RDMA/uverbs: Add CQ buffer UMEM attribute and driver helpers

Add UVERBS_ATTR_CREATE_CQ_BUF_UMEM and two driver-facing
wrappers, ib_umem_get_cq_buf() and ib_umem_get_cq_buf_or_va(),
that pin a CQ buffer umem from it. The wrappers reuse the
existing legacy CQ buffer-attr filler.

Link: https://patch.msgid.link/r/20260529134312.2836341-7-jiri@resnulli.us
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index d364a5ab055805e11d2c31b8ad45cf5023f62a61..b3261b924a718d6381daa2ca88122bbcec2c8760 100644 (file)
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -497,7 +497,7 @@ struct ib_umem *ib_umem_get_attr_or_va(struct ib_device *device,
 }
 EXPORT_SYMBOL(ib_umem_get_attr_or_va);
 
-static int uverbs_create_cq_get_buffer_desc(struct uverbs_attr_bundle *attrs,
+static int uverbs_create_cq_get_buffer_desc(const struct uverbs_attr_bundle *attrs,
                                            struct ib_uverbs_buffer_desc *desc)
 {
        struct ib_device *ib_dev = attrs->context->device;
@@ -547,6 +547,61 @@ static int uverbs_create_cq_get_buffer_desc(struct uverbs_attr_bundle *attrs,
        return -ENODATA;
 }
 
+/**
+ * ib_umem_get_cq_buf - Pin a CQ buffer umem from per-command attributes.
+ * @device:  IB device.
+ * @attrs:   uverbs attribute bundle (may be NULL).
+ * @size:    minimum required CQ buffer length.
+ * @access:  IB access flags.
+ *
+ * Resolves the CQ buffer from the new UMEM attribute or the legacy
+ * CQ buffer attributes. There is no UHW VA fallback, so the caller
+ * must arrange its own backing (typically an in-kernel allocation)
+ * when no source is available.
+ *
+ * Return: caller-owned umem on success; NULL when no source supplied
+ * a buffer; ERR_PTR(...) on error.
+ */
+struct ib_umem *ib_umem_get_cq_buf(struct ib_device *device,
+                                  const struct uverbs_attr_bundle *attrs,
+                                  size_t size, int access)
+{
+       return ib_umem_get_from_attrs(device, attrs,
+                                     UVERBS_ATTR_CREATE_CQ_BUF_UMEM,
+                                     uverbs_create_cq_get_buffer_desc,
+                                     size, access);
+}
+EXPORT_SYMBOL(ib_umem_get_cq_buf);
+
+/**
+ * ib_umem_get_cq_buf_or_va - Pin a CQ buffer umem with UHW VA fallback.
+ * @device:  IB device.
+ * @attrs:   uverbs attribute bundle (may be NULL).
+ * @addr:    UHW user VA used when no per-command attribute matched.
+ * @size:    on the attr / legacy paths, the minimum required umem length
+ *           validated post-pin; on the VA fallback path, the length to pin.
+ * @access:  IB access flags.
+ *
+ * Like ib_umem_get_cq_buf(), but pins @addr/@size when neither the
+ * UMEM attribute nor the legacy CQ buffer attributes are supplied.
+ *
+ * See ib_umem_get_attr_or_va() for the note on @size's dual role and
+ * the migration path for drivers that would distinguish a user-supplied
+ * length from a driver-computed minimum.
+ *
+ * Return: caller-owned umem on success, ERR_PTR(...) on error.
+ */
+struct ib_umem *ib_umem_get_cq_buf_or_va(struct ib_device *device,
+                                        const struct uverbs_attr_bundle *attrs,
+                                        u64 addr, size_t size, int access)
+{
+       return ib_umem_get_from_attrs_or_va(device, attrs,
+                                           UVERBS_ATTR_CREATE_CQ_BUF_UMEM,
+                                           uverbs_create_cq_get_buffer_desc,
+                                           addr, size, access);
+}
+EXPORT_SYMBOL(ib_umem_get_cq_buf_or_va);
+
 /**
  * ib_umem_get_cq_tmp - Temporary CQ buffer umem getter.
  * @device: IB device.

diff --git a/drivers/infiniband/core/uverbs_std_types_cq.c b/drivers/infiniband/core/uverbs_std_types_cq.c
index 711bad0aa8a3fcc0783e02a92e889f4f1904764c..05d1294762c0be3c33635d9552bcfe30c1672b9b 100644 (file)
--- a/drivers/infiniband/core/uverbs_std_types_cq.c
+++ b/drivers/infiniband/core/uverbs_std_types_cq.c
@@ -215,6 +215,8 @@ DECLARE_UVERBS_NAMED_METHOD(
        UVERBS_ATTR_PTR_IN(UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET,
                           UVERBS_ATTR_TYPE(u64),
                           UA_OPTIONAL),
+       UVERBS_ATTR_UMEM(UVERBS_ATTR_CREATE_CQ_BUF_UMEM,
+                        UA_OPTIONAL),
        UVERBS_ATTR_UHW());
 
 static int UVERBS_HANDLER(UVERBS_METHOD_CQ_DESTROY)(

diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index 0d6e90a35f3abd4ea079911ad9706caa241ea620..492c8d36573030f42c84054b2a52153ffa05117f 100644 (file)
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -90,6 +90,12 @@ struct ib_umem *ib_umem_get_attr_or_va(struct ib_device *device,
                                       const struct uverbs_attr_bundle *attrs,
                                       u16 attr_id, u64 addr, size_t size,
                                       int access);
+struct ib_umem *ib_umem_get_cq_buf(struct ib_device *device,
+                                  const struct uverbs_attr_bundle *attrs,
+                                  size_t size, int access);
+struct ib_umem *ib_umem_get_cq_buf_or_va(struct ib_device *device,
+                                        const struct uverbs_attr_bundle *attrs,
+                                        u64 addr, size_t size, int access);
 struct ib_umem *ib_umem_get_cq_tmp(struct ib_device *device,
                                   struct uverbs_attr_bundle *attrs);
 
@@ -210,6 +216,20 @@ ib_umem_get_attr_or_va(struct ib_device *device,
        return ERR_PTR(-EOPNOTSUPP);
 }
 static inline struct ib_umem *
+ib_umem_get_cq_buf(struct ib_device *device,
+                  const struct uverbs_attr_bundle *attrs, size_t size,
+                  int access)
+{
+       return ERR_PTR(-EOPNOTSUPP);
+}
+static inline struct ib_umem *
+ib_umem_get_cq_buf_or_va(struct ib_device *device,
+                        const struct uverbs_attr_bundle *attrs, u64 addr,
+                        size_t size, int access)
+{
+       return ERR_PTR(-EOPNOTSUPP);
+}
+static inline struct ib_umem *
 ib_umem_get_cq_tmp(struct ib_device *device, struct uverbs_attr_bundle *attrs)
 {
        return ERR_PTR(-EOPNOTSUPP);

diff --git a/include/uapi/rdma/ib_user_ioctl_cmds.h b/include/uapi/rdma/ib_user_ioctl_cmds.h
index 72041c1b0ea51671d3faf8d06e7c678f3eff9f2e..02835b7fd76d2e456bf33ac4ae7ccc811c54f28b 100644 (file)
--- a/include/uapi/rdma/ib_user_ioctl_cmds.h
+++ b/include/uapi/rdma/ib_user_ioctl_cmds.h
@@ -117,6 +117,7 @@ enum uverbs_attrs_create_cq_cmd_attr_ids {
        UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH,
        UVERBS_ATTR_CREATE_CQ_BUFFER_FD,
        UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET,
+       UVERBS_ATTR_CREATE_CQ_BUF_UMEM,
 };
 
 enum uverbs_attrs_destroy_cq_cmd_attr_ids {