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Commit d9aaed83 authored by Artemy Kovalyov's avatar Artemy Kovalyov Committed by David S. Miller
Browse files

{net,IB}/mlx5: Refactor page fault handling



* Update page fault event according to last specification.
* Separate code path for page fault EQ, completion EQ and async EQ.
* Move page fault handling work queue from mlx5_ib static variable
  into mlx5_core page fault EQ.
* Allocate memory to store ODP event dynamically as the
  events arrive, since in atomic context - use mempool.
* Make mlx5_ib page fault handler run in process context.

Signed-off-by: default avatarArtemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
Signed-off-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 223cdc72
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+3 −11
Original line number Diff line number Diff line
@@ -3319,6 +3319,9 @@ static struct mlx5_interface mlx5_ib_interface = {
	.add            = mlx5_ib_add,
	.remove         = mlx5_ib_remove,
	.event          = mlx5_ib_event,
#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
	.pfault		= mlx5_ib_pfault,
#endif
	.protocol	= MLX5_INTERFACE_PROTOCOL_IB,
};

@@ -3329,25 +3332,14 @@ static int __init mlx5_ib_init(void)
	if (deprecated_prof_sel != 2)
		pr_warn("prof_sel is deprecated for mlx5_ib, set it for mlx5_core\n");

	err = mlx5_ib_odp_init();
	if (err)
		return err;

	err = mlx5_register_interface(&mlx5_ib_interface);
	if (err)
		goto clean_odp;

	return err;

clean_odp:
	mlx5_ib_odp_cleanup();
	return err;
}

static void __exit mlx5_ib_cleanup(void)
{
	mlx5_unregister_interface(&mlx5_ib_interface);
	mlx5_ib_odp_cleanup();
}

module_init(mlx5_ib_init);
+2 −47
Original line number Diff line number Diff line
@@ -277,29 +277,6 @@ struct mlx5_ib_rwq_ind_table {
	u32			rqtn;
};

/*
 * Connect-IB can trigger up to four concurrent pagefaults
 * per-QP.
 */
enum mlx5_ib_pagefault_context {
	MLX5_IB_PAGEFAULT_RESPONDER_READ,
	MLX5_IB_PAGEFAULT_REQUESTOR_READ,
	MLX5_IB_PAGEFAULT_RESPONDER_WRITE,
	MLX5_IB_PAGEFAULT_REQUESTOR_WRITE,
	MLX5_IB_PAGEFAULT_CONTEXTS
};

static inline enum mlx5_ib_pagefault_context
	mlx5_ib_get_pagefault_context(struct mlx5_pagefault *pagefault)
{
	return pagefault->flags & (MLX5_PFAULT_REQUESTOR | MLX5_PFAULT_WRITE);
}

struct mlx5_ib_pfault {
	struct work_struct	work;
	struct mlx5_pagefault	mpfault;
};

struct mlx5_ib_ubuffer {
	struct ib_umem	       *umem;
	int			buf_size;
@@ -385,20 +362,6 @@ struct mlx5_ib_qp {
	/* Store signature errors */
	bool			signature_en;

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
	/*
	 * A flag that is true for QP's that are in a state that doesn't
	 * allow page faults, and shouldn't schedule any more faults.
	 */
	int                     disable_page_faults;
	/*
	 * The disable_page_faults_lock protects a QP's disable_page_faults
	 * field, allowing for a thread to atomically check whether the QP
	 * allows page faults, and if so schedule a page fault.
	 */
	spinlock_t              disable_page_faults_lock;
	struct mlx5_ib_pfault	pagefaults[MLX5_IB_PAGEFAULT_CONTEXTS];
#endif
	struct list_head	qps_list;
	struct list_head	cq_recv_list;
	struct list_head	cq_send_list;
@@ -869,18 +832,13 @@ struct ib_rwq_ind_table *mlx5_ib_create_rwq_ind_table(struct ib_device *device,
int mlx5_ib_destroy_rwq_ind_table(struct ib_rwq_ind_table *wq_ind_table);

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
extern struct workqueue_struct *mlx5_ib_page_fault_wq;

void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev);
void mlx5_ib_mr_pfault_handler(struct mlx5_ib_qp *qp,
			       struct mlx5_ib_pfault *pfault);
void mlx5_ib_odp_create_qp(struct mlx5_ib_qp *qp);
void mlx5_ib_pfault(struct mlx5_core_dev *mdev, void *context,
		    struct mlx5_pagefault *pfault);
int mlx5_ib_odp_init_one(struct mlx5_ib_dev *ibdev);
void mlx5_ib_odp_remove_one(struct mlx5_ib_dev *ibdev);
int __init mlx5_ib_odp_init(void);
void mlx5_ib_odp_cleanup(void);
void mlx5_ib_qp_disable_pagefaults(struct mlx5_ib_qp *qp);
void mlx5_ib_qp_enable_pagefaults(struct mlx5_ib_qp *qp);
void mlx5_ib_invalidate_range(struct ib_umem *umem, unsigned long start,
			      unsigned long end);
#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
@@ -889,13 +847,10 @@ static inline void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev)
	return;
}

static inline void mlx5_ib_odp_create_qp(struct mlx5_ib_qp *qp)		{}
static inline int mlx5_ib_odp_init_one(struct mlx5_ib_dev *ibdev) { return 0; }
static inline void mlx5_ib_odp_remove_one(struct mlx5_ib_dev *ibdev)	{}
static inline int mlx5_ib_odp_init(void) { return 0; }
static inline void mlx5_ib_odp_cleanup(void)				{}
static inline void mlx5_ib_qp_disable_pagefaults(struct mlx5_ib_qp *qp) {}
static inline void mlx5_ib_qp_enable_pagefaults(struct mlx5_ib_qp *qp)  {}

#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */

+110 −190
Original line number Diff line number Diff line
@@ -41,8 +41,6 @@
 * a pagefault. */
#define MMU_NOTIFIER_TIMEOUT 1000

struct workqueue_struct *mlx5_ib_page_fault_wq;

void mlx5_ib_invalidate_range(struct ib_umem *umem, unsigned long start,
			      unsigned long end)
{
@@ -162,38 +160,38 @@ static struct mlx5_ib_mr *mlx5_ib_odp_find_mr_lkey(struct mlx5_ib_dev *dev,
	return container_of(mmkey, struct mlx5_ib_mr, mmkey);
}

static void mlx5_ib_page_fault_resume(struct mlx5_ib_qp *qp,
				      struct mlx5_ib_pfault *pfault,
static void mlx5_ib_page_fault_resume(struct mlx5_ib_dev *dev,
				      struct mlx5_pagefault *pfault,
				      int error)
{
	struct mlx5_ib_dev *dev = to_mdev(qp->ibqp.pd->device);
	u32 qpn = qp->trans_qp.base.mqp.qpn;
	int wq_num = pfault->event_subtype == MLX5_PFAULT_SUBTYPE_WQE ?
		     pfault->wqe.wq_num : pfault->token;
	int ret = mlx5_core_page_fault_resume(dev->mdev,
					      qpn,
					      pfault->mpfault.flags,
					      pfault->token,
					      wq_num,
					      pfault->type,
					      error);
	if (ret)
		pr_err("Failed to resolve the page fault on QP 0x%x\n", qpn);
		mlx5_ib_err(dev, "Failed to resolve the page fault on WQ 0x%x\n",
			    wq_num);
}

/*
 * Handle a single data segment in a page-fault WQE.
 * Handle a single data segment in a page-fault WQE or RDMA region.
 *
 * Returns number of pages retrieved on success. The caller will continue to
 * Returns number of 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 and possibly move the QP to an error state.
 * On other errors the QP should also be closed with an error.
 *  abort the page fault handling.
 */
static int pagefault_single_data_segment(struct mlx5_ib_qp *qp,
					 struct mlx5_ib_pfault *pfault,
static int pagefault_single_data_segment(struct mlx5_ib_dev *mib_dev,
					 u32 key, u64 io_virt, size_t bcnt,
					 u32 *bytes_committed,
					 u32 *bytes_mapped)
{
	struct mlx5_ib_dev *mib_dev = to_mdev(qp->ibqp.pd->device);
	int srcu_key;
	unsigned int current_seq;
	u64 start_idx;
@@ -219,12 +217,7 @@ static int pagefault_single_data_segment(struct mlx5_ib_qp *qp,
			 key);
		if (bytes_mapped)
			*bytes_mapped +=
				(bcnt - pfault->mpfault.bytes_committed);
		goto srcu_unlock;
	}
	if (mr->ibmr.pd != qp->ibqp.pd) {
		pr_err("Page-fault with different PDs for QP and MR.\n");
		ret = -EFAULT;
				(bcnt - *bytes_committed);
		goto srcu_unlock;
	}

@@ -240,8 +233,8 @@ static int pagefault_single_data_segment(struct mlx5_ib_qp *qp,
	 * in all iterations (in iteration 2 and above,
	 * bytes_committed == 0).
	 */
	io_virt += pfault->mpfault.bytes_committed;
	bcnt -= pfault->mpfault.bytes_committed;
	io_virt += *bytes_committed;
	bcnt -= *bytes_committed;

	start_idx = (io_virt - (mr->mmkey.iova & PAGE_MASK)) >> PAGE_SHIFT;

@@ -300,7 +293,7 @@ static int pagefault_single_data_segment(struct mlx5_ib_qp *qp,
		}
	}
	srcu_read_unlock(&mib_dev->mr_srcu, srcu_key);
	pfault->mpfault.bytes_committed = 0;
	*bytes_committed = 0;
	return ret ? ret : npages;
}

@@ -322,8 +315,9 @@ static int pagefault_single_data_segment(struct mlx5_ib_qp *qp,
 * Returns the number of pages loaded if positive, zero for an empty WQE, or a
 * negative error code.
 */
static int pagefault_data_segments(struct mlx5_ib_qp *qp,
				   struct mlx5_ib_pfault *pfault, void *wqe,
static int pagefault_data_segments(struct mlx5_ib_dev *dev,
				   struct mlx5_pagefault *pfault,
				   struct mlx5_ib_qp *qp, void *wqe,
				   void *wqe_end, u32 *bytes_mapped,
				   u32 *total_wqe_bytes, int receive_queue)
{
@@ -367,22 +361,23 @@ static int pagefault_data_segments(struct mlx5_ib_qp *qp,

		if (!inline_segment && total_wqe_bytes) {
			*total_wqe_bytes += bcnt - min_t(size_t, bcnt,
					pfault->mpfault.bytes_committed);
					pfault->bytes_committed);
		}

		/* A zero length data segment designates a length of 2GB. */
		if (bcnt == 0)
			bcnt = 1U << 31;

		if (inline_segment || bcnt <= pfault->mpfault.bytes_committed) {
			pfault->mpfault.bytes_committed -=
		if (inline_segment || bcnt <= pfault->bytes_committed) {
			pfault->bytes_committed -=
				min_t(size_t, bcnt,
				      pfault->mpfault.bytes_committed);
				      pfault->bytes_committed);
			continue;
		}

		ret = pagefault_single_data_segment(qp, pfault, key, io_virt,
						    bcnt, bytes_mapped);
		ret = pagefault_single_data_segment(dev, key, io_virt, bcnt,
						    &pfault->bytes_committed,
						    bytes_mapped);
		if (ret < 0)
			break;
		npages += ret;
@@ -396,12 +391,11 @@ static int pagefault_data_segments(struct mlx5_ib_qp *qp,
 * scatter-gather list, and set wqe_end to the end of the WQE.
 */
static int mlx5_ib_mr_initiator_pfault_handler(
	struct mlx5_ib_qp *qp, struct mlx5_ib_pfault *pfault,
	void **wqe, void **wqe_end, int wqe_length)
	struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault,
	struct mlx5_ib_qp *qp, void **wqe, void **wqe_end, int wqe_length)
{
	struct mlx5_ib_dev *dev = to_mdev(qp->ibqp.pd->device);
	struct mlx5_wqe_ctrl_seg *ctrl = *wqe;
	u16 wqe_index = pfault->mpfault.wqe.wqe_index;
	u16 wqe_index = pfault->wqe.wqe_index;
	unsigned ds, opcode;
#if defined(DEBUG)
	u32 ctrl_wqe_index, ctrl_qpn;
@@ -502,10 +496,9 @@ static int mlx5_ib_mr_initiator_pfault_handler(
 * scatter-gather list, and set wqe_end to the end of the WQE.
 */
static int mlx5_ib_mr_responder_pfault_handler(
	struct mlx5_ib_qp *qp, struct mlx5_ib_pfault *pfault,
	void **wqe, void **wqe_end, int wqe_length)
	struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault,
	struct mlx5_ib_qp *qp, void **wqe, void **wqe_end, int wqe_length)
{
	struct mlx5_ib_dev *dev = to_mdev(qp->ibqp.pd->device);
	struct mlx5_ib_wq *wq = &qp->rq;
	int wqe_size = 1 << wq->wqe_shift;

@@ -542,70 +535,83 @@ static int mlx5_ib_mr_responder_pfault_handler(
	return 0;
}

static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_qp *qp,
					  struct mlx5_ib_pfault *pfault)
static struct mlx5_ib_qp *mlx5_ib_odp_find_qp(struct mlx5_ib_dev *dev,
					      u32 wq_num)
{
	struct mlx5_core_qp *mqp = __mlx5_qp_lookup(dev->mdev, wq_num);

	if (!mqp) {
		mlx5_ib_err(dev, "QPN 0x%6x not found\n", wq_num);
		return NULL;
	}

	return to_mibqp(mqp);
}

static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_dev *dev,
					  struct mlx5_pagefault *pfault)
{
	struct mlx5_ib_dev *dev = to_mdev(qp->ibqp.pd->device);
	int ret;
	void *wqe, *wqe_end;
	u32 bytes_mapped, total_wqe_bytes;
	char *buffer = NULL;
	int resume_with_error = 0;
	u16 wqe_index = pfault->mpfault.wqe.wqe_index;
	int requestor = pfault->mpfault.flags & MLX5_PFAULT_REQUESTOR;
	u32 qpn = qp->trans_qp.base.mqp.qpn;
	int resume_with_error = 1;
	u16 wqe_index = pfault->wqe.wqe_index;
	int requestor = pfault->type & MLX5_PFAULT_REQUESTOR;
	struct mlx5_ib_qp *qp;

	buffer = (char *)__get_free_page(GFP_KERNEL);
	if (!buffer) {
		mlx5_ib_err(dev, "Error allocating memory for IO page fault handling.\n");
		resume_with_error = 1;
		goto resolve_page_fault;
	}

	qp = mlx5_ib_odp_find_qp(dev, pfault->wqe.wq_num);
	if (!qp)
		goto resolve_page_fault;

	ret = mlx5_ib_read_user_wqe(qp, requestor, wqe_index, buffer,
				    PAGE_SIZE, &qp->trans_qp.base);
	if (ret < 0) {
		mlx5_ib_err(dev, "Failed reading a WQE following page fault, error=%x, wqe_index=%x, qpn=%x\n",
			    -ret, wqe_index, qpn);
		resume_with_error = 1;
		mlx5_ib_err(dev, "Failed reading a WQE following page fault, error=%d, wqe_index=%x, qpn=%x\n",
			    ret, wqe_index, pfault->token);
		goto resolve_page_fault;
	}

	wqe = buffer;
	if (requestor)
		ret = mlx5_ib_mr_initiator_pfault_handler(qp, pfault, &wqe,
		ret = mlx5_ib_mr_initiator_pfault_handler(dev, pfault, qp, &wqe,
							  &wqe_end, ret);
	else
		ret = mlx5_ib_mr_responder_pfault_handler(qp, pfault, &wqe,
		ret = mlx5_ib_mr_responder_pfault_handler(dev, pfault, qp, &wqe,
							  &wqe_end, ret);
	if (ret < 0) {
		resume_with_error = 1;
	if (ret < 0)
		goto resolve_page_fault;
	}

	if (wqe >= wqe_end) {
		mlx5_ib_err(dev, "ODP fault on invalid WQE.\n");
		resume_with_error = 1;
		goto resolve_page_fault;
	}

	ret = pagefault_data_segments(qp, pfault, wqe, wqe_end, &bytes_mapped,
				      &total_wqe_bytes, !requestor);
	ret = pagefault_data_segments(dev, pfault, qp, wqe, wqe_end,
				      &bytes_mapped, &total_wqe_bytes,
				      !requestor);
	if (ret == -EAGAIN) {
		resume_with_error = 0;
		goto resolve_page_fault;
	} else if (ret < 0 || total_wqe_bytes > bytes_mapped) {
		mlx5_ib_err(dev, "Error getting user pages for page fault. Error: 0x%x\n",
			    -ret);
		resume_with_error = 1;
		if (ret != -ENOENT)
			mlx5_ib_err(dev, "Error getting user pages for page fault. Error: %d\n",
				    ret);
		goto resolve_page_fault;
	}

	resume_with_error = 0;
resolve_page_fault:
	mlx5_ib_page_fault_resume(qp, pfault, resume_with_error);
	mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x resume_with_error=%d, flags: 0x%x\n",
		    qpn, resume_with_error,
		    pfault->mpfault.flags);

	mlx5_ib_page_fault_resume(dev, pfault, resume_with_error);
	mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x resume_with_error=%d, type: 0x%x\n",
		    pfault->token, resume_with_error,
		    pfault->type);
	free_page((unsigned long)buffer);
}

@@ -615,15 +621,14 @@ static int pages_in_range(u64 address, u32 length)
		(address & PAGE_MASK)) >> PAGE_SHIFT;
}

static void mlx5_ib_mr_rdma_pfault_handler(struct mlx5_ib_qp *qp,
					   struct mlx5_ib_pfault *pfault)
static void mlx5_ib_mr_rdma_pfault_handler(struct mlx5_ib_dev *dev,
					   struct mlx5_pagefault *pfault)
{
	struct mlx5_pagefault *mpfault = &pfault->mpfault;
	u64 address;
	u32 length;
	u32 prefetch_len = mpfault->bytes_committed;
	u32 prefetch_len = pfault->bytes_committed;
	int prefetch_activated = 0;
	u32 rkey = mpfault->rdma.r_key;
	u32 rkey = pfault->rdma.r_key;
	int ret;

	/* The RDMA responder handler handles the page fault in two parts.
@@ -632,38 +637,40 @@ static void mlx5_ib_mr_rdma_pfault_handler(struct mlx5_ib_qp *qp,
	 * prefetches more pages. The second operation cannot use the pfault
	 * context and therefore uses the dummy_pfault context allocated on
	 * the stack */
	struct mlx5_ib_pfault dummy_pfault = {};

	dummy_pfault.mpfault.bytes_committed = 0;
	pfault->rdma.rdma_va += pfault->bytes_committed;
	pfault->rdma.rdma_op_len -= min(pfault->bytes_committed,
					 pfault->rdma.rdma_op_len);
	pfault->bytes_committed = 0;

	mpfault->rdma.rdma_va += mpfault->bytes_committed;
	mpfault->rdma.rdma_op_len -= min(mpfault->bytes_committed,
					 mpfault->rdma.rdma_op_len);
	mpfault->bytes_committed = 0;

	address = mpfault->rdma.rdma_va;
	length  = mpfault->rdma.rdma_op_len;
	address = pfault->rdma.rdma_va;
	length  = pfault->rdma.rdma_op_len;

	/* For some operations, the hardware cannot tell the exact message
	 * length, and in those cases it reports zero. Use prefetch
	 * logic. */
	if (length == 0) {
		prefetch_activated = 1;
		length = mpfault->rdma.packet_size;
		length = pfault->rdma.packet_size;
		prefetch_len = min(MAX_PREFETCH_LEN, prefetch_len);
	}

	ret = pagefault_single_data_segment(qp, pfault, rkey, address, length,
					    NULL);
	ret = pagefault_single_data_segment(dev, rkey, address, length,
					    &pfault->bytes_committed, NULL);
	if (ret == -EAGAIN) {
		/* We're racing with an invalidation, don't prefetch */
		prefetch_activated = 0;
	} else if (ret < 0 || pages_in_range(address, length) > ret) {
		mlx5_ib_page_fault_resume(qp, pfault, 1);
		mlx5_ib_page_fault_resume(dev, pfault, 1);
		if (ret != -ENOENT)
			mlx5_ib_warn(dev, "PAGE FAULT error %d. QP 0x%x, type: 0x%x\n",
				     ret, pfault->token, pfault->type);
		return;
	}

	mlx5_ib_page_fault_resume(qp, pfault, 0);
	mlx5_ib_page_fault_resume(dev, pfault, 0);
	mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x, type: 0x%x, prefetch_activated: %d\n",
		    pfault->token, pfault->type,
		    prefetch_activated);

	/* At this point, there might be a new pagefault already arriving in
	 * the eq, switch to the dummy pagefault for the rest of the
@@ -671,112 +678,39 @@ static void mlx5_ib_mr_rdma_pfault_handler(struct mlx5_ib_qp *qp,
	 * work-queue is being fenced. */

	if (prefetch_activated) {
		ret = pagefault_single_data_segment(qp, &dummy_pfault, rkey,
						    address,
		u32 bytes_committed = 0;

		ret = pagefault_single_data_segment(dev, rkey, address,
						    prefetch_len,
						    NULL);
						    &bytes_committed, NULL);
		if (ret < 0) {
			pr_warn("Prefetch failed (ret = %d, prefetch_activated = %d) for QPN %d, address: 0x%.16llx, length = 0x%.16x\n",
				ret, prefetch_activated,
				qp->ibqp.qp_num, address, prefetch_len);
			mlx5_ib_warn(dev, "Prefetch failed. ret: %d, QP 0x%x, address: 0x%.16llx, length = 0x%.16x\n",
				     ret, pfault->token, address,
				     prefetch_len);
		}
	}
}

void mlx5_ib_mr_pfault_handler(struct mlx5_ib_qp *qp,
			       struct mlx5_ib_pfault *pfault)
void mlx5_ib_pfault(struct mlx5_core_dev *mdev, void *context,
		    struct mlx5_pagefault *pfault)
{
	u8 event_subtype = pfault->mpfault.event_subtype;
	struct mlx5_ib_dev *dev = context;
	u8 event_subtype = pfault->event_subtype;

	switch (event_subtype) {
	case MLX5_PFAULT_SUBTYPE_WQE:
		mlx5_ib_mr_wqe_pfault_handler(qp, pfault);
		mlx5_ib_mr_wqe_pfault_handler(dev, pfault);
		break;
	case MLX5_PFAULT_SUBTYPE_RDMA:
		mlx5_ib_mr_rdma_pfault_handler(qp, pfault);
		mlx5_ib_mr_rdma_pfault_handler(dev, pfault);
		break;
	default:
		pr_warn("Invalid page fault event subtype: 0x%x\n",
		mlx5_ib_err(dev, "Invalid page fault event subtype: 0x%x\n",
			    event_subtype);
		mlx5_ib_page_fault_resume(qp, pfault, 1);
		break;
		mlx5_ib_page_fault_resume(dev, pfault, 1);
	}
}

static void mlx5_ib_qp_pfault_action(struct work_struct *work)
{
	struct mlx5_ib_pfault *pfault = container_of(work,
						     struct mlx5_ib_pfault,
						     work);
	enum mlx5_ib_pagefault_context context =
		mlx5_ib_get_pagefault_context(&pfault->mpfault);
	struct mlx5_ib_qp *qp = container_of(pfault, struct mlx5_ib_qp,
					     pagefaults[context]);
	mlx5_ib_mr_pfault_handler(qp, pfault);
}

void mlx5_ib_qp_disable_pagefaults(struct mlx5_ib_qp *qp)
{
	unsigned long flags;

	spin_lock_irqsave(&qp->disable_page_faults_lock, flags);
	qp->disable_page_faults = 1;
	spin_unlock_irqrestore(&qp->disable_page_faults_lock, flags);

	/*
	 * Note that at this point, we are guarenteed that no more
	 * work queue elements will be posted to the work queue with
	 * the QP we are closing.
	 */
	flush_workqueue(mlx5_ib_page_fault_wq);
}

void mlx5_ib_qp_enable_pagefaults(struct mlx5_ib_qp *qp)
{
	unsigned long flags;

	spin_lock_irqsave(&qp->disable_page_faults_lock, flags);
	qp->disable_page_faults = 0;
	spin_unlock_irqrestore(&qp->disable_page_faults_lock, flags);
}

static void mlx5_ib_pfault_handler(struct mlx5_core_qp *qp,
				   struct mlx5_pagefault *pfault)
{
	/*
	 * Note that we will only get one fault event per QP per context
	 * (responder/initiator, read/write), until we resolve the page fault
	 * with the mlx5_ib_page_fault_resume command. Since this function is
	 * called from within the work element, there is no risk of missing
	 * events.
	 */
	struct mlx5_ib_qp *mibqp = to_mibqp(qp);
	enum mlx5_ib_pagefault_context context =
		mlx5_ib_get_pagefault_context(pfault);
	struct mlx5_ib_pfault *qp_pfault = &mibqp->pagefaults[context];

	qp_pfault->mpfault = *pfault;

	/* No need to stop interrupts here since we are in an interrupt */
	spin_lock(&mibqp->disable_page_faults_lock);
	if (!mibqp->disable_page_faults)
		queue_work(mlx5_ib_page_fault_wq, &qp_pfault->work);
	spin_unlock(&mibqp->disable_page_faults_lock);
}

void mlx5_ib_odp_create_qp(struct mlx5_ib_qp *qp)
{
	int i;

	qp->disable_page_faults = 1;
	spin_lock_init(&qp->disable_page_faults_lock);

	qp->trans_qp.base.mqp.pfault_handler = mlx5_ib_pfault_handler;

	for (i = 0; i < MLX5_IB_PAGEFAULT_CONTEXTS; ++i)
		INIT_WORK(&qp->pagefaults[i].work, mlx5_ib_qp_pfault_action);
}

int mlx5_ib_odp_init_one(struct mlx5_ib_dev *ibdev)
{
	int ret;
@@ -793,17 +727,3 @@ void mlx5_ib_odp_remove_one(struct mlx5_ib_dev *ibdev)
	cleanup_srcu_struct(&ibdev->mr_srcu);
}
int __init mlx5_ib_odp_init(void)
{
	mlx5_ib_page_fault_wq = alloc_ordered_workqueue("mlx5_ib_page_faults",
							WQ_MEM_RECLAIM);
	if (!mlx5_ib_page_fault_wq)
		return -ENOMEM;

	return 0;
}

void mlx5_ib_odp_cleanup(void)
{
	destroy_workqueue(mlx5_ib_page_fault_wq);
}
+0 −26
Original line number Diff line number Diff line
@@ -1526,9 +1526,6 @@ static int create_qp_common(struct mlx5_ib_dev *dev, struct ib_pd *pd,
	       &qp->raw_packet_qp.rq.base :
	       &qp->trans_qp.base;

	if (init_attr->qp_type != IB_QPT_RAW_PACKET)
		mlx5_ib_odp_create_qp(qp);

	mutex_init(&qp->mutex);
	spin_lock_init(&qp->sq.lock);
	spin_lock_init(&qp->rq.lock);
@@ -1923,7 +1920,6 @@ static void destroy_qp_common(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp)

	if (qp->state != IB_QPS_RESET) {
		if (qp->ibqp.qp_type != IB_QPT_RAW_PACKET) {
			mlx5_ib_qp_disable_pagefaults(qp);
			err = mlx5_core_qp_modify(dev->mdev,
						  MLX5_CMD_OP_2RST_QP, 0,
						  NULL, &base->mqp);
@@ -2823,16 +2819,6 @@ static int __mlx5_ib_modify_qp(struct ib_qp *ibqp,
	if (mlx5_st < 0)
		goto out;

	/* If moving to a reset or error state, we must disable page faults on
	 * this QP and flush all current page faults. Otherwise a stale page
	 * fault may attempt to work on this QP after it is reset and moved
	 * again to RTS, and may cause the driver and the device to get out of
	 * sync. */
	if (cur_state != IB_QPS_RESET && cur_state != IB_QPS_ERR &&
	    (new_state == IB_QPS_RESET || new_state == IB_QPS_ERR) &&
	    (qp->ibqp.qp_type != IB_QPT_RAW_PACKET))
		mlx5_ib_qp_disable_pagefaults(qp);

	if (mlx5_cur >= MLX5_QP_NUM_STATE || mlx5_new >= MLX5_QP_NUM_STATE ||
	    !optab[mlx5_cur][mlx5_new])
		goto out;
@@ -2864,10 +2850,6 @@ static int __mlx5_ib_modify_qp(struct ib_qp *ibqp,
	if (err)
		goto out;

	if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT &&
	    (qp->ibqp.qp_type != IB_QPT_RAW_PACKET))
		mlx5_ib_qp_enable_pagefaults(qp);

	qp->state = new_state;

	if (attr_mask & IB_QP_ACCESS_FLAGS)
@@ -4533,14 +4515,6 @@ int mlx5_ib_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *qp_attr,
		return mlx5_ib_gsi_query_qp(ibqp, qp_attr, qp_attr_mask,
					    qp_init_attr);

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
	/*
	 * Wait for any outstanding page faults, in case the user frees memory
	 * based upon this query's result.
	 */
	flush_workqueue(mlx5_ib_page_fault_wq);
#endif

	mutex_lock(&qp->mutex);

	if (qp->ibqp.qp_type == IB_QPT_RAW_PACKET) {
+33 −0
Original line number Diff line number Diff line
@@ -71,6 +71,16 @@ void mlx5_add_device(struct mlx5_interface *intf, struct mlx5_priv *priv)
	if (dev_ctx->context) {
		spin_lock_irq(&priv->ctx_lock);
		list_add_tail(&dev_ctx->list, &priv->ctx_list);
#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
		if (dev_ctx->intf->pfault) {
			if (priv->pfault) {
				mlx5_core_err(dev, "multiple page fault handlers not supported");
			} else {
				priv->pfault_ctx = dev_ctx->context;
				priv->pfault = dev_ctx->intf->pfault;
			}
		}
#endif
		spin_unlock_irq(&priv->ctx_lock);
	} else {
		kfree(dev_ctx);
@@ -97,6 +107,15 @@ void mlx5_remove_device(struct mlx5_interface *intf, struct mlx5_priv *priv)
	if (!dev_ctx)
		return;

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
	spin_lock_irq(&priv->ctx_lock);
	if (priv->pfault == dev_ctx->intf->pfault)
		priv->pfault = NULL;
	spin_unlock_irq(&priv->ctx_lock);

	synchronize_srcu(&priv->pfault_srcu);
#endif

	spin_lock_irq(&priv->ctx_lock);
	list_del(&dev_ctx->list);
	spin_unlock_irq(&priv->ctx_lock);
@@ -329,6 +348,20 @@ void mlx5_core_event(struct mlx5_core_dev *dev, enum mlx5_dev_event event,
	spin_unlock_irqrestore(&priv->ctx_lock, flags);
}

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
void mlx5_core_page_fault(struct mlx5_core_dev *dev,
			  struct mlx5_pagefault *pfault)
{
	struct mlx5_priv *priv = &dev->priv;
	int srcu_idx;

	srcu_idx = srcu_read_lock(&priv->pfault_srcu);
	if (priv->pfault)
		priv->pfault(dev, priv->pfault_ctx, pfault);
	srcu_read_unlock(&priv->pfault_srcu, srcu_idx);
}
#endif

void mlx5_dev_list_lock(void)
{
	mutex_lock(&mlx5_intf_mutex);
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