linux/drivers/gpu/drm/vkms/vkms_drv.h
Haneen Mohammed 6c234fe37c drm/vkms: Implement CRC debugfs API
This patch implement the necessary functions to compute and add CRCs
entries:

- Implement the set_crc_source() callback.
- Compute CRC using crc32 on the visible part of the framebuffer.
- Use ordered workqueue per output to compute and add CRC at the end
  of a vblank.
- Use appropriate synchronization methods since the CRC computation must
  be atomic wrt the generated vblank event for a given atomic update, by
  using spinlock across atomic_begin/atomic_flush to wrap the event
  handling code completely and match the flip event with the CRC.

Since vkms_crc_work_handle() can sleep, spinlock can't be acquired
while accessing vkms_output->primary_crc to compute CRC.
To make sure the data is updated and released without conflict with
the vkms_crc_work_handle(), the work_struct is flushed @crtc_destroy
and the data is updated before scheduling the work handle again, as
follow:

* CRC data update:
1- store vkms_crc_data {fb, src} per plane_state
2- @plane_duplicate_state -> allocate vkms_crc_data
3- during atomic commit (@atomic_update) ->
	a) copy {fb, src} to plane_state->crc_data
	b) get reference to fb,
3- @plane_destroy_state -> a) if (fb refcount) remove reference to fb
			   b) deallocate crc_data

* Atomic Commit:
1- vkms_plane_atomic_check
2- vkms_prepare_fb -> vmap vkms_gem_obj->vaddr
3- atomic_begin -> hold crc spinlock
4- atomic_plane_update -> a) update vkms_output->primary_crc
			  b) get reference to fb
5- atomic_flush -> a) send vblank event while holding event_lock
		   b) release crc spinlock

* hrtimer regular callback:
1- hold crc spinlock
2- drm_crtc_handle_vblank()
3- queue vkms_crc_work_handle
4- release crc spinlock

* cleanup:
1- @cleanup_fb ->vunmap vkms_gem_obj->vaddr
2- @crtc_destroy -> flush work struct
3- @plane_destroy -> a) if (fb refcount) remove reference to fb
		     b) deallocate crc_data

Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
[seanpaul fixed typo in vkms_crtc s/vblamk/vblank/]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b948327f48c3e70ab232b4a0848ee6d033b26484.1533171495.git.hamohammed.sa@gmail.com
2018-08-03 14:52:58 -04:00

131 lines
3.2 KiB
C

#ifndef _VKMS_DRV_H_
#define _VKMS_DRV_H_
#include <drm/drmP.h>
#include <drm/drm.h>
#include <drm/drm_gem.h>
#include <drm/drm_encoder.h>
#include <linux/hrtimer.h>
#define XRES_MIN 32
#define YRES_MIN 32
#define XRES_DEF 1024
#define YRES_DEF 768
#define XRES_MAX 8192
#define YRES_MAX 8192
static const u32 vkms_formats[] = {
DRM_FORMAT_XRGB8888,
};
struct vkms_crc_data {
struct drm_rect src;
struct drm_framebuffer fb;
};
/**
* vkms_plane_state - Driver specific plane state
* @base: base plane state
* @crc_data: data required for CRC computation
*/
struct vkms_plane_state {
struct drm_plane_state base;
struct vkms_crc_data *crc_data;
};
/**
* vkms_crtc_state - Driver specific CRTC state
* @base: base CRTC state
* @crc_work: work struct to compute and add CRC entries
* @n_frame: frame number for computed CRC
*/
struct vkms_crtc_state {
struct drm_crtc_state base;
struct work_struct crc_work;
unsigned int n_frame;
};
struct vkms_output {
struct drm_crtc crtc;
struct drm_encoder encoder;
struct drm_connector connector;
struct hrtimer vblank_hrtimer;
ktime_t period_ns;
struct drm_pending_vblank_event *event;
bool crc_enabled;
/* ordered wq for crc_work */
struct workqueue_struct *crc_workq;
/* protects concurrent access to crc_data */
spinlock_t lock;
};
struct vkms_device {
struct drm_device drm;
struct platform_device *platform;
struct vkms_output output;
};
struct vkms_gem_object {
struct drm_gem_object gem;
struct mutex pages_lock; /* Page lock used in page fault handler */
struct page **pages;
unsigned int vmap_count;
void *vaddr;
};
#define drm_crtc_to_vkms_output(target) \
container_of(target, struct vkms_output, crtc)
#define drm_device_to_vkms_device(target) \
container_of(target, struct vkms_device, drm)
#define drm_gem_to_vkms_gem(target)\
container_of(target, struct vkms_gem_object, gem)
#define to_vkms_crtc_state(target)\
container_of(target, struct vkms_crtc_state, base)
#define to_vkms_plane_state(target)\
container_of(target, struct vkms_plane_state, base)
/* CRTC */
int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
struct drm_plane *primary, struct drm_plane *cursor);
bool vkms_get_vblank_timestamp(struct drm_device *dev, unsigned int pipe,
int *max_error, ktime_t *vblank_time,
bool in_vblank_irq);
int vkms_output_init(struct vkms_device *vkmsdev);
struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev);
/* Gem stuff */
struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
struct drm_file *file,
u32 *handle,
u64 size);
vm_fault_t vkms_gem_fault(struct vm_fault *vmf);
int vkms_dumb_create(struct drm_file *file, struct drm_device *dev,
struct drm_mode_create_dumb *args);
int vkms_dumb_map(struct drm_file *file, struct drm_device *dev,
u32 handle, u64 *offset);
void vkms_gem_free_object(struct drm_gem_object *obj);
int vkms_gem_vmap(struct drm_gem_object *obj);
void vkms_gem_vunmap(struct drm_gem_object *obj);
/* CRC Support */
int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name,
size_t *values_cnt);
void vkms_crc_work_handle(struct work_struct *work);
#endif /* _VKMS_DRV_H_ */