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-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1449979438-12038-2-git-send-email-geyslan@gmail.com>
Date:	Sun, 13 Dec 2015 01:03:39 -0300
From:	"Geyslan G. Bem" <geyslan@...il.com>
To:	peter.senna@...il.com
Cc:	"Geyslan G. Bem" <geyslan@...il.com>, linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Alan Stern <stern@...land.harvard.edu>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: [PATCH v2 01/10] usb: host: ehci-sched: refactor scan_isoc function

This patch removes an infinite 'for' loop and makes use of the already
existing 'restart' tag instead, reducing one leading tab.

It also puts the easier evaluation (live variable) to be the first in
two conditionals.

  if (live && frame == now_frame) { ...

  if (live && ((frame == now_frame) || ...

The comments and code were corrected conforming file coding style.

Tested by compilation only.
Caught by checkpatch:
 WARNING: Too many leading tabs - consider code refactoring

Signed-off-by: Geyslan G. Bem <geyslan@...il.com>
---
  v2:
    Fixes file coding indentation.
    Puts 'live' variable as the first evaluation in two ifs.
---
 drivers/usb/host/ehci-sched.c | 201 +++++++++++++++++++++---------------------
 1 file changed, 100 insertions(+), 101 deletions(-)

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index f9a3327..eb14143 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -2379,9 +2379,11 @@ static int sitd_submit (struct ehci_hcd *ehci, struct urb *urb,
 
 static void scan_isoc(struct ehci_hcd *ehci)
 {
-	unsigned	uf, now_frame, frame;
-	unsigned	fmask = ehci->periodic_size - 1;
-	bool		modified, live;
+	unsigned		uf, now_frame, frame;
+	unsigned		fmask = ehci->periodic_size - 1;
+	bool			modified, live;
+	union ehci_shadow	q, *q_p;
+	__hc32			type, *hw_p;
 
 	/*
 	 * When running, scan from last scan point up to "now"
@@ -2399,119 +2401,116 @@ static void scan_isoc(struct ehci_hcd *ehci)
 	ehci->now_frame = now_frame;
 
 	frame = ehci->last_iso_frame;
-	for (;;) {
-		union ehci_shadow	q, *q_p;
-		__hc32			type, *hw_p;
 
 restart:
-		/* scan each element in frame's queue for completions */
-		q_p = &ehci->pshadow [frame];
-		hw_p = &ehci->periodic [frame];
-		q.ptr = q_p->ptr;
-		type = Q_NEXT_TYPE(ehci, *hw_p);
-		modified = false;
-
-		while (q.ptr != NULL) {
-			switch (hc32_to_cpu(ehci, type)) {
-			case Q_TYPE_ITD:
-				/* If this ITD is still active, leave it for
-				 * later processing ... check the next entry.
-				 * No need to check for activity unless the
-				 * frame is current.
-				 */
-				if (frame == now_frame && live) {
-					rmb();
-					for (uf = 0; uf < 8; uf++) {
-						if (q.itd->hw_transaction[uf] &
-							    ITD_ACTIVE(ehci))
-							break;
-					}
-					if (uf < 8) {
-						q_p = &q.itd->itd_next;
-						hw_p = &q.itd->hw_next;
-						type = Q_NEXT_TYPE(ehci,
-							q.itd->hw_next);
-						q = *q_p;
+	/* Scan each element in frame's queue for completions */
+	q_p = &ehci->pshadow[frame];
+	hw_p = &ehci->periodic[frame];
+	q.ptr = q_p->ptr;
+	type = Q_NEXT_TYPE(ehci, *hw_p);
+	modified = false;
+
+	while (q.ptr != NULL) {
+		switch (hc32_to_cpu(ehci, type)) {
+		case Q_TYPE_ITD:
+			/*
+			 * If this ITD is still active, leave it for
+			 * later processing ... check the next entry.
+			 * No need to check for activity unless the
+			 * frame is current.
+			 */
+			if (live && frame == now_frame) {
+				rmb();
+				for (uf = 0; uf < 8; uf++) {
+					if (q.itd->hw_transaction[uf] &
+							ITD_ACTIVE(ehci))
 						break;
-					}
 				}
-
-				/* Take finished ITDs out of the schedule
-				 * and process them:  recycle, maybe report
-				 * URB completion.  HC won't cache the
-				 * pointer for much longer, if at all.
-				 */
-				*q_p = q.itd->itd_next;
-				if (!ehci->use_dummy_qh ||
-				    q.itd->hw_next != EHCI_LIST_END(ehci))
-					*hw_p = q.itd->hw_next;
-				else
-					*hw_p = cpu_to_hc32(ehci,
-							ehci->dummy->qh_dma);
-				type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
-				wmb();
-				modified = itd_complete (ehci, q.itd);
-				q = *q_p;
-				break;
-			case Q_TYPE_SITD:
-				/* If this SITD is still active, leave it for
-				 * later processing ... check the next entry.
-				 * No need to check for activity unless the
-				 * frame is current.
-				 */
-				if (((frame == now_frame) ||
-				     (((frame + 1) & fmask) == now_frame))
-				    && live
-				    && (q.sitd->hw_results &
-					SITD_ACTIVE(ehci))) {
-
-					q_p = &q.sitd->sitd_next;
-					hw_p = &q.sitd->hw_next;
+				if (uf < 8) {
+					q_p = &q.itd->itd_next;
+					hw_p = &q.itd->hw_next;
 					type = Q_NEXT_TYPE(ehci,
-							q.sitd->hw_next);
+							q.itd->hw_next);
 					q = *q_p;
 					break;
 				}
+			}
+
+			/*
+			 * Take finished ITDs out of the schedule
+			 * and process them:  recycle, maybe report
+			 * URB completion.  HC won't cache the
+			 * pointer for much longer, if at all.
+			 */
+			*q_p = q.itd->itd_next;
+			if (!ehci->use_dummy_qh ||
+					q.itd->hw_next != EHCI_LIST_END(ehci))
+				*hw_p = q.itd->hw_next;
+			else
+				*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
+			type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
+			wmb();
+			modified = itd_complete(ehci, q.itd);
+			q = *q_p;
+			break;
+		case Q_TYPE_SITD:
+			/*
+			 * If this SITD is still active, leave it for
+			 * later processing ... check the next entry.
+			 * No need to check for activity unless the
+			 * frame is current.
+			 */
+			if (live && ((frame == now_frame) ||
+					(((frame + 1) & fmask) == now_frame))
+				&& (q.sitd->hw_results & SITD_ACTIVE(ehci))) {
 
-				/* Take finished SITDs out of the schedule
-				 * and process them:  recycle, maybe report
-				 * URB completion.
-				 */
-				*q_p = q.sitd->sitd_next;
-				if (!ehci->use_dummy_qh ||
-				    q.sitd->hw_next != EHCI_LIST_END(ehci))
-					*hw_p = q.sitd->hw_next;
-				else
-					*hw_p = cpu_to_hc32(ehci,
-							ehci->dummy->qh_dma);
+				q_p = &q.sitd->sitd_next;
+				hw_p = &q.sitd->hw_next;
 				type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
-				wmb();
-				modified = sitd_complete (ehci, q.sitd);
 				q = *q_p;
 				break;
-			default:
-				ehci_dbg(ehci, "corrupt type %d frame %d shadow %p\n",
-					type, frame, q.ptr);
-				// BUG ();
-				/* FALL THROUGH */
-			case Q_TYPE_QH:
-			case Q_TYPE_FSTN:
-				/* End of the iTDs and siTDs */
-				q.ptr = NULL;
-				break;
 			}
 
-			/* assume completion callbacks modify the queue */
-			if (unlikely(modified && ehci->isoc_count > 0))
-				goto restart;
-		}
-
-		/* Stop when we have reached the current frame */
-		if (frame == now_frame)
+			/*
+			 * Take finished SITDs out of the schedule
+			 * and process them:  recycle, maybe report
+			 * URB completion.
+			 */
+			*q_p = q.sitd->sitd_next;
+			if (!ehci->use_dummy_qh ||
+					q.sitd->hw_next != EHCI_LIST_END(ehci))
+				*hw_p = q.sitd->hw_next;
+			else
+				*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
+			type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
+			wmb();
+			modified = sitd_complete(ehci, q.sitd);
+			q = *q_p;
 			break;
+		default:
+			ehci_dbg(ehci, "corrupt type %d frame %d shadow %p\n",
+					type, frame, q.ptr);
+			/* BUG(); */
+			/* FALL THROUGH */
+		case Q_TYPE_QH:
+		case Q_TYPE_FSTN:
+			/* End of the iTDs and siTDs */
+			q.ptr = NULL;
+			break;
+		}
 
-		/* The last frame may still have active siTDs */
-		ehci->last_iso_frame = frame;
-		frame = (frame + 1) & fmask;
+		/* Assume completion callbacks modify the queue */
+		if (unlikely(modified && ehci->isoc_count > 0))
+			goto restart;
 	}
+
+	/* Stop when we have reached the current frame */
+	if (frame == now_frame)
+		return;
+
+	/* The last frame may still have active siTDs */
+	ehci->last_iso_frame = frame;
+	frame = (frame + 1) & fmask;
+
+	goto restart;
 }
-- 
2.6.3

--
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ