Commit 8474b025 authored by Mikko Perttunen's avatar Mikko Perttunen Committed by Thierry Reding

gpu: host1x: Refactor channel allocation code

This is largely a rewrite of the Host1x channel allocation code, bringing
several changes:

- The previous code could deadlock due to an interaction
  between the 'reflock' mutex and CDMA timeout handling.
  This gets rid of the mutex.
- Support for more than 32 channels, required for Tegra186
- General refactoring, including better encapsulation
  of channel ownership handling into channel.c
Signed-off-by: default avatarMikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Dmitry Osipenko's avatarDmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko's avatarDmitry Osipenko <digetx@gmail.com>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent 03f0de77
......@@ -38,7 +38,7 @@ static int gr2d_init(struct host1x_client *client)
client->syncpts[0] = host1x_syncpt_request(client->dev, flags);
if (!client->syncpts[0]) {
host1x_channel_free(gr2d->channel);
host1x_channel_put(gr2d->channel);
return -ENOMEM;
}
......@@ -57,7 +57,7 @@ static int gr2d_exit(struct host1x_client *client)
return err;
host1x_syncpt_free(client->syncpts[0]);
host1x_channel_free(gr2d->channel);
host1x_channel_put(gr2d->channel);
return 0;
}
......
......@@ -48,7 +48,7 @@ static int gr3d_init(struct host1x_client *client)
client->syncpts[0] = host1x_syncpt_request(client->dev, flags);
if (!client->syncpts[0]) {
host1x_channel_free(gr3d->channel);
host1x_channel_put(gr3d->channel);
return -ENOMEM;
}
......@@ -67,7 +67,7 @@ static int gr3d_exit(struct host1x_client *client)
return err;
host1x_syncpt_free(client->syncpts[0]);
host1x_channel_free(gr3d->channel);
host1x_channel_put(gr3d->channel);
return 0;
}
......
......@@ -182,7 +182,7 @@ static int vic_init(struct host1x_client *client)
free_syncpt:
host1x_syncpt_free(client->syncpts[0]);
free_channel:
host1x_channel_free(vic->channel);
host1x_channel_put(vic->channel);
detach_device:
if (tegra->domain)
iommu_detach_device(tegra->domain, vic->dev);
......@@ -203,7 +203,7 @@ static int vic_exit(struct host1x_client *client)
return err;
host1x_syncpt_free(client->syncpts[0]);
host1x_channel_free(vic->channel);
host1x_channel_put(vic->channel);
if (vic->domain) {
iommu_detach_device(vic->domain, vic->dev);
......
......@@ -24,19 +24,33 @@
#include "job.h"
/* Constructor for the host1x device list */
int host1x_channel_list_init(struct host1x *host)
int host1x_channel_list_init(struct host1x_channel_list *chlist,
unsigned int num_channels)
{
INIT_LIST_HEAD(&host->chlist.list);
mutex_init(&host->chlist_mutex);
if (host->info->nb_channels > BITS_PER_LONG) {
WARN(1, "host1x hardware has more channels than supported by the driver\n");
return -ENOSYS;
chlist->channels = kcalloc(num_channels, sizeof(struct host1x_channel),
GFP_KERNEL);
if (!chlist->channels)
return -ENOMEM;
chlist->allocated_channels =
kcalloc(BITS_TO_LONGS(num_channels), sizeof(unsigned long),
GFP_KERNEL);
if (!chlist->allocated_channels) {
kfree(chlist->channels);
return -ENOMEM;
}
bitmap_zero(chlist->allocated_channels, num_channels);
return 0;
}
void host1x_channel_list_free(struct host1x_channel_list *chlist)
{
kfree(chlist->allocated_channels);
kfree(chlist->channels);
}
int host1x_job_submit(struct host1x_job *job)
{
struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
......@@ -47,86 +61,107 @@ EXPORT_SYMBOL(host1x_job_submit);
struct host1x_channel *host1x_channel_get(struct host1x_channel *channel)
{
int err = 0;
kref_get(&channel->refcount);
mutex_lock(&channel->reflock);
return channel;
}
EXPORT_SYMBOL(host1x_channel_get);
if (channel->refcount == 0)
err = host1x_cdma_init(&channel->cdma);
/**
* host1x_channel_get_index() - Attempt to get channel reference by index
* @host: Host1x device object
* @index: Index of channel
*
* If channel number @index is currently allocated, increase its refcount
* and return a pointer to it. Otherwise, return NULL.
*/
struct host1x_channel *host1x_channel_get_index(struct host1x *host,
unsigned int index)
{
struct host1x_channel *ch = &host->channel_list.channels[index];
if (!err)
channel->refcount++;
if (!kref_get_unless_zero(&ch->refcount))
return NULL;
mutex_unlock(&channel->reflock);
return ch;
}
static void release_channel(struct kref *kref)
{
struct host1x_channel *channel =
container_of(kref, struct host1x_channel, refcount);
struct host1x *host = dev_get_drvdata(channel->dev->parent);
struct host1x_channel_list *chlist = &host->channel_list;
host1x_hw_cdma_stop(host, &channel->cdma);
host1x_cdma_deinit(&channel->cdma);
return err ? NULL : channel;
clear_bit(channel->id, chlist->allocated_channels);
}
EXPORT_SYMBOL(host1x_channel_get);
void host1x_channel_put(struct host1x_channel *channel)
{
mutex_lock(&channel->reflock);
kref_put(&channel->refcount, release_channel);
}
EXPORT_SYMBOL(host1x_channel_put);
if (channel->refcount == 1) {
struct host1x *host = dev_get_drvdata(channel->dev->parent);
static struct host1x_channel *acquire_unused_channel(struct host1x *host)
{
struct host1x_channel_list *chlist = &host->channel_list;
unsigned int max_channels = host->info->nb_channels;
unsigned int index;
host1x_hw_cdma_stop(host, &channel->cdma);
host1x_cdma_deinit(&channel->cdma);
index = find_first_zero_bit(chlist->allocated_channels, max_channels);
if (index >= max_channels) {
dev_err(host->dev, "failed to find free channel\n");
return NULL;
}
channel->refcount--;
chlist->channels[index].id = index;
mutex_unlock(&channel->reflock);
set_bit(index, chlist->allocated_channels);
return &chlist->channels[index];
}
EXPORT_SYMBOL(host1x_channel_put);
/**
* host1x_channel_request() - Allocate a channel
* @device: Host1x unit this channel will be used to send commands to
*
* Allocates a new host1x channel for @device. If there are no free channels,
* this will sleep until one becomes available. May return NULL if CDMA
* initialization fails.
*/
struct host1x_channel *host1x_channel_request(struct device *dev)
{
struct host1x *host = dev_get_drvdata(dev->parent);
unsigned int max_channels = host->info->nb_channels;
struct host1x_channel *channel = NULL;
unsigned long index;
struct host1x_channel_list *chlist = &host->channel_list;
struct host1x_channel *channel;
int err;
mutex_lock(&host->chlist_mutex);
channel = acquire_unused_channel(host);
if (!channel)
return NULL;
index = find_first_zero_bit(&host->allocated_channels, max_channels);
if (index >= max_channels)
goto fail;
kref_init(&channel->refcount);
mutex_init(&channel->submitlock);
channel->dev = dev;
channel = kzalloc(sizeof(*channel), GFP_KERNEL);
if (!channel)
err = host1x_hw_channel_init(host, channel, channel->id);
if (err < 0)
goto fail;
err = host1x_hw_channel_init(host, channel, index);
err = host1x_cdma_init(&channel->cdma);
if (err < 0)
goto fail;
/* Link device to host1x_channel */
channel->dev = dev;
/* Add to channel list */
list_add_tail(&channel->list, &host->chlist.list);
host->allocated_channels |= BIT(index);
mutex_unlock(&host->chlist_mutex);
return channel;
fail:
dev_err(dev, "failed to init channel\n");
kfree(channel);
mutex_unlock(&host->chlist_mutex);
return NULL;
}
EXPORT_SYMBOL(host1x_channel_request);
clear_bit(channel->id, chlist->allocated_channels);
void host1x_channel_free(struct host1x_channel *channel)
{
struct host1x *host = dev_get_drvdata(channel->dev->parent);
dev_err(dev, "failed to initialize channel\n");
host->allocated_channels &= ~BIT(channel->id);
list_del(&channel->list);
kfree(channel);
return NULL;
}
EXPORT_SYMBOL(host1x_channel_free);
EXPORT_SYMBOL(host1x_channel_request);
......@@ -20,17 +20,21 @@
#define __HOST1X_CHANNEL_H
#include <linux/io.h>
#include <linux/kref.h>
#include "cdma.h"
struct host1x;
struct host1x_channel;
struct host1x_channel {
struct list_head list;
struct host1x_channel_list {
struct host1x_channel *channels;
unsigned long *allocated_channels;
};
unsigned int refcount;
struct host1x_channel {
struct kref refcount;
unsigned int id;
struct mutex reflock;
struct mutex submitlock;
void __iomem *regs;
struct device *dev;
......@@ -38,9 +42,10 @@ struct host1x_channel {
};
/* channel list operations */
int host1x_channel_list_init(struct host1x *host);
#define host1x_for_each_channel(host, channel) \
list_for_each_entry(channel, &host->chlist.list, list)
int host1x_channel_list_init(struct host1x_channel_list *chlist,
unsigned int num_channels);
void host1x_channel_list_free(struct host1x_channel_list *chlist);
struct host1x_channel *host1x_channel_get_index(struct host1x *host,
unsigned int index);
#endif
......@@ -43,24 +43,19 @@ void host1x_debug_output(struct output *o, const char *fmt, ...)
o->fn(o->ctx, o->buf, len);
}
static int show_channels(struct host1x_channel *ch, void *data, bool show_fifo)
static int show_channel(struct host1x_channel *ch, void *data, bool show_fifo)
{
struct host1x *m = dev_get_drvdata(ch->dev->parent);
struct output *o = data;
mutex_lock(&ch->reflock);
mutex_lock(&ch->cdma.lock);
if (ch->refcount) {
mutex_lock(&ch->cdma.lock);
if (show_fifo)
host1x_hw_show_channel_fifo(m, ch, o);
if (show_fifo)
host1x_hw_show_channel_fifo(m, ch, o);
host1x_hw_show_channel_cdma(m, ch, o);
host1x_hw_show_channel_cdma(m, ch, o);
mutex_unlock(&ch->cdma.lock);
}
mutex_unlock(&ch->reflock);
mutex_unlock(&ch->cdma.lock);
return 0;
}
......@@ -94,28 +89,22 @@ static void show_syncpts(struct host1x *m, struct output *o)
host1x_debug_output(o, "\n");
}
static void show_all(struct host1x *m, struct output *o)
static void show_all(struct host1x *m, struct output *o, bool show_fifo)
{
struct host1x_channel *ch;
int i;
host1x_hw_show_mlocks(m, o);
show_syncpts(m, o);
host1x_debug_output(o, "---- channels ----\n");
host1x_for_each_channel(m, ch)
show_channels(ch, o, true);
}
static void show_all_no_fifo(struct host1x *host1x, struct output *o)
{
struct host1x_channel *ch;
host1x_hw_show_mlocks(host1x, o);
show_syncpts(host1x, o);
host1x_debug_output(o, "---- channels ----\n");
for (i = 0; i < m->info->nb_channels; ++i) {
struct host1x_channel *ch = host1x_channel_get_index(m, i);
host1x_for_each_channel(host1x, ch)
show_channels(ch, o, false);
if (ch) {
show_channel(ch, o, show_fifo);
host1x_channel_put(ch);
}
}
}
static int host1x_debug_show_all(struct seq_file *s, void *unused)
......@@ -125,7 +114,7 @@ static int host1x_debug_show_all(struct seq_file *s, void *unused)
.ctx = s
};
show_all(s->private, &o);
show_all(s->private, &o, true);
return 0;
}
......@@ -137,7 +126,7 @@ static int host1x_debug_show(struct seq_file *s, void *unused)
.ctx = s
};
show_all_no_fifo(s->private, &o);
show_all(s->private, &o, false);
return 0;
}
......@@ -216,7 +205,7 @@ void host1x_debug_dump(struct host1x *host1x)
.fn = write_to_printk
};
show_all(host1x, &o);
show_all(host1x, &o, true);
}
void host1x_debug_dump_syncpts(struct host1x *host1x)
......
......@@ -198,7 +198,8 @@ static int host1x_probe(struct platform_device *pdev)
host->iova_end = geometry->aperture_end;
}
err = host1x_channel_list_init(host);
err = host1x_channel_list_init(&host->channel_list,
host->info->nb_channels);
if (err) {
dev_err(&pdev->dev, "failed to initialize channel list\n");
goto fail_detach_device;
......@@ -207,7 +208,7 @@ static int host1x_probe(struct platform_device *pdev)
err = clk_prepare_enable(host->clk);
if (err < 0) {
dev_err(&pdev->dev, "failed to enable clock\n");
goto fail_detach_device;
goto fail_free_channels;
}
err = reset_control_deassert(host->rst);
......@@ -244,6 +245,8 @@ static int host1x_probe(struct platform_device *pdev)
reset_control_assert(host->rst);
fail_unprepare_disable:
clk_disable_unprepare(host->clk);
fail_free_channels:
host1x_channel_list_free(&host->channel_list);
fail_detach_device:
if (host->domain) {
put_iova_domain(&host->iova);
......
......@@ -129,10 +129,8 @@ struct host1x {
struct host1x_syncpt *nop_sp;
struct mutex syncpt_mutex;
struct mutex chlist_mutex;
struct host1x_channel chlist;
unsigned long allocated_channels;
unsigned int num_allocated_channels;
struct host1x_channel_list channel_list;
struct dentry *debugfs;
......
......@@ -181,10 +181,6 @@ static int channel_submit(struct host1x_job *job)
static int host1x_channel_init(struct host1x_channel *ch, struct host1x *dev,
unsigned int index)
{
ch->id = index;
mutex_init(&ch->reflock);
mutex_init(&ch->submitlock);
ch->regs = dev->regs + index * HOST1X_CHANNEL_SIZE;
return 0;
}
......
......@@ -172,7 +172,6 @@ struct host1x_channel;
struct host1x_job;
struct host1x_channel *host1x_channel_request(struct device *dev);
void host1x_channel_free(struct host1x_channel *channel);
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);
......
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