts(efx, false);
+ efx_disable_interrupts(efx);
efx_nic_fini_interrupt(efx);
efx_fini_port(efx);
efx->type->fini(efx);
@@ -2538,7 +2569,7 @@ static void efx_pci_remove(struct pci_dev *pci_dev)
/* Mark the NIC as fini, then stop the interface */
rtnl_lock();
dev_close(efx->net_dev);
- efx_stop_interrupts(efx, false);
+ efx_disable_interrupts(efx);
rtnl_unlock();
efx_sriov_fini(efx);
@@ -2640,7 +2671,7 @@ static int efx_pci_probe_main(struct efx_nic *efx)
rc = efx_nic_init_interrupt(efx);
if (rc)
goto fail5;
- efx_start_interrupts(efx, false);
+ efx_enable_interrupts(efx);
return 0;
@@ -2761,7 +2792,7 @@ static int efx_pm_freeze(struct device *dev)
efx_device_detach_sync(efx);
efx_stop_all(efx);
- efx_stop_interrupts(efx, false);
+ efx_disable_interrupts(efx);
}
rtnl_unlock();
@@ -2776,7 +2807,7 @@ static int efx_pm_thaw(struct device *dev)
rtnl_lock();
if (efx->state != STATE_DISABLED) {
- efx_start_interrupts(efx, false);
+ efx_enable_interrupts(efx);
mutex_lock(&efx->mac_lock);
efx->phy_op->reconfigure(efx);
@@ -2879,7 +2910,7 @@ static pci_ers_result_t efx_io_error_detected(struct pci_dev *pdev,
efx_device_detach_sync(efx);
efx_stop_all(efx);
- efx_stop_interrupts(efx, false);
+ efx_disable_interrupts(efx);
status = PCI_ERS_RESULT_NEED_RESET;
} else {
diff --git a/drivers/net/ethernet/sfc/falcon.c b/drivers/net/ethernet/sfc/falcon.c
index f87710e9f8cd..f8de38243348 100644
--- a/drivers/net/ethernet/sfc/falcon.c
+++ b/drivers/net/ethernet/sfc/falcon.c
@@ -367,6 +367,9 @@ irqreturn_t falcon_legacy_interrupt_a1(int irq, void *dev_id)
"IRQ %d on CPU %d status " EFX_OWORD_FMT "\n",
irq, raw_smp_processor_id(), EFX_OWORD_VAL(*int_ker));
+ if (!likely(ACCESS_ONCE(efx->irq_soft_enabled)))
+ return IRQ_HANDLED;
+
/* Check to see if we have a serious error condition */
syserr = EFX_OWORD_FIELD(*int_ker, FSF_AZ_NET_IVEC_FATAL_INT);
if (unlikely(syserr))
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index ad89d7d990f5..7c9637203ea0 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -420,6 +420,21 @@ struct efx_channel {
};
/**
+ * struct efx_msi_context - Context for each MSI
+ * @efx: The associated NIC
+ * @index: Index of the channel/IRQ
+ * @name: Name of the channel/IRQ
+ *
+ * Unlike &struct efx_channel, this is never reallocated and is always
+ * safe for the IRQ handler to access.
+ */
+struct efx_msi_context {
+ struct efx_nic *efx;
+ unsigned int index;
+ char name[IFNAMSIZ + 6];
+};
+
+/**
* struct efx_channel_type - distinguishes traffic and extra channels
* @handle_no_channel: Handle failure to allocate an extra channel
* @pre_probe: Set up extra state prior to initialisation
@@ -669,7 +684,6 @@ struct vfdi_status;
* @pci_dev: The PCI device
* @type: Controller type attributes
* @legacy_irq: IRQ number
- * @legacy_irq_enabled: Are IRQs enabled on NIC (INT_EN_KER register)?
* @workqueue: Workqueue for port reconfigures and the HW monitor.
* Work items do not hold and must not acquire RTNL.
* @workqueue_name: Name of workqueue
@@ -686,7 +700,7 @@ struct vfdi_status;
* @tx_queue: TX DMA queues
* @rx_queue: RX DMA queues
* @channel: Channels
- * @channel_name: Names for channels and their IRQs
+ * @msi_context: Context for each MSI
* @extra_channel_types: Types of extra (non-traffic) channels that
* should be allocated for this NIC
* @rxq_entries: Size of receive queues requested by user.
@@ -709,6 +723,8 @@ struct vfdi_status;
* @rx_scatter: Scatter mode enabled for receives
* @int_error_count: Number of internal errors seen recently
* @int_error_expire: Time at which error count will be expired
+ * @irq_soft_enabled: Are IRQs soft-enabled? If not, IRQ handler will
+ * acknowledge but do nothing else.
* @irq_status: Interrupt status buffer
* @irq_zero_count: Number of legacy IRQs seen with queue flags == 0
* @irq_level: IRQ level/index for IRQs not triggered by an event queue
@@ -786,7 +802,6 @@ struct efx_nic {
unsigned int port_num;
const struct efx_nic_type *type;
int legacy_irq;
- bool legacy_irq_enabled;
bool eeh_disabled_legacy_irq;
struct workqueue_struct *workqueue;
char workqueue_name[16];
@@ -804,7 +819,7 @@ struct efx_nic {
unsigned long reset_pending;
struct efx_channel *channel[EFX_MAX_CHANNELS];
- char channel_name[EFX_MAX_CHANNELS][IFNAMSIZ + 6];
+ struct efx_msi_context msi_context[EFX_MAX_CHANNELS];
const struct efx_channel_type *
extra_channel_type[EFX_MAX_EXTRA_CHANNELS];
@@ -835,6 +850,7 @@ struct efx_nic {
unsigned int_error_count;
unsigned long int_error_expire;
+ bool irq_soft_enabled;
struct efx_buffer irq_status;
unsigned irq_zero_count;
unsigned irq_level;
diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index f758333b4d85..c17d659f4525 100644
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -1567,6 +1567,7 @@ irqreturn_t efx_nic_fatal_interrupt(struct efx_nic *efx)
static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
{
struct efx_nic *efx = dev_id;
+ bool soft_enabled = ACCESS_ONCE(efx->irq_soft_enabled);
efx_oword_t *int_ker = efx->irq_status.addr;
irqreturn_t result = IRQ_NONE;
struct efx_channel *channel;
@@ -1574,12 +1575,6 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
u32 queues;
int syserr;
- /* Could this be ours? If interrupts are disabled then the
- * channel state may not be valid.
- */
- if (!efx->legacy_irq_enabled)
- return result;
-
/* Read the ISR which also ACKs the interrupts */
efx_readd(efx, &reg, FR_BZ_INT_ISR0);
queues = EFX_EXTRACT_DWORD(reg, 0, 31);
@@ -1595,7 +1590,7 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
}
/* Handle non-event-queue sources */
- if (queues & (1U << efx->irq_level)) {
+ if (queues & (1U << efx->irq_level) && soft_enabled) {
syserr = EFX_OWORD_FIELD(*int_ker, FSF_AZ_NET_IVEC_FATAL_INT);
if (unlikely(syserr))
return efx_nic_fatal_interrupt(efx);
@@ -1607,10 +1602,12 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
efx->irq_zero_count = 0;
/* Schedule processing of any interrupting queues */
- efx_for_each_channel(channel, efx) {
- if (queues & 1)
- efx_schedule_channel_irq(channel);
- queues >>= 1;
+ if (likely(soft_enabled)) {
+ efx_for_each_channel(channel, efx) {
+ if (queues & 1)
+ efx_schedule_channel_irq(channel);
+ queues >>= 1;
+ }
}
result = IRQ_HANDLED;
@@ -1623,12 +1620,15 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
result = IRQ_HANDLED;
/* Ensure we schedule or rearm all event queues */
- efx_for_each_channel(channel, efx) {
- event = efx_event(channel, channel->eventq_read_ptr);
- if (efx_event_present(event))
- efx_schedule_channel_irq(channel);
- else
- efx_nic_eventq_read_ack(channel);
+ if (likely(soft_enabled)) {
+ efx_for_each_channel(channel, efx) {
+ event = efx_event(channel,
+ channel->eventq_read_ptr);
+ if (efx_event_present(event))
+ efx_schedule_channel_irq(channel);
+ else
+ efx_nic_eventq_read_ack(channel);
+ }
}
}
@@ -1649,8 +1649,8 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
*/
static irqreturn_t efx_msi_interrupt(int irq, void *dev_id)
{
- struct efx_channel *channel = *(struct efx_channel **)dev_id;
- struct efx_nic *efx = channel->efx;
+ struct efx_msi_context *context = dev_id;
+ struct efx_nic *efx = context->efx;
efx_oword_t *int_ker = efx->irq_status.addr;
int syserr;
@@ -1658,8 +1658,11 @@ static irqreturn_t efx_msi_interrupt(int irq, void *dev_id)
"IRQ %d on CPU %d status " EFX_OWORD_FMT "\n",
irq, raw_smp_processor_id(), EFX_OWORD_VAL(*int_ker));
+ if (!likely(ACCESS_ONCE(efx->irq_soft_enabled)))
+ return IRQ_HANDLED;
+
/* Handle non-event-queue sources */
- if (channel->channel == efx->irq_level) {
+ if (context->index == efx->irq_level) {
syserr = EFX_OWORD_FIELD(*int_ker, FSF_AZ_NET_IVEC_FATAL_INT);
if (unlikely(syserr))
return efx_nic_fatal_interrupt(efx);
@@ -1667,7 +1670,7 @@ static irqreturn_t efx_msi_interrupt(int irq, void *dev_id)
}
/* Schedule processing of the channel */
- efx_schedule_channel_irq(channel);
+ efx_schedule_channel_irq(efx->channel[context->index]);
return IRQ_HANDLED;
}
@@ -1739,8 +1742,8 @@ int efx_nic_init_interrupt(struct efx_nic *efx)
efx_for_each_channel(channel, efx) {
rc = request_irq(channel->irq, efx_msi_interrupt,
IRQF_PROBE_SHARED, /* Not shared */
- efx->channel_name[channel->channel],
- &efx->channel[channel->channel]);
+ efx->msi_context[channel->channel].name,
+ &efx->msi_context[channel->channel]);
if (rc) {
netif_err(efx, drv, efx->net_dev,
"failed to hook IRQ %d\n", channel->irq);
@@ -1769,7 +1772,7 @@ int efx_nic_init_interrupt(struct efx_nic *efx)
efx_for_each_channel(channel, efx) {
if (n_irqs-- == 0)
break;
- free_irq(channel->irq, &efx->channel[channel->channel]);
+ free_irq(channel->irq, &efx->msi_context[channel->channel]);
}
fail1:
return rc;
@@ -1787,7 +1790,7 @@ void efx_nic_fini_interrupt(struct efx_nic *efx)
/* Disable MSI/MSI-X interrupts */
efx_for_each_channel(channel, efx)
- free_irq(channel->irq, &efx->channel[channel->channel]);
+ free_irq(channel->irq, &efx->msi_context[channel->channel]);
/* ACK legacy interrupt */
if (efx_nic_rev(efx) >= EFX_REV_FALCON_B0)