diff options
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/dma-buf.h | 50 | ||||
| -rw-r--r-- | include/uapi/linux/kfd_ioctl.h | 16 |
2 files changed, 58 insertions, 8 deletions
diff --git a/include/uapi/linux/dma-buf.h b/include/uapi/linux/dma-buf.h index 7f30393b92c3..8e4a2ca0bcbf 100644 --- a/include/uapi/linux/dma-buf.h +++ b/include/uapi/linux/dma-buf.h @@ -22,8 +22,56 @@ #include <linux/types.h> -/* begin/end dma-buf functions used for userspace mmap. */ +/** + * struct dma_buf_sync - Synchronize with CPU access. + * + * When a DMA buffer is accessed from the CPU via mmap, it is not always + * possible to guarantee coherency between the CPU-visible map and underlying + * memory. To manage coherency, DMA_BUF_IOCTL_SYNC must be used to bracket + * any CPU access to give the kernel the chance to shuffle memory around if + * needed. + * + * Prior to accessing the map, the client must call DMA_BUF_IOCTL_SYNC + * with DMA_BUF_SYNC_START and the appropriate read/write flags. Once the + * access is complete, the client should call DMA_BUF_IOCTL_SYNC with + * DMA_BUF_SYNC_END and the same read/write flags. + * + * The synchronization provided via DMA_BUF_IOCTL_SYNC only provides cache + * coherency. It does not prevent other processes or devices from + * accessing the memory at the same time. If synchronization with a GPU or + * other device driver is required, it is the client's responsibility to + * wait for buffer to be ready for reading or writing before calling this + * ioctl with DMA_BUF_SYNC_START. Likewise, the client must ensure that + * follow-up work is not submitted to GPU or other device driver until + * after this ioctl has been called with DMA_BUF_SYNC_END? + * + * If the driver or API with which the client is interacting uses implicit + * synchronization, waiting for prior work to complete can be done via + * poll() on the DMA buffer file descriptor. If the driver or API requires + * explicit synchronization, the client may have to wait on a sync_file or + * other synchronization primitive outside the scope of the DMA buffer API. + */ struct dma_buf_sync { + /** + * @flags: Set of access flags + * + * DMA_BUF_SYNC_START: + * Indicates the start of a map access session. + * + * DMA_BUF_SYNC_END: + * Indicates the end of a map access session. + * + * DMA_BUF_SYNC_READ: + * Indicates that the mapped DMA buffer will be read by the + * client via the CPU map. + * + * DMA_BUF_SYNC_WRITE: + * Indicates that the mapped DMA buffer will be written by the + * client via the CPU map. + * + * DMA_BUF_SYNC_RW: + * An alias for DMA_BUF_SYNC_READ | DMA_BUF_SYNC_WRITE. + */ __u64 flags; }; diff --git a/include/uapi/linux/kfd_ioctl.h b/include/uapi/linux/kfd_ioctl.h index 3cb5b5dd9f77..af96af174dc4 100644 --- a/include/uapi/linux/kfd_ioctl.h +++ b/include/uapi/linux/kfd_ioctl.h @@ -31,9 +31,10 @@ * - 1.3 - Add SMI events support * - 1.4 - Indicate new SRAM EDC bit in device properties * - 1.5 - Add SVM API + * - 1.6 - Query clear flags in SVM get_attr API */ #define KFD_IOCTL_MAJOR_VERSION 1 -#define KFD_IOCTL_MINOR_VERSION 5 +#define KFD_IOCTL_MINOR_VERSION 6 struct kfd_ioctl_get_version_args { __u32 major_version; /* from KFD */ @@ -575,18 +576,19 @@ struct kfd_ioctl_svm_attribute { * @KFD_IOCTL_SVM_ATTR_PREFERRED_LOC or * @KFD_IOCTL_SVM_ATTR_PREFETCH_LOC resepctively. For * @KFD_IOCTL_SVM_ATTR_SET_FLAGS, flags of all pages will be - * aggregated by bitwise AND. The minimum migration granularity - * throughout the range will be returned for - * @KFD_IOCTL_SVM_ATTR_GRANULARITY. + * aggregated by bitwise AND. That means, a flag will be set in the + * output, if that flag is set for all pages in the range. For + * @KFD_IOCTL_SVM_ATTR_CLR_FLAGS, flags of all pages will be + * aggregated by bitwise NOR. That means, a flag will be set in the + * output, if that flag is clear for all pages in the range. + * The minimum migration granularity throughout the range will be + * returned for @KFD_IOCTL_SVM_ATTR_GRANULARITY. * * Querying of accessibility attributes works by initializing the * attribute type to @KFD_IOCTL_SVM_ATTR_ACCESS and the value to the * GPUID being queried. Multiple attributes can be given to allow * querying multiple GPUIDs. The ioctl function overwrites the * attribute type to indicate the access for the specified GPU. - * - * @KFD_IOCTL_SVM_ATTR_CLR_FLAGS is invalid for - * @KFD_IOCTL_SVM_OP_GET_ATTR. */ struct kfd_ioctl_svm_args { __u64 start_addr; |