git: e66c1b51850c - main - nvme: Define NVME_MPS_SHIFT

From: Warner Losh <imp_at_FreeBSD.org>
Date: Fri, 15 Apr 2022 20:46:42 UTC
The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=e66c1b51850cbe5e2b02a13131dfce83a0c9a121

commit e66c1b51850cbe5e2b02a13131dfce83a0c9a121
Author:     Warner Losh <imp@FreeBSD.org>
AuthorDate: 2022-04-15 20:40:41 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2022-04-15 20:46:18 +0000

    nvme: Define NVME_MPS_SHIFT
    
    The memory page size (MPS) is expressed in terms of a 2^(number + 12)
    and other items in the system inherit this. Create a define rather than
    sprinkling 12 everywehere.
    
    Sponsored by:           Netflix
    Reviewed by:            chuck
    Differential Revision:  https://reviews.freebsd.org/D34865
---
 sys/dev/nvme/nvme.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sys/dev/nvme/nvme.h b/sys/dev/nvme/nvme.h
index 55e94c40dd2c..e120656d0050 100644
--- a/sys/dev/nvme/nvme.h
+++ b/sys/dev/nvme/nvme.h
@@ -65,6 +65,9 @@
 /* Host memory buffer sizes are always in 4096 byte chunks */
 #define	NVME_HMB_UNITS			4096
 
+/* Many items are expressed in terms of power of two times MPS */
+#define NVME_MPS_SHIFT			12
+
 /* Register field definitions */
 #define NVME_CAP_LO_REG_MQES_SHIFT			(0)
 #define NVME_CAP_LO_REG_MQES_MASK			(0xFFFF)