Date:   Tue, 27 Mar 2018 17:42:28 +0100
From:   Edward Cree <ecree@...arflare.com>
To:     <linux-net-drivers@...arflare.com>,
        David Miller <davem@...emloft.net>
CC:     netdev <netdev@...r.kernel.org>
Subject: [PATCH net-next 2/6] sfc: give ef10 its own rwsem in the filter table
 instead of filter_lock

efx->filter_lock remains in place for use on farch, but EF10 now ignores it.
EFX_EF10_FILTER_FLAG_BUSY is no longer needed, hence it is removed.

Signed-off-by: Edward Cree <ecree@...arflare.com>
---
 drivers/net/ethernet/sfc/ef10.c       | 361 ++++++++++++++--------------------
 drivers/net/ethernet/sfc/efx.c        |   1 -
 drivers/net/ethernet/sfc/net_driver.h |   2 +-
 3 files changed, 151 insertions(+), 213 deletions(-)

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index bcbaba330fb5..9db1b9144e70 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -96,17 +96,15 @@ struct efx_ef10_filter_table {
 		MC_CMD_GET_PARSER_DISP_INFO_OUT_SUPPORTED_MATCHES_MAXNUM * 2];
 	unsigned int rx_match_count;
 
+	struct rw_semaphore lock; /* Protects entries */
 	struct {
 		unsigned long spec;	/* pointer to spec plus flag bits */
-/* BUSY flag indicates that an update is in progress.  AUTO_OLD is
- * used to mark and sweep MAC filters for the device address lists.
- */
-#define EFX_EF10_FILTER_FLAG_BUSY	1UL
+/* AUTO_OLD is used to mark and sweep MAC filters for the device address lists. */
+/* unused flag	1UL */
 #define EFX_EF10_FILTER_FLAG_AUTO_OLD	2UL
 #define EFX_EF10_FILTER_FLAGS		3UL
 		u64 handle;		/* firmware handle */
 	} *entry;
-	wait_queue_head_t waitq;
 /* Shadow of net_device address lists, guarded by mac_lock */
 	struct efx_ef10_dev_addr dev_uc_list[EFX_EF10_FILTER_DEV_UC_MAX];
 	struct efx_ef10_dev_addr dev_mc_list[EFX_EF10_FILTER_DEV_MC_MAX];
@@ -4302,26 +4300,33 @@ static s32 efx_ef10_filter_insert(struct efx_nic *efx,
 				  struct efx_filter_spec *spec,
 				  bool replace_equal)
 {
-	struct efx_ef10_filter_table *table = efx->filter_state;
 	DECLARE_BITMAP(mc_rem_map, EFX_EF10_FILTER_SEARCH_LIMIT);
+	struct efx_ef10_filter_table *table;
 	struct efx_filter_spec *saved_spec;
 	struct efx_rss_context *ctx = NULL;
 	unsigned int match_pri, hash;
 	unsigned int priv_flags;
 	bool replacing = false;
+	unsigned int depth, i;
 	int ins_index = -1;
 	DEFINE_WAIT(wait);
 	bool is_mc_recip;
 	s32 rc;
 
+	down_read(&efx->filter_sem);
+	table = efx->filter_state;
+	down_write(&table->lock);
+
 	/* For now, only support RX filters */
 	if ((spec->flags & (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)) !=
-	    EFX_FILTER_FLAG_RX)
-		return -EINVAL;
+	    EFX_FILTER_FLAG_RX) {
+		rc = -EINVAL;
+		goto out_unlock;
+	}
 
 	rc = efx_ef10_filter_pri(table, spec);
 	if (rc < 0)
-		return rc;
+		goto out_unlock;
 	match_pri = rc;
 
 	hash = efx_ef10_filter_hash(spec);
@@ -4335,86 +4340,64 @@ static s32 efx_ef10_filter_insert(struct efx_nic *efx,
 							 &efx->rss_context.list);
 		else
 			ctx = &efx->rss_context;
-		if (!ctx)
-			return -ENOENT;
-		if (ctx->context_id == EFX_EF10_RSS_CONTEXT_INVALID)
-			return -EOPNOTSUPP;
+		if (!ctx) {
+			rc = -ENOENT;
+			goto out_unlock;
+		}
+		if (ctx->context_id == EFX_EF10_RSS_CONTEXT_INVALID) {
+			rc = -EOPNOTSUPP;
+			goto out_unlock;
+		}
 	}
 
 	/* Find any existing filters with the same match tuple or
-	 * else a free slot to insert at.  If any of them are busy,
-	 * we have to wait and retry.
+	 * else a free slot to insert at.
 	 */
-	for (;;) {
-		unsigned int depth = 1;
-		unsigned int i;
-
-		spin_lock_bh(&efx->filter_lock);
+	for (depth = 1; depth < EFX_EF10_FILTER_SEARCH_LIMIT; depth++) {
+		i = (hash + depth) & (HUNT_FILTER_TBL_ROWS - 1);
+		saved_spec = efx_ef10_filter_entry_spec(table, i);
 
-		for (;;) {
-			i = (hash + depth) & (HUNT_FILTER_TBL_ROWS - 1);
-			saved_spec = efx_ef10_filter_entry_spec(table, i);
-
-			if (!saved_spec) {
-				if (ins_index < 0)
-					ins_index = i;
-			} else if (efx_ef10_filter_equal(spec, saved_spec)) {
-				if (table->entry[i].spec &
-				    EFX_EF10_FILTER_FLAG_BUSY)
-					break;
-				if (spec->priority < saved_spec->priority &&
-				    spec->priority != EFX_FILTER_PRI_AUTO) {
-					rc = -EPERM;
-					goto out_unlock;
-				}
-				if (!is_mc_recip) {
-					/* This is the only one */
-					if (spec->priority ==
-					    saved_spec->priority &&
-					    !replace_equal) {
-						rc = -EEXIST;
-						goto out_unlock;
-					}
-					ins_index = i;
-					goto found;
-				} else if (spec->priority >
-					   saved_spec->priority ||
-					   (spec->priority ==
-					    saved_spec->priority &&
-					    replace_equal)) {
-					if (ins_index < 0)
-						ins_index = i;
-					else
-						__set_bit(depth, mc_rem_map);
-				}
+		if (!saved_spec) {
+			if (ins_index < 0)
+				ins_index = i;
+		} else if (efx_ef10_filter_equal(spec, saved_spec)) {
+			if (spec->priority < saved_spec->priority &&
+			    spec->priority != EFX_FILTER_PRI_AUTO) {
+				rc = -EPERM;
+				goto out_unlock;
 			}
-
-			/* Once we reach the maximum search depth, use
-			 * the first suitable slot or return -EBUSY if
-			 * there was none
-			 */
-			if (depth == EFX_EF10_FILTER_SEARCH_LIMIT) {
-				if (ins_index < 0) {
-					rc = -EBUSY;
+			if (!is_mc_recip) {
+				/* This is the only one */
+				if (spec->priority ==
+				    saved_spec->priority &&
+				    !replace_equal) {
+					rc = -EEXIST;
 					goto out_unlock;
 				}
-				goto found;
+				ins_index = i;
+				break;
+			} else if (spec->priority >
+				   saved_spec->priority ||
+				   (spec->priority ==
+				    saved_spec->priority &&
+				    replace_equal)) {
+				if (ins_index < 0)
+					ins_index = i;
+				else
+					__set_bit(depth, mc_rem_map);
 			}
-
-			++depth;
 		}
-
-		prepare_to_wait(&table->waitq, &wait, TASK_UNINTERRUPTIBLE);
-		spin_unlock_bh(&efx->filter_lock);
-		schedule();
 	}
 
-found:
-	/* Create a software table entry if necessary, and mark it
-	 * busy.  We might yet fail to insert, but any attempt to
-	 * insert a conflicting filter while we're waiting for the
-	 * firmware must find the busy entry.
+	/* Once we reach the maximum search depth, use the first suitable
+	 * slot, or return -EBUSY if there was none
 	 */
+	if (ins_index < 0) {
+		rc = -EBUSY;
+		goto out_unlock;
+	}
+
+	/* Create a software table entry if necessary. */
 	saved_spec = efx_ef10_filter_entry_spec(table, ins_index);
 	if (saved_spec) {
 		if (spec->priority == EFX_FILTER_PRI_AUTO &&
@@ -4438,28 +4421,13 @@ static s32 efx_ef10_filter_insert(struct efx_nic *efx,
 		*saved_spec = *spec;
 		priv_flags = 0;
 	}
-	efx_ef10_filter_set_entry(table, ins_index, saved_spec,
-				  priv_flags | EFX_EF10_FILTER_FLAG_BUSY);
-
-	/* Mark lower-priority multicast recipients busy prior to removal */
-	if (is_mc_recip) {
-		unsigned int depth, i;
-
-		for (depth = 0; depth < EFX_EF10_FILTER_SEARCH_LIMIT; depth++) {
-			i = (hash + depth) & (HUNT_FILTER_TBL_ROWS - 1);
-			if (test_bit(depth, mc_rem_map))
-				table->entry[i].spec |=
-					EFX_EF10_FILTER_FLAG_BUSY;
-		}
-	}
-
-	spin_unlock_bh(&efx->filter_lock);
+	efx_ef10_filter_set_entry(table, ins_index, saved_spec, priv_flags);
 
+	/* Actually insert the filter on the HW */
 	rc = efx_ef10_filter_push(efx, spec, &table->entry[ins_index].handle,
 				  ctx, replacing);
 
 	/* Finalise the software table entry */
-	spin_lock_bh(&efx->filter_lock);
 	if (rc == 0) {
 		if (replacing) {
 			/* Update the fields that may differ */
@@ -4475,6 +4443,12 @@ static s32 efx_ef10_filter_insert(struct efx_nic *efx,
 	} else if (!replacing) {
 		kfree(saved_spec);
 		saved_spec = NULL;
+	} else {
+		/* We failed to replace, so the old filter is still present.
+		 * Roll back the software table to reflect this.  In fact the
+		 * efx_ef10_filter_set_entry() call below will do the right
+		 * thing, so nothing extra is needed here.
+		 */
 	}
 	efx_ef10_filter_set_entry(table, ins_index, saved_spec, priv_flags);
 
@@ -4496,7 +4470,6 @@ static s32 efx_ef10_filter_insert(struct efx_nic *efx,
 			priv_flags = efx_ef10_filter_entry_flags(table, i);
 
 			if (rc == 0) {
-				spin_unlock_bh(&efx->filter_lock);
 				MCDI_SET_DWORD(inbuf, FILTER_OP_IN_OP,
 					       MC_CMD_FILTER_OP_IN_OP_UNSUBSCRIBE);
 				MCDI_SET_QWORD(inbuf, FILTER_OP_IN_HANDLE,
@@ -4504,15 +4477,12 @@ static s32 efx_ef10_filter_insert(struct efx_nic *efx,
 				rc = efx_mcdi_rpc(efx, MC_CMD_FILTER_OP,
 						  inbuf, sizeof(inbuf),
 						  NULL, 0, NULL);
-				spin_lock_bh(&efx->filter_lock);
 			}
 
 			if (rc == 0) {
 				kfree(saved_spec);
 				saved_spec = NULL;
 				priv_flags = 0;
-			} else {
-				priv_flags &= ~EFX_EF10_FILTER_FLAG_BUSY;
 			}
 			efx_ef10_filter_set_entry(table, i, saved_spec,
 						  priv_flags);
@@ -4523,10 +4493,9 @@ static s32 efx_ef10_filter_insert(struct efx_nic *efx,
 	if (rc == 0)
 		rc = efx_ef10_make_filter_id(match_pri, ins_index);
 
-	wake_up_all(&table->waitq);
 out_unlock:
-	spin_unlock_bh(&efx->filter_lock);
-	finish_wait(&table->waitq, &wait);
+	up_write(&table->lock);
+	up_read(&efx->filter_sem);
 	return rc;
 }
 
@@ -4539,6 +4508,8 @@ static void efx_ef10_filter_update_rx_scatter(struct efx_nic *efx)
  * If !by_index, remove by ID
  * If by_index, remove by index
  * Filter ID may come from userland and must be range-checked.
+ * Caller must hold efx->filter_sem for read, and efx->filter_state->lock
+ * for write.
  */
 static int efx_ef10_filter_remove_internal(struct efx_nic *efx,
 					   unsigned int priority_mask,
@@ -4553,45 +4524,23 @@ static int efx_ef10_filter_remove_internal(struct efx_nic *efx,
 	DEFINE_WAIT(wait);
 	int rc;
 
-	/* Find the software table entry and mark it busy.  Don't
-	 * remove it yet; any attempt to update while we're waiting
-	 * for the firmware must find the busy entry.
-	 */
-	for (;;) {
-		spin_lock_bh(&efx->filter_lock);
-		if (!(table->entry[filter_idx].spec &
-		      EFX_EF10_FILTER_FLAG_BUSY))
-			break;
-		prepare_to_wait(&table->waitq, &wait, TASK_UNINTERRUPTIBLE);
-		spin_unlock_bh(&efx->filter_lock);
-		schedule();
-	}
-
 	spec = efx_ef10_filter_entry_spec(table, filter_idx);
 	if (!spec ||
 	    (!by_index &&
 	     efx_ef10_filter_pri(table, spec) !=
-	     efx_ef10_filter_get_unsafe_pri(filter_id))) {
-		rc = -ENOENT;
-		goto out_unlock;
-	}
+	     efx_ef10_filter_get_unsafe_pri(filter_id)))
+		return -ENOENT;
 
 	if (spec->flags & EFX_FILTER_FLAG_RX_OVER_AUTO &&
 	    priority_mask == (1U << EFX_FILTER_PRI_AUTO)) {
 		/* Just remove flags */
 		spec->flags &= ~EFX_FILTER_FLAG_RX_OVER_AUTO;
 		table->entry[filter_idx].spec &= ~EFX_EF10_FILTER_FLAG_AUTO_OLD;
-		rc = 0;
-		goto out_unlock;
-	}
-
-	if (!(priority_mask & (1U << spec->priority))) {
-		rc = -ENOENT;
-		goto out_unlock;
+		return 0;
 	}
 
-	table->entry[filter_idx].spec |= EFX_EF10_FILTER_FLAG_BUSY;
-	spin_unlock_bh(&efx->filter_lock);
+	if (!(priority_mask & (1U << spec->priority)))
+		return -ENOENT;
 
 	if (spec->flags & EFX_FILTER_FLAG_RX_OVER_AUTO) {
 		/* Reset to an automatic filter */
@@ -4609,7 +4558,6 @@ static int efx_ef10_filter_remove_internal(struct efx_nic *efx,
 					  &efx->rss_context,
 					  true);
 
-		spin_lock_bh(&efx->filter_lock);
 		if (rc == 0)
 			*spec = new_spec;
 	} else {
@@ -4624,7 +4572,6 @@ static int efx_ef10_filter_remove_internal(struct efx_nic *efx,
 		rc = efx_mcdi_rpc_quiet(efx, MC_CMD_FILTER_OP,
 					inbuf, sizeof(inbuf), NULL, 0, NULL);
 
-		spin_lock_bh(&efx->filter_lock);
 		if ((rc == 0) || (rc == -ENOENT)) {
 			/* Filter removed OK or didn't actually exist */
 			kfree(spec);
@@ -4636,11 +4583,6 @@ static int efx_ef10_filter_remove_internal(struct efx_nic *efx,
 		}
 	}
 
-	table->entry[filter_idx].spec &= ~EFX_EF10_FILTER_FLAG_BUSY;
-	wake_up_all(&table->waitq);
-out_unlock:
-	spin_unlock_bh(&efx->filter_lock);
-	finish_wait(&table->waitq, &wait);
 	return rc;
 }
 
@@ -4648,17 +4590,33 @@ static int efx_ef10_filter_remove_safe(struct efx_nic *efx,
 				       enum efx_filter_priority priority,
 				       u32 filter_id)
 {
-	return efx_ef10_filter_remove_internal(efx, 1U << priority,
-					       filter_id, false);
+	struct efx_ef10_filter_table *table;
+	int rc;
+
+	down_read(&efx->filter_sem);
+	table = efx->filter_state;
+	down_write(&table->lock);
+	rc = efx_ef10_filter_remove_internal(efx, 1U << priority, filter_id,
+					     false);
+	up_write(&table->lock);
+	up_read(&efx->filter_sem);
+	return rc;
 }
 
+/* Caller must hold efx->filter_sem for read */
 static void efx_ef10_filter_remove_unsafe(struct efx_nic *efx,
 					  enum efx_filter_priority priority,
 					  u32 filter_id)
 {
+	struct efx_ef10_filter_table *table = efx->filter_state;
+
 	if (filter_id == EFX_EF10_FILTER_ID_INVALID)
 		return;
-	efx_ef10_filter_remove_internal(efx, 1U << priority, filter_id, true);
+
+	down_write(&table->lock);
+	efx_ef10_filter_remove_internal(efx, 1U << priority, filter_id,
+					true);
+	up_write(&table->lock);
 }
 
 static int efx_ef10_filter_get_safe(struct efx_nic *efx,
@@ -4666,11 +4624,13 @@ static int efx_ef10_filter_get_safe(struct efx_nic *efx,
 				    u32 filter_id, struct efx_filter_spec *spec)
 {
 	unsigned int filter_idx = efx_ef10_filter_get_unsafe_id(filter_id);
-	struct efx_ef10_filter_table *table = efx->filter_state;
 	const struct efx_filter_spec *saved_spec;
+	struct efx_ef10_filter_table *table;
 	int rc;
 
-	spin_lock_bh(&efx->filter_lock);
+	down_read(&efx->filter_sem);
+	table = efx->filter_state;
+	down_read(&table->lock);
 	saved_spec = efx_ef10_filter_entry_spec(table, filter_idx);
 	if (saved_spec && saved_spec->priority == priority &&
 	    efx_ef10_filter_pri(table, saved_spec) ==
@@ -4680,13 +4640,15 @@ static int efx_ef10_filter_get_safe(struct efx_nic *efx,
 	} else {
 		rc = -ENOENT;
 	}
-	spin_unlock_bh(&efx->filter_lock);
+	up_read(&table->lock);
+	up_read(&efx->filter_sem);
 	return rc;
 }
 
 static int efx_ef10_filter_clear_rx(struct efx_nic *efx,
-				     enum efx_filter_priority priority)
+				    enum efx_filter_priority priority)
 {
+	struct efx_ef10_filter_table *table;
 	unsigned int priority_mask;
 	unsigned int i;
 	int rc;
@@ -4694,31 +4656,40 @@ static int efx_ef10_filter_clear_rx(struct efx_nic *efx,
 	priority_mask = (((1U << (priority + 1)) - 1) &
 			 ~(1U << EFX_FILTER_PRI_AUTO));
 
+	down_read(&efx->filter_sem);
+	table = efx->filter_state;
+	down_write(&table->lock);
 	for (i = 0; i < HUNT_FILTER_TBL_ROWS; i++) {
 		rc = efx_ef10_filter_remove_internal(efx, priority_mask,
 						     i, true);
 		if (rc && rc != -ENOENT)
-			return rc;
+			break;
+		rc = 0;
 	}
 
-	return 0;
+	up_write(&table->lock);
+	up_read(&efx->filter_sem);
+	return rc;
 }
 
 static u32 efx_ef10_filter_count_rx_used(struct efx_nic *efx,
 					 enum efx_filter_priority priority)
 {
-	struct efx_ef10_filter_table *table = efx->filter_state;
+	struct efx_ef10_filter_table *table;
 	unsigned int filter_idx;
 	s32 count = 0;
 
-	spin_lock_bh(&efx->filter_lock);
+	down_read(&efx->filter_sem);
+	table = efx->filter_state;
+	down_read(&table->lock);
 	for (filter_idx = 0; filter_idx < HUNT_FILTER_TBL_ROWS; filter_idx++) {
 		if (table->entry[filter_idx].spec &&
 		    efx_ef10_filter_entry_spec(table, filter_idx)->priority ==
 		    priority)
 			++count;
 	}
-	spin_unlock_bh(&efx->filter_lock);
+	up_read(&table->lock);
+	up_read(&efx->filter_sem);
 	return count;
 }
 
@@ -4733,12 +4704,15 @@ static s32 efx_ef10_filter_get_rx_ids(struct efx_nic *efx,
 				      enum efx_filter_priority priority,
 				      u32 *buf, u32 size)
 {
-	struct efx_ef10_filter_table *table = efx->filter_state;
+	struct efx_ef10_filter_table *table;
 	struct efx_filter_spec *spec;
 	unsigned int filter_idx;
 	s32 count = 0;
 
-	spin_lock_bh(&efx->filter_lock);
+	down_read(&efx->filter_sem);
+	table = efx->filter_state;
+	down_read(&table->lock);
+
 	for (filter_idx = 0; filter_idx < HUNT_FILTER_TBL_ROWS; filter_idx++) {
 		spec = efx_ef10_filter_entry_spec(table, filter_idx);
 		if (spec && spec->priority == priority) {
@@ -4752,73 +4726,44 @@ static s32 efx_ef10_filter_get_rx_ids(struct efx_nic *efx,
 					filter_idx);
 		}
 	}
-	spin_unlock_bh(&efx->filter_lock);
+	up_read(&table->lock);
+	up_read(&efx->filter_sem);
 	return count;
 }
 
 #ifdef CONFIG_RFS_ACCEL
 
-static void
-efx_ef10_filter_rfs_expire_complete(struct efx_nic *efx,
-				    unsigned long filter_idx,
-				    int rc, efx_dword_t *outbuf,
-				    size_t outlen_actual);
-
 static bool efx_ef10_filter_rfs_expire_one(struct efx_nic *efx, u32 flow_id,
 					   unsigned int filter_idx)
 {
-	struct efx_ef10_filter_table *table = efx->filter_state;
+	struct efx_ef10_filter_table *table;
 	struct efx_filter_spec *spec;
-	MCDI_DECLARE_BUF(inbuf,
-			 MC_CMD_FILTER_OP_IN_HANDLE_OFST +
-			 MC_CMD_FILTER_OP_IN_HANDLE_LEN);
-	bool ret = true;
+	bool ret;
 
-	spin_lock_bh(&efx->filter_lock);
+	down_read(&efx->filter_sem);
+	table = efx->filter_state;
+	down_write(&table->lock);
 	spec = efx_ef10_filter_entry_spec(table, filter_idx);
-	if (!spec ||
-	    (table->entry[filter_idx].spec & EFX_EF10_FILTER_FLAG_BUSY) ||
-	    spec->priority != EFX_FILTER_PRI_HINT ||
-	    !rps_may_expire_flow(efx->net_dev, spec->dmaq_id,
+
+	if (!spec || spec->priority != EFX_FILTER_PRI_HINT) {
+		ret = true;
+		goto out_unlock;
+	}
+
+	if (!rps_may_expire_flow(efx->net_dev, spec->dmaq_id,
 				 flow_id, filter_idx)) {
 		ret = false;
 		goto out_unlock;
 	}
 
-	MCDI_SET_DWORD(inbuf, FILTER_OP_IN_OP,
-		       MC_CMD_FILTER_OP_IN_OP_REMOVE);
-	MCDI_SET_QWORD(inbuf, FILTER_OP_IN_HANDLE,
-		       table->entry[filter_idx].handle);
-	if (efx_mcdi_rpc_async(efx, MC_CMD_FILTER_OP, inbuf, sizeof(inbuf), 0,
-			       efx_ef10_filter_rfs_expire_complete, filter_idx))
-		ret = false;
-	else
-		table->entry[filter_idx].spec |= EFX_EF10_FILTER_FLAG_BUSY;
+	ret = efx_ef10_filter_remove_internal(efx, 1U << spec->priority,
+					      filter_idx, true) == 0;
 out_unlock:
-	spin_unlock_bh(&efx->filter_lock);
+	up_write(&table->lock);
+	up_read(&efx->filter_sem);
 	return ret;
 }
 
-static void
-efx_ef10_filter_rfs_expire_complete(struct efx_nic *efx,
-				    unsigned long filter_idx,
-				    int rc, efx_dword_t *outbuf,
-				    size_t outlen_actual)
-{
-	struct efx_ef10_filter_table *table = efx->filter_state;
-	struct efx_filter_spec *spec =
-		efx_ef10_filter_entry_spec(table, filter_idx);
-
-	spin_lock_bh(&efx->filter_lock);
-	if (rc == 0) {
-		kfree(spec);
-		efx_ef10_filter_set_entry(table, filter_idx, NULL, 0);
-	}
-	table->entry[filter_idx].spec &= ~EFX_EF10_FILTER_FLAG_BUSY;
-	wake_up_all(&table->waitq);
-	spin_unlock_bh(&efx->filter_lock);
-}
-
 #endif /* CONFIG_RFS_ACCEL */
 
 static int efx_ef10_filter_match_flags_from_mcdi(bool encap, u32 mcdi_flags)
@@ -5011,9 +4956,9 @@ static int efx_ef10_filter_table_probe(struct efx_nic *efx)
 	table->vlan_filter =
 		!!(efx->net_dev->features & NETIF_F_HW_VLAN_CTAG_FILTER);
 	INIT_LIST_HEAD(&table->vlan_list);
+	init_rwsem(&table->lock);
 
 	efx->filter_state = table;
-	init_waitqueue_head(&table->waitq);
 
 	list_for_each_entry(vlan, &nic_data->vlan_list, list) {
 		rc = efx_ef10_filter_add_vlan(efx, vlan->vid);
@@ -5055,7 +5000,7 @@ static void efx_ef10_filter_table_restore(struct efx_nic *efx)
 	if (!table)
 		return;
 
-	spin_lock_bh(&efx->filter_lock);
+	down_write(&table->lock);
 
 	for (filter_idx = 0; filter_idx < HUNT_FILTER_TBL_ROWS; filter_idx++) {
 		spec = efx_ef10_filter_entry_spec(table, filter_idx);
@@ -5093,15 +5038,11 @@ static void efx_ef10_filter_table_restore(struct efx_nic *efx)
 			}
 		}
 
-		table->entry[filter_idx].spec |= EFX_EF10_FILTER_FLAG_BUSY;
-		spin_unlock_bh(&efx->filter_lock);
-
 		rc = efx_ef10_filter_push(efx, spec,
 					  &table->entry[filter_idx].handle,
 					  ctx, false);
 		if (rc)
 			failed++;
-		spin_lock_bh(&efx->filter_lock);
 
 		if (rc) {
 not_restored:
@@ -5113,13 +5054,10 @@ static void efx_ef10_filter_table_restore(struct efx_nic *efx)
 
 			kfree(spec);
 			efx_ef10_filter_set_entry(table, filter_idx, NULL, 0);
-		} else {
-			table->entry[filter_idx].spec &=
-				~EFX_EF10_FILTER_FLAG_BUSY;
 		}
 	}
 
-	spin_unlock_bh(&efx->filter_lock);
+	up_write(&table->lock);
 
 	/* This can happen validly if the MC's capabilities have changed, so
 	 * is not an error.
@@ -5187,6 +5125,8 @@ static void efx_ef10_filter_mark_one_old(struct efx_nic *efx, uint16_t *id)
 	struct efx_ef10_filter_table *table = efx->filter_state;
 	unsigned int filter_idx;
 
+	efx_rwsem_assert_write_locked(&table->lock);
+
 	if (*id != EFX_EF10_FILTER_ID_INVALID) {
 		filter_idx = efx_ef10_filter_get_unsafe_id(*id);
 		if (!table->entry[filter_idx].spec)
@@ -5222,10 +5162,10 @@ static void efx_ef10_filter_mark_old(struct efx_nic *efx)
 	struct efx_ef10_filter_table *table = efx->filter_state;
 	struct efx_ef10_filter_vlan *vlan;
 
-	spin_lock_bh(&efx->filter_lock);
+	down_write(&table->lock);
 	list_for_each_entry(vlan, &table->vlan_list, list)
 		_efx_ef10_filter_vlan_mark_old(efx, vlan);
-	spin_unlock_bh(&efx->filter_lock);
+	up_write(&table->lock);
 }
 
 static void efx_ef10_filter_uc_addr_list(struct efx_nic *efx)
@@ -5502,10 +5442,7 @@ static int efx_ef10_filter_insert_def(struct efx_nic *efx,
 	return rc;
 }
 
-/* Remove filters that weren't renewed.  Since nothing else changes the AUTO_OLD
- * flag or removes these filters, we don't need to hold the filter_lock while
- * scanning for these filters.
- */
+/* Remove filters that weren't renewed. */
 static void efx_ef10_filter_remove_old(struct efx_nic *efx)
 {
 	struct efx_ef10_filter_table *table = efx->filter_state;
@@ -5514,6 +5451,7 @@ static void efx_ef10_filter_remove_old(struct efx_nic *efx)
 	int rc;
 	int i;
 
+	down_write(&table->lock);
 	for (i = 0; i < HUNT_FILTER_TBL_ROWS; i++) {
 		if (READ_ONCE(table->entry[i].spec) &
 		    EFX_EF10_FILTER_FLAG_AUTO_OLD) {
@@ -5525,6 +5463,7 @@ static void efx_ef10_filter_remove_old(struct efx_nic *efx)
 				remove_failed++;
 		}
 	}
+	up_write(&table->lock);
 
 	if (remove_failed)
 		netif_info(efx, drv, efx->net_dev,
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 0be93abdb2ad..cb9273016916 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -1783,7 +1783,6 @@ static int efx_probe_filters(struct efx_nic *efx)
 {
 	int rc;
 
-	spin_lock_init(&efx->filter_lock);
 	init_rwsem(&efx->filter_sem);
 	mutex_lock(&efx->mac_lock);
 	down_write(&efx->filter_sem);
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index fe0c5322454d..6f37a4dbe268 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -836,7 +836,7 @@ struct efx_rss_context {
  * @loopback_mode: Loopback status
  * @loopback_modes: Supported loopback mode bitmask
  * @loopback_selftest: Offline self-test private state
- * @filter_sem: Filter table rw_semaphore, for freeing the table
+ * @filter_sem: Filter table rw_semaphore, protects existence of @filter_state
  * @filter_lock: Filter table lock, for mere content changes
  * @filter_state: Architecture-dependent filter table state
  * @rps_mutex: Protects RPS state of all channels

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