From: Alexander Aksenov <a.aksenov@samsung.com>
Date: Wed, 2 Apr 2014 07:25:06 +0000 (+0400)
Subject: [FIX] Buffer: disabling irqs in the same func
X-Git-Tag: Tizen_SDK_2.3~96
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=560d181252e50997e26daf057b41e70cc6e1a987;p=kernel%2Fswap-modules.git

[FIX] Buffer: disabling irqs in the same func

Now subbuffer spinlock and irqs disabling for
looking for this subbuffer are separated

Change-Id: I0018b3739a06905f1321287fe5ee7ccf1645d7d2
Signed-off-by: Alexander Aksenov <a.aksenov@samsung.com>
---

diff --git a/buffer/buffer_queue.c b/buffer/buffer_queue.c
index 8744b21..2b2f6ec 100644
--- a/buffer/buffer_queue.c
+++ b/buffer/buffer_queue.c
@@ -424,7 +424,7 @@ struct swap_subbuffer *get_from_write_list(size_t size, void **ptr_to_write)
 			write_queue.start_ptr->full_buffer_part += size;
 
 			/* Lock rw sync. Should be unlocked in swap_buffer_write() */
-			sync_lock(&result->buffer_sync);
+			sync_lock_no_flags(&result->buffer_sync);
 			break;
 		/* This subbuffer is not enough => it goes to read list */
 		} else {
diff --git a/buffer/kernel_operations.h b/buffer/kernel_operations.h
index 9327c1e..feb544b 100644
--- a/buffer/kernel_operations.h
+++ b/buffer/kernel_operations.h
@@ -62,18 +62,43 @@ static inline void sync_init(struct sync_t *buffer_sync)
 	spin_lock_init(&buffer_sync->spinlock);
 }
 
-/* Lock spinlock */
+/* Lock spinlock with save flags */
 static inline void sync_lock(struct sync_t *buffer_sync)
 {
 	spin_lock_irqsave(&buffer_sync->spinlock, buffer_sync->flags);
 }
 
-/* Unlock spinlock */
+/* Unlock spinlock with restore flags */
 static inline void sync_unlock(struct sync_t *buffer_sync)
 {
 	spin_unlock_irqrestore(&buffer_sync->spinlock, buffer_sync->flags);
 }
 
+/* Lock spinlock */
+static inline void sync_lock_no_flags(struct sync_t *buffer_sync)
+{
+	spin_lock(&buffer_sync->spinlock);
+}
+
+/* Unlock spinlock */
+static inline void sync_unlock_no_flags(struct sync_t *buffer_sync)
+{
+	spin_unlock(&buffer_sync->spinlock);
+}
+
+/* Disable preemption and irqs */
+static inline void swap_irq_disable(unsigned long *flags)
+{
+	preempt_disable();
+	local_irq_save(*flags);
+}
+
+/* Enable preemption and irqs */
+static inline void swap_irq_enable(unsigned long *flags)
+{
+	local_irq_restore(*flags);
+	preempt_enable();
+}
 
 /* SWAP SUBBUFER */
 
diff --git a/buffer/swap_buffer_module.c b/buffer/swap_buffer_module.c
index fb0f72b..211601a 100644
--- a/buffer/swap_buffer_module.c
+++ b/buffer/swap_buffer_module.c
@@ -170,6 +170,7 @@ ssize_t swap_buffer_write(void *data, size_t size)
 	int result = E_SB_SUCCESS;
 	struct swap_subbuffer *buffer_to_write = NULL;
 	void *ptr_to_write = NULL;
+	unsigned long flags = 0;
 
 	/* Size sanitization */
 	if ((size > subbuffers_size) || (size == 0))
@@ -179,10 +180,15 @@ ssize_t swap_buffer_write(void *data, size_t size)
 	if (!(swap_buffer_status & BUFFER_WORK))
 		return -E_SB_IS_STOPPED;
 
+	/* We're going to look for writable buffer, so disable irqs */
+	swap_irq_disable(&flags);
+
 	/* Get next write buffer and occupying semaphore */
 	buffer_to_write = get_from_write_list(size, &ptr_to_write);
-	if (!buffer_to_write)
+	if (!buffer_to_write) {
+		swap_irq_enable(&flags);
 		return -E_SB_NO_WRITABLE_BUFFERS;
+	}
 
 	/* Check for overlapping */
 	if (areas_overlap(ptr_to_write, data, size)) {
@@ -204,9 +210,10 @@ ssize_t swap_buffer_write(void *data, size_t size)
 			low_mem_cb();
 	}
 
-	/* Unlock sync (Locked in get_from_write_list()) */
+	/* Unlock sync (Locked in get_from_write_list()) and enable irqs */
 buf_write_sem_post:
-	sync_unlock(&buffer_to_write->buffer_sync);
+	sync_unlock_no_flags(&buffer_to_write->buffer_sync);
+	swap_irq_enable(&flags);
 
 	return result;
 }