Allow 3rd party extensions to verb routines

In order to support OFED, vendor specific calls, or new ibverbs
operations, define a generic extension mechanism.  This allows
OFED, an RDMA vendor, or another registered 3rd party (for
example, the librdmacm) to define RDMA extensions, plus provides
a backwards compatible way to add new features to ibverbs.

Users which make use extensions are aware that they are not
only using an extended call, but are given information regarding
how widely the extension by be supported based on the name of the
extension.  E.g. a VENDOR extension is specific to a vendor, whereas
an OFA extension is standardized within an organization.
Support for extended functions, data structures, and enums are defined.

Extensions are referenced by name.  There is an assumption that
extension names are prefixed relative to the supporting party.
Until an extension has been incorporated into libibverbs, it
should be defined in an appropriate external header file.

Driver libraries that support extensions are given a new
registration call, ibv_register_device_ext().  Use of this call
indicates to libibverbs that the library allocates extended
versions of struct ibv_device and struct ibv_context.

The following new APIs are added to libibverbs to applications
to use to determine if an extension is supported and to obtain the
extended function calls.

ibv_have_ext_ops - returns true if an extension is supported
ibv_get_device_ext_ops - return extended operations for a device
ibv_get_ext_ops - return extended operations for an open context

To maintain backwards compatibility with existing applications,
internally, the library uses the last byte of the device name
to record if the device was registered with extension support.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>

diff --git a/include/infiniband/driver.h b/include/infiniband/driver.h
index 9a81416febb54852784faf677d5eeb65c7f89204..e48abfdf5857ee3cc7c3421bc58ef304482ff01c 100644 (file)
--- a/include/infiniband/driver.h
+++ b/include/infiniband/driver.h
@@ -57,6 +57,7 @@ typedef struct ibv_device *(*ibv_driver_init_func)(const char *uverbs_sys_path,
                                                   int abi_version);
 
 void ibv_register_driver(const char *name, ibv_driver_init_func init_func);
+void ibv_register_driver_ext(const char *name, ibv_driver_init_func init_func);
 int ibv_cmd_get_context(struct ibv_context *context, struct ibv_get_context *cmd,
                        size_t cmd_size, struct ibv_get_context_resp *resp,
                        size_t resp_size);

diff --git a/include/infiniband/verbs.h b/include/infiniband/verbs.h
index 6acfc8131f42641bfc48b848806befaa9dade56a..5b1fa35ae31a1a9c58fcfa1ceac69d2d25b28f8f 100644 (file)
--- a/include/infiniband/verbs.h
+++ b/include/infiniband/verbs.h
@@ -55,6 +55,15 @@
 
 BEGIN_C_DECLS
 
+enum ibv_extension_type {
+       IBV_EXTENSION_COMMON,
+       IBV_EXTENSION_VENDOR,
+       IBV_EXTENSION_OFA,
+       IBV_EXTENSION_RDMA_CM
+};
+#define IBV_EXTENSION_BASE_SHIFT 24
+#define IBV_EXTENSION_MASK 0xFF000000
+
 union ibv_gid {
        uint8_t                 raw[16];
        struct {
@@ -92,7 +101,8 @@ enum ibv_device_cap_flags {
        IBV_DEVICE_SYS_IMAGE_GUID       = 1 << 11,
        IBV_DEVICE_RC_RNR_NAK_GEN       = 1 << 12,
        IBV_DEVICE_SRQ_RESIZE           = 1 << 13,
-       IBV_DEVICE_N_NOTIFY_CQ          = 1 << 14
+       IBV_DEVICE_N_NOTIFY_CQ          = 1 << 14,
+       IBV_DEVICE_EXTENSIONS           = 1 << (IBV_EXTENSION_BASE_SHIFT - 1)
 };
 
 enum ibv_atomic_cap {
@@ -632,6 +642,13 @@ struct ibv_device {
        char                    dev_path[IBV_SYSFS_PATH_MAX];
        /* Path to infiniband class device in sysfs */
        char                    ibdev_path[IBV_SYSFS_PATH_MAX];
+
+       /* Following fields only available if device supports extensions */
+       void                   *private;
+       int                     (*have_ext_ops)(struct ibv_device *device,
+                                               const char *ext_name);
+       void *                  (*get_device_ext_ops)(struct ibv_device *device,
+                                                     const char *ext_name);
 };
 
 struct ibv_context_ops {
@@ -700,6 +717,11 @@ struct ibv_context {
        int                     num_comp_vectors;
        pthread_mutex_t         mutex;
        void                   *abi_compat;
+
+       /* Following fields only available if device supports extensions */
+       void                   *private;
+       void *                  (*get_ext_ops)(struct ibv_context *context,
+                                              const char *ext_name);
 };
 
 /**
@@ -732,6 +754,17 @@ const char *ibv_get_device_name(struct ibv_device *device);
  */
 uint64_t ibv_get_device_guid(struct ibv_device *device);
 
+/**
+ * ibv_have_ext_ops - Return true if device supports the requested
+ * extended operations.
+ */
+int ibv_have_ext_ops(struct ibv_device *device, const char *name);
+
+/**
+ * ibv_get_device_ext_ops - Return extended operations.
+ */
+void *ibv_get_device_ext_ops(struct ibv_device *device, const char *name);
+
 /**
  * ibv_open_device - Initialize device for use
  */
@@ -742,6 +775,11 @@ struct ibv_context *ibv_open_device(struct ibv_device *device);
  */
 int ibv_close_device(struct ibv_context *context);
 
+/**
+ * ibv_get_ext_ops - Return extended operations.
+ */
+void *ibv_get_ext_ops(struct ibv_context *context, const char *name);
+
 /**
  * ibv_get_async_event - Get next async event
  * @event: Pointer to use to return async event

diff --git a/src/device.c b/src/device.c
index 57988955c84839a35385515aaa486b7b6f4625e9..8e59340f1bc6f4029bbb456ce9068ca3033f8c03 100644 (file)
--- a/src/device.c
+++ b/src/device.c
@@ -181,6 +181,24 @@ int __ibv_close_device(struct ibv_context *context)
 }
 default_symver(__ibv_close_device, ibv_close_device);
 
+int __ibv_have_ext_ops(struct ibv_device *device, const char *name)
+{
+       if (!ibv_get_ext_support(device))
+               return ENOSYS;
+
+       return device->have_ext_ops(device, name);
+}
+default_symver(__ibv_have_ext_ops, ibv_have_ext_ops);
+
+void *__ibv_get_device_ext_ops(struct ibv_device *device, const char *name)
+{
+       if (!ibv_get_ext_support(device) || !device->get_device_ext_ops)
+               return NULL;
+
+       return device->get_device_ext_ops(device, name);
+}
+default_symver(__ibv_get_device_ext_ops, ibv_get_device_ext_ops);
+
 int __ibv_get_async_event(struct ibv_context *context,
                          struct ibv_async_event *event)
 {

diff --git a/src/ibverbs.h b/src/ibverbs.h
index 6a6e3c848ccaa4efe57fde2e4a5c0e4a61681bc5..33bdee23ab51e057806c1ca22e24a596cc3f3b13 100644 (file)
--- a/src/ibverbs.h
+++ b/src/ibverbs.h
@@ -35,6 +35,7 @@
 #define IB_VERBS_H
 
 #include <pthread.h>
+#include <string.h>
 
 #include <infiniband/driver.h>
 
@@ -102,4 +103,21 @@ HIDDEN int ibverbs_init(struct ibv_device ***list);
                (cmd)->response  = (uintptr_t) (out);                   \
        } while (0)
 
+/*
+ * Support for extended operations is recorded at the end of
+ * the name character array.  This way we don't need to query
+ * for the device capabilities with every call.
+ */
+static inline int ibv_get_ext_support(struct ibv_device *device)
+{
+       return device->name[IBV_SYSFS_NAME_MAX - 1];
+}
+
+static inline void ibv_set_ext_support(struct ibv_device *device,
+                                      int ext_supported)
+{
+       if (strlen(device->name) < IBV_SYSFS_NAME_MAX - 1)
+               device->name[IBV_SYSFS_NAME_MAX - 1] = (char) ext_supported;
+}
+
 #endif /* IB_VERBS_H */

diff --git a/src/init.c b/src/init.c
index 8d6786e509cb578d684388fb23de7117dc4487ec..f805c68bd5ab6bf27bebf66db4df24f0745b705a 100644 (file)
--- a/src/init.c
+++ b/src/init.c
@@ -71,6 +71,7 @@ struct ibv_driver {
        const char             *name;
        ibv_driver_init_func    init_func;
        struct ibv_driver      *next;
+       int                     ext_support;
 };
 
 static struct ibv_sysfs_dev *sysfs_dev_list;
@@ -153,7 +154,8 @@ static int find_sysfs_devs(void)
        return ret;
 }
 
-void ibv_register_driver(const char *name, ibv_driver_init_func init_func)
+static void __ibv_register_driver(const char *name, ibv_driver_init_func init_func,
+                                 int ext_support)
 {
        struct ibv_driver *driver;
 
@@ -166,6 +168,7 @@ void ibv_register_driver(const char *name, ibv_driver_init_func init_func)
        driver->name      = name;
        driver->init_func = init_func;
        driver->next      = NULL;
+       driver->ext_support = ext_support;
 
        if (tail_driver)
                tail_driver->next = driver;
@@ -174,6 +177,16 @@ void ibv_register_driver(const char *name, ibv_driver_init_func init_func)
        tail_driver = driver;
 }
 
+void ibv_register_driver(const char *name, ibv_driver_init_func init_func)
+{
+       __ibv_register_driver(name, init_func, 0);
+}
+
+void ibv_register_driver_ext(const char *name, ibv_driver_init_func init_func)
+{
+       __ibv_register_driver(name, init_func, 1);
+}
+
 static void load_driver(const char *name)
 {
        char *so_name;
@@ -369,6 +382,8 @@ static struct ibv_device *try_driver(struct ibv_driver *driver,
        strcpy(dev->name,       sysfs_dev->ibdev_name);
        strcpy(dev->ibdev_path, sysfs_dev->ibdev_path);
 
+       ibv_set_ext_support(dev, driver->ext_support);
+
        return dev;
 }
 

diff --git a/src/libibverbs.map b/src/libibverbs.map
index 1827da058331a7b1de10681ea8e1ef18ed53ad3b..422e07f87615d76b3992340042f09039acb05f2f 100644 (file)
--- a/src/libibverbs.map
+++ b/src/libibverbs.map
@@ -96,4 +96,9 @@ IBVERBS_1.1 {
                ibv_port_state_str;
                ibv_event_type_str;
                ibv_wc_status_str;
+
+               ibv_register_driver_ext;
+               ibv_have_ext_ops;
+               ibv_get_device_ext_ops;
+               ibv_get_ext_ops;
 } IBVERBS_1.0;

diff --git a/src/verbs.c b/src/verbs.c
index ba3c0a4cda6f730469c5db462ebdc5c46e2d14f4..a34a78480236247b52205a8bfcf212a997b75342 100644 (file)
--- a/src/verbs.c
+++ b/src/verbs.c
@@ -76,6 +76,15 @@ enum ibv_rate mult_to_ibv_rate(int mult)
        }
 }
 
+void *__ibv_get_ext_ops(struct ibv_context *context, const char *name)
+{
+       if (!ibv_get_ext_support(context->device) || !context->get_ext_ops)
+               return NULL;
+
+       return context->get_ext_ops(context, name);
+}
+default_symver(__ibv_get_ext_ops, ibv_get_ext_ops);
+
 int __ibv_query_device(struct ibv_context *context,
                       struct ibv_device_attr *device_attr)
 {