sfc: Fix IRQ cleanup in case of a probe failure

The lifetime of an irq_cpu_rmap is odd: we have to allocate it before
installing IRQ handlers and free it before removing the IRQ handlers.
As a result of this asymmetry, it was omitted from some failure paths.

On another failure path, we could try to remove IRQ handlers we
had not yet installed.

Move the irq_cpu_rmap allocation and freeing alongside IRQ handler
installation and removal, in efx_nic_{init,fini}_interrupts().
Count the number of IRQ handlers successfully installed and only
remove those on the failure path.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 787c9eb..e7284a2 100644 (file)
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -21,7 +21,6 @@
 #include <linux/ethtool.h>
 #include <linux/topology.h>
 #include <linux/gfp.h>
-#include <linux/cpu_rmap.h>
 #include <linux/aer.h>
 #include <linux/interrupt.h>
 #include "net_driver.h"
@@ -1284,29 +1283,6 @@ static unsigned int efx_wanted_parallelism(struct efx_nic *efx)
        return count;
 }
 
-static int
-efx_init_rx_cpu_rmap(struct efx_nic *efx, struct msix_entry *xentries)
-{
-#ifdef CONFIG_RFS_ACCEL
-       unsigned int i;
-       int rc;
-
-       efx->net_dev->rx_cpu_rmap = alloc_irq_cpu_rmap(efx->n_rx_channels);
-       if (!efx->net_dev->rx_cpu_rmap)
-               return -ENOMEM;
-       for (i = 0; i < efx->n_rx_channels; i++) {
-               rc = irq_cpu_rmap_add(efx->net_dev->rx_cpu_rmap,
-                                     xentries[i].vector);
-               if (rc) {
-                       free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
-                       efx->net_dev->rx_cpu_rmap = NULL;
-                       return rc;
-               }
-       }
-#endif
-       return 0;
-}
-
 /* Probe the number and type of interrupts we are able to obtain, and
  * the resulting numbers of channels and RX queues.
  */
@@ -1360,11 +1336,6 @@ static int efx_probe_interrupts(struct efx_nic *efx)
                                efx->n_tx_channels = n_channels;
                                efx->n_rx_channels = n_channels;
                        }
-                       rc = efx_init_rx_cpu_rmap(efx, xentries);
-                       if (rc) {
-                               pci_disable_msix(efx->pci_dev);
-                               return rc;
-                       }
                        for (i = 0; i < efx->n_channels; i++)
                                efx_get_channel(efx, i)->irq =
                                        xentries[i].vector;
@@ -2608,10 +2579,6 @@ static void efx_pci_remove_main(struct efx_nic *efx)
        BUG_ON(efx->state == STATE_READY);
        cancel_work_sync(&efx->reset_work);
 
-#ifdef CONFIG_RFS_ACCEL
-       free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
-       efx->net_dev->rx_cpu_rmap = NULL;
-#endif
        efx_stop_interrupts(efx, false);
        efx_nic_fini_interrupt(efx);
        efx_fini_port(efx);

diff --git a/drivers/net/ethernet/sfc/nic.c b/drivers/net/ethernet/sfc/nic.c
index f2b864c..56ed3bc 100644 (file)
--- a/drivers/net/ethernet/sfc/nic.c
+++ b/drivers/net/ethernet/sfc/nic.c
@@ -14,6 +14,7 @@
 #include <linux/pci.h>
 #include <linux/module.h>
 #include <linux/seq_file.h>
+#include <linux/cpu_rmap.h>
 #include "net_driver.h"
 #include "bitfield.h"
 #include "efx.h"
@@ -1706,6 +1707,7 @@ void efx_nic_push_rx_indir_table(struct efx_nic *efx)
 int efx_nic_init_interrupt(struct efx_nic *efx)
 {
        struct efx_channel *channel;
+       unsigned int n_irqs;
        int rc;
 
        if (!EFX_INT_MODE_USE_MSI(efx)) {
@@ -1726,7 +1728,19 @@ int efx_nic_init_interrupt(struct efx_nic *efx)
                return 0;
        }
 
+#ifdef CONFIG_RFS_ACCEL
+       if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
+               efx->net_dev->rx_cpu_rmap =
+                       alloc_irq_cpu_rmap(efx->n_rx_channels);
+               if (!efx->net_dev->rx_cpu_rmap) {
+                       rc = -ENOMEM;
+                       goto fail1;
+               }
+       }
+#endif
+
        /* Hook MSI or MSI-X interrupt */
+       n_irqs = 0;
        efx_for_each_channel(channel, efx) {
                rc = request_irq(channel->irq, efx_msi_interrupt,
                                 IRQF_PROBE_SHARED, /* Not shared */
@@ -1737,13 +1751,31 @@ int efx_nic_init_interrupt(struct efx_nic *efx)
                                  "failed to hook IRQ %d\n", channel->irq);
                        goto fail2;
                }
+               ++n_irqs;
+
+#ifdef CONFIG_RFS_ACCEL
+               if (efx->interrupt_mode == EFX_INT_MODE_MSIX &&
+                   channel->channel < efx->n_rx_channels) {
+                       rc = irq_cpu_rmap_add(efx->net_dev->rx_cpu_rmap,
+                                             channel->irq);
+                       if (rc)
+                               goto fail2;
+               }
+#endif
        }
 
        return 0;
 
  fail2:
-       efx_for_each_channel(channel, efx)
+#ifdef CONFIG_RFS_ACCEL
+       free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
+       efx->net_dev->rx_cpu_rmap = NULL;
+#endif
+       efx_for_each_channel(channel, efx) {
+               if (n_irqs-- == 0)
+                       break;
                free_irq(channel->irq, &efx->channel[channel->channel]);
+       }
  fail1:
        return rc;
 }
@@ -1753,11 +1785,14 @@ void efx_nic_fini_interrupt(struct efx_nic *efx)
        struct efx_channel *channel;
        efx_oword_t reg;
 
+#ifdef CONFIG_RFS_ACCEL
+       free_irq_cpu_rmap(efx->net_dev->rx_cpu_rmap);
+       efx->net_dev->rx_cpu_rmap = NULL;
+#endif
+
        /* Disable MSI/MSI-X interrupts */
-       efx_for_each_channel(channel, efx) {
-               if (channel->irq)
-                       free_irq(channel->irq, &efx->channel[channel->channel]);
-       }
+       efx_for_each_channel(channel, efx)
+               free_irq(channel->irq, &efx->channel[channel->channel]);
 
        /* ACK legacy interrupt */
        if (efx_nic_rev(efx) >= EFX_REV_FALCON_B0)