LU-14798 lnet: add LNet GPU Direct Support

[fs/lustre-release.git] / lnet / include / lnet / lnet_rdma.h

diff --git a/lnet/include/lnet/lnet_rdma.h b/lnet/include/lnet/lnet_rdma.h
new file mode 100644 (file)
index 0000000..6aa5367
--- /dev/null
+++ b/lnet/include/lnet/lnet_rdma.h
@@ -0,0 +1,89 @@
+#ifndef LUSTRE_NVFS_H
+#define LUSTRE_NVFS_H
+
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/blkdev.h>
+#include <linux/cpumask.h>
+#include <linux/scatterlist.h>
+#include <linux/percpu-defs.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+
+#define REGSTR2(x) x##_register_nvfs_dma_ops
+#define REGSTR(x)  REGSTR2(x)
+
+#define UNREGSTR2(x) x##_unregister_nvfs_dma_ops
+#define UNREGSTR(x)  UNREGSTR2(x)
+
+#define MODULE_PREFIX lustre_v1
+
+#define REGISTER_FUNC REGSTR(MODULE_PREFIX)
+#define UNREGISTER_FUNC UNREGSTR(MODULE_PREFIX)
+
+#define NVFS_IO_ERR                    -1
+#define NVFS_CPU_REQ                   -2
+
+#define NVFS_HOLD_TIME_MS 1000
+
+struct nvfs_dma_rw_ops {
+       unsigned long long ft_bmap; /* feature bitmap */
+
+       int (*nvfs_blk_rq_map_sg) (struct request_queue *q,
+                                  struct request *req,
+                                  struct scatterlist *sglist);
+
+       int (*nvfs_dma_map_sg_attrs) (struct device *device,
+                                     struct scatterlist *sglist,
+                                     int nents,
+                                     enum dma_data_direction dma_dir,
+                                     unsigned long attrs);
+
+       int (*nvfs_dma_unmap_sg)  (struct device *device,
+                                  struct scatterlist *sglist,
+                                  int nents,
+                                  enum dma_data_direction dma_dir);
+       bool (*nvfs_is_gpu_page) (struct page *);
+       unsigned int (*nvfs_gpu_index) (struct page *page);
+       unsigned int (*nvfs_device_priority) (struct device *dev, unsigned int dev_index);
+};
+
+/* feature list for dma_ops, values indicate bit pos */
+enum ft_bits {
+       nvfs_ft_prep_sglist         = 1ULL << 0,
+       nvfs_ft_map_sglist          = 1ULL << 1,
+       nvfs_ft_is_gpu_page         = 1ULL << 2,
+       nvfs_ft_device_priority     = 1ULL << 3,
+};
+
+/* check features for use in registration with vendor drivers */
+#define NVIDIA_FS_CHECK_FT_SGLIST_PREP(ops) \
+       ((ops)->ft_bmap & nvfs_ft_prep_sglist)
+#define NVIDIA_FS_CHECK_FT_SGLIST_DMA(ops) \
+       ((ops)->ft_bmap & nvfs_ft_map_sglist)
+#define NVIDIA_FS_CHECK_FT_GPU_PAGE(ops) \
+       ((ops)->ft_bmap & nvfs_ft_is_gpu_page)
+#define NVIDIA_FS_CHECK_FT_DEVICE_PRIORITY(ops) \
+       ((ops)->ft_bmap & nvfs_ft_device_priority)
+
+int REGISTER_FUNC (struct nvfs_dma_rw_ops *ops);
+
+void UNREGISTER_FUNC (void);
+
+unsigned int lnet_get_dev_prio(struct device *dev,
+                              unsigned int dev_idx);
+int lnet_rdma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
+                          int nents, enum dma_data_direction direction);
+int lnet_rdma_unmap_sg(struct device *dev,
+                      struct scatterlist *sg, int nents,
+                      enum dma_data_direction direction);
+bool lnet_is_rdma_only_page(struct page *page);
+unsigned int lnet_get_dev_idx(struct page *page);
+
+/* DMA_ATTR_NO_WARN was added to kernel v4.8-11962-ga9a62c9 */
+#ifndef DMA_ATTR_NO_WARN
+#define DMA_ATTR_NO_WARN 0
+#endif
+
+#endif /* LUSTRE_NVFS_H */
+