[PATCH 4/5] soc: fsl: dpio: add a device_link at dpaa2_io_service_register

[Ioana Ciornei]

Automatically add a device link between the actual device requesting the
dpaa2_io_service_register and the underlying dpaa2_io used. This link
will ensure that when a DPIO device, which is indirectly used by other
devices, is unbound any consumer devices will be also unbound from their
drivers.

For example, any DPNI, bound to the dpaa2-eth driver, which is using
DPIO devices will be unbound before its supplier device.

Also, add a new parameter to the dpaa2_io_service_[de]register functions
to specify the requesting device (ie the consumer).

Signed-off-by: Ioana Ciornei <ioana.ciornei@xxxxxxx>
---
 drivers/crypto/caam/caamalg_qi2.c                |  6 +++---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c |  9 +++++----
 drivers/soc/fsl/dpio/dpio-service.c              | 16 ++++++++++++++--
 include/soc/fsl/dpaa2-io.h                       |  6 ++++--
 4 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/drivers/crypto/caam/caamalg_qi2.c b/drivers/crypto/caam/caamalg_qi2.c
index 7d8ac02..3167539 100644
--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -4371,7 +4371,7 @@ static int __cold dpaa2_dpseci_dpio_setup(struct dpaa2_caam_priv *priv)
 		nctx->cb = dpaa2_caam_fqdan_cb;
 
 		/* Register notification callbacks */
-		err = dpaa2_io_service_register(NULL, nctx);
+		err = dpaa2_io_service_register(NULL, nctx, dev);
 		if (unlikely(err)) {
 			dev_dbg(dev, "No affine DPIO for cpu %d\n", cpu);
 			nctx->cb = NULL;
@@ -4404,7 +4404,7 @@ static int __cold dpaa2_dpseci_dpio_setup(struct dpaa2_caam_priv *priv)
 		ppriv = per_cpu_ptr(priv->ppriv, cpu);
 		if (!ppriv->nctx.cb)
 			break;
-		dpaa2_io_service_deregister(NULL, &ppriv->nctx);
+		dpaa2_io_service_deregister(NULL, &ppriv->nctx, dev);
 	}
 
 	for_each_online_cpu(cpu) {
@@ -4424,7 +4424,7 @@ static void __cold dpaa2_dpseci_dpio_free(struct dpaa2_caam_priv *priv)
 
 	for_each_online_cpu(cpu) {
 		ppriv = per_cpu_ptr(priv->ppriv, cpu);
-		dpaa2_io_service_deregister(NULL, &ppriv->nctx);
+		dpaa2_io_service_deregister(NULL, &ppriv->nctx, priv->dev);
 		dpaa2_io_store_destroy(ppriv->store);
 
 		if (++i == priv->num_pairs)
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index 04d5c44..e8790f9 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -1570,7 +1570,7 @@ static int setup_dpio(struct dpaa2_eth_priv *priv)
 
 		/* Register the new context */
 		channel->dpio = dpaa2_io_service_select(i);
-		err = dpaa2_io_service_register(channel->dpio, nctx);
+		err = dpaa2_io_service_register(channel->dpio, nctx, dev);
 		if (err) {
 			dev_dbg(dev, "No affine DPIO for cpu %d\n", i);
 			/* If no affine DPIO for this core, there's probably
@@ -1610,7 +1610,7 @@ static int setup_dpio(struct dpaa2_eth_priv *priv)
 	return 0;
 
 err_set_cdan:
-	dpaa2_io_service_deregister(channel->dpio, nctx);
+	dpaa2_io_service_deregister(channel->dpio, nctx, dev);
 err_service_reg:
 	free_channel(priv, channel);
 err_alloc_ch:
@@ -1630,13 +1630,14 @@ static int setup_dpio(struct dpaa2_eth_priv *priv)
 
 static void free_dpio(struct dpaa2_eth_priv *priv)
 {
-	int i;
+	struct device *dev = priv->net_dev->dev.parent;
 	struct dpaa2_eth_channel *ch;
+	int i;
 
 	/* deregister CDAN notifications and free channels */
 	for (i = 0; i < priv->num_channels; i++) {
 		ch = priv->channel[i];
-		dpaa2_io_service_deregister(ch->dpio, &ch->nctx);
+		dpaa2_io_service_deregister(ch->dpio, &ch->nctx, dev);
 		free_channel(priv, ch);
 	}
 }
diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c
index 87e01710..01b24ac 100644
--- a/drivers/soc/fsl/dpio/dpio-service.c
+++ b/drivers/soc/fsl/dpio/dpio-service.c
@@ -237,6 +237,7 @@ int dpaa2_io_get_cpu(struct dpaa2_io *d)
  *                               notifications on the given DPIO service.
  * @d:   the given DPIO service.
  * @ctx: the notification context.
+ * @dev: the device that requests the register
  *
  * The caller should make the MC command to attach a DPAA2 object to
  * a DPIO after this function completes successfully.  In that way:
@@ -251,14 +252,20 @@ int dpaa2_io_get_cpu(struct dpaa2_io *d)
  * Return 0 for success, or -ENODEV for failure.
  */
 int dpaa2_io_service_register(struct dpaa2_io *d,
-			      struct dpaa2_io_notification_ctx *ctx)
+			      struct dpaa2_io_notification_ctx *ctx,
+			      struct device *dev)
 {
+	struct device_link *link;
 	unsigned long irqflags;
 
 	d = service_select_by_cpu(d, ctx->desired_cpu);
 	if (!d)
 		return -ENODEV;
 
+	link = device_link_add(dev, d->dev, DL_FLAG_AUTOREMOVE_CONSUMER);
+	if (!link)
+		return -EINVAL;
+
 	ctx->dpio_id = d->dpio_desc.dpio_id;
 	ctx->qman64 = (u64)(uintptr_t)ctx;
 	ctx->dpio_private = d;
@@ -279,12 +286,14 @@ int dpaa2_io_service_register(struct dpaa2_io *d,
  * dpaa2_io_service_deregister - The opposite of 'register'.
  * @service: the given DPIO service.
  * @ctx: the notification context.
+ * @dev: the device that requests to be deregistered
  *
  * This function should be called only after sending the MC command to
  * to detach the notification-producing device from the DPIO.
  */
 void dpaa2_io_service_deregister(struct dpaa2_io *service,
-				 struct dpaa2_io_notification_ctx *ctx)
+				 struct dpaa2_io_notification_ctx *ctx,
+				 struct device *dev)
 {
 	struct dpaa2_io *d = ctx->dpio_private;
 	unsigned long irqflags;
@@ -295,6 +304,9 @@ void dpaa2_io_service_deregister(struct dpaa2_io *service,
 	spin_lock_irqsave(&d->lock_notifications, irqflags);
 	list_del(&ctx->node);
 	spin_unlock_irqrestore(&d->lock_notifications, irqflags);
+
+	if (dev)
+		device_link_remove(dev, d->dev);
 }
 EXPORT_SYMBOL_GPL(dpaa2_io_service_deregister);
 
diff --git a/include/soc/fsl/dpaa2-io.h b/include/soc/fsl/dpaa2-io.h
index 5b5ba26..850e46d 100644
--- a/include/soc/fsl/dpaa2-io.h
+++ b/include/soc/fsl/dpaa2-io.h
@@ -94,9 +94,11 @@ struct dpaa2_io_notification_ctx {
 int dpaa2_io_get_cpu(struct dpaa2_io *d);
 
 int dpaa2_io_service_register(struct dpaa2_io *service,
-			      struct dpaa2_io_notification_ctx *ctx);
+			      struct dpaa2_io_notification_ctx *ctx,
+			      struct device *dev);
 void dpaa2_io_service_deregister(struct dpaa2_io *service,
-				 struct dpaa2_io_notification_ctx *ctx);
+				 struct dpaa2_io_notification_ctx *ctx,
+				 struct device *dev);
 int dpaa2_io_service_rearm(struct dpaa2_io *service,
 			   struct dpaa2_io_notification_ctx *ctx);
 
-- 
1.9.1