freedreno/README


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

Note that current msm kernel driver is a bit strange.  It provides a
DRM interface for GEM, which is basically sufficient to have DRI2
working.  But it does not provide KMS.  And interface to 2d and 3d
cores is via different other devices (/dev/kgsl-*).  This is not
quite how I'd write a DRM driver, but at this stage it is useful for
xf86-video-freedreno and fdre (and eventual gallium driver) to be
able to work on existing kernel driver from QCOM, to allow to
capture cmdstream dumps from the binary blob drivers without having
to reboot.  So libdrm_freedreno attempts to hide most of the crazy.
The intention is that when there is a proper kernel driver, it will
be mostly just changes in libdrm_freedreno to adapt the gallium
driver and xf86-video-freedreno (ignoring the fbdev->KMS changes).

So don't look at freedreno as an example of how to write a libdrm
module or a DRM driver.. it is just an attempt to paper over a non-
standard kernel driver architecture.
/*-
 * Copyright 2003 Eric Anholt
 * All Rights Reserved.
 *
 * 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
 * ERIC ANHOLT 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.
 */

/** @file drm_vm.c
 * Support code for mmaping of DRM maps.
 */

#include "drmP.h"
#include "drm.h"

int drm_mmap(struct cdev *kdev, vm_offset_t offset, vm_paddr_t *paddr,
    int prot)
{
	struct drm_device *dev = drm_get_device_from_kdev(kdev);
	struct drm_file *file_priv;
	drm_local_map_t *map;
	enum drm_map_type type;
	vm_paddr_t phys;

	DRM_LOCK();
	TAILQ_FOREACH(file_priv, &dev->files, link)
		if (file_priv->pid == curthread->td_proc->p_pid &&
		    file_priv->uid == curthread->td_ucred->cr_svuid &&
		    file_priv->authenticated == 1)
			break;
	DRM_UNLOCK();

	if (!file_priv)
		return EACCES;

	if (dev->dma && offset >= 0 && offset < ptoa(dev->dma->page_count)) {
		drm_device_dma_t *dma = dev->dma;

		DRM_SPINLOCK(&dev->dma_lock);

		if (dma->pagelist != NULL) {
			unsigned long page = offset >> PAGE_SHIFT;
			unsigned long phys = dma->pagelist[page];

			DRM_SPINUNLOCK(&dev->dma_lock);
			*paddr = phys;
			return 0;
		} else {