isci: cleanup/optimize queue increment macros

Every single i/o or event completion incurs a test and branch to see if
the cycle bit changed.  For power-of-2 queue sizes the cycle bit can be
read directly from the rollover of the queue pointer.

Likely premature optimization, but the hidden if() and hidden
assignments / side-effects in the macros were already asking to be
cleaned up.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/scsi/isci/isci.h b/drivers/scsi/isci/isci.h
index 81bade421b96..207328369edd 100644
--- a/drivers/scsi/isci/isci.h
+++ b/drivers/scsi/isci/isci.h
@@ -90,7 +90,8 @@ enum sci_controller_mode {
 #define SCI_MAX_DOMAINS  SCI_MAX_PORTS
 
 #define SCU_MAX_CRITICAL_NOTIFICATIONS    (384)
-#define SCU_MAX_EVENTS                    (128)
+#define SCU_MAX_EVENTS_SHIFT              (7)
+#define SCU_MAX_EVENTS                    (1 << SCU_MAX_EVENTS_SHIFT)
 #define SCU_MAX_UNSOLICITED_FRAMES        (128)
 #define SCU_MAX_COMPLETION_QUEUE_SCRATCH  (128)
 #define SCU_MAX_COMPLETION_QUEUE_ENTRIES  (SCU_MAX_CRITICAL_NOTIFICATIONS \
@@ -98,6 +99,7 @@ enum sci_controller_mode {
                                            + SCU_MAX_UNSOLICITED_FRAMES \
                                            + SCI_MAX_IO_REQUESTS \
                                            + SCU_MAX_COMPLETION_QUEUE_SCRATCH)
+#define SCU_MAX_COMPLETION_QUEUE_SHIFT    (ilog2(SCU_MAX_COMPLETION_QUEUE_ENTRIES))
 
 #define SCU_ABSOLUTE_MAX_UNSOLICITED_FRAMES (4096)
 #define SCU_UNSOLICITED_FRAME_BUFFER_SIZE   (1024)