linux-kernel - [PATCH 1/2] xhci: Use ilog2() rather than __ffs() for calculating SEGMENT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 28 Mar 2013 18:48:28 +0000
From:	David Howells <dhowells@...hat.com>
To:	sarah.a.sharp@...ux.intel.com
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] xhci: Use ilog2() rather than __ffs() for calculating
 SEGMENT_SHIFT

Use ilog2() rather than __ffs() for calculating SEGMENT_SHIFT as ilog2() can
be worked out at compile time, whereas __ffs() must be calculated at runtime.

Signed-off-by: David Howells <dhowells@...hat.com>
cc: Sarah Sharp <sarah.a.sharp@...ux.intel.com>
cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
cc: linux-usb@...r.kernel.org
---

 drivers/usb/host/xhci.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 2c510e4..558ba50 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1235,7 +1235,7 @@ union xhci_trb {
 /* Allow two commands + a link TRB, along with any reserved command TRBs */
 #define MAX_RSVD_CMD_TRBS	(TRBS_PER_SEGMENT - 3)
 #define SEGMENT_SIZE		(TRBS_PER_SEGMENT*16)
-#define SEGMENT_SHIFT		(__ffs(SEGMENT_SIZE))
+#define SEGMENT_SHIFT		(ilog2(SEGMENT_SIZE))
 /* TRB buffer pointers can't cross 64KB boundaries */
 #define TRB_MAX_BUFF_SHIFT		16
 #define TRB_MAX_BUFF_SIZE	(1 << TRB_MAX_BUFF_SHIFT)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/