Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
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include/linux/virtio_config.h
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include/linux/virtio_config.h
···
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#include <linux/bug.h>
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#include <linux/virtio.h>
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#include <linux/virtio_byteorder.h>
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#include <linux/compiler_types.h>
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#include <uapi/linux/virtio_config.h>
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struct irq_affinity;
···
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return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
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}
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/*
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* Only the checker differentiates between __virtioXX and __uXX types. But we
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* try to share as much code as we can with the regular GCC build.
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*/
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#if !defined(CONFIG_CC_IS_GCC) && !defined(__CHECKER__)
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/* Not a checker - we can keep things simple */
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#define __virtio_native_typeof(x) typeof(x)
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#else
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/*
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* We build this out of a couple of helper macros in a vain attempt to
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* help you keep your lunch down while reading it.
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*/
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#define __virtio_pick_value(x, type, then, otherwise) \
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__builtin_choose_expr(__same_type(x, type), then, otherwise)
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#define __virtio_pick_type(x, type, then, otherwise) \
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__virtio_pick_value(x, type, (then)0, otherwise)
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#define __virtio_pick_endian(x, x16, x32, x64, otherwise) \
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__virtio_pick_type(x, x16, __u16, \
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__virtio_pick_type(x, x32, __u32, \
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__virtio_pick_type(x, x64, __u64, \
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otherwise)))
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#define __virtio_native_typeof(x) typeof( \
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__virtio_pick_type(x, __u8, __u8, \
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__virtio_pick_endian(x, __virtio16, __virtio32, __virtio64, \
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__virtio_pick_endian(x, __le16, __le32, __le64, \
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__virtio_pick_endian(x, __u16, __u32, __u64, \
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/* No other type allowed */ \
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(void)0)))))
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#endif
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#define __virtio_native_type(structname, member) \
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__virtio_native_typeof(((structname*)0)->member)
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#define __virtio_typecheck(structname, member, val) \
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/* Must match the member's type, and be integer */ \
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typecheck(__virtio_native_type(structname, member), (val))
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/* Config space accessors. */
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#define virtio_cread(vdev, structname, member, ptr) \
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do { \
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might_sleep(); \
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/* Must match the member's type, and be integer */ \
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if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
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if (!__virtio_typecheck(structname, member, *(ptr))) \
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(*ptr) = 1; \
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\
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switch (sizeof(*ptr)) { \
···
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do { \
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might_sleep(); \
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/* Must match the member's type, and be integer */ \
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if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
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if (!__virtio_typecheck(structname, member, *(ptr))) \
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BUG_ON((*ptr) == 1); \
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\
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switch (sizeof(*ptr)) { \