include/drm/drm_drv.h

/*
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * Copyright (c) 2009-2010, Code Aurora Forum.
 * Copyright 2016 Intel Corp.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef _DRM_DRV_H_
#define _DRM_DRV_H_

#include <linux/list.h>
#include <linux/irqreturn.h>
#include <linux/uuid.h>

#include <drm/drm_device.h>

struct drm_file;
struct drm_gem_object;
struct drm_master;
struct drm_minor;
struct dma_buf_attachment;
struct drm_display_mode;
struct drm_mode_create_dumb;
struct drm_printer;

/**
 * enum drm_driver_feature - feature flags
 *
 * See &drm_driver.driver_features, drm_device.driver_features and
 * drm_core_check_feature().
 */
enum drm_driver_feature {
    /**
     * @DRIVER_GEM:
     *
     * Driver use the GEM memory manager. This should be set for all modern
     * drivers.
     */
    DRIVER_GEM = BIT(0),
    /**
     * @DRIVER_MODESET:
     *
     * Driver supports mode setting interfaces (KMS).
     */
    DRIVER_MODESET = BIT(1),
    /**
     * @DRIVER_RENDER:
     *
     * Driver supports dedicated render nodes. See also the :ref:`section on
     * render nodes <drm_render_node>` for details.
     */
    DRIVER_RENDER = BIT(3),
    /**
     * @DRIVER_ATOMIC:
     *
     * Driver supports the full atomic modesetting userspace API. Drivers
     * which only use atomic internally, but do not the support the full
     * userspace API (e.g. not all properties converted to atomic, or
     * multi-plane updates are not guaranteed to be tear-free) should not
     * set this flag.
     */
    DRIVER_ATOMIC = BIT(4),
    /**
     * @DRIVER_SYNCOBJ:
     *
     * Driver supports &drm_syncobj for explicit synchronization of command
     * submission.
     */
    DRIVER_SYNCOBJ = BIT(5),
    /**
     * @DRIVER_SYNCOBJ_TIMELINE:
     *
     * Driver supports the timeline flavor of &drm_syncobj for explicit
     * synchronization of command submission.
     */
    DRIVER_SYNCOBJ_TIMELINE = BIT(6),

    /* IMPORTANT: Below are all the legacy flags, add new ones above. */

    /**
     * @DRIVER_USE_AGP:
     *
     * Set up DRM AGP support, see drm_agp_init(), the DRM core will manage
     * AGP resources. New drivers don't need this.
     */
    DRIVER_USE_AGP = BIT(25),
    /**
     * @DRIVER_LEGACY:
     *
     * Denote a legacy driver using shadow attach. Do not use.
     */
    DRIVER_LEGACY = BIT(26),
    /**
     * @DRIVER_PCI_DMA:
     *
     * Driver is capable of PCI DMA, mapping of PCI DMA buffers to userspace
     * will be enabled. Only for legacy drivers. Do not use.
     */
    DRIVER_PCI_DMA = BIT(27),
    /**
     * @DRIVER_SG:
     *
     * Driver can perform scatter/gather DMA, allocation and mapping of
     * scatter/gather buffers will be enabled. Only for legacy drivers. Do
     * not use.
     */
    DRIVER_SG = BIT(28),

    /**
     * @DRIVER_HAVE_DMA:
     *
     * Driver supports DMA, the userspace DMA API will be supported. Only
     * for legacy drivers. Do not use.
     */
    DRIVER_HAVE_DMA = BIT(29),
    /**
     * @DRIVER_HAVE_IRQ:
     *
     * Legacy irq support. Only for legacy drivers. Do not use.
     *
     * New drivers can either use the drm_irq_install() and
     * drm_irq_uninstall() helper functions, or roll their own irq support
     * code by calling request_irq() directly.
     */
    DRIVER_HAVE_IRQ = BIT(30),
    /**
     * @DRIVER_KMS_LEGACY_CONTEXT:
     *
     * Used only by nouveau for backwards compatibility with existing
     * userspace.  Do not use.
     */
    DRIVER_KMS_LEGACY_CONTEXT = BIT(31),
};

/**
 * struct drm_driver - DRM driver structure
 *
 * This structure represent the common code for a family of cards. There will be
 * one &struct drm_device for each card present in this family. It contains lots
 * of vfunc entries, and a pile of those probably should be moved to more
 * appropriate places like &drm_mode_config_funcs or into a new operations
 * structure for GEM drivers.
 */
struct drm_driver {
    /**
     * @load
     *
     * Backward-compatible driver callback to complete initialization steps
     * after the driver is registered.  For this reason, may suffer from
     * race conditions and its use is deprecated for new drivers.  It is
     * therefore only supported for existing drivers not yet converted to
     * the new scheme.  See devm_drm_dev_alloc() and drm_dev_register() for
     * proper and race-free way to set up a &struct drm_device.
     *
     * This is deprecated, do not use!
     *
     * Returns
     *
     * Zero on success, non-zero value on failure.
     */
    int (*load)(struct drm_device *, unsigned long flags);

    /**
     * @open
     *
     * Driver callback when a new &struct drm_file is opened. Useful for
     * setting up driver-private data structures like buffer allocators,
     * execution contexts or similar things. Such driver-private resources
     * must be released again in @postclose.
     *
     * Since the display/modeset side of DRM can only be owned by exactly
     * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
     * there should never be a need to set up any modeset related resources
     * in this callback. Doing so would be a driver design bug.
     *
     * Returns
     *
     * 0 on success, a negative error code on failure, which will be
     * promoted to userspace as the result of the open() system call.
     */
    int (*open)(struct drm_device *, struct drm_file *);

    /**
     * @postclose
     *
     * One of the driver callbacks when a new &struct drm_file is closed.
     * Useful for tearing down driver-private data structures allocated in
     * @open like buffer allocators, execution contexts or similar things.
     *
     * Since the display/modeset side of DRM can only be owned by exactly
     * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
     * there should never be a need to tear down any modeset related
     * resources in this callback. Doing so would be a driver design bug.
     */
    void (*postclose)(struct drm_device *, struct drm_file *);

    /**
     * @lastclose
     *
     * Called when the last &struct drm_file has been closed and there's
     * currently no userspace client for the &struct drm_device.
     *
     * Modern drivers should only use this to force-restore the fbdev
     * framebuffer using drm_fb_helper_restore_fbdev_mode_unlocked().
     * Anything else would indicate there's something seriously wrong.
     * Modern drivers can also use this to execute delayed power switching
     * state changes, e.g. in conjunction with the :ref:`vga_switcheroo`
     * infrastructure.
     *
     * This is called after @postclose hook has been called.
     *
     * NOTE
     *
     * All legacy drivers use this callback to de-initialize the hardware.
     * This is purely because of the shadow-attach model, where the DRM
     * kernel driver does not really own the hardware. Instead ownershipe is
     * handled with the help of userspace through an inheritedly racy dance
     * to set/unset the VT into raw mode.
     *
     * Legacy drivers initialize the hardware in the @firstopen callback,
     * which isn't even called for modern drivers.
     */
    void (*lastclose)(struct drm_device *);

    /**
     * @unload
     *
     * Reverse the effects of the driver load callback.  Ideally,
     * the clean up performed by the driver should happen in the
     * reverse order of the initialization.  Similarly to the load
     * hook, this handler is deprecated and its usage should be
     * dropped in favor of an open-coded teardown function at the
     * driver layer.  See drm_dev_unregister() and drm_dev_put()
     * for the proper way to remove a &struct drm_device.
     *
     * The unload() hook is called right after unregistering
     * the device.
     *
     */
    void (*unload)(struct drm_device *);

    /**
     * @release
     *
     * Optional callback for destroying device data after the final
     * reference is released, i.e. the device is being destroyed.
     *
     * This is deprecated, clean up all memory allocations associated with a
     * &drm_device using drmm_add_action(), drmm_kmalloc() and related
     * managed resources functions.
     */
    void (*release)(struct drm_device *);

    /**
     * @irq_handler
     *
     * Interrupt handler called when using drm_irq_install(). Not used by
     * drivers which implement their own interrupt handling.
     */
    irqreturn_t (*irq_handler)(int irq, void *arg);

    /**
     * @irq_preinstall
     *
     * Optional callback used by drm_irq_install() which is called before
     * the interrupt handler is registered. This should be used to clear out
     * any pending interrupts (from e.g. firmware based drives) and reset
     * the interrupt handling registers.
     */
    void (*irq_preinstall)(struct drm_device *dev);

    /**
     * @irq_postinstall
     *
     * Optional callback used by drm_irq_install() which is called after
     * the interrupt handler is registered. This should be used to enable
     * interrupt generation in the hardware.
     */
    int (*irq_postinstall)(struct drm_device *dev);

    /**
     * @irq_uninstall
     *
     * Optional callback used by drm_irq_uninstall() which is called before
     * the interrupt handler is unregistered. This should be used to disable
     * interrupt generation in the hardware.
     */
    void (*irq_uninstall)(struct drm_device *dev);

    /**
     * @master_set
     *
     * Called whenever the minor master is set. Only used by vmwgfx.
     */
    void (*master_set)(struct drm_device *dev, struct drm_file *file_priv, bool from_open);
    /**
     * @master_drop
     *
     * Called whenever the minor master is dropped. Only used by vmwgfx.
     */
    void (*master_drop)(struct drm_device *dev, struct drm_file *file_priv);

    /**
     * @debugfs_init
     *
     * Allows drivers to create driver-specific debugfs files.
     */
    void (*debugfs_init)(struct drm_minor *minor);

    /**
     * @gem_free_object_unlocked: deconstructor for drm_gem_objects
     *
     * This is deprecated and should not be used by new drivers. Use
     * &drm_gem_object_funcs.free instead.
     */
    void (*gem_free_object_unlocked)(struct drm_gem_object *obj);

    /**
     * @gem_open_object
     *
     * This callback is deprecated in favour of &drm_gem_object_funcs.open.
     *
     * Driver hook called upon gem handle creation
     */
    int (*gem_open_object)(struct drm_gem_object *, struct drm_file *);

    /**
     * @gem_close_object
     *
     * This callback is deprecated in favour of &drm_gem_object_funcs.close.
     *
     * Driver hook called upon gem handle release
     */
    void (*gem_close_object)(struct drm_gem_object *, struct drm_file *);

    /**
     * @gem_create_object: constructor for gem objects
     *
     * Hook for allocating the GEM object struct, for use by the CMA and
     * SHMEM GEM helpers.
     */
    struct drm_gem_object *(*gem_create_object)(struct drm_device *dev, size_t size);
    /**
     * @prime_handle_to_fd
     *
     * Main PRIME export function. Should be implemented with
     * drm_gem_prime_handle_to_fd() for GEM based drivers.
     *
     * For an in-depth discussion see :ref:`PRIME buffer sharing
     * documentation <prime_buffer_sharing>`.
     */
    int (*prime_handle_to_fd)(struct drm_device *dev, struct drm_file *file_priv, uint32_t handle, uint32_t flags,
                              int *prime_fd);
    /**
     * @prime_fd_to_handle
     *
     * Main PRIME import function. Should be implemented with
     * drm_gem_prime_fd_to_handle() for GEM based drivers.
     *
     * For an in-depth discussion see :ref:`PRIME buffer sharing
     * documentation <prime_buffer_sharing>`.
     */
    int (*prime_fd_to_handle)(struct drm_device *dev, struct drm_file *file_priv, int prime_fd, uint32_t *handle);
    /**
     * @gem_prime_export
     *
     * Export hook for GEM drivers. Deprecated in favour of
     * &drm_gem_object_funcs.export.
     */
    struct dma_buf *(*gem_prime_export)(struct drm_gem_object *obj, int flags);
    /**
     * @gem_prime_import
     *
     * Import hook for GEM drivers.
     *
     * This defaults to drm_gem_prime_import() if not set.
     */
    struct drm_gem_object *(*gem_prime_import)(struct drm_device *dev, struct dma_buf *dma_buf);

    /**
     * @gem_prime_pin
     *
     * Deprecated hook in favour of &drm_gem_object_funcs.pin.
     */
    int (*gem_prime_pin)(struct drm_gem_object *obj);

    /**
     * @gem_prime_unpin
     *
     * Deprecated hook in favour of &drm_gem_object_funcs.unpin.
     */
    void (*gem_prime_unpin)(struct drm_gem_object *obj);

    /**
     * @gem_prime_get_sg_table
     *
     * Deprecated hook in favour of &drm_gem_object_funcs.get_sg_table.
     */
    struct sg_table *(*gem_prime_get_sg_table)(struct drm_gem_object *obj);

    /**
     * @gem_prime_import_sg_table
     *
     * Optional hook used by the PRIME helper functions
     * drm_gem_prime_import() respectively drm_gem_prime_import_dev().
     */
    struct drm_gem_object *(*gem_prime_import_sg_table)(struct drm_device *dev, struct dma_buf_attachment *attach,
                                                        struct sg_table *sgt);
    /**
     * @gem_prime_vmap
     *
     * Deprecated vmap hook for GEM drivers. Please use
     * &drm_gem_object_funcs.vmap instead.
     */
    void *(*gem_prime_vmap)(struct drm_gem_object *obj);

    /**
     * @gem_prime_vunmap
     *
     * Deprecated vunmap hook for GEM drivers. Please use
     * &drm_gem_object_funcs.vunmap instead.
     */
    void (*gem_prime_vunmap)(struct drm_gem_object *obj, void *vaddr);

    /**
     * @gem_prime_mmap
     *
     * mmap hook for GEM drivers, used to implement dma-buf mmap in the
     * PRIME helpers.
     *
     * There's way too much duplication going on here, and also moved
     * to &drm_gem_object_funcs.
     */
    int (*gem_prime_mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma);

    /**
     * @gem_prime_get_uuid
     *
     * get_uuid hook for GEM drivers. Retrieves the virtio uuid of the
     * given GEM buffer.
     */
    int (*gem_prime_get_uuid)(struct drm_gem_object *obj, uuid_t *uuid);

    /**
     * @dumb_create
     *
     * This creates a new dumb buffer in the driver's backing storage manager (GEM,
     * TTM or something else entirely) and returns the resulting buffer handle. This
     * handle can then be wrapped up into a framebuffer modeset object.
     *
     * Note that userspace is not allowed to use such objects for render
     * acceleration - drivers must create their own private ioctls for such a use
     * case.
     *
     * Width, height and depth are specified in the &drm_mode_create_dumb
     * argument. The callback needs to fill the handle, pitch and size for
     * the created buffer.
     *
     * Called by the user via ioctl.
     *
     * Returns
     *
     * Zero on success, negative errno on failure.
     */
    int (*dumb_create)(struct drm_file *file_priv, struct drm_device *dev, struct drm_mode_create_dumb *args);
    /**
     * @dumb_map_offset
     *
     * Allocate an offset in the drm device node's address space to be able to
     * memory map a dumb buffer.
     *
     * The default implementation is drm_gem_create_mmap_offset(). GEM based
     * drivers must not overwrite this.
     *
     * Called by the user via ioctl.
     *
     * Returns
     *
     * Zero on success, negative errno on failure.
     */
    int (*dumb_map_offset)(struct drm_file *file_priv, struct drm_device *dev, uint32_t handle, uint64_t *offset);
    /**
     * @dumb_destroy
     *
     * This destroys the userspace handle for the given dumb backing storage buffer.
     * Since buffer objects must be reference counted in the kernel a buffer object
     * won't be immediately freed if a framebuffer modeset object still uses it.
     *
     * Called by the user via ioctl.
     *
     * The default implementation is drm_gem_dumb_destroy(). GEM based drivers
     * must not overwrite this.
     *
     * Returns
     *
     * Zero on success, negative errno on failure.
     */
    int (*dumb_destroy)(struct drm_file *file_priv, struct drm_device *dev, uint32_t handle);

    /**
     * @gem_vm_ops: Driver private ops for this object
     *
     * For GEM drivers this is deprecated in favour of
     * &drm_gem_object_funcs.vm_ops.
     */
    const struct vm_operations_struct *gem_vm_ops;

    /** @major: driver major number */
    int major;
    /** @minor: driver minor number */
    int minor;
    /** @patchlevel: driver patch level */
    int patchlevel;
    /** @name: driver name */
    char *name;
    /** @desc: driver description */
    char *desc;
    /** @date: driver date */
    char *date;

    /**
     * @driver_features:
     * Driver features, see &enum drm_driver_feature. Drivers can disable
     * some features on a per-instance basis using
     * &drm_device.driver_features.
     */
    u32 driver_features;

    /**
     * @ioctls:
     *
     * Array of driver-private IOCTL description entries. See the chapter on
     * :ref:`IOCTL support in the userland interfaces
     * chapter<drm_driver_ioctl>` for the full details.
     */

    const struct drm_ioctl_desc *ioctls;
    /** @num_ioctls: Number of entries in @ioctls. */
    int num_ioctls;

    /**
     * @fops:
     *
     * File operations for the DRM device node. See the discussion in
     * :ref:`file operations<drm_driver_fops>` for in-depth coverage and
     * some examples.
     */
    const struct file_operations *fops;

    /* Everything below here is for legacy driver, never use! */
    /* private: */

    /* List of devices hanging off this driver with stealth attach. */
    struct list_head legacy_dev_list;
    int (*firstopen)(struct drm_device *);
    void (*preclose)(struct drm_device *, struct drm_file *file_priv);
    int (*dma_ioctl)(struct drm_device *dev, void *data, struct drm_file *file_priv);
    int (*dma_quiescent)(struct drm_device *);
    int (*context_dtor)(struct drm_device *dev, int context);
    u32 (*get_vblank_counter)(struct drm_device *dev, unsigned int pipe);
    int (*enable_vblank)(struct drm_device *dev, unsigned int pipe);
    void (*disable_vblank)(struct drm_device *dev, unsigned int pipe);
    int dev_priv_size;
};

void *_devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver, size_t size, size_t offset);

/**
 * devm_drm_dev_alloc - Resource managed allocation of a &drm_device instance
 * @parent: Parent device object
 * @driver: DRM driver
 * @type: the type of the struct which contains struct &drm_device
 * @member: the name of the &drm_device within @type.
 *
 * This allocates and initialize a new DRM device. No device registration is done.
 * Call drm_dev_register() to advertice the device to user space and register it
 * with other core subsystems. This should be done last in the device
 * initialization sequence to make sure userspace can't access an inconsistent
 * state.
 *
 * The initial ref-count of the object is 1. Use drm_dev_get() and
 * drm_dev_put() to take and drop further ref-counts.
 *
 * It is recommended that drivers embed &struct drm_device into their own device
 * structure.
 *
 * Note that this manages the lifetime of the resulting &drm_device
 * automatically using devres. The DRM device initialized with this function is
 * automatically put on driver detach using drm_dev_put().
 *
 * RETURNS:
 * Pointer to new DRM device, or ERR_PTR on failure.
 */
#define devm_drm_dev_alloc(parent, driver, type, member)                                                               \
    ((type *)_devm_drm_dev_alloc(parent, driver, sizeof(type), offsetof(type, member)))

struct drm_device *drm_dev_alloc(struct drm_driver *driver, struct device *parent);
int drm_dev_register(struct drm_device *dev, unsigned long flags);
void drm_dev_unregister(struct drm_device *dev);

void drm_dev_get(struct drm_device *dev);
void drm_dev_put(struct drm_device *dev);
void drm_put_dev(struct drm_device *dev);
bool drm_dev_enter(struct drm_device *dev, int *idx);
void drm_dev_exit(int idx);
void drm_dev_unplug(struct drm_device *dev);

/**
 * drm_dev_is_unplugged - is a DRM device unplugged
 * @dev: DRM device
 *
 * This function can be called to check whether a hotpluggable is unplugged.
 * Unplugging itself is singalled through drm_dev_unplug(). If a device is
 * unplugged, these two functions guarantee that any store before calling
 * drm_dev_unplug() is visible to callers of this function after it completes
 *
 * WARNING: This function fundamentally races against drm_dev_unplug(). It is
 * recommended that drivers instead use the underlying drm_dev_enter() and
 * drm_dev_exit() function pairs.
 */
static inline bool drm_dev_is_unplugged(struct drm_device *dev)
{
    int idx;

    if (drm_dev_enter(dev, &idx)) {
        drm_dev_exit(idx);
        return false;
    }

    return true;
}

/**
 * drm_core_check_all_features - check driver feature flags mask
 * @dev: DRM device to check
 * @features: feature flag(s) mask
 *
 * This checks @dev for driver features, see &drm_driver.driver_features,
 * &drm_device.driver_features, and the various &enum drm_driver_feature flags.
 *
 * Returns true if all features in the @features mask are supported, false
 * otherwise.
 */
static inline bool drm_core_check_all_features(const struct drm_device *dev, u32 features)
{
    u32 supported = dev->driver->driver_features & dev->driver_features;

    return features && (supported & features) == features;
}

/**
 * drm_core_check_feature - check driver feature flags
 * @dev: DRM device to check
 * @feature: feature flag
 *
 * This checks @dev for driver features, see &drm_driver.driver_features,
 * &drm_device.driver_features, and the various &enum drm_driver_feature flags.
 *
 * Returns true if the @feature is supported, false otherwise.
 */
static inline bool drm_core_check_feature(const struct drm_device *dev, enum drm_driver_feature feature)
{
    return drm_core_check_all_features(dev, feature);
}

/**
 * drm_drv_uses_atomic_modeset - check if the driver implements
 * atomic_commit()
 * @dev: DRM device
 *
 * This check is useful if drivers do not have DRIVER_ATOMIC set but
 * have atomic modesetting internally implemented.
 */
static inline bool drm_drv_uses_atomic_modeset(struct drm_device *dev)
{
    return drm_core_check_feature(dev, DRIVER_ATOMIC) ||
           (dev->mode_config.funcs && dev->mode_config.funcs->atomic_commit != NULL);
}

int drm_dev_set_unique(struct drm_device *dev, const char *name);

#endif