5 files changed, 36 insertions, 28 deletions

diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h
index a3541ac6ea01..e0b66d158d79 100644
--- a/drivers/net/ethernet/sfc/efx.h
+++ b/drivers/net/ethernet/sfc/efx.h
@@ -145,6 +145,12 @@ static inline void efx_schedule_channel(struct efx_channel *channel)
         napi_schedule(&channel->napi_str);
 }
 
+static inline void efx_schedule_channel_irq(struct efx_channel *channel)
+{
+        channel->last_irq_cpu = raw_smp_processor_id();
+        efx_schedule_channel(channel);
+}
+
 extern void efx_link_status_changed(struct efx_nic *efx);
 extern void efx_link_set_advertising(struct efx_nic *efx, u32);
 extern void efx_link_set_wanted_fc(struct efx_nic *efx, u8);
diff --git a/drivers/net/ethernet/sfc/falcon.c b/drivers/net/ethernet/sfc/falcon.c
index b4e91edec0fa..98285115df10 100644
--- a/drivers/net/ethernet/sfc/falcon.c
+++ b/drivers/net/ethernet/sfc/falcon.c
@@ -189,9 +189,9 @@ irqreturn_t falcon_legacy_interrupt_a1(int irq, void *dev_id)
         falcon_irq_ack_a1(efx);
 
         if (queues & 1)
-                efx_schedule_channel(efx_get_channel(efx, 0));
+                efx_schedule_channel_irq(efx_get_channel(efx, 0));
         if (queues & 2)
-                efx_schedule_channel(efx_get_channel(efx, 1));
+                efx_schedule_channel_irq(efx_get_channel(efx, 1));
         return IRQ_HANDLED;
 }
 /**************************************************************************
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 8ce4d068bba5..a4cf8cb8180c 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -325,6 +325,7 @@ enum efx_rx_alloc_method {
  * @eventq_mask: Event queue pointer mask
  * @eventq_read_ptr: Event queue read pointer
  * @last_eventq_read_ptr: Last event queue read pointer value.
+ * @last_irq_cpu: Last CPU to handle interrupt for this channel
  * @irq_count: Number of IRQs since last adaptive moderation decision
  * @irq_mod_score: IRQ moderation score
  * @rx_alloc_level: Watermark based heuristic counter for pushing descriptors
@@ -355,6 +356,7 @@ struct efx_channel {
         unsigned int eventq_read_ptr;
         unsigned int last_eventq_read_ptr;
 
+        int last_irq_cpu;
         unsigned int irq_count;
         unsigned int irq_mod_score;
 #ifdef CONFIG_RFS_ACCEL
@@ -648,7 +650,7 @@ struct efx_filter_state;
  * @int_error_expire: Time at which error count will be expired
  * @irq_status: Interrupt status buffer
  * @irq_zero_count: Number of legacy IRQs seen with queue flags == 0
- * @fatal_irq_level: IRQ level (bit number) used for serious errors
+ * @irq_level: IRQ level/index for IRQs not triggered by an event queue
  * @mtd_list: List of MTDs attached to the NIC
  * @nic_data: Hardware dependent state
  * @mac_lock: MAC access lock. Protects @port_enabled, @phy_mode,
@@ -679,10 +681,9 @@ struct efx_filter_state;
  * @loopback_selftest: Offline self-test private state
  * @monitor_work: Hardware monitor workitem
  * @biu_lock: BIU (bus interface unit) lock
- * @last_irq_cpu: Last CPU to handle interrupt.
- *      This register is written with the SMP processor ID whenever an
- *      interrupt is handled.  It is used by efx_nic_test_interrupt()
- *      to verify that an interrupt has occurred.
+ * @last_irq_cpu: Last CPU to handle a possible test interrupt.  This
+ *      field is used by efx_test_interrupts() to verify that an
+ *      interrupt has occurred.
  * @n_rx_nodesc_drop_cnt: RX no descriptor drop count
  * @mac_stats: MAC statistics. These include all statistics the MACs
  *      can provide.  Generic code converts these into a standard
@@ -735,7 +736,7 @@ struct efx_nic {
 
         struct efx_buffer irq_status;
         unsigned irq_zero_count;
-        unsigned fatal_irq_level;
+        unsigned irq_level;
 
 #ifdef CONFIG_SFC_MTD
         struct list_head mtd_list;
@@ -779,7 +780,7 @@ struct efx_nic {
 
         struct delayed_work monitor_work ____cacheline_aligned_in_smp;
         spinlock_t biu_lock;
-        volatile signed int last_irq_cpu;
+        int last_irq_cpu;
         unsigned n_rx_nodesc_drop_cnt;
         struct efx_mac_stats mac_stats;
         spinlock_t stats_lock;
diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index bf07bd0488cf..de7aa1c8ebda 100644
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -1311,7 +1311,7 @@ static inline void efx_nic_interrupts(struct efx_nic *efx,
         efx_oword_t int_en_reg_ker;
 
         EFX_POPULATE_OWORD_3(int_en_reg_ker,
-                             FRF_AZ_KER_INT_LEVE_SEL, efx->fatal_irq_level,
+                             FRF_AZ_KER_INT_LEVE_SEL, efx->irq_level,
                              FRF_AZ_KER_INT_KER, force,
                              FRF_AZ_DRV_INT_EN_KER, enabled);
         efx_writeo(efx, &int_en_reg_ker, FR_AZ_INT_EN_KER);
@@ -1427,11 +1427,12 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
         efx_readd(efx, &reg, FR_BZ_INT_ISR0);
         queues = EFX_EXTRACT_DWORD(reg, 0, 31);
 
-        /* Check to see if we have a serious error condition */
-        if (queues & (1U << efx->fatal_irq_level)) {
+        /* Handle non-event-queue sources */
+        if (queues & (1U << efx->irq_level)) {
                 syserr = EFX_OWORD_FIELD(*int_ker, FSF_AZ_NET_IVEC_FATAL_INT);
                 if (unlikely(syserr))
                         return efx_nic_fatal_interrupt(efx);
+                efx->last_irq_cpu = raw_smp_processor_id();
         }
 
         if (queues != 0) {
@@ -1441,7 +1442,7 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
                 /* Schedule processing of any interrupting queues */
                 efx_for_each_channel(channel, efx) {
                         if (queues & 1)
-                                efx_schedule_channel(channel);
+                                efx_schedule_channel_irq(channel);
                         queues >>= 1;
                 }
                 result = IRQ_HANDLED;
@@ -1458,18 +1459,16 @@ static irqreturn_t efx_legacy_interrupt(int irq, void *dev_id)
                 efx_for_each_channel(channel, efx) {
                         event = efx_event(channel, channel->eventq_read_ptr);
                         if (efx_event_present(event))
-                                efx_schedule_channel(channel);
+                                efx_schedule_channel_irq(channel);
                         else
                                 efx_nic_eventq_read_ack(channel);
                 }
         }
 
-        if (result == IRQ_HANDLED) {
-                efx->last_irq_cpu = raw_smp_processor_id();
+        if (result == IRQ_HANDLED)
                 netif_vdbg(efx, intr, efx->net_dev,
                            "IRQ %d on CPU %d status " EFX_DWORD_FMT "\n",
                            irq, raw_smp_processor_id(), EFX_DWORD_VAL(reg));
-        }
 
         return result;
 }
@@ -1488,20 +1487,20 @@ static irqreturn_t efx_msi_interrupt(int irq, void *dev_id)
         efx_oword_t *int_ker = efx->irq_status.addr;
         int syserr;
 
-        efx->last_irq_cpu = raw_smp_processor_id();
         netif_vdbg(efx, intr, efx->net_dev,
                    "IRQ %d on CPU %d status " EFX_OWORD_FMT "\n",
                    irq, raw_smp_processor_id(), EFX_OWORD_VAL(*int_ker));
 
-        /* Check to see if we have a serious error condition */
-        if (channel->channel == efx->fatal_irq_level) {
+        /* Handle non-event-queue sources */
+        if (channel->channel == efx->irq_level) {
                 syserr = EFX_OWORD_FIELD(*int_ker, FSF_AZ_NET_IVEC_FATAL_INT);
                 if (unlikely(syserr))
                         return efx_nic_fatal_interrupt(efx);
+                efx->last_irq_cpu = raw_smp_processor_id();
         }
 
         /* Schedule processing of the channel */
-        efx_schedule_channel(channel);
+        efx_schedule_channel_irq(channel);
 
         return IRQ_HANDLED;
 }
@@ -1640,10 +1639,10 @@ void efx_nic_init_common(struct efx_nic *efx)
 
         if (EFX_WORKAROUND_17213(efx) && !EFX_INT_MODE_USE_MSI(efx))
                 /* Use an interrupt level unused by event queues */
-                efx->fatal_irq_level = 0x1f;
+                efx->irq_level = 0x1f;
         else
                 /* Use a valid MSI-X vector */
-                efx->fatal_irq_level = 0;
+                efx->irq_level = 0;
 
         /* Enable all the genuinely fatal interrupts.  (They are still
          * masked by the overall interrupt mask, controlled by
diff --git a/drivers/net/ethernet/sfc/selftest.c b/drivers/net/ethernet/sfc/selftest.c
index 0f8478924475..7def480570c3 100644
--- a/drivers/net/ethernet/sfc/selftest.c
+++ b/drivers/net/ethernet/sfc/selftest.c
@@ -130,6 +130,8 @@ static int efx_test_chip(struct efx_nic *efx, struct efx_self_tests *tests)
 static int efx_test_interrupts(struct efx_nic *efx,
                                struct efx_self_tests *tests)
 {
+        int cpu;
+
         netif_dbg(efx, drv, efx->net_dev, "testing interrupts\n");
         tests->interrupt = -1;
 
@@ -142,7 +144,8 @@ static int efx_test_interrupts(struct efx_nic *efx,
         /* Wait for arrival of test interrupt. */
         netif_dbg(efx, drv, efx->net_dev, "waiting for test interrupt\n");
         schedule_timeout_uninterruptible(HZ / 10);
-        if (efx->last_irq_cpu >= 0)
+        cpu = ACCESS_ONCE(efx->last_irq_cpu);
+        if (cpu >= 0)
                 goto success;
 
         netif_err(efx, drv, efx->net_dev, "timed out waiting for interrupt\n");
@@ -150,8 +153,7 @@ static int efx_test_interrupts(struct efx_nic *efx,
 
  success:
         netif_dbg(efx, drv, efx->net_dev, "%s test interrupt seen on CPU%d\n",
-                  INT_MODE(efx),
-                efx->last_irq_cpu);
+                  INT_MODE(efx), cpu);
         tests->interrupt = 1;
         return 0;
 }
@@ -165,7 +167,7 @@ static int efx_test_eventq_irq(struct efx_channel *channel,
         bool napi_ran, dma_seen, int_seen;
 
         read_ptr = channel->eventq_read_ptr;
-        channel->efx->last_irq_cpu = -1;
+        channel->last_irq_cpu = -1;
         smp_wmb();
 
         efx_nic_generate_test_event(channel);
@@ -182,7 +184,7 @@ static int efx_test_eventq_irq(struct efx_channel *channel,
         } else {
                 napi_ran = false;
                 dma_seen = efx_nic_event_present(channel);
-                int_seen = efx->last_irq_cpu >= 0;
+                int_seen = ACCESS_ONCE(channel->last_irq_cpu) >= 0;
         }
         napi_enable(&channel->napi_str);
         efx_nic_eventq_read_ack(channel);