IB/mlx5: Extract page fault code (1b7dbc26) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/infiniband/hw/mlx5/odp.c

+104 −99

Original line number	Diff line number	Diff line
		@@ -511,81 +511,38 @@ void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *imr)
		wait_event(imr->q_leaf_free, !atomic_read(&imr->num_leaf_free));
		}

		/*
		* Handle a single data segment in a page-fault WQE or RDMA region.
		*
		* Returns number of OS pages retrieved on success. The caller may continue to
		* the next data segment.
		* Can return the following error codes:
		* -EAGAIN to designate a temporary error. The caller will abort handling the
		* page fault and resolve it.
		* -EFAULT when there's an error mapping the requested pages. The caller will
		* abort the page fault handling.
		*/
		static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
		u32 key, u64 io_virt, size_t bcnt,
		u32 *bytes_committed,
		u32 *bytes_mapped)
		static int pagefault_mr(struct mlx5_ib_dev dev, struct mlx5_ib_mr mr,
		u64 io_virt, size_t bcnt, u32 *bytes_mapped)
		{
		int srcu_key;
		unsigned int current_seq = 0;
		u64 start_idx, page_mask;
		int npages = 0, ret = 0;
		struct mlx5_ib_mr *mr;
		u64 access_mask = ODP_READ_ALLOWED_BIT;
		int npages = 0, page_shift, np;
		u64 start_idx, page_mask;
		struct ib_umem_odp *odp;
		int implicit = 0;
		int current_seq;
		size_t size;
		int page_shift;

		srcu_key = srcu_read_lock(&dev->mr_srcu);
		mr = mlx5_ib_odp_find_mr_lkey(dev, key);
		/*
		* If we didn't find the MR, it means the MR was closed while we were
		* handling the ODP event. In this case we return -EFAULT so that the
		* QP will be closed.
		*/
		if (!mr \|\| !mr->ibmr.pd) {
		mlx5_ib_dbg(dev, "Failed to find relevant mr for lkey=0x%06x, probably the MR was destroyed\n",
		key);
		ret = -EFAULT;
		goto srcu_unlock;
		}
		if (!mr->umem->odp_data) {
		mlx5_ib_dbg(dev, "skipping non ODP MR (lkey=0x%06x) in page fault handler.\n",
		key);
		if (bytes_mapped)
		*bytes_mapped +=
		(bcnt - *bytes_committed);
		goto srcu_unlock;
		}

		/*
		* Avoid branches - this code will perform correctly
		* in all iterations (in iteration 2 and above,
		* bytes_committed == 0).
		*/
		io_virt += *bytes_committed;
		bcnt -= *bytes_committed;
		int ret;

		if (!mr->umem->odp_data->page_list) {
		odp = implicit_mr_get_data(mr, io_virt, bcnt);

		if (IS_ERR(odp)) {
		ret = PTR_ERR(odp);
		goto srcu_unlock;
		}
		if (IS_ERR(odp))
		return PTR_ERR(odp);
		mr = odp->private;
		implicit = 1;

		} else {
		odp = mr->umem->odp_data;
		}

		next_mr:
		size = min_t(size_t, bcnt, ib_umem_end(odp->umem) - io_virt);

		page_shift = mr->umem->page_shift;
		page_mask = ~(BIT(page_shift) - 1);
		start_idx = (io_virt - (mr->mmkey.iova & page_mask)) >> page_shift;

		if (mr->umem->writable)
		access_mask \|= ODP_WRITE_ALLOWED_BIT;

		next_mr:
		current_seq = READ_ONCE(odp->notifiers_seq);
		/*
		* Ensure the sequence number is valid for some time before we call
		@@ -593,20 +550,13 @@ static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
		*/
		smp_rmb();

		size = min_t(size_t, bcnt, ib_umem_end(odp->umem) - io_virt);
		start_idx = (io_virt - (mr->mmkey.iova & page_mask)) >> page_shift;

		if (mr->umem->writable)
		access_mask \|= ODP_WRITE_ALLOWED_BIT;

		ret = ib_umem_odp_map_dma_pages(mr->umem, io_virt, size,
		access_mask, current_seq);

		if (ret < 0)
		goto srcu_unlock;
		goto out;

		if (ret > 0) {
		int np = ret;
		np = ret;

		mutex_lock(&odp->umem_mutex);
		if (!ib_umem_mmu_notifier_retry(mr->umem, current_seq)) {
		@@ -616,28 +566,27 @@ static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
		* checks this.
		*/
		ret = mlx5_ib_update_xlt(mr, start_idx, np,
		page_shift,
		MLX5_IB_UPD_XLT_ATOMIC);
		page_shift, MLX5_IB_UPD_XLT_ATOMIC);
		} else {
		ret = -EAGAIN;
		}
		mutex_unlock(&odp->umem_mutex);

		if (ret < 0) {
		if (ret != -EAGAIN)
		mlx5_ib_err(dev, "Failed to update mkey page tables\n");
		goto srcu_unlock;
		goto out;
		}

		if (bytes_mapped) {
		u32 new_mappings = (np << page_shift) -
		(io_virt - round_down(io_virt,
		1 << page_shift));
		(io_virt - round_down(io_virt, 1 << page_shift));
		*bytes_mapped += min_t(u32, new_mappings, size);
		}

		npages += np << (page_shift - PAGE_SHIFT);
		}

		bcnt -= size;

		if (unlikely(bcnt)) {
		struct ib_umem_odp *next;

		@@ -646,17 +595,18 @@ static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
		if (unlikely(!next \|\| next->umem->address != io_virt)) {
		mlx5_ib_dbg(dev, "next implicit leaf removed at 0x%llx. got %p\n",
		io_virt, next);
		ret = -EAGAIN;
		goto srcu_unlock_no_wait;
		return -EAGAIN;
		}
		odp = next;
		mr = odp->private;
		goto next_mr;
		}

		srcu_unlock:
		return npages;

		out:
		if (ret == -EAGAIN) {
		if (implicit \|\| !odp->dying) {
		if (mr->parent \|\| !odp->dying) {
		unsigned long timeout =
		msecs_to_jiffies(MMU_NOTIFIER_TIMEOUT);

		@@ -672,7 +622,62 @@ static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
		}
		}

		srcu_unlock_no_wait:
		return ret;
		}

		/*
		* Handle a single data segment in a page-fault WQE or RDMA region.
		*
		* Returns number of OS pages retrieved on success. The caller may continue to
		* the next data segment.
		* Can return the following error codes:
		* -EAGAIN to designate a temporary error. The caller will abort handling the
		* page fault and resolve it.
		* -EFAULT when there's an error mapping the requested pages. The caller will
		* abort the page fault handling.
		*/
		static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
		u32 key, u64 io_virt, size_t bcnt,
		u32 *bytes_committed,
		u32 *bytes_mapped)
		{
		int npages = 0, srcu_key, ret;
		struct mlx5_ib_mr *mr;
		size_t size;

		srcu_key = srcu_read_lock(&dev->mr_srcu);
		mr = mlx5_ib_odp_find_mr_lkey(dev, key);
		/*
		* If we didn't find the MR, it means the MR was closed while we were
		* handling the ODP event. In this case we return -EFAULT so that the
		* QP will be closed.
		*/
		if (!mr \|\| !mr->ibmr.pd) {
		mlx5_ib_dbg(dev, "Failed to find relevant mr for lkey=0x%06x, probably the MR was destroyed\n",
		key);
		ret = -EFAULT;
		goto srcu_unlock;
		}
		if (!mr->umem->odp_data) {
		mlx5_ib_dbg(dev, "skipping non ODP MR (lkey=0x%06x) in page fault handler.\n",
		key);
		if (bytes_mapped)
		*bytes_mapped +=
		(bcnt - *bytes_committed);
		goto srcu_unlock;
		}

		/*
		* Avoid branches - this code will perform correctly
		* in all iterations (in iteration 2 and above,
		* bytes_committed == 0).
		*/
		io_virt += *bytes_committed;
		bcnt -= *bytes_committed;

		npages = pagefault_mr(dev, mr, io_virt, size, bytes_mapped);

		srcu_unlock:
		srcu_read_unlock(&dev->mr_srcu, srcu_key);
		*bytes_committed = 0;
		return ret ? ret : npages;