[PATCH 220/437] misc: cxl: convert to read/write iterators

[Jens Axboe]

Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
 drivers/misc/cxl/api.c  |  7 +++----
 drivers/misc/cxl/cxl.h  |  2 +-
 drivers/misc/cxl/file.c | 23 +++++++++++------------
 include/misc/cxl.h      |  3 +--
 4 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index d85c56530863..54e1f5b917e2 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -375,10 +375,9 @@ __poll_t cxl_fd_poll(struct file *file, struct poll_table_struct *poll)
 	return afu_poll(file, poll);
 }
 EXPORT_SYMBOL_GPL(cxl_fd_poll);
-ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
-			loff_t *off)
+ssize_t cxl_fd_read(struct kiocb *iocb, struct iov_iter *to)
 {
-	return afu_read(file, buf, count, off);
+	return afu_read(iocb, to);
 }
 EXPORT_SYMBOL_GPL(cxl_fd_read);
 
@@ -410,7 +409,7 @@ struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
 	if (fops) {
 		PATCH_FOPS(open);
 		PATCH_FOPS(poll);
-		PATCH_FOPS(read);
+		PATCH_FOPS(read_iter);
 		PATCH_FOPS(release);
 		PATCH_FOPS(unlocked_ioctl);
 		PATCH_FOPS(compat_ioctl);
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index 6ad0ab892675..6b6738b28f69 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -1045,7 +1045,7 @@ int afu_release(struct inode *inode, struct file *file);
 long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 int afu_mmap(struct file *file, struct vm_area_struct *vm);
 __poll_t afu_poll(struct file *file, struct poll_table_struct *poll);
-ssize_t afu_read(struct file *file, char __user *buf, size_t count, loff_t *off);
+ssize_t afu_read(struct kiocb *iocb, struct iov_iter *to);
 extern const struct file_operations afu_fops;
 
 struct cxl *cxl_guest_init_adapter(struct device_node *np, struct platform_device *dev);
diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index 012e11b959bc..c911bd785f26 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -385,7 +385,7 @@ __poll_t afu_poll(struct file *file, struct poll_table_struct *poll)
 }
 
 static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
-				     char __user *buf,
+				     struct iov_iter *to,
 				     struct cxl_event *event,
 				     struct cxl_event_afu_driver_reserved *pl)
 {
@@ -403,14 +403,13 @@ static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
 	}
 
 	/* Copy event header */
-	if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {
+	if (!copy_to_iter_full(event, sizeof(struct cxl_event_header), to)) {
 		ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
 		return -EFAULT;
 	}
 
 	/* Copy event data */
-	buf += sizeof(struct cxl_event_header);
-	if (copy_to_user(buf, &pl->data, pl->data_size)) {
+	if (!copy_to_iter_full(&pl->data, pl->data_size, to)) {
 		ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
 		return -EFAULT;
 	}
@@ -419,11 +418,11 @@ static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
 	return event->header.size;
 }
 
-ssize_t afu_read(struct file *file, char __user *buf, size_t count,
-			loff_t *off)
+ssize_t afu_read(struct kiocb *iocb, struct iov_iter *to)
 {
-	struct cxl_context *ctx = file->private_data;
+	struct cxl_context *ctx = iocb->ki_filp->private_data;
 	struct cxl_event_afu_driver_reserved *pl = NULL;
+	size_t count = iov_iter_count(to);
 	struct cxl_event event;
 	unsigned long flags;
 	int rc;
@@ -447,7 +446,7 @@ ssize_t afu_read(struct file *file, char __user *buf, size_t count,
 			goto out;
 		}
 
-		if (file->f_flags & O_NONBLOCK) {
+		if (iocb->ki_filp->f_flags & O_NONBLOCK) {
 			rc = -EAGAIN;
 			goto out;
 		}
@@ -505,9 +504,9 @@ ssize_t afu_read(struct file *file, char __user *buf, size_t count,
 	spin_unlock_irqrestore(&ctx->lock, flags);
 
 	if (event.header.type == CXL_EVENT_AFU_DRIVER)
-		return afu_driver_event_copy(ctx, buf, &event, pl);
+		return afu_driver_event_copy(ctx, to, &event, pl);
 
-	if (copy_to_user(buf, &event, event.header.size))
+	if (!copy_to_iter_full(&event, event.header.size, to))
 		return -EFAULT;
 	return event.header.size;
 
@@ -525,7 +524,7 @@ const struct file_operations afu_fops = {
 	.owner		= THIS_MODULE,
 	.open           = afu_open,
 	.poll		= afu_poll,
-	.read		= afu_read,
+	.read_iter	= afu_read,
 	.release        = afu_release,
 	.unlocked_ioctl = afu_ioctl,
 	.compat_ioctl   = afu_compat_ioctl,
@@ -536,7 +535,7 @@ static const struct file_operations afu_master_fops = {
 	.owner		= THIS_MODULE,
 	.open           = afu_master_open,
 	.poll		= afu_poll,
-	.read		= afu_read,
+	.read_iter	= afu_read,
 	.release        = afu_release,
 	.unlocked_ioctl = afu_ioctl,
 	.compat_ioctl   = afu_compat_ioctl,
diff --git a/include/misc/cxl.h b/include/misc/cxl.h
index d8044299d654..3758f9c8f83f 100644
--- a/include/misc/cxl.h
+++ b/include/misc/cxl.h
@@ -196,8 +196,7 @@ int cxl_fd_release(struct inode *inode, struct file *file);
 long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm);
 __poll_t cxl_fd_poll(struct file *file, struct poll_table_struct *poll);
-ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
-			   loff_t *off);
+ssize_t cxl_fd_read(struct kiocb *iocb, struct iov_iter *to);
 
 /*
  * For EEH, a driver may want to assert a PERST will reload the same image
-- 
2.43.0