Commit 9764723d authored by Mikko Perttunen's avatar Mikko Perttunen Committed by Thierry Reding
Browse files

gpu: host1x: Add locking in channel allocation 



Add locking around channel allocation to avoid race conditions.

Signed-off-by: default avatarMikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230901111510.663401-1-cyndis@kapsi.fi
parent f170bed5

drivers/gpu/host1x/channel.c

+7 −0
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ int host1x_channel_list_init(struct host1x_channel_list *chlist, 
		return -ENOMEM;

	}



	mutex_init(&chlist->lock);



	return 0;

}
@@ -104,8 +106,11 @@ static struct host1x_channel *acquire_unused_channel(struct host1x *host) 
	unsigned int max_channels = host->info->nb_channels;

	unsigned int index;



	mutex_lock(&chlist->lock);



	index = find_first_zero_bit(chlist->allocated_channels, max_channels);

	if (index >= max_channels) {

		mutex_unlock(&chlist->lock);

		dev_err(host->dev, "failed to find free channel\n");

		return NULL;

	}
@@ -114,6 +119,8 @@ static struct host1x_channel *acquire_unused_channel(struct host1x *host) 


	set_bit(index, chlist->allocated_channels);



	mutex_unlock(&chlist->lock);



	return &chlist->channels[index];

}

drivers/gpu/host1x/channel.h

+3 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


#include <linux/io.h>

#include <linux/kref.h>

#include <linux/mutex.h>



#include "cdma.h"
@@ -18,6 +19,8 @@ struct host1x_channel; 


struct host1x_channel_list {

	struct host1x_channel *channels;



	struct mutex lock;

	unsigned long *allocated_channels;

};