Add an implementation of dma_fences based on syncpoints. Syncpoint interrupts are used to signal fences. Additionally, after software signaling has been enabled, a 30 second timeout is started. If the syncpoint threshold is not reached within this period, the fence is signalled with an -ETIMEDOUT error code. This is to allow fences that would never reach their syncpoint threshold to be cleaned up.
Additionally, add a new /dev/host1x IOCTL for creating sync_file file descriptors backed by syncpoint fences.
Signed-off-by: Mikko Perttunen mperttunen@nvidia.com --- v4: * Fix _signal prototype and include it to avoid warning * Remove use of unused local in error path v3: * Move declaration of host1x_fence_extract to public header --- drivers/gpu/host1x/Makefile | 1 + drivers/gpu/host1x/fence.c | 208 ++++++++++++++++++++++++++++++++++++ drivers/gpu/host1x/fence.h | 13 +++ drivers/gpu/host1x/intr.c | 9 ++ drivers/gpu/host1x/intr.h | 2 + drivers/gpu/host1x/uapi.c | 103 ++++++++++++++++++ include/linux/host1x.h | 4 + 7 files changed, 340 insertions(+) create mode 100644 drivers/gpu/host1x/fence.c create mode 100644 drivers/gpu/host1x/fence.h
diff --git a/drivers/gpu/host1x/Makefile b/drivers/gpu/host1x/Makefile index 882f928d75e1..a48af2cefae1 100644 --- a/drivers/gpu/host1x/Makefile +++ b/drivers/gpu/host1x/Makefile @@ -10,6 +10,7 @@ host1x-y = \ debug.o \ mipi.o \ uapi.o \ + fence.o \ hw/host1x01.o \ hw/host1x02.o \ hw/host1x04.o \ diff --git a/drivers/gpu/host1x/fence.c b/drivers/gpu/host1x/fence.c new file mode 100644 index 000000000000..b2484606c311 --- /dev/null +++ b/drivers/gpu/host1x/fence.c @@ -0,0 +1,208 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Syncpoint dma_fence implementation + * + * Copyright (c) 2020, NVIDIA Corporation. + */ + +#include <linux/dma-fence.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/sync_file.h> + +#include "fence.h" +#include "intr.h" +#include "syncpt.h" + +DEFINE_SPINLOCK(lock); + +struct host1x_syncpt_fence { + struct dma_fence base; + + atomic_t signaling; + + struct host1x_syncpt *sp; + u32 threshold; + + struct host1x_waitlist *waiter; + void *waiter_ref; + + struct delayed_work timeout_work; +}; + +static const char *syncpt_fence_get_driver_name(struct dma_fence *f) +{ + return "host1x"; +} + +static const char *syncpt_fence_get_timeline_name(struct dma_fence *f) +{ + return "syncpoint"; +} + +static bool syncpt_fence_enable_signaling(struct dma_fence *f) +{ + struct host1x_syncpt_fence *sf = + container_of(f, struct host1x_syncpt_fence, base); + int err; + + if (host1x_syncpt_is_expired(sf->sp, sf->threshold)) + return false; + + dma_fence_get(f); + + /* + * The dma_fence framework requires the fence driver to keep a + * reference to any fences for which 'enable_signaling' has been + * called (and that have not been signalled). + * + * We provide a userspace API to create arbitrary syncpoint fences, + * so we cannot normally guarantee that all fences get signalled. + * As such, setup a timeout, so that long-lasting fences will get + * reaped eventually. + */ + schedule_delayed_work(&sf->timeout_work, msecs_to_jiffies(30000)); + + err = host1x_intr_add_action(sf->sp->host, sf->sp, sf->threshold, + HOST1X_INTR_ACTION_SIGNAL_FENCE, f, + sf->waiter, &sf->waiter_ref); + if (err) { + cancel_delayed_work_sync(&sf->timeout_work); + dma_fence_put(f); + return false; + } + + /* intr framework takes ownership of waiter */ + sf->waiter = NULL; + + /* + * The fence may get signalled at any time after the above call, + * so we need to initialize all state used by signalling + * before it. + */ + + return true; +} + +static void syncpt_fence_release(struct dma_fence *f) +{ + struct host1x_syncpt_fence *sf = + container_of(f, struct host1x_syncpt_fence, base); + + if (sf->waiter) + kfree(sf->waiter); + + dma_fence_free(f); +} + +const struct dma_fence_ops syncpt_fence_ops = { + .get_driver_name = syncpt_fence_get_driver_name, + .get_timeline_name = syncpt_fence_get_timeline_name, + .enable_signaling = syncpt_fence_enable_signaling, + .release = syncpt_fence_release, +}; + +void host1x_fence_signal(struct host1x_syncpt_fence *f) +{ + if (atomic_xchg(&f->signaling, 1)) + return; + + /* + * Cancel pending timeout work - if it races, it will + * not get 'f->signaling' and return. + */ + cancel_delayed_work_sync(&f->timeout_work); + + host1x_intr_put_ref(f->sp->host, f->sp->id, f->waiter_ref); + + dma_fence_signal(&f->base); + dma_fence_put(&f->base); +} + +static void do_fence_timeout(struct work_struct *work) +{ + struct delayed_work *dwork = (struct delayed_work *)work; + struct host1x_syncpt_fence *f = + container_of(dwork, struct host1x_syncpt_fence, timeout_work); + + if (atomic_xchg(&f->signaling, 1)) + return; + + /* + * Cancel pending timeout work - if it races, it will + * not get 'f->signaling' and return. + */ + host1x_intr_put_ref(f->sp->host, f->sp->id, f->waiter_ref); + + dma_fence_set_error(&f->base, -ETIMEDOUT); + dma_fence_signal(&f->base); + dma_fence_put(&f->base); +} + +struct dma_fence *host1x_fence_create(struct host1x_syncpt *sp, u32 threshold) +{ + struct host1x_syncpt_fence *fence; + + fence = kzalloc(sizeof(*fence), GFP_KERNEL); + if (!fence) + return ERR_PTR(-ENOMEM); + + fence->waiter = kzalloc(sizeof(*fence->waiter), GFP_KERNEL); + if (!fence->waiter) + return ERR_PTR(-ENOMEM); + + fence->sp = sp; + fence->threshold = threshold; + + dma_fence_init(&fence->base, &syncpt_fence_ops, &lock, + dma_fence_context_alloc(1), 0); + + INIT_DELAYED_WORK(&fence->timeout_work, do_fence_timeout); + + return &fence->base; +} +EXPORT_SYMBOL(host1x_fence_create); + +int host1x_fence_create_fd(struct host1x_syncpt *sp, u32 threshold) +{ + struct sync_file *file; + struct dma_fence *f; + int fd; + + f = host1x_fence_create(sp, threshold); + if (IS_ERR(f)) + return PTR_ERR(f); + + fd = get_unused_fd_flags(O_CLOEXEC); + if (fd < 0) { + dma_fence_put(f); + return fd; + } + + file = sync_file_create(f); + dma_fence_put(f); + if (!file) + return -ENOMEM; + + fd_install(fd, file->file); + + return fd; +} +EXPORT_SYMBOL(host1x_fence_create_fd); + +int host1x_fence_extract(struct dma_fence *fence, u32 *id, u32 *threshold) +{ + struct host1x_syncpt_fence *f; + + if (fence->ops != &syncpt_fence_ops) + return -EINVAL; + + f = container_of(fence, struct host1x_syncpt_fence, base); + + *id = f->sp->id; + *threshold = f->threshold; + + return 0; +} +EXPORT_SYMBOL(host1x_fence_extract); diff --git a/drivers/gpu/host1x/fence.h b/drivers/gpu/host1x/fence.h new file mode 100644 index 000000000000..70c91de82f14 --- /dev/null +++ b/drivers/gpu/host1x/fence.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2020, NVIDIA Corporation. + */ + +#ifndef HOST1X_FENCE_H +#define HOST1X_FENCE_H + +struct host1x_syncpt_fence; + +void host1x_fence_signal(struct host1x_syncpt_fence *fence); + +#endif diff --git a/drivers/gpu/host1x/intr.c b/drivers/gpu/host1x/intr.c index 5d328d20ce6d..19b59c5c94d0 100644 --- a/drivers/gpu/host1x/intr.c +++ b/drivers/gpu/host1x/intr.c @@ -13,6 +13,7 @@ #include <trace/events/host1x.h> #include "channel.h" #include "dev.h" +#include "fence.h" #include "intr.h"
/* Wait list management */ @@ -121,12 +122,20 @@ static void action_wakeup_interruptible(struct host1x_waitlist *waiter) wake_up_interruptible(wq); }
+static void action_signal_fence(struct host1x_waitlist *waiter) +{ + struct host1x_syncpt_fence *f = waiter->data; + + host1x_fence_signal(f); +} + typedef void (*action_handler)(struct host1x_waitlist *waiter);
static const action_handler action_handlers[HOST1X_INTR_ACTION_COUNT] = { action_submit_complete, action_wakeup, action_wakeup_interruptible, + action_signal_fence, };
static void run_handlers(struct list_head completed[HOST1X_INTR_ACTION_COUNT]) diff --git a/drivers/gpu/host1x/intr.h b/drivers/gpu/host1x/intr.h index aac38194398f..dedbd0f700fb 100644 --- a/drivers/gpu/host1x/intr.h +++ b/drivers/gpu/host1x/intr.h @@ -33,6 +33,8 @@ enum host1x_intr_action { */ HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
+ HOST1X_INTR_ACTION_SIGNAL_FENCE, + HOST1X_INTR_ACTION_COUNT };
diff --git a/drivers/gpu/host1x/uapi.c b/drivers/gpu/host1x/uapi.c index 27b8761c3f35..e931756a5e16 100644 --- a/drivers/gpu/host1x/uapi.c +++ b/drivers/gpu/host1x/uapi.c @@ -11,8 +11,10 @@ #include <linux/fs.h> #include <linux/host1x.h> #include <linux/nospec.h> +#include <linux/sync_file.h>
#include "dev.h" +#include "fence.h" #include "syncpt.h" #include "uapi.h"
@@ -195,6 +197,99 @@ static int dev_file_ioctl_alloc_syncpoint(struct host1x *host1x, return err; }
+static int dev_file_ioctl_create_fence(struct host1x *host1x, void __user *data) +{ + struct host1x_create_fence args; + unsigned long copy_err; + int fd; + + copy_err = copy_from_user(&args, data, sizeof(args)); + if (copy_err) + return -EFAULT; + + if (args.reserved[0]) + return -EINVAL; + + if (args.id >= host1x_syncpt_nb_pts(host1x)) + return -EINVAL; + + args.id = array_index_nospec(args.id, host1x_syncpt_nb_pts(host1x)); + + fd = host1x_fence_create_fd(&host1x->syncpt[args.id], args.threshold); + if (fd < 0) + return fd; + + args.fence_fd = fd; + + copy_err = copy_to_user(data, &args, sizeof(args)); + if (copy_err) + return -EFAULT; + + return 0; +} + +static int dev_file_ioctl_fence_extract(struct host1x *host1x, void __user *data) +{ + struct host1x_fence_extract_fence __user *fences_user_ptr; + struct dma_fence *fence, **fences; + struct host1x_fence_extract args; + struct dma_fence_array *array; + unsigned int num_fences, i; + unsigned long copy_err; + int err; + + copy_err = copy_from_user(&args, data, sizeof(args)); + if (copy_err) + return -EFAULT; + + fences_user_ptr = u64_to_user_ptr(args.fences_ptr); + + if (args.reserved[0] || args.reserved[1]) + return -EINVAL; + + fence = sync_file_get_fence(args.fence_fd); + if (!fence) + return -EINVAL; + + array = to_dma_fence_array(fence); + if (array) { + fences = array->fences; + num_fences = array->num_fences; + } else { + fences = &fence; + num_fences = 1; + } + + for (i = 0; i < min(num_fences, args.num_fences); i++) { + struct host1x_fence_extract_fence f; + + err = host1x_fence_extract(fences[i], &f.id, &f.threshold); + if (err) + goto put_fence; + + copy_err = copy_to_user(fences_user_ptr + i, &f, sizeof(f)); + if (copy_err) { + err = -EFAULT; + goto put_fence; + } + } + + args.num_fences = i+1; + + copy_err = copy_to_user(data, &args, sizeof(args)); + if (copy_err) { + err = -EFAULT; + goto put_fence; + } + + return 0; + +put_fence: + dma_fence_put(fence); + + return err; +} + static long dev_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -210,6 +305,14 @@ static long dev_file_ioctl(struct file *file, unsigned int cmd, err = dev_file_ioctl_alloc_syncpoint(file->private_data, data); break;
+ case HOST1X_IOCTL_CREATE_FENCE: + err = dev_file_ioctl_create_fence(file->private_data, data); + break; + + case HOST1X_IOCTL_FENCE_EXTRACT: + err = dev_file_ioctl_fence_extract(file->private_data, data); + break; + default: err = -ENOTTY; } diff --git a/include/linux/host1x.h b/include/linux/host1x.h index 8f6d61e13e05..bcfb1cc9a1c1 100644 --- a/include/linux/host1x.h +++ b/include/linux/host1x.h @@ -165,6 +165,10 @@ u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base);
struct host1x_syncpt *host1x_syncpt_fd_get(int fd);
+struct dma_fence *host1x_fence_create(struct host1x_syncpt *sp, u32 threshold); +int host1x_fence_create_fd(struct host1x_syncpt *sp, u32 threshold); +int host1x_fence_extract(struct dma_fence *fence, u32 *id, u32 *threshold); + /* * host1x channel */