1 files changed, 70 insertions, 8 deletions

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 2d572f6c8ec8..d93ed4e86a17 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -24,6 +24,7 @@
 #include <linux/kobject.h>
 #include <linux/cdev.h>
 #include <linux/uio_driver.h>
+#include <linux/dma-mapping.h>
 
 #define UIO_MAX_DEVICES		(1U << MINORBITS)
 
@@ -117,7 +118,7 @@ static const struct sysfs_ops map_sysfs_ops = {
 	.show = map_type_show,
 };
 
-static struct kobj_type map_attr_type = {
+static const struct kobj_type map_attr_type = {
 	.release	= map_release,
 	.sysfs_ops	= &map_sysfs_ops,
 	.default_groups	= map_groups,
@@ -206,7 +207,7 @@ static const struct sysfs_ops portio_sysfs_ops = {
 	.show = portio_type_show,
 };
 
-static struct kobj_type portio_attr_type = {
+static const struct kobj_type portio_attr_type = {
 	.release	= portio_release,
 	.sysfs_ops	= &portio_sysfs_ops,
 	.default_groups	= portio_groups,
@@ -437,22 +438,36 @@ void uio_event_notify(struct uio_info *info)
 EXPORT_SYMBOL_GPL(uio_event_notify);
 
 /**
- * uio_interrupt - hardware interrupt handler
+ * uio_interrupt_handler - hardware interrupt handler
  * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
  * @dev_id: Pointer to the devices uio_device structure
  */
-static irqreturn_t uio_interrupt(int irq, void *dev_id)
+static irqreturn_t uio_interrupt_handler(int irq, void *dev_id)
 {
 	struct uio_device *idev = (struct uio_device *)dev_id;
 	irqreturn_t ret;
 
 	ret = idev->info->handler(irq, idev->info);
 	if (ret == IRQ_HANDLED)
-		uio_event_notify(idev->info);
+		ret = IRQ_WAKE_THREAD;
 
 	return ret;
 }
 
+/**
+ * uio_interrupt_thread - irq thread handler
+ * @irq: IRQ number
+ * @dev_id: Pointer to the devices uio_device structure
+ */
+static irqreturn_t uio_interrupt_thread(int irq, void *dev_id)
+{
+	struct uio_device *idev = (struct uio_device *)dev_id;
+
+	uio_event_notify(idev->info);
+
+	return IRQ_HANDLED;
+}
+
 struct uio_listener {
 	struct uio_device *dev;
 	s32 event_count;
@@ -550,7 +565,7 @@ static __poll_t uio_poll(struct file *filep, poll_table *wait)
 
 	mutex_lock(&idev->info_lock);
 	if (!idev->info || !idev->info->irq)
-		ret = -EIO;
+		ret = EPOLLERR;
 	mutex_unlock(&idev->info_lock);
 
 	if (ret)
@@ -759,6 +774,49 @@ static int uio_mmap_physical(struct vm_area_struct *vma)
 			       vma->vm_page_prot);
 }
 
+static int uio_mmap_dma_coherent(struct vm_area_struct *vma)
+{
+	struct uio_device *idev = vma->vm_private_data;
+	struct uio_mem *mem;
+	void *addr;
+	int ret = 0;
+	int mi;
+
+	mi = uio_find_mem_index(vma);
+	if (mi < 0)
+		return -EINVAL;
+
+	mem = idev->info->mem + mi;
+
+	if (mem->addr & ~PAGE_MASK)
+		return -ENODEV;
+	if (mem->dma_addr & ~PAGE_MASK)
+		return -ENODEV;
+	if (!mem->dma_device)
+		return -ENODEV;
+	if (vma->vm_end - vma->vm_start > mem->size)
+		return -EINVAL;
+
+	dev_warn(mem->dma_device,
+		 "use of UIO_MEM_DMA_COHERENT is highly discouraged");
+
+	/*
+	 * UIO uses offset to index into the maps for a device.
+	 * We need to clear vm_pgoff for dma_mmap_coherent.
+	 */
+	vma->vm_pgoff = 0;
+
+	addr = (void *)(uintptr_t)mem->addr;
+	ret = dma_mmap_coherent(mem->dma_device,
+				vma,
+				addr,
+				mem->dma_addr,
+				vma->vm_end - vma->vm_start);
+	vma->vm_pgoff = mi;
+
+	return ret;
+}
+
 static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
 {
 	struct uio_listener *listener = filep->private_data;
@@ -806,6 +864,9 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
 	case UIO_MEM_VIRTUAL:
 		ret = uio_mmap_logical(vma);
 		break;
+	case UIO_MEM_DMA_COHERENT:
+		ret = uio_mmap_dma_coherent(vma);
+		break;
 	default:
 		ret = -EINVAL;
 	}
@@ -977,8 +1038,8 @@ int __uio_register_device(struct module *owner,
 		 * FDs at the time of unregister and therefore may not be
 		 * freed until they are released.
 		 */
-		ret = request_irq(info->irq, uio_interrupt,
-				  info->irq_flags, info->name, idev);
+		ret = request_threaded_irq(info->irq, uio_interrupt_handler, uio_interrupt_thread,
+					   info->irq_flags, info->name, idev);
 		if (ret) {
 			info->uio_dev = NULL;
 			goto err_request_irq;
@@ -1084,4 +1145,5 @@ static void __exit uio_exit(void)
 
 module_init(uio_init)
 module_exit(uio_exit)
+MODULE_DESCRIPTION("Userspace IO core module");
 MODULE_LICENSE("GPL v2");