On Thu, Feb 21, 2019 at 10:41:41AM -0800, Matthew Wilcox wrote:
> - Rename it to 'objects', as requested in todo.rst
Yay, thanks!
> - Also convert leases IDR to XArray as the two are occasionally used by
> the same code (see drm_mode_get_lease_ioctl())
> - Refactor drm_mode_create_lease_ioctl() to create the new drm_master
> early to avoid creating an XArray on the stack and reparenting it
> afterwards.
All lgtm, also the idr_replace replacement.
One thing I wonder: For the lesse object xa, we really only store 0/1 in
there, and I don't think that'll change. There was once the idea that we'd
look up objects for a lease directly, bypassing the main object idr. But
that doesn't work due to unregister/hotunplug rules, or at least it would
be pain not worth having. Might be worth it to a lookup structure
optimized for that. Or does XA already autocompress that for us? The
object id are likely fairly compressed, good chance all the ones you need
for a lease will fit into the first 64 id.
> Signed-off-by: Matthew Wilcox <wi...@infradead.org>
> ---
> Documentation/gpu/todo.rst | 3 -
> drivers/gpu/drm/drm_auth.c | 4 +-
> drivers/gpu/drm/drm_lease.c | 136 ++++++++++++++----------------
> drivers/gpu/drm/drm_mode_config.c | 3 +-
> drivers/gpu/drm/drm_mode_object.c | 47 +++++------
> include/drm/drm_auth.h | 2 +-
> include/drm/drm_mode_config.h | 6 +-
> 7 files changed, 90 insertions(+), 111 deletions(-)
>
> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
> index 14191b64446d..41da7b06195c 100644
> --- a/Documentation/gpu/todo.rst
> +++ b/Documentation/gpu/todo.rst
> @@ -354,9 +354,6 @@ KMS cleanups
>
> Some of these date from the very introduction of KMS in 2008 ...
>
> -- drm_mode_config.crtc_idr is misnamed, since it contains all KMS object.
> Should
> - be renamed to drm_mode_config.object_idr.
> -
> - drm_display_mode doesn't need to be derived from drm_mode_object. That's
> leftovers from older (never merged into upstream) KMS designs where modes
> where set using their ID, including support to add/remove modes.
> diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c
> index 1813507f9b9c..c6967f0b095d 100644
> --- a/drivers/gpu/drm/drm_auth.c
> +++ b/drivers/gpu/drm/drm_auth.c
> @@ -110,7 +110,7 @@ struct drm_master *drm_master_create(struct drm_device
> *dev)
> /* initialize the tree of output resource lessees */
> master->lessor = NULL;
> master->lessee_id = 0;
> - idr_init(&master->leases);
> + xa_init(&master->leases);
XA_FALGS_ALLOC1, for safety to make sure we never store 0 (considered
invalid id throughout at least modern drm)?
-Daniel
> xa_init_flags(&master->lessees, XA_FLAGS_ALLOC1);
>
> return master;
> @@ -345,7 +345,7 @@ static void drm_master_destroy(struct kref *kref)
>
> drm_legacy_master_rmmaps(dev, master);
>
> - idr_destroy(&master->leases);
> + xa_destroy(&master->leases);
>
> kfree(master->unique);
> kfree(master);
> diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
> index 47830f9ec616..1e88f406c738 100644
> --- a/drivers/gpu/drm/drm_lease.c
> +++ b/drivers/gpu/drm/drm_lease.c
> @@ -20,8 +20,6 @@
> #include <drm/drm_auth.h>
> #include <drm/drm_crtc_helper.h>
>
> -static uint64_t drm_lease_idr_object;
> -
> /**
> * drm_lease_owner - return ancestor owner drm_master
> * @master: drm_master somewhere within tree of lessees and lessors
> @@ -69,7 +67,7 @@ static int _drm_lease_held_master(struct drm_master
> *master, int id)
> {
> lockdep_assert_held(&master->dev->mode_config.idr_mutex);
> if (master->lessor)
> - return idr_find(&master->leases, id) != NULL;
> + return xa_load(&master->leases, id) != NULL;
> return true;
> }
>
> @@ -183,7 +181,7 @@ uint32_t drm_lease_filter_crtcs(struct drm_file
> *file_priv, uint32_t crtcs_in)
> /*
> * drm_lease_create - create a new drm_master with leased objects (idr_mutex
> not held)
> * @lessor: lease holder (or owner) of objects
> - * @leases: objects to lease to the new drm_master
> + * @lessee: leaser of objects
> *
> * Uses drm_master_create to allocate a new drm_master, then checks to
> * make sure all of the desired objects can be leased, atomically
> @@ -195,35 +193,30 @@ uint32_t drm_lease_filter_crtcs(struct drm_file
> *file_priv, uint32_t crtcs_in)
> * ERR_PTR(-EEXIST) same object specified more than once in the
> provided list
> * ERR_PTR(-ENOMEM) allocation failed
> */
> -static struct drm_master *drm_lease_create(struct drm_master *lessor, struct
> idr *leases)
> +static struct drm_master *drm_lease_create(struct drm_master *lessor,
> + struct drm_master *lessee)
> {
> struct drm_device *dev = lessor->dev;
> int error;
> - struct drm_master *lessee;
> - int object;
> void *entry;
> + unsigned long index;
>
> DRM_DEBUG_LEASE("lessor %d\n", lessor->lessee_id);
>
> - lessee = drm_master_create(lessor->dev);
> - if (!lessee) {
> - DRM_DEBUG_LEASE("drm_master_create failed\n");
> - return ERR_PTR(-ENOMEM);
> - }
> -
> mutex_lock(&dev->mode_config.idr_mutex);
>
> - idr_for_each_entry(leases, entry, object) {
> + xa_for_each(&lessee->leases, index, entry) {
> error = 0;
> - if (!idr_find(&dev->mode_config.crtc_idr, object))
> + if (!xa_load(&dev->mode_config.objects, index))
> error = -ENOENT;
> - else if (!_drm_lease_held_master(lessor, object))
> + else if (!_drm_lease_held_master(lessor, index))
> error = -EACCES;
> - else if (_drm_has_leased(lessor, object))
> + else if (_drm_has_leased(lessor, index))
> error = -EBUSY;
>
> if (error != 0) {
> - DRM_DEBUG_LEASE("object %d failed %d\n", object, error);
> + DRM_DEBUG_LEASE("object %d failed %d\n", (u32)index,
> + error);
> goto out_lessee;
> }
> }
> @@ -236,8 +229,6 @@ static struct drm_master *drm_lease_create(struct
> drm_master *lessor, struct idr
>
> lessee->lessor = drm_master_get(lessor);
>
> - /* Move the leases over */
> - lessee->leases = *leases;
> DRM_DEBUG_LEASE("new lessee %d %p, lessor %d %p\n", lessee->lessee_id,
> lessee, lessor->lessee_id, lessor);
>
> mutex_unlock(&dev->mode_config.idr_mutex);
> @@ -246,8 +237,6 @@ static struct drm_master *drm_lease_create(struct
> drm_master *lessor, struct idr
> out_lessee:
> mutex_unlock(&dev->mode_config.idr_mutex);
>
> - drm_master_put(&lessee);
> -
> return ERR_PTR(error);
> }
>
> @@ -292,8 +281,6 @@ void drm_lease_destroy(struct drm_master *master)
> */
> static void _drm_lease_revoke(struct drm_master *top)
> {
> - int object;
> - void *entry;
> struct drm_master *master = top;
>
> lockdep_assert_held(&top->dev->mode_config.idr_mutex);
> @@ -309,8 +296,7 @@ static void _drm_lease_revoke(struct drm_master *top)
> DRM_DEBUG_LEASE("revoke leases for %p %d\n", master,
> master->lessee_id);
>
> /* Evacuate the lease */
> - idr_for_each_entry(&master->leases, entry, object)
> - idr_remove(&master->leases, object);
> + xa_destroy(&master->leases);
>
> /* Depth-first tree walk */
> tmp = xa_find(&master->lessees, &index, ULONG_MAX, XA_PRESENT);
> @@ -378,11 +364,9 @@ static int validate_lease(struct drm_device *dev,
> return 0;
> }
>
> -static int fill_object_idr(struct drm_device *dev,
> - struct drm_file *lessor_priv,
> - struct idr *leases,
> - int object_count,
> - u32 *object_ids)
> +static int fill_object_array(struct drm_device *dev,
> + struct drm_file *lessor_priv, struct xarray *leases,
> + int object_count, u32 *object_ids)
> {
> struct drm_mode_object **objects;
> u32 o;
> @@ -431,14 +415,14 @@ static int fill_object_idr(struct drm_device *dev,
> DRM_DEBUG_LEASE("Adding object %d to lease\n", object_id);
>
> /*
> - * We're using an IDR to hold the set of leased
> + * We're using an array to hold the set of leased
> * objects, but we don't need to point at the object's
> - * data structure from the lease as the main crtc_idr
> + * data structure from the lease as the main object array
> * will be used to actually find that. Instead, all we
> * really want is a 'leased/not-leased' result, for
> * which any non-NULL pointer will work fine.
> */
> - ret = idr_alloc(leases, &drm_lease_idr_object , object_id,
> object_id + 1, GFP_KERNEL);
> + ret = xa_insert(leases, object_id, xa_mk_value(0), GFP_KERNEL);
> if (ret < 0) {
> DRM_DEBUG_LEASE("Object %d cannot be inserted into
> leases (%d)\n",
> object_id, ret);
> @@ -446,19 +430,21 @@ static int fill_object_idr(struct drm_device *dev,
> }
> if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) {
> struct drm_crtc *crtc = obj_to_crtc(obj);
> - ret = idr_alloc(leases, &drm_lease_idr_object,
> crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL);
> + ret = xa_insert(leases, crtc->primary->base.id,
> + xa_mk_value(0), GFP_KERNEL);
> if (ret < 0) {
> DRM_DEBUG_LEASE("Object primary plane %d cannot
> be inserted into leases (%d)\n",
> object_id, ret);
> goto out_free_objects;
> }
> - if (crtc->cursor) {
> - ret = idr_alloc(leases, &drm_lease_idr_object,
> crtc->cursor->base.id, crtc->cursor->base.id + 1, GFP_KERNEL);
> - if (ret < 0) {
> - DRM_DEBUG_LEASE("Object cursor plane %d
> cannot be inserted into leases (%d)\n",
> - object_id, ret);
> - goto out_free_objects;
> - }
> + if (!crtc->cursor)
> + continue;
> + ret = xa_insert(leases, crtc->cursor->base.id,
> + xa_mk_value(0), GFP_KERNEL);
> + if (ret < 0) {
> + DRM_DEBUG_LEASE("Object cursor plane %d cannot
> be inserted into leases (%d)\n",
> + object_id, ret);
> + goto out_free_objects;
> }
> }
> }
> @@ -490,9 +476,8 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
> struct drm_mode_create_lease *cl = data;
> size_t object_count;
> int ret = 0;
> - struct idr leases;
> struct drm_master *lessor = lessor_priv->master;
> - struct drm_master *lessee = NULL;
> + struct drm_master *lessee;
> struct file *lessee_file = NULL;
> struct file *lessor_file = lessor_priv->filp;
> struct drm_file *lessee_priv;
> @@ -520,37 +505,42 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
> return -EINVAL;
> }
>
> - object_count = cl->object_count;
> + lessee = drm_master_create(lessor->dev);
> + if (!lessee) {
> + DRM_DEBUG_LEASE("drm_master_create failed\n");
> + return -ENOMEM;
> + }
>
> - object_ids = memdup_user(u64_to_user_ptr(cl->object_ids), object_count
> * sizeof(__u32));
> - if (IS_ERR(object_ids))
> - return PTR_ERR(object_ids);
> + object_count = cl->object_count;
>
> - idr_init(&leases);
> + object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
> + array_size(object_count, sizeof(__u32)));
> + if (IS_ERR(object_ids)) {
> + ret = PTR_ERR(object_ids);
> + goto out_lessee;
> + }
>
> - /* fill and validate the object idr */
> - ret = fill_object_idr(dev, lessor_priv, &leases,
> + /* fill and validate the object array */
> + ret = fill_object_array(dev, lessor_priv, &lessee->leases,
> object_count, object_ids);
> kfree(object_ids);
> if (ret) {
> DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret);
> - idr_destroy(&leases);
> - return ret;
> + goto out_lessee;
> }
>
> /* Allocate a file descriptor for the lease */
> - fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
> - if (fd < 0) {
> - idr_destroy(&leases);
> - return fd;
> - }
> + ret = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
> + if (ret < 0)
> + goto out_lessee;
> + fd = ret;
>
> DRM_DEBUG_LEASE("Creating lease\n");
> - lessee = drm_lease_create(lessor, &leases);
> + lessee = drm_lease_create(lessor, lessee);
>
> if (IS_ERR(lessee)) {
> ret = PTR_ERR(lessee);
> - goto out_leases;
> + goto out_fd;
> }
>
> /* Clone the lessor file to create a new file for us */
> @@ -558,7 +548,7 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
> lessee_file = file_clone_open(lessor_file);
> if (IS_ERR(lessee_file)) {
> ret = PTR_ERR(lessee_file);
> - goto out_lessee;
> + goto out_fd;
> }
>
> lessee_priv = lessee_file->private_data;
> @@ -579,13 +569,11 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev,
> DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
> return 0;
>
> +out_fd:
> + put_unused_fd(fd);
> out_lessee:
> drm_master_put(&lessee);
>
> -out_leases:
> - put_unused_fd(fd);
> - idr_destroy(&leases);
> -
> DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
> return ret;
> }
> @@ -627,7 +615,7 @@ int drm_mode_list_lessees_ioctl(struct drm_device *dev,
> count = 0;
> xa_for_each(&lessor->lessees, index, lessee) {
> /* Only list un-revoked leases */
> - if (!idr_is_empty(&lessee->leases)) {
> + if (!xa_empty(&lessee->leases)) {
> if (count_lessees > count) {
> DRM_DEBUG_LEASE("Add lessee %d\n",
> lessee->lessee_id);
> ret = put_user(lessee->lessee_id, lessee_ids +
> count);
> @@ -663,10 +651,10 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev,
> __u32 __user *object_ids = (__u32 __user *) (uintptr_t)
> (arg->objects_ptr);
> __u32 count_objects = arg->count_objects;
> struct drm_master *lessee = lessee_priv->master;
> - struct idr *object_idr;
> + struct xarray *objects;
> int count;
> void *entry;
> - int object;
> + unsigned long index;
> int ret = 0;
>
> if (arg->pad)
> @@ -682,16 +670,16 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev,
>
> if (lessee->lessor == NULL)
> /* owner can use all objects */
> - object_idr = &lessee->dev->mode_config.crtc_idr;
> + objects = &lessee->dev->mode_config.objects;
> else
> - /* lessee can only use allowed object */
> - object_idr = &lessee->leases;
> + /* lessee can only use allowed objects */
> + objects = &lessee->leases;
>
> count = 0;
> - idr_for_each_entry(object_idr, entry, object) {
> + xa_for_each(objects, index, entry) {
> if (count_objects > count) {
> - DRM_DEBUG_LEASE("adding object %d\n", object);
> - ret = put_user(object, object_ids + count);
> + DRM_DEBUG_LEASE("adding object %d\n", (u32)index);
> + ret = put_user((u32)index, object_ids + count);
> if (ret)
> break;
> }
> diff --git a/drivers/gpu/drm/drm_mode_config.c
> b/drivers/gpu/drm/drm_mode_config.c
> index 609b30d7dcb1..10c616e0f591 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -393,7 +393,7 @@ void drm_mode_config_init(struct drm_device *dev)
> INIT_LIST_HEAD(&dev->mode_config.property_list);
> INIT_LIST_HEAD(&dev->mode_config.property_blob_list);
> INIT_LIST_HEAD(&dev->mode_config.plane_list);
> - idr_init(&dev->mode_config.crtc_idr);
> + xa_init_flags(&dev->mode_config.objects, XA_FLAGS_ALLOC1);
> xa_init_flags(&dev->mode_config.tiles, XA_FLAGS_ALLOC1);
> ida_init(&dev->mode_config.connector_ida);
> spin_lock_init(&dev->mode_config.connector_list_lock);
> @@ -495,7 +495,6 @@ void drm_mode_config_cleanup(struct drm_device *dev)
> }
>
> ida_destroy(&dev->mode_config.connector_ida);
> - idr_destroy(&dev->mode_config.crtc_idr);
> drm_modeset_lock_fini(&dev->mode_config.connection_mutex);
> }
> EXPORT_SYMBOL(drm_mode_config_cleanup);
> diff --git a/drivers/gpu/drm/drm_mode_object.c
> b/drivers/gpu/drm/drm_mode_object.c
> index 004191d01772..686fba472abf 100644
> --- a/drivers/gpu/drm/drm_mode_object.c
> +++ b/drivers/gpu/drm/drm_mode_object.c
> @@ -37,24 +37,23 @@ int __drm_mode_object_add(struct drm_device *dev, struct
> drm_mode_object *obj,
> {
> int ret;
>
> - mutex_lock(&dev->mode_config.idr_mutex);
> - ret = idr_alloc(&dev->mode_config.crtc_idr, register_obj ? obj : NULL,
> - 1, 0, GFP_KERNEL);
> - if (ret >= 0) {
> - /*
> - * Set up the object linking under the protection of the idr
> - * lock so that other users can't see inconsistent state.
> - */
> - obj->id = ret;
> - obj->type = obj_type;
> - if (obj_free_cb) {
> - obj->free_cb = obj_free_cb;
> - kref_init(&obj->refcount);
> - }
> + /*
> + * Initialise the object before putting the object in the array
> + * so that other users can't see inconsistent state. The ID is
> + * initialised before the object is inserted into the array with
> + * a write barrier so even RCU-protected walkers can't see an
> + * uninitialised ID.
> + */
> + obj->type = obj_type;
> + if (obj_free_cb) {
> + obj->free_cb = obj_free_cb;
> + kref_init(&obj->refcount);
> }
> - mutex_unlock(&dev->mode_config.idr_mutex);
>
> - return ret < 0 ? ret : 0;
> + ret = xa_alloc(&dev->mode_config.objects, &obj->id,
> + register_obj ? obj : NULL, xa_limit_31b, GFP_KERNEL);
> +
> + return ret;
> }
>
> /**
> @@ -78,9 +77,7 @@ int drm_mode_object_add(struct drm_device *dev,
> void drm_mode_object_register(struct drm_device *dev,
> struct drm_mode_object *obj)
> {
> - mutex_lock(&dev->mode_config.idr_mutex);
> - idr_replace(&dev->mode_config.crtc_idr, obj, obj->id);
> - mutex_unlock(&dev->mode_config.idr_mutex);
> + xa_store(&dev->mode_config.objects, obj->id, obj, 0);
> }
>
> /**
> @@ -97,12 +94,10 @@ void drm_mode_object_register(struct drm_device *dev,
> void drm_mode_object_unregister(struct drm_device *dev,
> struct drm_mode_object *object)
> {
> - mutex_lock(&dev->mode_config.idr_mutex);
> if (object->id) {
> - idr_remove(&dev->mode_config.crtc_idr, object->id);
> + xa_erase(&dev->mode_config.objects, object->id);
> object->id = 0;
> }
> - mutex_unlock(&dev->mode_config.idr_mutex);
> }
>
> /**
> @@ -128,10 +123,10 @@ struct drm_mode_object *__drm_mode_object_find(struct
> drm_device *dev,
> struct drm_file *file_priv,
> uint32_t id, uint32_t type)
> {
> - struct drm_mode_object *obj = NULL;
> + struct drm_mode_object *obj;
>
> - mutex_lock(&dev->mode_config.idr_mutex);
> - obj = idr_find(&dev->mode_config.crtc_idr, id);
> + xa_lock(&dev->mode_config.objects);
> + obj = xa_load(&dev->mode_config.objects, id);
> if (obj && type != DRM_MODE_OBJECT_ANY && obj->type != type)
> obj = NULL;
> if (obj && obj->id != id)
> @@ -145,7 +140,7 @@ struct drm_mode_object *__drm_mode_object_find(struct
> drm_device *dev,
> if (!kref_get_unless_zero(&obj->refcount))
> obj = NULL;
> }
> - mutex_unlock(&dev->mode_config.idr_mutex);
> + xa_unlock(&dev->mode_config.objects);
>
> return obj;
> }
> diff --git a/include/drm/drm_auth.h b/include/drm/drm_auth.h
> index fbb58264538b..88c8bbf14916 100644
> --- a/include/drm/drm_auth.h
> +++ b/include/drm/drm_auth.h
> @@ -90,7 +90,7 @@ struct drm_master {
>
> struct drm_master *lessor;
> int lessee_id;
> - struct idr leases;
> + struct xarray leases;
> struct xarray lessees;
> };
>
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index fea334d99201..64bdf66d878c 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -397,12 +397,12 @@ struct drm_mode_config {
> struct mutex idr_mutex;
>
> /**
> - * @crtc_idr:
> + * @objects:
> *
> - * Main KMS ID tracking object. Use this idr for all IDs, fb, crtc,
> + * Main KMS ID tracking object. Use this array for all IDs, fb, crtc,
> * connector, modes - just makes life easier to have only one.
> */
> - struct idr crtc_idr;
> + struct xarray objects;
>
> /**
> * @tiles:
> --
> 2.20.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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