On Tue, Mar 23, 2021 at 04:50:23PM +0100, Maarten Lankhorst wrote:
> i915_gem_object_pin_map potentially needs a ww context, so ensure we
> have one we can revoke.
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
We shouldn't hand-roll our own vm_access callback, generic_access_phys
should be used here instead.
I've applied this, but can you pls do a follow up patch here?
Thanks, Daniel
> ---
> drivers/gpu/drm/i915/gem/i915_gem_mman.c | 24 ++++++++++++++++++++++--
> 1 file changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> index 163208a6260d..2561a2f1e54f 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> @@ -421,7 +421,9 @@ vm_access(struct vm_area_struct *area, unsigned long addr,
> {
> struct i915_mmap_offset *mmo = area->vm_private_data;
> struct drm_i915_gem_object *obj = mmo->obj;
> + struct i915_gem_ww_ctx ww;
> void *vaddr;
> + int err = 0;
>
> if (i915_gem_object_is_readonly(obj) && write)
> return -EACCES;
> @@ -430,10 +432,18 @@ vm_access(struct vm_area_struct *area, unsigned long addr,
> if (addr >= obj->base.size)
> return -EINVAL;
>
> + i915_gem_ww_ctx_init(&ww, true);
> +retry:
> + err = i915_gem_object_lock(obj, &ww);
> + if (err)
> + goto out;
> +
> /* As this is primarily for debugging, let's focus on simplicity */
> vaddr = i915_gem_object_pin_map(obj, I915_MAP_FORCE_WC);
> - if (IS_ERR(vaddr))
> - return PTR_ERR(vaddr);
> + if (IS_ERR(vaddr)) {
> + err = PTR_ERR(vaddr);
> + goto out;
> + }
>
> if (write) {
> memcpy(vaddr + addr, buf, len);
> @@ -443,6 +453,16 @@ vm_access(struct vm_area_struct *area, unsigned long addr,
> }
>
> i915_gem_object_unpin_map(obj);
> +out:
> + if (err == -EDEADLK) {
> + err = i915_gem_ww_ctx_backoff(&ww);
> + if (!err)
> + goto retry;
> + }
> + i915_gem_ww_ctx_fini(&ww);
> +
> + if (err)
> + return err;
>
> return len;
> }
> --
> 2.31.0
>
> _______________________________________________
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> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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