Index: head/sys/dev/nvme/nvme.h
===================================================================
--- head/sys/dev/nvme/nvme.h
+++ head/sys/dev/nvme/nvme.h
@@ -69,6 +69,14 @@
 #define NVME_CAP_LO_REG_AMS_MASK			(0x3)
 #define NVME_CAP_LO_REG_TO_SHIFT			(24)
 #define NVME_CAP_LO_REG_TO_MASK				(0xFF)
+#define NVME_CAP_LO_MQES(x) \
+	(((x) >> NVME_CAP_LO_REG_MQES_SHIFT) & NVME_CAP_LO_REG_MQES_MASK)
+#define NVME_CAP_LO_CQR(x) \
+	(((x) >> NVME_CAP_LO_REG_CQR_SHIFT) & NVME_CAP_LO_REG_CQR_MASK)
+#define NVME_CAP_LO_AMS(x) \
+	(((x) >> NVME_CAP_LO_REG_AMS_SHIFT) & NVME_CAP_LO_REG_AMS_MASK)
+#define NVME_CAP_LO_TO(x) \
+	(((x) >> NVME_CAP_LO_REG_TO_SHIFT) & NVME_CAP_LO_REG_TO_MASK)
 
 #define NVME_CAP_HI_REG_DSTRD_SHIFT			(0)
 #define NVME_CAP_HI_REG_DSTRD_MASK			(0xF)
@@ -78,6 +86,14 @@
 #define NVME_CAP_HI_REG_MPSMIN_MASK			(0xF)
 #define NVME_CAP_HI_REG_MPSMAX_SHIFT			(20)
 #define NVME_CAP_HI_REG_MPSMAX_MASK			(0xF)
+#define NVME_CAP_HI_DSTRD(x) \
+	(((x) >> NVME_CAP_HI_REG_DSTRD_SHIFT) & NVME_CAP_HI_REG_DSTRD_MASK)
+#define NVME_CAP_HI_CSS_NVM(x) \
+	(((x) >> NVME_CAP_HI_REG_CSS_NVM_SHIFT) & NVME_CAP_HI_REG_CSS_NVM_MASK)
+#define NVME_CAP_HI_MPSMIN(x) \
+	(((x) >> NVME_CAP_HI_REG_MPSMIN_SHIFT) & NVME_CAP_HI_REG_MPSMIN_MASK)
+#define NVME_CAP_HI_MPSMAX(x) \
+	(((x) >> NVME_CAP_HI_REG_MPSMAX_SHIFT) & NVME_CAP_HI_REG_MPSMAX_MASK)
 
 #define NVME_CC_REG_EN_SHIFT				(0)
 #define NVME_CC_REG_EN_MASK				(0x1)
Index: head/sys/dev/nvme/nvme_ctrlr.c
===================================================================
--- head/sys/dev/nvme/nvme_ctrlr.c
+++ head/sys/dev/nvme/nvme_ctrlr.c
@@ -137,7 +137,7 @@
 	 *  the MQES field in the capabilities register.
 	 */
 	cap_lo = nvme_mmio_read_4(ctrlr, cap_lo);
-	mqes = (cap_lo >> NVME_CAP_LO_REG_MQES_SHIFT) & NVME_CAP_LO_REG_MQES_MASK;
+	mqes = NVME_CAP_LO_MQES(cap_lo);
 	num_entries = min(num_entries, mqes + 1);
 
 	num_trackers = NVME_IO_TRACKERS;
@@ -1246,16 +1246,16 @@
 	 *  other than zero, but this driver is not set up to handle that.
 	 */
 	cap_hi = nvme_mmio_read_4(ctrlr, cap_hi);
-	dstrd = (cap_hi >> NVME_CAP_HI_REG_DSTRD_SHIFT) & NVME_CAP_HI_REG_DSTRD_MASK;
+	dstrd = NVME_CAP_HI_DSTRD(cap_hi);
 	if (dstrd != 0)
 		return (ENXIO);
 
-	mpsmin = (cap_hi >> NVME_CAP_HI_REG_MPSMIN_SHIFT) & NVME_CAP_HI_REG_MPSMIN_MASK;
+	mpsmin = NVME_CAP_HI_MPSMIN(cap_hi);
 	ctrlr->min_page_size = 1 << (12 + mpsmin);
 
 	/* Get ready timeout value from controller, in units of 500ms. */
 	cap_lo = nvme_mmio_read_4(ctrlr, cap_lo);
-	to = ((cap_lo >> NVME_CAP_LO_REG_TO_SHIFT) & NVME_CAP_LO_REG_TO_MASK) + 1;
+	to = NVME_CAP_LO_TO(cap_lo) + 1;
 	ctrlr->ready_timeout_in_ms = to * 500;
 
 	timeout_period = NVME_DEFAULT_TIMEOUT_PERIOD;