diff options
| -rw-r--r-- | drivers/infiniband/core/umem.c | 34 | ||||
| -rw-r--r-- | include/rdma/ib_umem.h | 2 |
2 files changed, 36 insertions, 0 deletions
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index e0f883292374..6f152628e0d2 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -292,3 +292,37 @@ int ib_umem_page_count(struct ib_umem *umem) return n; } EXPORT_SYMBOL(ib_umem_page_count); + +/* + * Copy from the given ib_umem's pages to the given buffer. + * + * umem - the umem to copy from + * offset - offset to start copying from + * dst - destination buffer + * length - buffer length + * + * Returns 0 on success, or an error code. + */ +int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, + size_t length) +{ + size_t end = offset + length; + int ret; + + if (offset > umem->length || length > umem->length - offset) { + pr_err("ib_umem_copy_from not in range. offset: %zd umem length: %zd end: %zd\n", + offset, umem->length, end); + return -EINVAL; + } + + ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->nmap, dst, length, + offset + ib_umem_offset(umem)); + + if (ret < 0) + return ret; + else if (ret != length) + return -EINVAL; + else + return 0; +} +EXPORT_SYMBOL(ib_umem_copy_from); diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index 7ed6d4ff58dc..45bb04bc88cd 100644 --- a/include/rdma/ib_umem.h +++ b/include/rdma/ib_umem.h @@ -84,6 +84,8 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, size_t size, int access, int dmasync); void ib_umem_release(struct ib_umem *umem); int ib_umem_page_count(struct ib_umem *umem); +int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, + size_t length); #else /* CONFIG_INFINIBAND_USER_MEM */ |