add debugfs statistics and some code cleanup

3 files changed, 47 insertions, 25 deletions

diff --git a/arch/arm/mach-mvf/mvf_sema4.c b/arch/arm/mach-mvf/mvf_sema4.c
index 311b56a69d73..00c3cb664d79 100644
--- a/arch/arm/mach-mvf/mvf_sema4.c
+++ b/arch/arm/mach-mvf/mvf_sema4.c
@@ -35,6 +35,8 @@
 #include <linux/time.h>
 //#endif
 
+#include <linux/debugfs.h>
+
 #include <linux/mvf_sema4.h>
 
 // ************************************ Local Data *************************************************
@@ -46,6 +48,9 @@ static bool initialized = false;
 // account for the way the bits are set / returned in CP0INE and CP0NTF
 static const int idx[16] = {3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8, 15, 14, 13, 12};
 
+// debugfs
+#define DEBUGFS_DIR "mvf_sema4"
+static struct dentry *debugfs_dir;
 
 // ************************************ Interrupt handler *************************************************
 
@@ -66,9 +71,12 @@ static irqreturn_t sema4_irq_handler(int irq, void *dev_id)
 			// make sure there's a gate assigned
 			if(gates[gate_num])
 			{
-				if(gates[gate_num]->use_interrupts)
+				if(gates[gate_num]->use_interrupts) {
 					// wake up whoever was aiting
 					wake_up_interruptible(&(gates[gate_num]->wait_queue));
+					// bump stats
+					gates[gate_num]->interrupts++;
+				}
 			}
 		}
 	}
@@ -78,19 +86,6 @@ static irqreturn_t sema4_irq_handler(int irq, void *dev_id)
 
 // ************************************ Utility functions *************************************************
 
-static int find_sema4(MVF_SEMA4 *sema4)
-{
-	int i;
-
-	for(i=0; i<NUM_GATES; i++)
-	{
-		if(gates[i] == sema4)
-			return i;
-	}
-
-	return -EINVAL;
-}
-
 static int initialize(void)
 {
 	int i;
@@ -109,6 +104,9 @@ static int initialize(void)
 		return -EIO;
 	}
 
+	// debugfs
+	debugfs_dir = debugfs_create_dir(DEBUGFS_DIR, NULL);
+
 	initialized = true;
 	return 0;
 }
@@ -118,6 +116,7 @@ int mvf_sema4_assign(int gate_num, bool use_interrupts, MVF_SEMA4** sema4_p)
 	int retval;
 	u32 cp0ine;
 	unsigned long irq_flags;
+	char debugfs_gatedir[4];
 
 	// take the opportunity to initialize the whole sub-system
 	if(!initialized)
@@ -136,6 +135,7 @@ int mvf_sema4_assign(int gate_num, bool use_interrupts, MVF_SEMA4** sema4_p)
 	*sema4_p = (MVF_SEMA4 *)kmalloc(sizeof(MVF_SEMA4), GFP_KERNEL);
 	if(*sema4_p == NULL)
 		return -ENOMEM;
+	memset(*sema4_p, 0, sizeof(MVF_SEMA4));
 
 	gates[gate_num] = *sema4_p;
 	(*sema4_p)->gate_num = gate_num;
@@ -151,6 +151,12 @@ int mvf_sema4_assign(int gate_num, bool use_interrupts, MVF_SEMA4** sema4_p)
 		local_irq_restore(irq_flags);
 	}
 
+	// debugfs
+	sprintf(debugfs_gatedir, "%d", gate_num);
+	debugfs_dir = debugfs_create_dir(debugfs_gatedir, debugfs_dir);
+	debugfs_create_u32("attempts", 0444, debugfs_dir, &(*sema4_p)->attempts);
+	debugfs_create_u32("interrupts", 0444, debugfs_dir, &(*sema4_p)->interrupts);
+
 	return 0;
 }
 
@@ -159,9 +165,10 @@ int mvf_sema4_deassign(MVF_SEMA4 *sema4)
 	u32 cp0ine;
 	unsigned long irq_flags;
 
-	int gate_num = find_sema4(sema4);
-	if(gate_num < 0)
-		return gate_num;
+	int gate_num;
+	if(!sema4)
+		return -EINVAL;
+	gate_num = sema4->gate_num;
 
 	if(sema4->use_interrupts)
 	{
@@ -181,15 +188,19 @@ int mvf_sema4_deassign(MVF_SEMA4 *sema4)
 int mvf_sema4_lock(MVF_SEMA4 *sema4, unsigned int timeout_us)
 {
 	int retval;
-	int gate_num = find_sema4(sema4);
-	if(gate_num < 0)
-		return gate_num;
+	int gate_num;
+	if(!sema4)
+		return -EINVAL;
+	gate_num = sema4->gate_num;
 
 	// cant use timeouts if not using interruppts
 	// TODO use spin lock if not using interrupts
 	if((!sema4->use_interrupts) && timeout_us)
 		return -EINVAL;
 
+	// bump stats
+	gates[gate_num]->attempts++;
+
 	// try to grab it
 	writeb(LOCK_VALUE, MVF_IO_ADDRESS(MVF_SEMA4_BASE_ADDR) + gate_num);
 	if(readb(MVF_IO_ADDRESS(MVF_SEMA4_BASE_ADDR) + gate_num) == LOCK_VALUE)
@@ -222,12 +233,11 @@ int mvf_sema4_lock(MVF_SEMA4 *sema4, unsigned int timeout_us)
 
 int mvf_sema4_unlock(MVF_SEMA4 *sema4)
 {
-	int gate_num = find_sema4(sema4);
-	if(gate_num < 0)
-		return gate_num;
+	if(!sema4)
+		return -EINVAL;
 
 	// unlock it
-	writeb(0, MVF_IO_ADDRESS(MVF_SEMA4_BASE_ADDR) + gate_num);
+	writeb(0, MVF_IO_ADDRESS(MVF_SEMA4_BASE_ADDR) + sema4->gate_num);
 
 	return 0;
 }
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 36bad1eaa428..65525e1c25b3 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -621,7 +621,7 @@ static int __init i2c_imx_probe(struct platform_device *pdev)
 
 #ifdef CONFIG_ARCH_MVF
 	// make sure not in use by MQX
-	if(mvf_sema4_assign(3, true, &sema4)) {
+	if(mvf_sema4_assign(MCC_I2C_SEMAPHORE_NUMBER, true, &sema4)) {
 		dev_err(&pdev->dev, "could not grab MQX semaphore\n");
 		goto fail5;
 	}
diff --git a/include/linux/mvf_sema4.h b/include/linux/mvf_sema4.h
index 898065afb23f..7a93551e4905 100644
--- a/include/linux/mvf_sema4.h
+++ b/include/linux/mvf_sema4.h
@@ -1,10 +1,22 @@
 #ifndef __MVF_SEMA4__
 #define __MVF_SEMA4__
 
+#include <linux/sched.h>
+
+#define MVF_SHMEM_SEMAPHORE_NUMBER      (1)
+#define MVF_PRINTF_SEMAPHORE_NUMBER     (2)
+#define MVF_I2C_SEMAPHORE_NUMBER        (3)
+#define MVF_RESERVED1_SEMAPHORE_NUMBER  (4)
+#define MVF_RESERVED2_SEMAPHORE_NUMBER  (5)
+
 typedef struct mvf_sema4_handle_struct {
 	int gate_num;
 	int use_interrupts;
 	wait_queue_head_t wait_queue;
+	// stats
+	unsigned long attempts;
+	unsigned long interrupts;
+	struct dentry *debugfs_file;
 } MVF_SEMA4;
 
 int mvf_sema4_assign(int gate_num, bool use_interrupts, MVF_SEMA4** sema4_p);