Commit 0bbed88a authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'ipa-fixes' 



Alex Elder says:

====================
net: ipa: fix two replenish bugs

This series contains two fixes for bugs in the IPA receive buffer
replenishing code.  The (new) second patch defines a bitmap to
represent endpoint the replenish enabled flag.  Its purpose is to
prepare for the third patch, which adds an additional flag.

Version 2 of this series uses bitmap operations in the second bug
fix rather than an atomic variable, as suggested by Jakub.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents c12837d1 998c0bd2

drivers/net/ipa/ipa_endpoint.c

+20 −8
Original line number Diff line number Diff line
@@ -1080,27 +1080,38 @@ static void ipa_endpoint_replenish(struct ipa_endpoint *endpoint, bool add_one) 
{

	struct gsi *gsi;

	u32 backlog;

	int delta;



	if (!endpoint->replenish_enabled) {

	if (!test_bit(IPA_REPLENISH_ENABLED, endpoint->replenish_flags)) {

		if (add_one)

			atomic_inc(&endpoint->replenish_saved);

		return;

	}



	/* If already active, just update the backlog */

	if (test_and_set_bit(IPA_REPLENISH_ACTIVE, endpoint->replenish_flags)) {

		if (add_one)

			atomic_inc(&endpoint->replenish_backlog);

		return;

	}



	while (atomic_dec_not_zero(&endpoint->replenish_backlog))

		if (ipa_endpoint_replenish_one(endpoint))

			goto try_again_later;



	clear_bit(IPA_REPLENISH_ACTIVE, endpoint->replenish_flags);



	if (add_one)

		atomic_inc(&endpoint->replenish_backlog);



	return;



try_again_later:

	/* The last one didn't succeed, so fix the backlog */

	backlog = atomic_inc_return(&endpoint->replenish_backlog);

	clear_bit(IPA_REPLENISH_ACTIVE, endpoint->replenish_flags);



	if (add_one)

		atomic_inc(&endpoint->replenish_backlog);

	/* The last one didn't succeed, so fix the backlog */

	delta = add_one ? 2 : 1;

	backlog = atomic_add_return(delta, &endpoint->replenish_backlog);



	/* Whenever a receive buffer transaction completes we'll try to

	 * replenish again.  It's unlikely, but if we fail to supply even
@@ -1120,7 +1131,7 @@ static void ipa_endpoint_replenish_enable(struct ipa_endpoint *endpoint) 
	u32 max_backlog;

	u32 saved;



	endpoint->replenish_enabled = true;

	set_bit(IPA_REPLENISH_ENABLED, endpoint->replenish_flags);

	while ((saved = atomic_xchg(&endpoint->replenish_saved, 0)))

		atomic_add(saved, &endpoint->replenish_backlog);
@@ -1134,7 +1145,7 @@ static void ipa_endpoint_replenish_disable(struct ipa_endpoint *endpoint) 
{

	u32 backlog;



	endpoint->replenish_enabled = false;

	clear_bit(IPA_REPLENISH_ENABLED, endpoint->replenish_flags);

	while ((backlog = atomic_xchg(&endpoint->replenish_backlog, 0)))

		atomic_add(backlog, &endpoint->replenish_saved);

}
@@ -1691,7 +1702,8 @@ static void ipa_endpoint_setup_one(struct ipa_endpoint *endpoint) 
		/* RX transactions require a single TRE, so the maximum

		 * backlog is the same as the maximum outstanding TREs.

		 */

		endpoint->replenish_enabled = false;

		clear_bit(IPA_REPLENISH_ENABLED, endpoint->replenish_flags);

		clear_bit(IPA_REPLENISH_ACTIVE, endpoint->replenish_flags);

		atomic_set(&endpoint->replenish_saved,

			   gsi_channel_tre_max(gsi, endpoint->channel_id));

		atomic_set(&endpoint->replenish_backlog, 0);

drivers/net/ipa/ipa_endpoint.h

+15 −2
Original line number Diff line number Diff line
@@ -40,6 +40,19 @@ enum ipa_endpoint_name { 


#define IPA_ENDPOINT_MAX		32	/* Max supported by driver */



/**

 * enum ipa_replenish_flag:	RX buffer replenish flags

 *

 * @IPA_REPLENISH_ENABLED:	Whether receive buffer replenishing is enabled

 * @IPA_REPLENISH_ACTIVE:	Whether replenishing is underway

 * @IPA_REPLENISH_COUNT:	Number of defined replenish flags

 */

enum ipa_replenish_flag {

	IPA_REPLENISH_ENABLED,

	IPA_REPLENISH_ACTIVE,

	IPA_REPLENISH_COUNT,	/* Number of flags (must be last) */

};



/**

 * struct ipa_endpoint - IPA endpoint information

 * @ipa:		IPA pointer
@@ -51,7 +64,7 @@ enum ipa_endpoint_name { 
 * @trans_tre_max:	Maximum number of TRE descriptors per transaction

 * @evt_ring_id:	GSI event ring used by the endpoint

 * @netdev:		Network device pointer, if endpoint uses one

 * @replenish_enabled:	Whether receive buffer replenishing is enabled

 * @replenish_flags:	Replenishing state flags

 * @replenish_ready:	Number of replenish transactions without doorbell

 * @replenish_saved:	Replenish requests held while disabled

 * @replenish_backlog:	Number of buffers needed to fill hardware queue
@@ -72,7 +85,7 @@ struct ipa_endpoint { 
	struct net_device *netdev;



	/* Receive buffer replenishing for RX endpoints */

	bool replenish_enabled;

	DECLARE_BITMAP(replenish_flags, IPA_REPLENISH_COUNT);

	u32 replenish_ready;

	atomic_t replenish_saved;

	atomic_t replenish_backlog;