cxgb4/iw_cxgb4: Doorbell Drop Avoidance Bug Fixes

[linux-2.6-block.git] / drivers / infiniband / hw / cxgb4 / provider.c

diff --git a/drivers/infiniband/hw/cxgb4/provider.c b/drivers/infiniband/hw/cxgb4/provider.c
index 7e94c9a656a1429d37c14bd2e7b8f4b8590d494e..e36d2a27c4315bfbeedd6e67dc8fba535ca82ead 100644 (file)
--- a/drivers/infiniband/hw/cxgb4/provider.c
+++ b/drivers/infiniband/hw/cxgb4/provider.c
@@ -106,15 +106,54 @@ static struct ib_ucontext *c4iw_alloc_ucontext(struct ib_device *ibdev,
 {
        struct c4iw_ucontext *context;
        struct c4iw_dev *rhp = to_c4iw_dev(ibdev);
+       static int warned;
+       struct c4iw_alloc_ucontext_resp uresp;
+       int ret = 0;
+       struct c4iw_mm_entry *mm = NULL;
 
        PDBG("%s ibdev %p\n", __func__, ibdev);
        context = kzalloc(sizeof(*context), GFP_KERNEL);
-       if (!context)
-               return ERR_PTR(-ENOMEM);
+       if (!context) {
+               ret = -ENOMEM;
+               goto err;
+       }
+
        c4iw_init_dev_ucontext(&rhp->rdev, &context->uctx);
        INIT_LIST_HEAD(&context->mmaps);
        spin_lock_init(&context->mmap_lock);
+
+       if (udata->outlen < sizeof(uresp)) {
+               if (!warned++)
+                       pr_err(MOD "Warning - downlevel libcxgb4 (non-fatal), device status page disabled.");
+               rhp->rdev.flags |= T4_STATUS_PAGE_DISABLED;
+       } else {
+               mm = kmalloc(sizeof(*mm), GFP_KERNEL);
+               if (!mm)
+                       goto err_free;
+
+               uresp.status_page_size = PAGE_SIZE;
+
+               spin_lock(&context->mmap_lock);
+               uresp.status_page_key = context->key;
+               context->key += PAGE_SIZE;
+               spin_unlock(&context->mmap_lock);
+
+               ret = ib_copy_to_udata(udata, &uresp, sizeof(uresp));
+               if (ret)
+                       goto err_mm;
+
+               mm->key = uresp.status_page_key;
+               mm->addr = virt_to_phys(rhp->rdev.status_page);
+               mm->len = PAGE_SIZE;
+               insert_mmap(context, mm);
+       }
        return &context->ibucontext;
+err_mm:
+       kfree(mm);
+err_free:
+       kfree(context);
+err:
+       return ERR_PTR(ret);
 }
 
 static int c4iw_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)