wct4xxp: Atomically set framer bits for maintenance modes.

Do not allow the interrupt handler or another CPU to change the value
between when we get the initial value and when we write the modified
value.

Also includes a minor formatting fix where braces were not aligned, and
remove 'inline' from t4_framer_in and t4_framer_out definitions.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Acked-by: Russ Meyerriecks <rmeyerriecks@digium.com>

git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@9931 a0bf4364-ded3-4de4-8d8a-66a801d63aff

1 files changed, 36 insertions, 30 deletions

diff --git a/drivers/dahdi/wct4xxp/base.c b/drivers/dahdi/wct4xxp/base.c
index 78e7d0a..68fe8b1 100644
--- a/drivers/dahdi/wct4xxp/base.c
+++ b/drivers/dahdi/wct4xxp/base.c
@@ -630,7 +630,8 @@ static inline unsigned int t4_pci_in(struct t4 *wc, const unsigned int addr)
 	return ret;
 }
 
-static inline unsigned int __t4_framer_in(struct t4 *wc, int unit, const unsigned int addr)
+static unsigned int __t4_framer_in(struct t4 *wc, int unit,
+				   const unsigned int addr)
 {
 	unsigned int ret;
 	unit &= 0x3;
@@ -656,7 +657,8 @@ static inline unsigned int __t4_framer_in(struct t4 *wc, int unit, const unsigne
 	return ret & 0xff;
 }
 
-static inline unsigned int t4_framer_in(struct t4 *wc, int unit, const unsigned int addr)
+static unsigned int
+t4_framer_in(struct t4 *wc, int unit, const unsigned int addr)
 {
 	unsigned long flags;
 	unsigned int ret;
@@ -667,7 +669,8 @@ static inline unsigned int t4_framer_in(struct t4 *wc, int unit, const unsigned
 
 }
 
-static inline void __t4_framer_out(struct t4 *wc, int unit, const unsigned int addr, const unsigned int value)
+static void __t4_framer_out(struct t4 *wc, int unit, const unsigned int addr,
+			    const unsigned int value)
 {
 	unit &= 0x3;
 	if (unlikely(debug & DEBUG_REGS))
@@ -697,7 +700,8 @@ static inline void __t4_framer_out(struct t4 *wc, int unit, const unsigned int a
 #endif	
 }
 
-static inline void t4_framer_out(struct t4 *wc, int unit, const unsigned int addr, const unsigned int value)
+static void t4_framer_out(struct t4 *wc, int unit, const unsigned int addr,
+			  const unsigned int value)
 {
 	unsigned long flags;
 	spin_lock_irqsave(&wc->reglock, flags);
@@ -1516,6 +1520,21 @@ static void t4_hdlc_hard_xmit(struct dahdi_chan *chan)
 		t4_hdlc_xmit_fifo(wc, span, ts);
 }
 
+/**
+ * t4_set_framer_bits - Atomically set bits in a framer register.
+ */
+static void t4_set_framer_bits(struct t4 *wc, unsigned int spanno,
+			       unsigned int const addr, u16 bits)
+{
+	unsigned long flags;
+	unsigned int reg;
+
+	spin_lock_irqsave(&wc->reglock, flags);
+	reg = __t4_framer_in(wc, spanno, addr);
+	__t4_framer_out(wc, spanno, addr, (reg | bits));
+	spin_unlock_irqrestore(&wc->reglock, flags);
+}
+
 static int t4_maint(struct dahdi_span *span, int cmd)
 {
 	struct t4_span *ts = container_of(span, struct t4_span, span);
@@ -1533,22 +1552,19 @@ static int t4_maint(struct dahdi_span *span, int cmd)
 			dev_info(&wc->dev->dev,
 				 "Turning on local loopback\n");
 			t4_clear_maint(span);
-			reg = t4_framer_in(wc, span->offset, LIM0_T);
-			t4_framer_out(wc, span->offset, LIM0_T, (reg|LIM0_LL));
+			t4_set_framer_bits(wc, span->offset, LIM0_T, LIM0_LL);
 			break;
 		case DAHDI_MAINT_NETWORKLINELOOP:
 			dev_info(&wc->dev->dev,
 				 "Turning on network line loopback\n");
 			t4_clear_maint(span);
-			reg = t4_framer_in(wc, span->offset, LIM1_T);
-			t4_framer_out(wc, span->offset, LIM1_T, (reg|LIM1_RL));
+			t4_set_framer_bits(wc, span->offset, LIM1_T, LIM1_RL);
 			break;
 		case DAHDI_MAINT_NETWORKPAYLOADLOOP:
 			dev_info(&wc->dev->dev,
 				 "Turning on network payload loopback\n");
 			t4_clear_maint(span);
-			reg = t4_framer_in(wc, span->offset, FMR2_T);
-			t4_framer_out(wc, span->offset, FMR2_T, (reg|FMR2_PLB));
+			t4_set_framer_bits(wc, span->offset, FMR2_T, FMR2_PLB);
 			break;
 		case DAHDI_MAINT_LOOPUP:
 		case DAHDI_MAINT_LOOPDOWN:
@@ -1578,8 +1594,7 @@ static int t4_maint(struct dahdi_span *span, int cmd)
 			break;
 		case DAHDI_MAINT_ALARM_SIM:
 			dev_info(&wc->dev->dev, "Invoking alarm state");
-			reg = t4_framer_in(wc, span->offset, FMR0);
-			t4_framer_out(wc, span->offset, FMR0, (reg|FMR0_SIM));
+			t4_set_framer_bits(wc, span->offset, FMR0, FMR0_SIM);
 			break;
 		default:
 			dev_info(&wc->dev->dev,
@@ -1596,39 +1611,30 @@ static int t4_maint(struct dahdi_span *span, int cmd)
 			dev_info(&wc->dev->dev,
 				 "Turning on local loopback\n");
 			t4_clear_maint(span);
-			reg = t4_framer_in(wc, span->offset, LIM0_T);
-			t4_framer_out(wc, span->offset, LIM0_T, (reg|LIM0_LL));
+			t4_set_framer_bits(wc, span->offset, LIM0_T, LIM0_LL);
 			break;
 		case DAHDI_MAINT_NETWORKLINELOOP:
 			dev_info(&wc->dev->dev,
 				 "Turning on network line loopback\n");
 			t4_clear_maint(span);
-			reg = t4_framer_in(wc, span->offset, LIM1_T);
-			t4_framer_out(wc, span->offset, LIM1_T, (reg|LIM1_RL));
+			t4_set_framer_bits(wc, span->offset, LIM1_T, LIM1_RL);
 			break;
 		case DAHDI_MAINT_NETWORKPAYLOADLOOP:
 			dev_info(&wc->dev->dev,
 				 "Turning on network payload loopback\n");
 			t4_clear_maint(span);
-			reg = t4_framer_in(wc, span->offset, FMR2_T);
-			t4_framer_out(wc, span->offset, FMR2_T, (reg|FMR2_PLB));
+			t4_set_framer_bits(wc, span->offset, FMR2_T, FMR2_PLB);
 			break;
 		case DAHDI_MAINT_LOOPUP:
 			dev_info(&wc->dev->dev, "Transmitting loopup code\n");
 			t4_clear_maint(span);
-			spin_lock_irqsave(&wc->reglock, flags);
-			reg = __t4_framer_in(wc, span->offset, FMR5);
-			__t4_framer_out(wc, span->offset, FMR5, (reg|FMR5_XLU));
-			spin_unlock_irqrestore(&wc->reglock, flags);
+			t4_set_framer_bits(wc, span->offset, FMR5, FMR5_XLU);
 			ts->span.maintstat = DAHDI_MAINT_REMOTELOOP;
 			break;
 		case DAHDI_MAINT_LOOPDOWN:
 			dev_info(&wc->dev->dev, "Transmitting loopdown code\n");
 			t4_clear_maint(span);
-			spin_lock_irqsave(&wc->reglock, flags);
-			reg = __t4_framer_in(wc, span->offset, FMR5);
-			__t4_framer_out(wc, span->offset, FMR5, (reg|FMR5_XLD));
-			spin_unlock_irqrestore(&wc->reglock, flags);
+			t4_set_framer_bits(wc, span->offset, FMR5, FMR5_XLD);
 			ts->span.maintstat = DAHDI_MAINT_NONE;
 			break;
 		case DAHDI_MAINT_FAS_DEFECT:
@@ -1672,13 +1678,13 @@ static int t4_maint(struct dahdi_span *span, int cmd)
 			t4_reset_counters(span);
 			break;
 		case DAHDI_MAINT_ALARM_SIM:
-			reg = t4_framer_in(wc, span->offset, FMR0);
+			spin_lock_irqsave(&wc->reglock, flags);
+			reg = __t4_framer_in(wc, span->offset, FMR0);
 
 			/*
 			 * The alarm simulation state machine requires us to
 			 * bring this bit up and down for at least 1 clock cycle
 			 */
-			spin_lock_irqsave(&wc->reglock, flags);
 			__t4_framer_out(wc, span->offset,
 					FMR0, (reg | FMR0_SIM));
 			udelay(1);
@@ -1698,8 +1704,8 @@ static int t4_maint(struct dahdi_span *span, int cmd)
 			dev_info(&wc->dev->dev, "Unknown T1 maint command:%d\n",
 									cmd);
 			break;
-	   }
-    }
+		}
+	}
 	return 0;
 }