[PATCH] IB uverbs: core API extensions

First of a series of patches which add support for direct userspace access to
InfiniBand hardware -- so-called "userspace verbs." I believe these patches
are ready to merge, but a final review would be useful.

These patches should incorporate all of the feedback from the discussion when
I posted an earlier version back in April (see
http://lkml.org/lkml/2005/4/4/267 for the start of the thread).  In
particular, memory pinned for use by userspace is accounted for in
current->mm->vm_locked and requests to pin memory are checked against
RLIMIT_MEMLOCK.

This patch:

Modify the ib_verbs.h header file with changes required for InfiniBand
userspace verbs support.  We add a few structures to keep track of userspace
context, and extend the driver API so that low-level drivers know when they're
creating resources that will be used from userspace.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 106 insertions, 18 deletions

diff --git a/drivers/infiniband/include/ib_verbs.h b/drivers/infiniband/include/ib_verbs.h
index cf01f044a223..e5bd9a10c201 100644
--- a/drivers/infiniband/include/ib_verbs.h
+++ b/drivers/infiniband/include/ib_verbs.h
@@ -4,6 +4,7 @@
  * Copyright (c) 2004 Intel Corporation.  All rights reserved.
  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
  * Copyright (c) 2004 Voltaire Corporation.  All rights reserved.
+ * Copyright (c) 2005 Cisco Systems.  All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -41,7 +42,10 @@
 
 #include <linux/types.h>
 #include <linux/device.h>
+
 #include <asm/atomic.h>
+#include <asm/scatterlist.h>
+#include <asm/uaccess.h>
 
 union ib_gid {
         u8      raw[16];
@@ -544,7 +548,7 @@ struct ib_send_wr {
         int                     num_sge;
         enum ib_wr_opcode       opcode;
         int                     send_flags;
-        u32                     imm_data;
+        __be32                  imm_data;
         union {
                 struct {
                         u64     remote_addr;
@@ -618,29 +622,86 @@ struct ib_fmr_attr {
         u8      page_size;
 };
 
+struct ib_ucontext {
+        struct ib_device       *device;
+        struct list_head        pd_list;
+        struct list_head        mr_list;
+        struct list_head        mw_list;
+        struct list_head        cq_list;
+        struct list_head        qp_list;
+        struct list_head        srq_list;
+        struct list_head        ah_list;
+        spinlock_t              lock;
+};
+
+struct ib_uobject {
+        u64                     user_handle;    /* handle given to us by userspace */
+        struct ib_ucontext     *context;        /* associated user context */
+        struct list_head        list;           /* link to context's list */
+        u32                     id;             /* index into kernel idr */
+};
+
+struct ib_umem {
+        unsigned long           user_base;
+        unsigned long           virt_base;
+        size_t                  length;
+        int                     offset;
+        int                     page_size;
+        int                     writable;
+        struct list_head        chunk_list;
+};
+
+struct ib_umem_chunk {
+        struct list_head        list;
+        int                     nents;
+        int                     nmap;
+        struct scatterlist      page_list[0];
+};
+
+struct ib_udata {
+        void __user *inbuf;
+        void __user *outbuf;
+        size_t       inlen;
+        size_t       outlen;
+};
+
+#define IB_UMEM_MAX_PAGE_CHUNK                                          \
+        ((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) /      \
+         ((void *) &((struct ib_umem_chunk *) 0)->page_list[1] -        \
+          (void *) &((struct ib_umem_chunk *) 0)->page_list[0]))
+
+struct ib_umem_object {
+        struct ib_uobject       uobject;
+        struct ib_umem          umem;
+};
+
 struct ib_pd {
-        struct ib_device *device;
-        atomic_t          usecnt; /* count all resources */
+        struct ib_device       *device;
+        struct ib_uobject      *uobject;
+        atomic_t                usecnt; /* count all resources */
 };
 
 struct ib_ah {
         struct ib_device        *device;
         struct ib_pd            *pd;
+        struct ib_uobject       *uobject;
 };
 
 typedef void (*ib_comp_handler)(struct ib_cq *cq, void *cq_context);
 
 struct ib_cq {
-        struct ib_device *device;
-        ib_comp_handler   comp_handler;
-        void             (*event_handler)(struct ib_event *, void *);
-        void *            cq_context;
-        int               cqe;
-        atomic_t          usecnt; /* count number of work queues */
+        struct ib_device       *device;
+        struct ib_uobject      *uobject;
+        ib_comp_handler         comp_handler;
+        void                  (*event_handler)(struct ib_event *, void *);
+        void *                  cq_context;
+        int                     cqe;
+        atomic_t                usecnt; /* count number of work queues */
 };
 
 struct ib_srq {
         struct ib_device        *device;
+        struct ib_uobject       *uobject;
         struct ib_pd            *pd;
         void                    *srq_context;
         atomic_t                usecnt;
@@ -652,6 +713,7 @@ struct ib_qp {
         struct ib_cq           *send_cq;
         struct ib_cq           *recv_cq;
         struct ib_srq          *srq;
+        struct ib_uobject      *uobject;
         void                  (*event_handler)(struct ib_event *, void *);
         void                   *qp_context;
         u32                     qp_num;
@@ -659,16 +721,18 @@ struct ib_qp {
 };
 
 struct ib_mr {
-        struct ib_device *device;
-        struct ib_pd     *pd;
-        u32               lkey;
-        u32               rkey;
-        atomic_t          usecnt; /* count number of MWs */
+        struct ib_device  *device;
+        struct ib_pd      *pd;
+        struct ib_uobject *uobject;
+        u32                lkey;
+        u32                rkey;
+        atomic_t           usecnt; /* count number of MWs */
 };
 
 struct ib_mw {
         struct ib_device        *device;
         struct ib_pd            *pd;
+        struct ib_uobject       *uobject;
         u32                     rkey;
 };
 
@@ -737,7 +801,14 @@ struct ib_device {
         int                        (*modify_port)(struct ib_device *device,
                                                   u8 port_num, int port_modify_mask,
                                                   struct ib_port_modify *port_modify);
-        struct ib_pd *             (*alloc_pd)(struct ib_device *device);
+        struct ib_ucontext *       (*alloc_ucontext)(struct ib_device *device,
+                                                     struct ib_udata *udata);
+        int                        (*dealloc_ucontext)(struct ib_ucontext *context);
+        int                        (*mmap)(struct ib_ucontext *context,
+                                           struct vm_area_struct *vma);
+        struct ib_pd *             (*alloc_pd)(struct ib_device *device,
+                                               struct ib_ucontext *context,
+                                               struct ib_udata *udata);
         int                        (*dealloc_pd)(struct ib_pd *pd);
         struct ib_ah *             (*create_ah)(struct ib_pd *pd,
                                                 struct ib_ah_attr *ah_attr);
@@ -747,7 +818,8 @@ struct ib_device {
                                                struct ib_ah_attr *ah_attr);
         int                        (*destroy_ah)(struct ib_ah *ah);
         struct ib_qp *             (*create_qp)(struct ib_pd *pd,
-                                                struct ib_qp_init_attr *qp_init_attr);
+                                                struct ib_qp_init_attr *qp_init_attr,
+                                                struct ib_udata *udata);
         int                        (*modify_qp)(struct ib_qp *qp,
                                                 struct ib_qp_attr *qp_attr,
                                                 int qp_attr_mask);
@@ -762,8 +834,9 @@ struct ib_device {
         int                        (*post_recv)(struct ib_qp *qp,
                                                 struct ib_recv_wr *recv_wr,
                                                 struct ib_recv_wr **bad_recv_wr);
-        struct ib_cq *             (*create_cq)(struct ib_device *device,
-                                                int cqe);
+        struct ib_cq *             (*create_cq)(struct ib_device *device, int cqe,
+                                                struct ib_ucontext *context,
+                                                struct ib_udata *udata);
         int                        (*destroy_cq)(struct ib_cq *cq);
         int                        (*resize_cq)(struct ib_cq *cq, int *cqe);
         int                        (*poll_cq)(struct ib_cq *cq, int num_entries,
@@ -780,6 +853,10 @@ struct ib_device {
                                                   int num_phys_buf,
                                                   int mr_access_flags,
                                                   u64 *iova_start);
+        struct ib_mr *             (*reg_user_mr)(struct ib_pd *pd,
+                                                  struct ib_umem *region,
+                                                  int mr_access_flags,
+                                                  struct ib_udata *udata);
         int                        (*query_mr)(struct ib_mr *mr,
                                                struct ib_mr_attr *mr_attr);
         int                        (*dereg_mr)(struct ib_mr *mr);
@@ -817,6 +894,7 @@ struct ib_device {
                                                   struct ib_mad *in_mad,
                                                   struct ib_mad *out_mad);
 
+        struct module               *owner;
         struct class_device          class_dev;
         struct kobject               ports_parent;
         struct list_head             port_list;
@@ -852,6 +930,16 @@ void *ib_get_client_data(struct ib_device *device, struct ib_client *client);
 void  ib_set_client_data(struct ib_device *device, struct ib_client *client,
                          void *data);
 
+static inline int ib_copy_from_udata(void *dest, struct ib_udata *udata, size_t len)
+{
+        return copy_from_user(dest, udata->inbuf, len) ? -EFAULT : 0;
+}
+
+static inline int ib_copy_to_udata(struct ib_udata *udata, void *src, size_t len)
+{
+        return copy_to_user(udata->outbuf, src, len) ? -EFAULT : 0;
+}
+
 int ib_register_event_handler  (struct ib_event_handler *event_handler);
 int ib_unregister_event_handler(struct ib_event_handler *event_handler);
 void ib_dispatch_event(struct ib_event *event);