Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:
 "Several fixes, most notably fix for virtio on swiotlb systems"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: silence an unused-variable warning
  virtio: hint if callbacks surprisingly might sleep
  virtio-ccw: wire up ->bus_name callback
  s390/virtio: handle find on invalid queue gracefully
  virtio-ccw: diag 500 may return a negative cookie
  virtio_balloon: remove the unnecessary 0-initialization
  virtio-balloon: improve update_balloon_size_func
  virtio-blk: Consider virtio_max_dma_size() for maximum segment size
  virtio: Introduce virtio_max_dma_size()
  dma: Introduce dma_max_mapping_size()
  swiotlb: Add is_swiotlb_active() function
  swiotlb: Introduce swiotlb_max_mapping_size()

4 files changed, 34 insertions, 0 deletions

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 70ad15758a70..75e60be91e5f 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -130,6 +130,7 @@ struct dma_map_ops {
 			enum dma_data_direction direction);
 	int (*dma_supported)(struct device *dev, u64 mask);
 	u64 (*get_required_mask)(struct device *dev);
+	size_t (*max_mapping_size)(struct device *dev);
 };
 
 #define DMA_MAPPING_ERROR		(~(dma_addr_t)0)
@@ -259,6 +260,8 @@ static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
 }
 #endif
 
+size_t dma_direct_max_mapping_size(struct device *dev);
+
 #ifdef CONFIG_HAS_DMA
 #include <asm/dma-mapping.h>
 
@@ -463,6 +466,7 @@ int dma_supported(struct device *dev, u64 mask);
 int dma_set_mask(struct device *dev, u64 mask);
 int dma_set_coherent_mask(struct device *dev, u64 mask);
 u64 dma_get_required_mask(struct device *dev);
+size_t dma_max_mapping_size(struct device *dev);
 #else /* CONFIG_HAS_DMA */
 static inline dma_addr_t dma_map_page_attrs(struct device *dev,
 		struct page *page, size_t offset, size_t size,
@@ -564,6 +568,10 @@ static inline u64 dma_get_required_mask(struct device *dev)
 {
 	return 0;
 }
+static inline size_t dma_max_mapping_size(struct device *dev)
+{
+	return 0;
+}
 #endif /* CONFIG_HAS_DMA */
 
 static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 54254388899e..361f62bb4a8e 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -73,6 +73,8 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
 		size_t size, enum dma_data_direction dir, unsigned long attrs);
 void __init swiotlb_exit(void);
 unsigned int swiotlb_max_segment(void);
+size_t swiotlb_max_mapping_size(struct device *dev);
+bool is_swiotlb_active(void);
 #else
 #define swiotlb_force SWIOTLB_NO_FORCE
 static inline bool is_swiotlb_buffer(phys_addr_t paddr)
@@ -92,6 +94,15 @@ static inline unsigned int swiotlb_max_segment(void)
 {
 	return 0;
 }
+static inline size_t swiotlb_max_mapping_size(struct device *dev)
+{
+	return SIZE_MAX;
+}
+
+static inline bool is_swiotlb_active(void)
+{
+	return false;
+}
 #endif /* CONFIG_SWIOTLB */
 
 extern void swiotlb_print_info(void);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index fa1b5da2804e..673fe3ef3607 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -157,6 +157,8 @@ int virtio_device_freeze(struct virtio_device *dev);
 int virtio_device_restore(struct virtio_device *dev);
 #endif
 
+size_t virtio_max_dma_size(struct virtio_device *vdev);
+
 #define virtio_device_for_each_vq(vdev, vq) \
 	list_for_each_entry(vq, &vdev->vqs, list)
 
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 987b6491b946..bb4cc4910750 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -290,6 +290,7 @@ static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
 /* Config space accessors. */
 #define virtio_cread(vdev, structname, member, ptr)			\
 	do {								\
+		might_sleep();						\
 		/* Must match the member's type, and be integer */	\
 		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
 			(*ptr) = 1;					\
@@ -319,6 +320,7 @@ static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
 /* Config space accessors. */
 #define virtio_cwrite(vdev, structname, member, ptr)			\
 	do {								\
+		might_sleep();						\
 		/* Must match the member's type, and be integer */	\
 		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
 			BUG_ON((*ptr) == 1);				\
@@ -358,6 +360,7 @@ static inline void __virtio_cread_many(struct virtio_device *vdev,
 		vdev->config->generation(vdev) : 0;
 	int i;
 
+	might_sleep();
 	do {
 		old = gen;
 
@@ -380,6 +383,8 @@ static inline void virtio_cread_bytes(struct virtio_device *vdev,
 static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
 {
 	u8 ret;
+
+	might_sleep();
 	vdev->config->get(vdev, offset, &ret, sizeof(ret));
 	return ret;
 }
@@ -387,6 +392,7 @@ static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
 static inline void virtio_cwrite8(struct virtio_device *vdev,
 				  unsigned int offset, u8 val)
 {
+	might_sleep();
 	vdev->config->set(vdev, offset, &val, sizeof(val));
 }
 
@@ -394,6 +400,8 @@ static inline u16 virtio_cread16(struct virtio_device *vdev,
 				 unsigned int offset)
 {
 	u16 ret;
+
+	might_sleep();
 	vdev->config->get(vdev, offset, &ret, sizeof(ret));
 	return virtio16_to_cpu(vdev, (__force __virtio16)ret);
 }
@@ -401,6 +409,7 @@ static inline u16 virtio_cread16(struct virtio_device *vdev,
 static inline void virtio_cwrite16(struct virtio_device *vdev,
 				   unsigned int offset, u16 val)
 {
+	might_sleep();
 	val = (__force u16)cpu_to_virtio16(vdev, val);
 	vdev->config->set(vdev, offset, &val, sizeof(val));
 }
@@ -409,6 +418,8 @@ static inline u32 virtio_cread32(struct virtio_device *vdev,
 				 unsigned int offset)
 {
 	u32 ret;
+
+	might_sleep();
 	vdev->config->get(vdev, offset, &ret, sizeof(ret));
 	return virtio32_to_cpu(vdev, (__force __virtio32)ret);
 }
@@ -416,6 +427,7 @@ static inline u32 virtio_cread32(struct virtio_device *vdev,
 static inline void virtio_cwrite32(struct virtio_device *vdev,
 				   unsigned int offset, u32 val)
 {
+	might_sleep();
 	val = (__force u32)cpu_to_virtio32(vdev, val);
 	vdev->config->set(vdev, offset, &val, sizeof(val));
 }
@@ -431,6 +443,7 @@ static inline u64 virtio_cread64(struct virtio_device *vdev,
 static inline void virtio_cwrite64(struct virtio_device *vdev,
 				   unsigned int offset, u64 val)
 {
+	might_sleep();
 	val = (__force u64)cpu_to_virtio64(vdev, val);
 	vdev->config->set(vdev, offset, &val, sizeof(val));
 }