diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/Makefile | 2 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_auth.c | 30 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_lease.c | 355 |
3 files changed, 385 insertions, 2 deletions
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index a3fdc5a68dff..81ff79336623 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -17,7 +17,7 @@ drm-y := drm_auth.o drm_bufs.o drm_cache.o \ drm_encoder.o drm_mode_object.o drm_property.o \ drm_plane.o drm_color_mgmt.o drm_print.o \ drm_dumb_buffers.o drm_mode_config.o drm_vblank.o \ - drm_syncobj.o + drm_syncobj.o drm_lease.o drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o drm-$(CONFIG_DRM_VM) += drm_vm.o diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index 7ff697389d74..4f0e274f4111 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -31,6 +31,7 @@ #include <drm/drmP.h> #include "drm_internal.h" #include "drm_legacy.h" +#include <drm/drm_lease.h> /** * DOC: master and authentication @@ -93,7 +94,7 @@ int drm_authmagic(struct drm_device *dev, void *data, return file ? 0 : -EINVAL; } -static struct drm_master *drm_master_create(struct drm_device *dev) +struct drm_master *drm_master_create(struct drm_device *dev) { struct drm_master *master; @@ -107,6 +108,14 @@ static struct drm_master *drm_master_create(struct drm_device *dev) idr_init(&master->magic_map); master->dev = dev; + /* initialize the tree of output resource lessees */ + master->lessor = NULL; + master->lessee_id = 0; + INIT_LIST_HEAD(&master->lessees); + INIT_LIST_HEAD(&master->lessee_list); + idr_init(&master->leases); + idr_init(&master->lessee_idr); + return master; } @@ -189,6 +198,12 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data, goto out_unlock; } + if (file_priv->master->lessor != NULL) { + DRM_DEBUG_LEASE("Attempt to set lessee %d as master\n", file_priv->master->lessee_id); + ret = -EINVAL; + goto out_unlock; + } + ret = drm_set_master(dev, file_priv, false); out_unlock: mutex_unlock(&dev->master_mutex); @@ -270,6 +285,13 @@ void drm_master_release(struct drm_file *file_priv) if (dev->master == file_priv->master) drm_drop_master(dev, file_priv); out: + if (drm_core_check_feature(dev, DRIVER_MODESET) && file_priv->is_master) { + /* Revoke any leases held by this or lessees, but only if + * this is the "real" master + */ + drm_lease_revoke(master); + } + /* drop the master reference held by the file priv */ if (file_priv->master) drm_master_put(&file_priv->master); @@ -310,12 +332,18 @@ static void drm_master_destroy(struct kref *kref) struct drm_master *master = container_of(kref, struct drm_master, refcount); struct drm_device *dev = master->dev; + if (drm_core_check_feature(dev, DRIVER_MODESET)) + drm_lease_destroy(master); + if (dev->driver->master_destroy) dev->driver->master_destroy(dev, master); drm_legacy_master_rmmaps(dev, master); idr_destroy(&master->magic_map); + idr_destroy(&master->leases); + idr_destroy(&master->lessee_idr); + kfree(master->unique); kfree(master); } diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c new file mode 100644 index 000000000000..030db1170570 --- /dev/null +++ b/drivers/gpu/drm/drm_lease.c @@ -0,0 +1,355 @@ +/* + * Copyright © 2017 Keith Packard <keithp@keithp.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include <drm/drmP.h> +#include "drm_internal.h" +#include "drm_legacy.h" +#include "drm_crtc_internal.h" +#include <drm/drm_lease.h> +#include <drm/drm_auth.h> +#include <drm/drm_crtc_helper.h> + +#define drm_for_each_lessee(lessee, lessor) \ + list_for_each_entry((lessee), &(lessor)->lessees, lessee_list) + +/** + * drm_lease_owner - return ancestor owner drm_master + * @master: drm_master somewhere within tree of lessees and lessors + * + * RETURN: + * + * drm_master at the top of the tree (i.e, with lessor NULL + */ +struct drm_master *drm_lease_owner(struct drm_master *master) +{ + while (master->lessor != NULL) + master = master->lessor; + return master; +} +EXPORT_SYMBOL(drm_lease_owner); + +/** + * _drm_find_lessee - find lessee by id (idr_mutex held) + * @master: drm_master of lessor + * @id: lessee_id + * + * RETURN: + * + * drm_master of the lessee if valid, NULL otherwise + */ + +static struct drm_master* +_drm_find_lessee(struct drm_master *master, int lessee_id) +{ + lockdep_assert_held(&master->dev->mode_config.idr_mutex); + return idr_find(&drm_lease_owner(master)->lessee_idr, lessee_id); +} + +/** + * _drm_lease_held_master - check to see if an object is leased (or owned) by master (idr_mutex held) + * @master: the master to check the lease status of + * @id: the id to check + * + * Checks if the specified master holds a lease on the object. Return + * value: + * + * true 'master' holds a lease on (or owns) the object + * false 'master' does not hold a lease. + */ +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 true; +} + +/** + * _drm_has_leased - check to see if an object has been leased (idr_mutex held) + * @master: the master to check the lease status of + * @id: the id to check + * + * Checks if any lessee of 'master' holds a lease on 'id'. Return + * value: + * + * true Some lessee holds a lease on the object. + * false No lessee has a lease on the object. + */ +static bool _drm_has_leased(struct drm_master *master, int id) +{ + struct drm_master *lessee; + + lockdep_assert_held(&master->dev->mode_config.idr_mutex); + drm_for_each_lessee(lessee, master) + if (_drm_lease_held_master(lessee, id)) + return true; + return false; +} + +/** + * _drm_lease_held - check drm_mode_object lease status (idr_mutex held) + * @master: the drm_master + * @id: the object id + * + * Checks if the specified master holds a lease on the object. Return + * value: + * + * true 'master' holds a lease on (or owns) the object + * false 'master' does not hold a lease. + */ +bool _drm_lease_held(struct drm_file *file_priv, int id) +{ + if (file_priv == NULL || file_priv->master == NULL) + return true; + + return _drm_lease_held_master(file_priv->master, id); +} +EXPORT_SYMBOL(_drm_lease_held); + +/** + * drm_lease_held - check drm_mode_object lease status (idr_mutex not held) + * @master: the drm_master + * @id: the object id + * + * Checks if the specified master holds a lease on the object. Return + * value: + * + * true 'master' holds a lease on (or owns) the object + * false 'master' does not hold a lease. + */ +bool drm_lease_held(struct drm_file *file_priv, int id) +{ + struct drm_master *master; + bool ret; + + if (file_priv == NULL || file_priv->master == NULL) + return true; + + master = file_priv->master; + mutex_lock(&master->dev->mode_config.idr_mutex); + ret = _drm_lease_held_master(master, id); + mutex_unlock(&master->dev->mode_config.idr_mutex); + return ret; +} +EXPORT_SYMBOL(drm_lease_held); + +/** + * drm_lease_filter_crtcs - restricted crtc set to leased values (idr_mutex not held) + * @file_priv: requestor file + * @crtcs: bitmask of crtcs to check + * + * Reconstructs a crtc mask based on the crtcs which are visible + * through the specified file. + */ +uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in) +{ + struct drm_master *master; + struct drm_device *dev; + struct drm_crtc *crtc; + int count_in, count_out; + uint32_t crtcs_out = 0; + + if (file_priv == NULL || file_priv->master == NULL) + return crtcs_in; + + master = file_priv->master; + dev = master->dev; + + count_in = count_out = 0; + mutex_lock(&master->dev->mode_config.idr_mutex); + list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) { + if (_drm_lease_held_master(master, crtc->base.id)) { + uint32_t mask_in = 1ul << count_in; + if ((crtcs_in & mask_in) != 0) { + uint32_t mask_out = 1ul << count_out; + crtcs_out |= mask_out; + } + count_out++; + } + count_in++; + } + mutex_unlock(&master->dev->mode_config.idr_mutex); + return crtcs_out; +} +EXPORT_SYMBOL(drm_lease_filter_crtcs); + +/* + * 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 + * + * Uses drm_master_create to allocate a new drm_master, then checks to + * make sure all of the desired objects can be leased, atomically + * leasing them to the new drmmaster. + * + * ERR_PTR(-EACCESS) some other master holds the title to any object + * ERR_PTR(-ENOENT) some object is not a valid DRM object for this device + * ERR_PTR(-EBUSY) some other lessee holds title to this object + * 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) +{ + struct drm_device *dev = lessor->dev; + int error; + struct drm_master *lessee; + int object; + int id; + void *entry; + + 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); + + /* Insert the new lessee into the tree */ + id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL); + if (id < 0) { + error = id; + goto out_lessee; + } + + lessee->lessee_id = id; + lessee->lessor = drm_master_get(lessor); + list_add_tail(&lessee->lessee_list, &lessor->lessees); + + idr_for_each_entry(leases, entry, object) { + error = 0; + if (!idr_find(&dev->mode_config.crtc_idr, object)) + error = -ENOENT; + else if (!_drm_lease_held_master(lessor, object)) + error = -EACCES; + else if (_drm_has_leased(lessor, object)) + error = -EBUSY; + + if (error != 0) { + DRM_DEBUG_LEASE("object %d failed %d\n", object, error); + goto out_lessee; + } + } + + /* 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); + return lessee; + +out_lessee: + drm_master_put(&lessee); + + mutex_unlock(&dev->mode_config.idr_mutex); + + return ERR_PTR(error); +} + +/** + * drm_lease_destroy - a master is going away (idr_mutex not held) + * @master: the drm_master being destroyed + * + * All lessees will have been destroyed as they + * hold a reference on their lessor. Notify any + * lessor for this master so that it can check + * the list of lessees. + */ +void drm_lease_destroy(struct drm_master *master) +{ + struct drm_device *dev = master->dev; + + mutex_lock(&dev->mode_config.idr_mutex); + + DRM_DEBUG_LEASE("drm_lease_destroy %d\n", master->lessee_id); + + /* This master is referenced by all lessees, hence it cannot be destroyed + * until all of them have been + */ + WARN_ON(!list_empty(&master->lessees)); + + /* Remove this master from the lessee idr in the owner */ + if (master->lessee_id != 0) { + DRM_DEBUG_LEASE("remove master %d from device list of lessees\n", master->lessee_id); + idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id); + } + + /* Remove this master from any lessee list it may be on */ + list_del(&master->lessee_list); + + mutex_unlock(&dev->mode_config.idr_mutex); + + if (master->lessor) { + /* Tell the master to check the lessee list */ + drm_sysfs_hotplug_event(dev); + drm_master_put(&master->lessor); + } + + DRM_DEBUG_LEASE("drm_lease_destroy done %d\n", master->lessee_id); +} + +/** + * _drm_lease_revoke - revoke access to all leased objects (idr_mutex held) + * @master: the master losing its lease + */ +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); + + /* + * Walk the tree starting at 'top' emptying all leases. Because + * the tree is fully connected, we can do this without recursing + */ + for (;;) { + 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); + + /* Depth-first list walk */ + + /* Down */ + if (!list_empty(&master->lessees)) { + master = list_first_entry(&master->lessees, struct drm_master, lessee_list); + } else { + /* Up */ + while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list)) + master = master->lessor; + + if (master == top) + break; + + /* Over */ + master = list_entry(master->lessee_list.next, struct drm_master, lessee_list); + } + } +} + +/** + * drm_lease_revoke - revoke access to all leased objects (idr_mutex not held) + * @top: the master losing its lease + */ +void drm_lease_revoke(struct drm_master *top) +{ + mutex_lock(&top->dev->mode_config.idr_mutex); + _drm_lease_revoke(top); + mutex_unlock(&top->dev->mode_config.idr_mutex); +} |