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>
diff --git a/drivers/scsi/isci/isci.h b/drivers/scsi/isci/isci.h
index 81bade4..2073283 100644
--- a/drivers/scsi/isci/isci.h
+++ b/drivers/scsi/isci/isci.h
@@ -90,7 +90,8 @@
#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 @@
+ 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)