qed: Fix scheduling in a tasklet while getting stats

Here we've got to a situation when tasklet called usleep_range() in PTT
acquire logic, thus welcome to the "scheduling while atomic" BUG().

  BUG: scheduling while atomic: swapper/24/0/0x00000100

   [<ffffffffb41c6199>] schedule+0x29/0x70
   [<ffffffffb41c5512>] schedule_hrtimeout_range_clock+0xb2/0x150
   [<ffffffffb41c55c3>] schedule_hrtimeout_range+0x13/0x20
   [<ffffffffb41c3bcf>] usleep_range+0x4f/0x70
   [<ffffffffc08d3e58>] qed_ptt_acquire+0x38/0x100 [qed]
   [<ffffffffc08eac48>] _qed_get_vport_stats+0x458/0x580 [qed]
   [<ffffffffc08ead8c>] qed_get_vport_stats+0x1c/0xd0 [qed]
   [<ffffffffc08dffd3>] qed_get_protocol_stats+0x93/0x100 [qed]
                        qed_mcp_send_protocol_stats
            case MFW_DRV_MSG_GET_LAN_STATS:
            case MFW_DRV_MSG_GET_FCOE_STATS:
            case MFW_DRV_MSG_GET_ISCSI_STATS:
            case MFW_DRV_MSG_GET_RDMA_STATS:
   [<ffffffffc08e36d8>] qed_mcp_handle_events+0x2d8/0x890 [qed]
                        qed_int_assertion
                        qed_int_attentions
   [<ffffffffc08d9490>] qed_int_sp_dpc+0xa50/0xdc0 [qed]
   [<ffffffffb3aa7623>] tasklet_action+0x83/0x140
   [<ffffffffb41d9125>] __do_softirq+0x125/0x2bb
   [<ffffffffb41d560c>] call_softirq+0x1c/0x30
   [<ffffffffb3a30645>] do_softirq+0x65/0xa0
   [<ffffffffb3aa78d5>] irq_exit+0x105/0x110
   [<ffffffffb41d8996>] do_IRQ+0x56/0xf0

Fix this by making caller to provide the context whether it could be in
atomic context flow or not when getting stats from QED driver.
QED driver based on the context provided decide to schedule out or not
when acquiring the PTT BAR window.

We faced the BUG_ON() while getting vport stats, but according to the
code same issue could happen for fcoe and iscsi statistics as well, so
fixing them too.

Fixes: 6c75424612a7 ("qed: Add support for NCSI statistics.")
Fixes: 1e128c81290a ("qed: Add support for hardware offloaded FCoE.")
Fixes: 2f2b2614e893 ("qed: Provide iSCSI statistics to management")
Cc: Sudarsana Kalluru <skalluru@marvell.com>
Cc: David Miller <davem@davemloft.net>
Cc: Manish Chopra <manishc@marvell.com>

Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/net/ethernet/qlogic/qed/qed_iscsi.h b/drivers/net/ethernet/qlogic/qed/qed_iscsi.h
index dec2b00259d4..974cb8d26608 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_iscsi.h
+++ b/drivers/net/ethernet/qlogic/qed/qed_iscsi.h
@@ -39,11 +39,14 @@ void qed_iscsi_free(struct qed_hwfn *p_hwfn);
  *
  * @cdev: Qed dev pointer.
  * @stats: Points to struct that will be filled with statistics.
+ * @is_atomic: Hint from the caller - if the func can sleep or not.
  *
+ * Context: The function should not sleep in case is_atomic == true.
  * Return: Void.
  */
 void qed_get_protocol_stats_iscsi(struct qed_dev *cdev,
-				  struct qed_mcp_iscsi_stats *stats);
+				  struct qed_mcp_iscsi_stats *stats,
+				  bool is_atomic);
 #else /* IS_ENABLED(CONFIG_QED_ISCSI) */
 static inline int qed_iscsi_alloc(struct qed_hwfn *p_hwfn)
 {
@@ -56,7 +59,8 @@ static inline void qed_iscsi_free(struct qed_hwfn *p_hwfn) {}
 
 static inline void
 qed_get_protocol_stats_iscsi(struct qed_dev *cdev,
-			     struct qed_mcp_iscsi_stats *stats) {}
+			     struct qed_mcp_iscsi_stats *stats,
+			     bool is_atomic) {}
 #endif /* IS_ENABLED(CONFIG_QED_ISCSI) */
 
 #endif