drm/ttm: Fix up io_mem_reserve / io_mem_free calling
This patch attempts to fix up shortcomings with the current calling
sequences.
1) There's a fastpath where no locking occurs and only io_mem_reserved is
called to obtain needed info for mapping. The fastpath is set per
memory type manager.
2) If the fastpath is disabled, io_mem_reserve and io_mem_free will be exactly
balanced and not called recursively for the same struct ttm_mem_reg.
3) Optionally the driver can choose to enable a per memory type manager LRU
eviction mechanism that, when io_mem_reserve returns -EAGAIN will attempt
to kill user-space mappings of memory in that manager to free up needed
resources
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 8dd446c..221b924 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -83,6 +83,8 @@
int i;
unsigned long address = (unsigned long)vmf->virtual_address;
int retval = VM_FAULT_NOPAGE;
+ struct ttm_mem_type_manager *man =
+ &bdev->man[bo->mem.mem_type];
/*
* Work around locking order reversal in fault / nopfn
@@ -130,12 +132,16 @@
} else
spin_unlock(&bdev->fence_lock);
-
- ret = ttm_mem_io_reserve(bdev, &bo->mem);
- if (ret) {
- retval = VM_FAULT_SIGBUS;
+ ret = ttm_mem_io_lock(man, true);
+ if (unlikely(ret != 0)) {
+ retval = VM_FAULT_NOPAGE;
goto out_unlock;
}
+ ret = ttm_mem_io_reserve_vm(bo);
+ if (unlikely(ret != 0)) {
+ retval = VM_FAULT_SIGBUS;
+ goto out_io_unlock;
+ }
page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
bo->vm_node->start - vma->vm_pgoff;
@@ -144,7 +150,7 @@
if (unlikely(page_offset >= bo->num_pages)) {
retval = VM_FAULT_SIGBUS;
- goto out_unlock;
+ goto out_io_unlock;
}
/*
@@ -182,7 +188,7 @@
page = ttm_tt_get_page(ttm, page_offset);
if (unlikely(!page && i == 0)) {
retval = VM_FAULT_OOM;
- goto out_unlock;
+ goto out_io_unlock;
} else if (unlikely(!page)) {
break;
}
@@ -200,14 +206,15 @@
else if (unlikely(ret != 0)) {
retval =
(ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
- goto out_unlock;
+ goto out_io_unlock;
}
address += PAGE_SIZE;
if (unlikely(++page_offset >= page_last))
break;
}
-
+out_io_unlock:
+ ttm_mem_io_unlock(man);
out_unlock:
ttm_bo_unreserve(bo);
return retval;