hwrng: core - Don't use a stack buffer in add_early_randomness()

[linux/fpc-iii.git] / include / drm / drm_fb_helper.h

/*
 * Copyright (c) 2006-2009 Red Hat Inc.
 * Copyright (c) 2006-2008 Intel Corporation
 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
 *
 * DRM framebuffer helper functions
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 *
 * Authors:
 *      Dave Airlie <airlied@linux.ie>
 *      Jesse Barnes <jesse.barnes@intel.com>
 */
#ifndef DRM_FB_HELPER_H
#define DRM_FB_HELPER_H

struct drm_fb_helper;

#include <drm/drm_crtc.h>
#include <linux/kgdb.h>

enum mode_set_atomic {
        LEAVE_ATOMIC_MODE_SET,
        ENTER_ATOMIC_MODE_SET,
};

struct drm_fb_offset {
        int x, y;
};

struct drm_fb_helper_crtc {
        struct drm_mode_set mode_set;
        struct drm_display_mode *desired_mode;
        int x, y;
};

/**
 * struct drm_fb_helper_surface_size - describes fbdev size and scanout surface size
 * @fb_width: fbdev width
 * @fb_height: fbdev height
 * @surface_width: scanout buffer width
 * @surface_height: scanout buffer height
 * @surface_bpp: scanout buffer bpp
 * @surface_depth: scanout buffer depth
 *
 * Note that the scanout surface width/height may be larger than the fbdev
 * width/height.  In case of multiple displays, the scanout surface is sized
 * according to the largest width/height (so it is large enough for all CRTCs
 * to scanout).  But the fbdev width/height is sized to the minimum width/
 * height of all the displays.  This ensures that fbcon fits on the smallest
 * of the attached displays.
 *
 * So what is passed to drm_fb_helper_fill_var() should be fb_width/fb_height,
 * rather than the surface size.
 */
struct drm_fb_helper_surface_size {
        u32 fb_width;
        u32 fb_height;
        u32 surface_width;
        u32 surface_height;
        u32 surface_bpp;
        u32 surface_depth;
};

/**
 * struct drm_fb_helper_funcs - driver callbacks for the fbdev emulation library
 *
 * Driver callbacks used by the fbdev emulation helper library.
 */
struct drm_fb_helper_funcs {
        /**
         * @gamma_set:
         *
         * Set the given gamma LUT register on the given CRTC.
         *
         * This callback is optional.
         *
         * FIXME:
         *
         * This callback is functionally redundant with the core gamma table
         * support and simply exists because the fbdev hasn't yet been
         * refactored to use the core gamma table interfaces.
         */
        void (*gamma_set)(struct drm_crtc *crtc, u16 red, u16 green,
                          u16 blue, int regno);
        /**
         * @gamma_get:
         *
         * Read the given gamma LUT register on the given CRTC, used to save the
         * current LUT when force-restoring the fbdev for e.g. kdbg.
         *
         * This callback is optional.
         *
         * FIXME:
         *
         * This callback is functionally redundant with the core gamma table
         * support and simply exists because the fbdev hasn't yet been
         * refactored to use the core gamma table interfaces.
         */
        void (*gamma_get)(struct drm_crtc *crtc, u16 *red, u16 *green,
                          u16 *blue, int regno);

        /**
         * @fb_probe:
         *
         * Driver callback to allocate and initialize the fbdev info structure.
         * Furthermore it also needs to allocate the DRM framebuffer used to
         * back the fbdev.
         *
         * This callback is mandatory.
         *
         * RETURNS:
         *
         * The driver should return 0 on success and a negative error code on
         * failure.
         */
        int (*fb_probe)(struct drm_fb_helper *helper,
                        struct drm_fb_helper_surface_size *sizes);

        /**
         * @initial_config:
         *
         * Driver callback to setup an initial fbdev display configuration.
         * Drivers can use this callback to tell the fbdev emulation what the
         * preferred initial configuration is. This is useful to implement
         * smooth booting where the fbdev (and subsequently all userspace) never
         * changes the mode, but always inherits the existing configuration.
         *
         * This callback is optional.
         *
         * RETURNS:
         *
         * The driver should return true if a suitable initial configuration has
         * been filled out and false when the fbdev helper should fall back to
         * the default probing logic.
         */
        bool (*initial_config)(struct drm_fb_helper *fb_helper,
                               struct drm_fb_helper_crtc **crtcs,
                               struct drm_display_mode **modes,
                               struct drm_fb_offset *offsets,
                               bool *enabled, int width, int height);
};

struct drm_fb_helper_connector {
        struct drm_connector *connector;
};

/**
 * struct drm_fb_helper - main structure to emulate fbdev on top of KMS
 * @fb: Scanout framebuffer object
 * @dev: DRM device
 * @crtc_count: number of possible CRTCs
 * @crtc_info: per-CRTC helper state (mode, x/y offset, etc)
 * @connector_count: number of connected connectors
 * @connector_info_alloc_count: size of connector_info
 * @connector_info: array of per-connector information
 * @funcs: driver callbacks for fb helper
 * @fbdev: emulated fbdev device info struct
 * @pseudo_palette: fake palette of 16 colors
 * @dirty_clip: clip rectangle used with deferred_io to accumulate damage to
 *              the screen buffer
 * @dirty_lock: spinlock protecting @dirty_clip
 * @dirty_work: worker used to flush the framebuffer
 * @resume_work: worker used during resume if the console lock is already taken
 *
 * This is the main structure used by the fbdev helpers. Drivers supporting
 * fbdev emulation should embedded this into their overall driver structure.
 * Drivers must also fill out a struct &drm_fb_helper_funcs with a few
 * operations.
 */
struct drm_fb_helper {
        struct drm_framebuffer *fb;
        struct drm_device *dev;
        int crtc_count;
        struct drm_fb_helper_crtc *crtc_info;
        int connector_count;
        int connector_info_alloc_count;
        struct drm_fb_helper_connector **connector_info;
        const struct drm_fb_helper_funcs *funcs;
        struct fb_info *fbdev;
        u32 pseudo_palette[17];
        struct drm_clip_rect dirty_clip;
        spinlock_t dirty_lock;
        struct work_struct dirty_work;
        struct work_struct resume_work;

        /**
         * @kernel_fb_list:
         *
         * Entry on the global kernel_fb_helper_list, used for kgdb entry/exit.
         */
        struct list_head kernel_fb_list;

        /**
         * @delayed_hotplug:
         *
         * A hotplug was received while fbdev wasn't in control of the DRM
         * device, i.e. another KMS master was active. The output configuration
         * needs to be reprobe when fbdev is in control again.
         */
        bool delayed_hotplug;
};

/**
 * define DRM_FB_HELPER_DEFAULT_OPS - helper define for drm drivers
 *
 * Helper define to register default implementations of drm_fb_helper
 * functions. To be used in struct fb_ops of drm drivers.
 */
#define DRM_FB_HELPER_DEFAULT_OPS \
        .fb_check_var   = drm_fb_helper_check_var, \
        .fb_set_par     = drm_fb_helper_set_par, \
        .fb_setcmap     = drm_fb_helper_setcmap, \
        .fb_blank       = drm_fb_helper_blank, \
        .fb_pan_display = drm_fb_helper_pan_display

#ifdef CONFIG_DRM_FBDEV_EMULATION
void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
                           const struct drm_fb_helper_funcs *funcs);
int drm_fb_helper_init(struct drm_device *dev,
                       struct drm_fb_helper *helper, int crtc_count,
                       int max_conn);
void drm_fb_helper_fini(struct drm_fb_helper *helper);
int drm_fb_helper_blank(int blank, struct fb_info *info);
int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
                              struct fb_info *info);
int drm_fb_helper_set_par(struct fb_info *info);
int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
                            struct fb_info *info);

int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper);

struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper);
void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper);
void drm_fb_helper_release_fbi(struct drm_fb_helper *fb_helper);
void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
                            uint32_t fb_width, uint32_t fb_height);
void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
                            uint32_t depth);

void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper);

void drm_fb_helper_deferred_io(struct fb_info *info,
                               struct list_head *pagelist);

ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
                               size_t count, loff_t *ppos);
ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
                                size_t count, loff_t *ppos);

void drm_fb_helper_sys_fillrect(struct fb_info *info,
                                const struct fb_fillrect *rect);
void drm_fb_helper_sys_copyarea(struct fb_info *info,
                                const struct fb_copyarea *area);
void drm_fb_helper_sys_imageblit(struct fb_info *info,
                                 const struct fb_image *image);

void drm_fb_helper_cfb_fillrect(struct fb_info *info,
                                const struct fb_fillrect *rect);
void drm_fb_helper_cfb_copyarea(struct fb_info *info,
                                const struct fb_copyarea *area);
void drm_fb_helper_cfb_imageblit(struct fb_info *info,
                                 const struct fb_image *image);

void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend);
void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
                                        bool suspend);

int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);

int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel);
int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper);
int drm_fb_helper_debug_enter(struct fb_info *info);
int drm_fb_helper_debug_leave(struct fb_info *info);
struct drm_display_mode *
drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
                        int width, int height);
struct drm_display_mode *
drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
                      int width, int height);

int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector);
int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
                                       struct drm_connector *connector);
#else
static inline void drm_fb_helper_prepare(struct drm_device *dev,
                                        struct drm_fb_helper *helper,
                                        const struct drm_fb_helper_funcs *funcs)
{
}

static inline int drm_fb_helper_init(struct drm_device *dev,
                       struct drm_fb_helper *helper, int crtc_count,
                       int max_conn)
{
        return 0;
}

static inline void drm_fb_helper_fini(struct drm_fb_helper *helper)
{
}

static inline int drm_fb_helper_blank(int blank, struct fb_info *info)
{
        return 0;
}

static inline int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
                                            struct fb_info *info)
{
        return 0;
}

static inline int drm_fb_helper_set_par(struct fb_info *info)
{
        return 0;
}

static inline int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
                                          struct fb_info *info)
{
        return 0;
}

static inline int
drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
{
        return 0;
}

static inline struct fb_info *
drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
{
        return NULL;
}

static inline void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
{
}
static inline void drm_fb_helper_release_fbi(struct drm_fb_helper *fb_helper)
{
}

static inline void drm_fb_helper_fill_var(struct fb_info *info,
                                          struct drm_fb_helper *fb_helper,
                                          uint32_t fb_width, uint32_t fb_height)
{
}

static inline void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
                                          uint32_t depth)
{
}

static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
                                        struct fb_info *info)
{
        return 0;
}

static inline void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
{
}

static inline void drm_fb_helper_deferred_io(struct fb_info *info,
                                             struct list_head *pagelist)
{
}

static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
                                             char __user *buf, size_t count,
                                             loff_t *ppos)
{
        return -ENODEV;
}

static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
                                              const char __user *buf,
                                              size_t count, loff_t *ppos)
{
        return -ENODEV;
}

static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
                                              const struct fb_fillrect *rect)
{
}

static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
                                              const struct fb_copyarea *area)
{
}

static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
                                               const struct fb_image *image)
{
}

static inline void drm_fb_helper_cfb_fillrect(struct fb_info *info,
                                              const struct fb_fillrect *rect)
{
}

static inline void drm_fb_helper_cfb_copyarea(struct fb_info *info,
                                              const struct fb_copyarea *area)
{
}

static inline void drm_fb_helper_cfb_imageblit(struct fb_info *info,
                                               const struct fb_image *image)
{
}

static inline void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper,
                                             bool suspend)
{
}

static inline void
drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper, bool suspend)
{
}

static inline int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
{
        return 0;
}

static inline int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper,
                                               int bpp_sel)
{
        return 0;
}

static inline int
drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
{
        return 0;
}

static inline int drm_fb_helper_debug_enter(struct fb_info *info)
{
        return 0;
}

static inline int drm_fb_helper_debug_leave(struct fb_info *info)
{
        return 0;
}

static inline struct drm_display_mode *
drm_has_preferred_mode(struct drm_fb_helper_connector *fb_connector,
                       int width, int height)
{
        return NULL;
}

static inline struct drm_display_mode *
drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
                      int width, int height)
{
        return NULL;
}

static inline int
drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper,
                                struct drm_connector *connector)
{
        return 0;
}

static inline int
drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
                                   struct drm_connector *connector)
{
        return 0;
}

#endif

static inline int
drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a,
                                              const char *name, bool primary)
{
#if IS_REACHABLE(CONFIG_FB)
        return remove_conflicting_framebuffers(a, name, primary);
#else
        return 0;
#endif
}

#endif