Add an option to host1x_channel_request to interruptibly wait for a free channel. This allows IOCTLs that acquire a channel to block the userspace.
Signed-off-by: Mikko Perttunen mperttunen@nvidia.com --- drivers/gpu/drm/tegra/drm.c | 9 +++++---- drivers/gpu/drm/tegra/gr2d.c | 6 +++--- drivers/gpu/drm/tegra/gr3d.c | 6 +++--- drivers/gpu/host1x/channel.c | 40 ++++++++++++++++++++++++++++++---------- drivers/gpu/host1x/channel.h | 1 + include/linux/host1x.h | 2 +- 6 files changed, 43 insertions(+), 21 deletions(-)
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c index 658bc8814f38..19f77c1a76c0 100644 --- a/drivers/gpu/drm/tegra/drm.c +++ b/drivers/gpu/drm/tegra/drm.c @@ -389,7 +389,8 @@ static int host1x_waitchk_copy_from_user(struct host1x_waitchk *dest, * Request a free hardware host1x channel for this user context, or if the * context already has one, bump its refcount. * - * Returns 0 on success, or -EBUSY if there were no free hardware channels. + * Returns 0 on success, -EINTR if wait for a free channel was interrupted, + * or other error. */ int tegra_drm_context_get_channel(struct tegra_drm_context *context) { @@ -398,10 +399,10 @@ int tegra_drm_context_get_channel(struct tegra_drm_context *context) mutex_lock(&context->lock);
if (context->pending_jobs == 0) { - context->channel = host1x_channel_request(client->dev); - if (!context->channel) { + context->channel = host1x_channel_request(client->dev, true); + if (IS_ERR(context->channel)) { mutex_unlock(&context->lock); - return -EBUSY; + return PTR_ERR(context->channel); } }
diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c index 3db3bcac48b9..c1853402f69b 100644 --- a/drivers/gpu/drm/tegra/gr2d.c +++ b/drivers/gpu/drm/tegra/gr2d.c @@ -32,9 +32,9 @@ static int gr2d_init(struct host1x_client *client) unsigned long flags = HOST1X_SYNCPT_HAS_BASE; struct gr2d *gr2d = to_gr2d(drm);
- gr2d->channel = host1x_channel_request(client->dev); - if (!gr2d->channel) - return -ENOMEM; + gr2d->channel = host1x_channel_request(client->dev, false); + if (IS_ERR(gr2d->channel)) + return PTR_ERR(gr2d->channel);
client->syncpts[0] = host1x_syncpt_request(client->dev, flags); if (!client->syncpts[0]) { diff --git a/drivers/gpu/drm/tegra/gr3d.c b/drivers/gpu/drm/tegra/gr3d.c index 279438342c8c..793a91d577cb 100644 --- a/drivers/gpu/drm/tegra/gr3d.c +++ b/drivers/gpu/drm/tegra/gr3d.c @@ -42,9 +42,9 @@ static int gr3d_init(struct host1x_client *client) unsigned long flags = HOST1X_SYNCPT_HAS_BASE; struct gr3d *gr3d = to_gr3d(drm);
- gr3d->channel = host1x_channel_request(client->dev); - if (!gr3d->channel) - return -ENOMEM; + gr3d->channel = host1x_channel_request(client->dev, false); + if (IS_ERR(gr3d->channel)) + return PTR_ERR(gr3d->channel);
client->syncpts[0] = host1x_syncpt_request(client->dev, flags); if (!client->syncpts[0]) { diff --git a/drivers/gpu/host1x/channel.c b/drivers/gpu/host1x/channel.c index 9d8cad12f9d8..eebcd51261df 100644 --- a/drivers/gpu/host1x/channel.c +++ b/drivers/gpu/host1x/channel.c @@ -43,6 +43,7 @@ int host1x_channel_list_init(struct host1x_channel_list *chlist, bitmap_zero(chlist->allocated_channels, num_channels);
mutex_init(&chlist->lock); + sema_init(&chlist->sema, num_channels);
return 0; } @@ -99,6 +100,8 @@ static void release_channel(struct kref *kref) host1x_cdma_deinit(&channel->cdma);
clear_bit(channel->id, chlist->allocated_channels); + + up(&chlist->sema); }
void host1x_channel_put(struct host1x_channel *channel) @@ -107,19 +110,30 @@ void host1x_channel_put(struct host1x_channel *channel) } EXPORT_SYMBOL(host1x_channel_put);
-static struct host1x_channel *acquire_unused_channel(struct host1x *host) +static struct host1x_channel *acquire_unused_channel(struct host1x *host, + bool wait) { struct host1x_channel_list *chlist = &host->channel_list; unsigned int max_channels = host->info->nb_channels; unsigned int index; + int err; + + if (wait) { + err = down_interruptible(&chlist->sema); + if (err) + return ERR_PTR(err); + } else { + if (down_trylock(&chlist->sema)) + return ERR_PTR(-EBUSY); + }
mutex_lock(&chlist->lock);
index = find_first_zero_bit(chlist->allocated_channels, max_channels); - if (index >= max_channels) { + if (WARN(index >= max_channels, "failed to find free channel")) { mutex_unlock(&chlist->lock); dev_err(host->dev, "failed to find free channel\n"); - return NULL; + return ERR_PTR(-EBUSY); }
chlist->channels[index].id = index; @@ -134,20 +148,26 @@ static struct host1x_channel *acquire_unused_channel(struct host1x *host) /** * host1x_channel_request() - Allocate a channel * @device: Host1x unit this channel will be used to send commands to + * @wait: Whether to wait for a free channels if all are reserved + * + * Allocates a new host1x channel for @device. If all channels are in use, + * and @wait is true, does an interruptible wait until one is available. * - * Allocates a new host1x channel for @device. May return NULL if CDMA - * initialization fails. + * If a channel was acquired, returns a pointer to it. Otherwise returns + * an error pointer with -EINTR if the wait was interrupted, -EBUSY + * if a channel could not be acquired or another error code if channel + * initialization failed. */ -struct host1x_channel *host1x_channel_request(struct device *dev) +struct host1x_channel *host1x_channel_request(struct device *dev, bool wait) { struct host1x *host = dev_get_drvdata(dev->parent); struct host1x_channel_list *chlist = &host->channel_list; struct host1x_channel *channel; int err;
- channel = acquire_unused_channel(host); - if (!channel) - return NULL; + channel = acquire_unused_channel(host, wait); + if (IS_ERR(channel)) + return channel;
kref_init(&channel->refcount); mutex_init(&channel->submitlock); @@ -168,6 +188,6 @@ struct host1x_channel *host1x_channel_request(struct device *dev)
dev_err(dev, "failed to initialize channel\n");
- return NULL; + return ERR_PTR(err); } EXPORT_SYMBOL(host1x_channel_request); diff --git a/drivers/gpu/host1x/channel.h b/drivers/gpu/host1x/channel.h index e68a8ae9a670..1f5cf8029b62 100644 --- a/drivers/gpu/host1x/channel.h +++ b/drivers/gpu/host1x/channel.h @@ -31,6 +31,7 @@ struct host1x_channel_list { struct host1x_channel *channels;
struct mutex lock; + struct semaphore sema; unsigned long *allocated_channels; };
diff --git a/include/linux/host1x.h b/include/linux/host1x.h index f931d28a68ff..2a34905d4408 100644 --- a/include/linux/host1x.h +++ b/include/linux/host1x.h @@ -171,7 +171,7 @@ u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base); struct host1x_channel; struct host1x_job;
-struct host1x_channel *host1x_channel_request(struct device *dev); +struct host1x_channel *host1x_channel_request(struct device *dev, bool wait); struct host1x_channel *host1x_channel_get(struct host1x_channel *channel); void host1x_channel_put(struct host1x_channel *channel); int host1x_job_submit(struct host1x_job *job);