Michael S. Tsirkin
2020-Aug-05 13:44 UTC
[PATCH v3 26/38] virtio_config: LE config space accessors
To be used by modern code, as well as to handle LE only fields such as balloon. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/linux/virtio_config.h | 65 +++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 441fd6dd42ab..5b5196fec899 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -375,6 +375,71 @@ static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val) sizeof(virtio_cwrite_v)); \ } while(0) +/* + * Nothing virtio-specific about these, but let's worry about generalizing + * these later. + */ +#define virtio_le_to_cpu(x) \ + _Generic((x), \ + __u8: (x), \ + __le16: le16_to_cpu(x), \ + __le32: le32_to_cpu(x), \ + __le64: le64_to_cpu(x) \ + ) + +#define virtio_cpu_to_le(x, m) \ + _Generic((m), \ + __u8: (x), \ + __le16: cpu_to_le16(x), \ + __le32: cpu_to_le32(x), \ + __le64: cpu_to_le64(x) \ + ) + +/* LE (e.g. modern) Config space accessors. */ +#define virtio_cread_le(vdev, structname, member, ptr) \ + do { \ + typeof(((structname*)0)->member) virtio_cread_v; \ + \ + might_sleep(); \ + /* Sanity check: must match the member's type */ \ + typecheck(typeof(virtio_le_to_cpu(virtio_cread_v)), *(ptr)); \ + \ + switch (sizeof(virtio_cread_v)) { \ + case 1: \ + case 2: \ + case 4: \ + vdev->config->get((vdev), \ + offsetof(structname, member), \ + &virtio_cread_v, \ + sizeof(virtio_cread_v)); \ + break; \ + default: \ + __virtio_cread_many((vdev), \ + offsetof(structname, member), \ + &virtio_cread_v, \ + 1, \ + sizeof(virtio_cread_v)); \ + break; \ + } \ + *(ptr) = virtio_le_to_cpu(virtio_cread_v); \ + } while(0) + +/* Config space accessors. */ +#define virtio_cwrite_le(vdev, structname, member, ptr) \ + do { \ + typeof(((structname*)0)->member) virtio_cwrite_v = \ + virtio_cpu_to_le(*(ptr), ((structname*)0)->member); \ + \ + might_sleep(); \ + /* Sanity check: must match the member's type */ \ + typecheck(typeof(virtio_le_to_cpu(virtio_cwrite_v)), *(ptr)); \ + \ + vdev->config->set((vdev), offsetof(structname, member), \ + &virtio_cwrite_v, \ + sizeof(virtio_cwrite_v)); \ + } while(0) + + /* Read @count fields, @bytes each. */ static inline void __virtio_cread_many(struct virtio_device *vdev, unsigned int offset, -- MST
Reasonably Related Threads
- [PATCH v3 24/38] virtio_config: rewrite using _Generic
- [vhost:vhost 32/52] include/linux/typecheck.h:12:18: warning: comparison of distinct pointer types lacks a cast
- [vhost:vhost 32/65] drivers/virtio/virtio_input.c:247:3: warning: comparison of distinct pointer types ('typeof (_Generic((virtio_cread_v), __u8: (virtio_cread_v), __le16: (__builtin_constant_p((__u16)((__u16)(__le16)(virtio_cread_v)))
- [PATCH v3 37/38] virtio_config: drop LE option from config space
- [PATCH v3 28/38] virtio_config: add virtio_cread_le_feature