X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fparisc%2Flib%2Fdebuglocks.c;h=5ac3eb04727661c0366bd0d24db184cac055aa5d;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=5166a9378cfa0bd2a9a395eb9d3f716b620fc4f5;hpb=87fc8d1bb10cd459024a742c6a10961fefcef18f;p=linux-2.6.git

diff --git a/arch/parisc/lib/debuglocks.c b/arch/parisc/lib/debuglocks.c
index 5166a9378..5ac3eb047 100644
--- a/arch/parisc/lib/debuglocks.c
+++ b/arch/parisc/lib/debuglocks.c
@@ -18,6 +18,11 @@
  *    You should have received a copy of the GNU General Public License
  *    along with this program; if not, write to the Free Software
  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *    We use pdc_printf() throughout the file for all output messages, to avoid
+ *    losing messages because of disabled interrupts. Since we're using these
+ *    messages for debugging purposes, it makes sense not to send them to the
+ *    linux console.
  */
 
 
@@ -27,12 +32,15 @@
 #include <linux/spinlock.h>
 #include <linux/hardirq.h>	/* in_interrupt() */
 #include <asm/system.h>
+#include <asm/hardirq.h>	/* in_interrupt() */
+#include <asm/pdc.h>
 
 #undef INIT_STUCK
 #define INIT_STUCK 1L << 30
 
 #ifdef CONFIG_DEBUG_SPINLOCK
 
+
 void _dbg_spin_lock(spinlock_t * lock, const char *base_file, int line_no)
 {
 	volatile unsigned int *a;
@@ -59,12 +67,14 @@ try_again:
 	 * <tausq> __ldcw() returns 1 if we get the lock; otherwise we
 	 * 	spin until the value of the lock changes, or we time out.
 	 */
+	mb();
 	a = __ldcw_align(lock);
 	while (stuck && (__ldcw(a) == 0))
 		while ((*a == 0) && --stuck);
+	mb();
 
 	if (unlikely(stuck <= 0)) {
-		printk(KERN_WARNING
+		pdc_printf(
 			"%s:%d: spin_lock(%s/%p) stuck in %s at %p(%d)"
 			" owned by %s:%d in %s at %p(%d)\n",
 			base_file, line_no, lock->module, lock,
@@ -84,7 +94,7 @@ try_again:
 	lock->bline = line_no;
 
 	if (unlikely(printed)) {
-		printk(KERN_WARNING
+		pdc_printf(
 			"%s:%d: spin_lock grabbed in %s at %p(%d) %ld ticks\n",
 			base_file, line_no, current->comm, inline_pc,
 			cpu, jiffies - started);
@@ -94,21 +104,28 @@ try_again:
 void _dbg_spin_unlock(spinlock_t * lock, const char *base_file, int line_no)
 {
 	CHECK_LOCK(lock);
-	volatile unsigned int *a = __ldcw_align(lock);
+	volatile unsigned int *a;
+	mb();
+	a = __ldcw_align(lock);
 	if (unlikely((*a != 0) && lock->babble)) {
 		lock->babble--;
-		printk(KERN_WARNING
+		pdc_printf(
 			"%s:%d: spin_unlock(%s:%p) not locked\n",
 			base_file, line_no, lock->module, lock);
 	}
 	*a = 1;	
+	mb();
 }
 
 int _dbg_spin_trylock(spinlock_t * lock, const char *base_file, int line_no)
 {
 	int ret;
-	volatile unsigned int *a = __ldcw_align(lock);
-	if ((ret = (__ldcw(a) != 0))) {
+	volatile unsigned int *a;
+	mb();
+	a = __ldcw_align(lock);
+	ret = (__ldcw(a) != 0);
+	mb();
+	if (ret) {
 		lock->oncpu = smp_processor_id();
 		lock->previous = __builtin_return_address(0);
 		lock->task = current;
@@ -150,7 +167,7 @@ void _dbg_write_lock(rwlock_t *rw, const char *bfile, int bline)
 	int cpu = smp_processor_id();
 	
 	if(unlikely(in_interrupt())) {	/* acquiring write lock in interrupt context, bad idea */
-		printk(KERN_WARNING "write_lock caller: %s:%d, IRQs enabled,\n", bfile, bline);
+		pdc_printf("write_lock caller: %s:%d, IRQs enabled,\n", bfile, bline);
 		BUG();
 	}
 
@@ -167,7 +184,7 @@ retry:
 		
 		stuck--;
 		if ((unlikely(stuck <= 0)) && (rw->counter < 0)) {
-			printk(KERN_WARNING
+			pdc_printf(
 				"%s:%d: write_lock stuck on writer"
 				" in %s at %p(%d) %ld ticks\n",
 				bfile, bline, current->comm, inline_pc,
@@ -176,7 +193,7 @@ retry:
 			printed = 1;
 		}
 		else if (unlikely(stuck <= 0)) {
-			printk(KERN_WARNING
+			pdc_printf(
 				"%s:%d: write_lock stuck on reader"
 				" in %s at %p(%d) %ld ticks\n",
 				bfile, bline, current->comm, inline_pc,
@@ -194,13 +211,47 @@ retry:
 	rw->counter = -1; /* remember we are locked */
 
 	if (unlikely(printed)) {
-		printk(KERN_WARNING
+		pdc_printf(
 			"%s:%d: write_lock grabbed in %s at %p(%d) %ld ticks\n",
 			bfile, bline, current->comm, inline_pc,
 			cpu, jiffies - started);
 	}
 }
 
+int _dbg_write_trylock(rwlock_t *rw, const char *bfile, int bline)
+{
+#if 0
+	void *inline_pc = __builtin_return_address(0);
+	int cpu = smp_processor_id();
+#endif
+	
+	if(unlikely(in_interrupt())) {	/* acquiring write lock in interrupt context, bad idea */
+		pdc_printf("write_lock caller: %s:%d, IRQs enabled,\n", bfile, bline);
+		BUG();
+	}
+
+	/* Note: if interrupts are disabled (which is most likely), the printk
+	will never show on the console. We might need a polling method to flush
+	the dmesg buffer anyhow. */
+	
+	_raw_spin_lock(&rw->lock);
+
+	if(rw->counter != 0) {
+		/* this basically never happens */
+		_raw_spin_unlock(&rw->lock);
+		
+		
+		return 0;
+	}
+
+	/* got it.  now leave without unlocking */
+	rw->counter = -1; /* remember we are locked */
+#if 0
+	pdc_printf("%s:%d: try write_lock grabbed in %s at %p(%d)\n",
+		   bfile, bline, current->comm, inline_pc, cpu);
+#endif
+}
+
 void _dbg_read_lock(rwlock_t * rw, const char *bfile, int bline)
 {
 #if 0
@@ -215,7 +266,7 @@ void _dbg_read_lock(rwlock_t * rw, const char *bfile, int bline)
 
 	rw->counter++;
 #if 0
-	printk(KERN_WARNING
+	pdc_printf(
 		"%s:%d: read_lock grabbed in %s at %p(%d) %ld ticks\n",
 		bfile, bline, current->comm, inline_pc,
 		cpu, jiffies - started);