nfp: add a mutex lock for the vNIC ctrl BAR

Soon we will try to write to the vNIC mailbox without RTNL held.
Add a new mutex to protect access to specific parts of the PCI
control BAR.

Move the mailbox size checking to the mailbox lock() helper, where
it can be more effective (happen prior to potential overwrite of
other data).

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 2 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index be37c2d6151c..df9aff2684ed 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -539,12 +539,17 @@ struct nfp_net_dp {
  * @shared_handler:     Handler for shared interrupts
  * @shared_name:        Name for shared interrupt
  * @me_freq_mhz:        ME clock_freq (MHz)
- * @reconfig_lock:	Protects HW reconfiguration request regs/machinery
+ * @reconfig_lock:	Protects @reconfig_posted, @reconfig_timer_active,
+ *			@reconfig_sync_present and HW reconfiguration request
+ *			regs/machinery from async requests (sync must take
+ *			@bar_lock)
  * @reconfig_posted:	Pending reconfig bits coming from async sources
  * @reconfig_timer_active:  Timer for reading reconfiguration results is pending
  * @reconfig_sync_present:  Some thread is performing synchronous reconfig
  * @reconfig_timer:	Timer for async reading of reconfig results
  * @reconfig_in_progress_update:	Update FW is processing now (debug only)
+ * @bar_lock:		vNIC config BAR access lock, protects: update,
+ *			mailbox area
  * @link_up:            Is the link up?
  * @link_status_lock:	Protects @link_* and ensures atomicity with BAR reading
  * @rx_coalesce_usecs:      RX interrupt moderation usecs delay parameter
@@ -615,6 +620,8 @@ struct nfp_net {
 	struct timer_list reconfig_timer;
 	u32 reconfig_in_progress_update;
 
+	struct mutex bar_lock;
+
 	u32 rx_coalesce_usecs;
 	u32 rx_coalesce_max_frames;
 	u32 tx_coalesce_usecs;
@@ -839,6 +846,16 @@ static inline void nfp_ctrl_unlock(struct nfp_net *nn)
 	spin_unlock_bh(&nn->r_vecs[0].lock);
 }
 
+static inline void nn_ctrl_bar_lock(struct nfp_net *nn)
+{
+	mutex_lock(&nn->bar_lock);
+}
+
+static inline void nn_ctrl_bar_unlock(struct nfp_net *nn)
+{
+	mutex_unlock(&nn->bar_lock);
+}
+
 /* Globals */
 extern const char nfp_driver_version[];
 
@@ -871,7 +888,9 @@ unsigned int nfp_net_rss_key_sz(struct nfp_net *nn);
 void nfp_net_rss_write_itbl(struct nfp_net *nn);
 void nfp_net_rss_write_key(struct nfp_net *nn);
 void nfp_net_coalesce_write_cfg(struct nfp_net *nn);
-int nfp_net_reconfig_mbox(struct nfp_net *nn, u32 mbox_cmd);
+int nfp_net_mbox_lock(struct nfp_net *nn, unsigned int data_size);
+int nfp_net_mbox_reconfig(struct nfp_net *nn, u32 mbox_cmd);
+int nfp_net_mbox_reconfig_and_unlock(struct nfp_net *nn, u32 mbox_cmd);
 
 unsigned int
 nfp_net_irqs_alloc(struct pci_dev *pdev, struct msix_entry *irq_entries,