vfio/type1: Refactor vfio_iommu_type1_ioctl()

This patch refactors the vfio_iommu_type1_ioctl() to use switch instead of
if-else, and each command got a helper function.

Cc: Kevin Tian <kevin.tian@intel.com>
CC: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/vfio_iommu_type1.c

@@ -2455,6 +2455,23 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
 	return ret;
 }
 
+static int vfio_iommu_type1_check_extension(struct vfio_iommu *iommu,
+					    unsigned long arg)
+{
+	switch (arg) {
+	case VFIO_TYPE1_IOMMU:
+	case VFIO_TYPE1v2_IOMMU:
+	case VFIO_TYPE1_NESTING_IOMMU:
+		return 1;
+	case VFIO_DMA_CC_IOMMU:
+		if (!iommu)
+			return 0;
+		return vfio_domains_have_iommu_cache(iommu);
+	default:
+		return 0;
+	}
+}
+
 static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps,
 		 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas,
 		 size_t size)
@@ -2531,27 +2548,11 @@ static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
 	return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig));
 }
 
-static long vfio_iommu_type1_ioctl(void *iommu_data,
-				   unsigned int cmd, unsigned long arg)
+static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
+				     unsigned long arg)
 {
-	struct vfio_iommu *iommu = iommu_data;
-	unsigned long minsz;
-
-	if (cmd == VFIO_CHECK_EXTENSION) {
-		switch (arg) {
-		case VFIO_TYPE1_IOMMU:
-		case VFIO_TYPE1v2_IOMMU:
-		case VFIO_TYPE1_NESTING_IOMMU:
-			return 1;
-		case VFIO_DMA_CC_IOMMU:
-			if (!iommu)
-				return 0;
-			return vfio_domains_have_iommu_cache(iommu);
-		default:
-			return 0;
-		}
-	} else if (cmd == VFIO_IOMMU_GET_INFO) {
 	struct vfio_iommu_type1_info info;
+	unsigned long minsz;
 	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
 	unsigned long capsz;
 	int ret;
@@ -2608,11 +2609,14 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 
 	return copy_to_user((void __user *)arg, &info, minsz) ?
 			-EFAULT : 0;
+}
 
-	} else if (cmd == VFIO_IOMMU_MAP_DMA) {
+static int vfio_iommu_type1_map_dma(struct vfio_iommu *iommu,
+				    unsigned long arg)
+{
 	struct vfio_iommu_type1_dma_map map;
-		uint32_t mask = VFIO_DMA_MAP_FLAG_READ |
-				VFIO_DMA_MAP_FLAG_WRITE;
+	unsigned long minsz;
+	uint32_t mask = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
 
 	minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
 
@@ -2623,10 +2627,14 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 		return -EINVAL;
 
 	return vfio_dma_do_map(iommu, &map);
+}
 
-	} else if (cmd == VFIO_IOMMU_UNMAP_DMA) {
+static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu,
+				      unsigned long arg)
+{
 	struct vfio_iommu_type1_dma_unmap unmap;
 	struct vfio_bitmap bitmap = { 0 };
+	unsigned long minsz;
 	int ret;
 
 	minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
@@ -2665,18 +2673,22 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 
 	return copy_to_user((void __user *)arg, &unmap, minsz) ?
 			-EFAULT : 0;
-	} else if (cmd == VFIO_IOMMU_DIRTY_PAGES) {
+}
+
+static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu,
+					unsigned long arg)
+{
 	struct vfio_iommu_type1_dirty_bitmap dirty;
 	uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START |
 			VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP |
 			VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
+	unsigned long minsz;
 	int ret = 0;
 
 	if (!iommu->v2)
 		return -EACCES;
 
-		minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap,
-				    flags);
+	minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, flags);
 
 	if (copy_from_user(&dirty, (void __user *)arg, minsz))
 		return -EFAULT;
@@ -2708,8 +2720,7 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 		}
 		mutex_unlock(&iommu->lock);
 		return 0;
-		} else if (dirty.flags &
-				 VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) {
+	} else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) {
 		struct vfio_iommu_type1_dirty_bitmap_get range;
 		unsigned long pgshift;
 		size_t data_size = dirty.argsz - minsz;
@@ -2754,7 +2765,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 
 		if (iommu->dirty_page_tracking)
 			ret = vfio_iova_dirty_bitmap(range.bitmap.data,
-						iommu, range.iova, range.size,
+						     iommu, range.iova,
+						     range.size,
 						     range.bitmap.pgsize);
 		else
 			ret = -EINVAL;
@@ -2763,9 +2775,29 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 
 		return ret;
 	}
-	}
 
+	return -EINVAL;
+}
+
+static long vfio_iommu_type1_ioctl(void *iommu_data,
+				   unsigned int cmd, unsigned long arg)
+{
+	struct vfio_iommu *iommu = iommu_data;
+
+	switch (cmd) {
+	case VFIO_CHECK_EXTENSION:
+		return vfio_iommu_type1_check_extension(iommu, arg);
+	case VFIO_IOMMU_GET_INFO:
+		return vfio_iommu_type1_get_info(iommu, arg);
+	case VFIO_IOMMU_MAP_DMA:
+		return vfio_iommu_type1_map_dma(iommu, arg);
+	case VFIO_IOMMU_UNMAP_DMA:
+		return vfio_iommu_type1_unmap_dma(iommu, arg);
+	case VFIO_IOMMU_DIRTY_PAGES:
+		return vfio_iommu_type1_dirty_pages(iommu, arg);
+	default:
 		return -ENOTTY;
+	}
 }
 
 static int vfio_iommu_type1_register_notifier(void *iommu_data,