Commit a4235ec0 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin
Browse files

virtio: allow __virtioXX, __leXX in config space 



Currently all config space fields are of the type __uXX.
This confuses people and some drivers (notably vdpa)
access them using CPU endian-ness - which only
works well for legacy or LE platforms.

Update virtio_cread/virtio_cwrite macros to allow __virtioXX
and __leXX field types. Follow-up patches will convert
config space to use these types.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarCornelia Huck <cohuck@redhat.com>
parent 54871968

include/linux/virtio_config.h

+48 −2
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <linux/bug.h>

#include <linux/virtio.h>

#include <linux/virtio_byteorder.h>

#include <linux/compiler_types.h>

#include <uapi/linux/virtio_config.h>



struct irq_affinity;
@@ -287,12 +288,57 @@ static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val) 
	return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);

}



/*

 * Only the checker differentiates between __virtioXX and __uXX types. But we

 * try to share as much code as we can with the regular GCC build.

 */

#if !defined(CONFIG_CC_IS_GCC) && !defined(__CHECKER__)



/* Not a checker - we can keep things simple */

#define __virtio_native_typeof(x) typeof(x)



#else



/*

 * We build this out of a couple of helper macros in a vain attempt to

 * help you keep your lunch down while reading it.

 */

#define __virtio_pick_value(x, type, then, otherwise)			\

	__builtin_choose_expr(__same_type(x, type), then, otherwise)



#define __virtio_pick_type(x, type, then, otherwise)			\

	__virtio_pick_value(x, type, (then)0, otherwise)



#define __virtio_pick_endian(x, x16, x32, x64, otherwise)			\

	__virtio_pick_type(x, x16, __u16,					\

		__virtio_pick_type(x, x32, __u32,				\

			__virtio_pick_type(x, x64, __u64,			\

				otherwise)))



#define __virtio_native_typeof(x) typeof(					\

	__virtio_pick_type(x, __u8, __u8,					\

		__virtio_pick_endian(x, __virtio16, __virtio32, __virtio64,	\

			__virtio_pick_endian(x, __le16, __le32, __le64,		\

				__virtio_pick_endian(x, __u16, __u32, __u64,	\

					/* No other type allowed */		\

					(void)0)))))



#endif



#define __virtio_native_type(structname, member) \

	__virtio_native_typeof(((structname*)0)->member)



#define __virtio_typecheck(structname, member, val) \

		/* Must match the member's type, and be integer */ \

		typecheck(__virtio_native_type(structname, member), (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))) \

		if (!__virtio_typecheck(structname, member, *(ptr)))	\

			(*ptr) = 1;					\

									\

		switch (sizeof(*ptr)) {					\
@@ -322,7 +368,7 @@ static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val) 
	do {								\

		might_sleep();						\

		/* Must match the member's type, and be integer */	\

		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \

		if (!__virtio_typecheck(structname, member, *(ptr)))	\

			BUG_ON((*ptr) == 1);				\

									\

		switch (sizeof(*ptr)) {					\