1282199Sdumbbell/* drm_pci.h -- PCI DMA memory management wrappers for DRM -*- linux-c -*- */
2282199Sdumbbell/**
3282199Sdumbbell * \file drm_pci.c
4282199Sdumbbell * \brief Functions and ioctls to manage PCI memory
5282199Sdumbbell *
6282199Sdumbbell * \warning These interfaces aren't stable yet.
7282199Sdumbbell *
8282199Sdumbbell * \todo Implement the remaining ioctl's for the PCI pools.
9282199Sdumbbell * \todo The wrappers here are so thin that they would be better off inlined..
10282199Sdumbbell *
11282199Sdumbbell * \author Jos�� Fonseca <jrfonseca@tungstengraphics.com>
12282199Sdumbbell * \author Leif Delgass <ldelgass@retinalburn.net>
13282199Sdumbbell */
14282199Sdumbbell
15282199Sdumbbell/*
16282199Sdumbbell * Copyright 2003 Jos�� Fonseca.
17282199Sdumbbell * Copyright 2003 Leif Delgass.
18235783Skib * All Rights Reserved.
19235783Skib *
20235783Skib * Permission is hereby granted, free of charge, to any person obtaining a
21235783Skib * copy of this software and associated documentation files (the "Software"),
22235783Skib * to deal in the Software without restriction, including without limitation
23235783Skib * the rights to use, copy, modify, merge, publish, distribute, sublicense,
24235783Skib * and/or sell copies of the Software, and to permit persons to whom the
25235783Skib * Software is furnished to do so, subject to the following conditions:
26235783Skib *
27235783Skib * The above copyright notice and this permission notice (including the next
28235783Skib * paragraph) shall be included in all copies or substantial portions of the
29235783Skib * Software.
30235783Skib *
31235783Skib * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
32235783Skib * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
33235783Skib * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
34282199Sdumbbell * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
35235783Skib * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
36235783Skib * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
37235783Skib */
38235783Skib
39235783Skib#include <sys/cdefs.h>
40235783Skib__FBSDID("$FreeBSD: releng/10.2/sys/dev/drm2/drm_pci.c 282199 2015-04-28 19:35:05Z dumbbell $");
41235783Skib
42235783Skib#include <dev/drm2/drmP.h>
43235783Skib
44282199Sdumbbellstatic int drm_msi = 1;	/* Enable by default. */
45282199SdumbbellSYSCTL_NODE(_hw, OID_AUTO, drm, CTLFLAG_RW, NULL, "DRM device");
46282199SdumbbellSYSCTL_INT(_hw_drm, OID_AUTO, msi, CTLFLAG_RDTUN, &drm_msi, 1,
47282199Sdumbbell    "Enable MSI interrupts for drm devices");
48282199Sdumbbell
49235783Skib/**********************************************************************/
50235783Skib/** \name PCI memory */
51235783Skib/*@{*/
52235783Skib
53235783Skibstatic void
54235783Skibdrm_pci_busdma_callback(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
55235783Skib{
56235783Skib	drm_dma_handle_t *dmah = arg;
57235783Skib
58235783Skib	if (error != 0)
59235783Skib		return;
60235783Skib
61235783Skib	KASSERT(nsegs == 1, ("drm_pci_busdma_callback: bad dma segment count"));
62235783Skib	dmah->busaddr = segs[0].ds_addr;
63235783Skib}
64235783Skib
65235783Skib/**
66282199Sdumbbell * \brief Allocate a PCI consistent memory block, for DMA.
67235783Skib */
68282199Sdumbbelldrm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size,
69282199Sdumbbell    size_t align, dma_addr_t maxaddr)
70235783Skib{
71235783Skib	drm_dma_handle_t *dmah;
72235783Skib	int ret;
73235783Skib
74235783Skib	/* Need power-of-two alignment, so fail the allocation if it isn't. */
75235783Skib	if ((align & (align - 1)) != 0) {
76235783Skib		DRM_ERROR("drm_pci_alloc with non-power-of-two alignment %d\n",
77235783Skib		    (int)align);
78235783Skib		return NULL;
79235783Skib	}
80235783Skib
81235783Skib	dmah = malloc(sizeof(drm_dma_handle_t), DRM_MEM_DMA, M_ZERO | M_NOWAIT);
82235783Skib	if (dmah == NULL)
83235783Skib		return NULL;
84235783Skib
85235783Skib	/* Make sure we aren't holding mutexes here */
86235783Skib	mtx_assert(&dev->dma_lock, MA_NOTOWNED);
87235783Skib	if (mtx_owned(&dev->dma_lock))
88235783Skib	    DRM_ERROR("called while holding dma_lock\n");
89235783Skib
90280353Sjah	ret = bus_dma_tag_create(
91282199Sdumbbell	    bus_get_dma_tag(dev->dev), /* parent */
92280353Sjah	    align, 0, /* align, boundary */
93235783Skib	    maxaddr, BUS_SPACE_MAXADDR, /* lowaddr, highaddr */
94235783Skib	    NULL, NULL, /* filtfunc, filtfuncargs */
95235783Skib	    size, 1, size, /* maxsize, nsegs, maxsegsize */
96235783Skib	    0, NULL, NULL, /* flags, lockfunc, lockfuncargs */
97235783Skib	    &dmah->tag);
98235783Skib	if (ret != 0) {
99235783Skib		free(dmah, DRM_MEM_DMA);
100235783Skib		return NULL;
101235783Skib	}
102235783Skib
103235783Skib	ret = bus_dmamem_alloc(dmah->tag, &dmah->vaddr,
104235783Skib	    BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_NOCACHE, &dmah->map);
105235783Skib	if (ret != 0) {
106235783Skib		bus_dma_tag_destroy(dmah->tag);
107235783Skib		free(dmah, DRM_MEM_DMA);
108235783Skib		return NULL;
109235783Skib	}
110235783Skib
111235783Skib	ret = bus_dmamap_load(dmah->tag, dmah->map, dmah->vaddr, size,
112235783Skib	    drm_pci_busdma_callback, dmah, BUS_DMA_NOWAIT);
113235783Skib	if (ret != 0) {
114235783Skib		bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
115235783Skib		bus_dma_tag_destroy(dmah->tag);
116235783Skib		free(dmah, DRM_MEM_DMA);
117235783Skib		return NULL;
118235783Skib	}
119235783Skib
120235783Skib	return dmah;
121235783Skib}
122235783Skib
123282199SdumbbellEXPORT_SYMBOL(drm_pci_alloc);
124282199Sdumbbell
125235783Skib/**
126282199Sdumbbell * \brief Free a PCI consistent memory block without freeing its descriptor.
127282199Sdumbbell *
128282199Sdumbbell * This function is for internal use in the Linux-specific DRM core code.
129235783Skib */
130282199Sdumbbellvoid __drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
131235783Skib{
132235783Skib	if (dmah == NULL)
133235783Skib		return;
134235783Skib
135235783Skib	bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
136235783Skib	bus_dma_tag_destroy(dmah->tag);
137282199Sdumbbell}
138235783Skib
139282199Sdumbbell/**
140282199Sdumbbell * \brief Free a PCI consistent memory block
141282199Sdumbbell */
142282199Sdumbbellvoid drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
143282199Sdumbbell{
144282199Sdumbbell	__drm_pci_free(dev, dmah);
145235783Skib	free(dmah, DRM_MEM_DMA);
146235783Skib}
147235783Skib
148282199SdumbbellEXPORT_SYMBOL(drm_pci_free);
149254848Sdumbbell
150282199Sdumbbellstatic int drm_get_pci_domain(struct drm_device *dev)
151282199Sdumbbell{
152282199Sdumbbell	return dev->pci_domain;
153282199Sdumbbell}
154282199Sdumbbell
155282199Sdumbbellstatic int drm_pci_get_irq(struct drm_device *dev)
156282199Sdumbbell{
157282199Sdumbbell
158282199Sdumbbell	if (dev->irqr)
159282199Sdumbbell		return (dev->irq);
160282199Sdumbbell
161282199Sdumbbell	dev->irqr = bus_alloc_resource_any(dev->dev, SYS_RES_IRQ,
162282199Sdumbbell	    &dev->irqrid, RF_SHAREABLE);
163282199Sdumbbell	if (!dev->irqr) {
164282199Sdumbbell		dev_err(dev->dev, "Failed to allocate IRQ\n");
165282199Sdumbbell		return (0);
166282199Sdumbbell	}
167282199Sdumbbell
168282199Sdumbbell	dev->irq = (int) rman_get_start(dev->irqr);
169282199Sdumbbell
170282199Sdumbbell	return (dev->irq);
171282199Sdumbbell}
172282199Sdumbbell
173282199Sdumbbellstatic void drm_pci_free_irq(struct drm_device *dev)
174282199Sdumbbell{
175282199Sdumbbell	if (dev->irqr == NULL)
176282199Sdumbbell		return;
177282199Sdumbbell
178282199Sdumbbell	bus_release_resource(dev->dev, SYS_RES_IRQ,
179282199Sdumbbell	    dev->irqrid, dev->irqr);
180282199Sdumbbell
181282199Sdumbbell	dev->irqr = NULL;
182282199Sdumbbell	dev->irq = 0;
183282199Sdumbbell}
184282199Sdumbbell
185282199Sdumbbellstatic const char *drm_pci_get_name(struct drm_device *dev)
186282199Sdumbbell{
187282199Sdumbbell	return dev->driver->name;
188282199Sdumbbell}
189282199Sdumbbell
190282199Sdumbbellint drm_pci_set_busid(struct drm_device *dev, struct drm_master *master)
191282199Sdumbbell{
192282199Sdumbbell	int len, ret;
193282199Sdumbbell	master->unique_len = 40;
194282199Sdumbbell	master->unique_size = master->unique_len;
195282199Sdumbbell	master->unique = malloc(master->unique_size, DRM_MEM_DRIVER, M_NOWAIT);
196282199Sdumbbell	if (master->unique == NULL)
197282199Sdumbbell		return -ENOMEM;
198282199Sdumbbell
199282199Sdumbbell
200282199Sdumbbell	len = snprintf(master->unique, master->unique_len,
201282199Sdumbbell		       "pci:%04x:%02x:%02x.%d",
202282199Sdumbbell		       dev->pci_domain,
203282199Sdumbbell		       dev->pci_bus,
204282199Sdumbbell		       dev->pci_slot,
205282199Sdumbbell		       dev->pci_func);
206282199Sdumbbell
207282199Sdumbbell	if (len >= master->unique_len) {
208282199Sdumbbell		DRM_ERROR("buffer overflow");
209282199Sdumbbell		ret = -EINVAL;
210282199Sdumbbell		goto err;
211282199Sdumbbell	} else
212282199Sdumbbell		master->unique_len = len;
213282199Sdumbbell
214282199Sdumbbell	return 0;
215282199Sdumbbellerr:
216282199Sdumbbell	return ret;
217282199Sdumbbell}
218282199Sdumbbell
219282199Sdumbbellint drm_pci_set_unique(struct drm_device *dev,
220282199Sdumbbell		       struct drm_master *master,
221282199Sdumbbell		       struct drm_unique *u)
222282199Sdumbbell{
223282199Sdumbbell	int domain, bus, slot, func, ret;
224282199Sdumbbell
225282199Sdumbbell	master->unique_len = u->unique_len;
226282199Sdumbbell	master->unique_size = u->unique_len + 1;
227282199Sdumbbell	master->unique = malloc(master->unique_size, DRM_MEM_DRIVER, M_WAITOK);
228282199Sdumbbell	if (!master->unique) {
229282199Sdumbbell		ret = -ENOMEM;
230282199Sdumbbell		goto err;
231282199Sdumbbell	}
232282199Sdumbbell
233282199Sdumbbell	if (copy_from_user(master->unique, u->unique, master->unique_len)) {
234282199Sdumbbell		ret = -EFAULT;
235282199Sdumbbell		goto err;
236282199Sdumbbell	}
237282199Sdumbbell
238282199Sdumbbell	master->unique[master->unique_len] = '\0';
239282199Sdumbbell
240282199Sdumbbell	/* Return error if the busid submitted doesn't match the device's actual
241282199Sdumbbell	 * busid.
242282199Sdumbbell	 */
243282199Sdumbbell	ret = sscanf(master->unique, "PCI:%d:%d:%d", &bus, &slot, &func);
244282199Sdumbbell	if (ret != 3) {
245282199Sdumbbell		ret = -EINVAL;
246282199Sdumbbell		goto err;
247282199Sdumbbell	}
248282199Sdumbbell
249282199Sdumbbell	domain = bus >> 8;
250282199Sdumbbell	bus &= 0xff;
251282199Sdumbbell
252282199Sdumbbell	if ((domain != dev->pci_domain) ||
253282199Sdumbbell	    (bus != dev->pci_bus) ||
254282199Sdumbbell	    (slot != dev->pci_slot) ||
255282199Sdumbbell	    (func != dev->pci_func)) {
256282199Sdumbbell		ret = -EINVAL;
257282199Sdumbbell		goto err;
258282199Sdumbbell	}
259282199Sdumbbell	return 0;
260282199Sdumbbellerr:
261282199Sdumbbell	return ret;
262282199Sdumbbell}
263282199Sdumbbell
264282199Sdumbbell
265282199Sdumbbellstatic int drm_pci_irq_by_busid(struct drm_device *dev, struct drm_irq_busid *p)
266282199Sdumbbell{
267282199Sdumbbell	if ((p->busnum >> 8) != drm_get_pci_domain(dev) ||
268282199Sdumbbell	    (p->busnum & 0xff) != dev->pci_bus ||
269282199Sdumbbell	    p->devnum != dev->pci_slot || p->funcnum != dev->pci_func)
270282199Sdumbbell		return -EINVAL;
271282199Sdumbbell
272282199Sdumbbell	p->irq = dev->irq;
273282199Sdumbbell
274282199Sdumbbell	DRM_DEBUG("%d:%d:%d => IRQ %d\n", p->busnum, p->devnum, p->funcnum,
275282199Sdumbbell		  p->irq);
276282199Sdumbbell	return 0;
277282199Sdumbbell}
278282199Sdumbbell
279282199Sdumbbellint drm_pci_agp_init(struct drm_device *dev)
280282199Sdumbbell{
281282199Sdumbbell	if (drm_core_has_AGP(dev)) {
282282199Sdumbbell		if (drm_pci_device_is_agp(dev))
283282199Sdumbbell			dev->agp = drm_agp_init(dev);
284282199Sdumbbell		if (drm_core_check_feature(dev, DRIVER_REQUIRE_AGP)
285282199Sdumbbell		    && (dev->agp == NULL)) {
286282199Sdumbbell			DRM_ERROR("Cannot initialize the agpgart module.\n");
287282199Sdumbbell			return -EINVAL;
288282199Sdumbbell		}
289282199Sdumbbell		if (drm_core_has_MTRR(dev)) {
290282199Sdumbbell			if (dev->agp && dev->agp->agp_info.ai_aperture_base != 0) {
291282199Sdumbbell				if (drm_mtrr_add(dev->agp->agp_info.ai_aperture_base,
292282199Sdumbbell				    dev->agp->agp_info.ai_aperture_size, DRM_MTRR_WC) == 0)
293282199Sdumbbell					dev->agp->agp_mtrr = 1;
294282199Sdumbbell				else
295282199Sdumbbell					dev->agp->agp_mtrr = -1;
296282199Sdumbbell			}
297282199Sdumbbell		}
298282199Sdumbbell	}
299282199Sdumbbell	return 0;
300282199Sdumbbell}
301282199Sdumbbell
302282199Sdumbbellstatic struct drm_bus drm_pci_bus = {
303282199Sdumbbell	.bus_type = DRIVER_BUS_PCI,
304282199Sdumbbell	.get_irq = drm_pci_get_irq,
305282199Sdumbbell	.free_irq = drm_pci_free_irq,
306282199Sdumbbell	.get_name = drm_pci_get_name,
307282199Sdumbbell	.set_busid = drm_pci_set_busid,
308282199Sdumbbell	.set_unique = drm_pci_set_unique,
309282199Sdumbbell	.irq_by_busid = drm_pci_irq_by_busid,
310282199Sdumbbell	.agp_init = drm_pci_agp_init,
311282199Sdumbbell};
312282199Sdumbbell
313282199Sdumbbell/**
314282199Sdumbbell * Register.
315282199Sdumbbell *
316282199Sdumbbell * \param pdev - PCI device structure
317282199Sdumbbell * \param ent entry from the PCI ID table with device type flags
318282199Sdumbbell * \return zero on success or a negative number on failure.
319282199Sdumbbell *
320282199Sdumbbell * Attempt to gets inter module "drm" information. If we are first
321282199Sdumbbell * then register the character device and inter module information.
322282199Sdumbbell * Try and register, if we fail to register, backout previous work.
323282199Sdumbbell */
324282199Sdumbbellint drm_get_pci_dev(device_t kdev, struct drm_device *dev,
325282199Sdumbbell		    struct drm_driver *driver)
326282199Sdumbbell{
327282199Sdumbbell	int ret;
328282199Sdumbbell
329282199Sdumbbell	DRM_DEBUG("\n");
330282199Sdumbbell
331282199Sdumbbell	driver->bus = &drm_pci_bus;
332282199Sdumbbell
333282199Sdumbbell	dev->dev = kdev;
334282199Sdumbbell
335282199Sdumbbell	dev->pci_domain = pci_get_domain(dev->dev);
336282199Sdumbbell	dev->pci_bus = pci_get_bus(dev->dev);
337282199Sdumbbell	dev->pci_slot = pci_get_slot(dev->dev);
338282199Sdumbbell	dev->pci_func = pci_get_function(dev->dev);
339282199Sdumbbell
340282199Sdumbbell	dev->pci_vendor = pci_get_vendor(dev->dev);
341282199Sdumbbell	dev->pci_device = pci_get_device(dev->dev);
342282199Sdumbbell	dev->pci_subvendor = pci_get_subvendor(dev->dev);
343282199Sdumbbell	dev->pci_subdevice = pci_get_subdevice(dev->dev);
344282199Sdumbbell
345282199Sdumbbell	sx_xlock(&drm_global_mutex);
346282199Sdumbbell
347282199Sdumbbell	if ((ret = drm_fill_in_dev(dev, driver))) {
348282199Sdumbbell		DRM_ERROR("Failed to fill in dev: %d\n", ret);
349282199Sdumbbell		goto err_g1;
350282199Sdumbbell	}
351282199Sdumbbell
352282199Sdumbbell	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
353282199Sdumbbell		ret = drm_get_minor(dev, &dev->control, DRM_MINOR_CONTROL);
354282199Sdumbbell		if (ret)
355282199Sdumbbell			goto err_g2;
356282199Sdumbbell	}
357282199Sdumbbell
358282199Sdumbbell	if ((ret = drm_get_minor(dev, &dev->primary, DRM_MINOR_LEGACY)))
359282199Sdumbbell		goto err_g3;
360282199Sdumbbell
361282199Sdumbbell	if (dev->driver->load) {
362282199Sdumbbell		ret = dev->driver->load(dev,
363282199Sdumbbell		    dev->id_entry->driver_private);
364282199Sdumbbell		if (ret)
365282199Sdumbbell			goto err_g4;
366282199Sdumbbell	}
367282199Sdumbbell
368282199Sdumbbell	/* setup the grouping for the legacy output */
369282199Sdumbbell	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
370282199Sdumbbell		ret = drm_mode_group_init_legacy_group(dev,
371282199Sdumbbell						&dev->primary->mode_group);
372282199Sdumbbell		if (ret)
373282199Sdumbbell			goto err_g5;
374282199Sdumbbell	}
375282199Sdumbbell
376282199Sdumbbell#ifdef FREEBSD_NOTYET
377282199Sdumbbell	list_add_tail(&dev->driver_item, &driver->device_list);
378282199Sdumbbell#endif /* FREEBSD_NOTYET */
379282199Sdumbbell
380282199Sdumbbell	DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
381282199Sdumbbell		 driver->name, driver->major, driver->minor, driver->patchlevel,
382282199Sdumbbell		 driver->date, device_get_nameunit(dev->dev), dev->primary->index);
383282199Sdumbbell
384282199Sdumbbell	sx_xunlock(&drm_global_mutex);
385282199Sdumbbell	return 0;
386282199Sdumbbell
387282199Sdumbbellerr_g5:
388282199Sdumbbell	if (dev->driver->unload)
389282199Sdumbbell		dev->driver->unload(dev);
390282199Sdumbbellerr_g4:
391282199Sdumbbell	drm_put_minor(&dev->primary);
392282199Sdumbbellerr_g3:
393282199Sdumbbell	if (drm_core_check_feature(dev, DRIVER_MODESET))
394282199Sdumbbell		drm_put_minor(&dev->control);
395282199Sdumbbellerr_g2:
396282199Sdumbbell	drm_cancel_fill_in_dev(dev);
397282199Sdumbbellerr_g1:
398282199Sdumbbell	sx_xunlock(&drm_global_mutex);
399282199Sdumbbell	return ret;
400282199Sdumbbell}
401282199SdumbbellEXPORT_SYMBOL(drm_get_pci_dev);
402282199Sdumbbell
403282199Sdumbbellint
404282199Sdumbbelldrm_pci_enable_msi(struct drm_device *dev)
405282199Sdumbbell{
406282199Sdumbbell	int msicount, ret;
407282199Sdumbbell
408282199Sdumbbell	if (!drm_msi)
409282199Sdumbbell		return (-ENOENT);
410282199Sdumbbell
411282199Sdumbbell	msicount = pci_msi_count(dev->dev);
412282199Sdumbbell	DRM_DEBUG("MSI count = %d\n", msicount);
413282199Sdumbbell	if (msicount > 1)
414282199Sdumbbell		msicount = 1;
415282199Sdumbbell
416282199Sdumbbell	ret = pci_alloc_msi(dev->dev, &msicount);
417282199Sdumbbell	if (ret == 0) {
418282199Sdumbbell		DRM_INFO("MSI enabled %d message(s)\n", msicount);
419282199Sdumbbell		dev->msi_enabled = 1;
420282199Sdumbbell		dev->irqrid = 1;
421282199Sdumbbell	}
422282199Sdumbbell
423282199Sdumbbell	return (-ret);
424282199Sdumbbell}
425282199Sdumbbell
426282199Sdumbbellvoid
427282199Sdumbbelldrm_pci_disable_msi(struct drm_device *dev)
428282199Sdumbbell{
429282199Sdumbbell
430282199Sdumbbell	if (!dev->msi_enabled)
431282199Sdumbbell		return;
432282199Sdumbbell
433282199Sdumbbell	pci_release_msi(dev->dev);
434282199Sdumbbell	dev->msi_enabled = 0;
435282199Sdumbbell	dev->irqrid = 0;
436282199Sdumbbell}
437282199Sdumbbell
438254848Sdumbbellint drm_pcie_get_speed_cap_mask(struct drm_device *dev, u32 *mask)
439254848Sdumbbell{
440254848Sdumbbell	device_t root;
441254848Sdumbbell	int pos;
442254848Sdumbbell	u32 lnkcap = 0, lnkcap2 = 0;
443254848Sdumbbell
444254848Sdumbbell	*mask = 0;
445282199Sdumbbell	if (!drm_pci_device_is_pcie(dev))
446254848Sdumbbell		return -EINVAL;
447254848Sdumbbell
448259237Sdumbbell	root =
449259237Sdumbbell	    device_get_parent( /* pcib             */
450259237Sdumbbell	    device_get_parent( /* `-- pci          */
451259237Sdumbbell	    device_get_parent( /*     `-- vgapci   */
452282199Sdumbbell	    dev->dev)));       /*         `-- drmn */
453254848Sdumbbell
454254848Sdumbbell	pos = 0;
455254848Sdumbbell	pci_find_cap(root, PCIY_EXPRESS, &pos);
456254848Sdumbbell	if (!pos)
457254848Sdumbbell		return -EINVAL;
458254848Sdumbbell
459254848Sdumbbell	/* we've been informed via and serverworks don't make the cut */
460254848Sdumbbell	if (pci_get_vendor(root) == PCI_VENDOR_ID_VIA ||
461254848Sdumbbell	    pci_get_vendor(root) == PCI_VENDOR_ID_SERVERWORKS)
462254848Sdumbbell		return -EINVAL;
463254848Sdumbbell
464254848Sdumbbell	lnkcap = pci_read_config(root, pos + PCIER_LINK_CAP, 4);
465254848Sdumbbell	lnkcap2 = pci_read_config(root, pos + PCIER_LINK_CAP2, 4);
466254848Sdumbbell
467254848Sdumbbell	lnkcap &= PCIEM_LINK_CAP_MAX_SPEED;
468254848Sdumbbell	lnkcap2 &= 0xfe;
469254848Sdumbbell
470254848Sdumbbell#define	PCI_EXP_LNKCAP2_SLS_2_5GB 0x02	/* Supported Link Speed 2.5GT/s */
471254848Sdumbbell#define	PCI_EXP_LNKCAP2_SLS_5_0GB 0x04	/* Supported Link Speed 5.0GT/s */
472254848Sdumbbell#define	PCI_EXP_LNKCAP2_SLS_8_0GB 0x08	/* Supported Link Speed 8.0GT/s */
473254848Sdumbbell
474254848Sdumbbell	if (lnkcap2) { /* PCIE GEN 3.0 */
475254848Sdumbbell		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
476254848Sdumbbell			*mask |= DRM_PCIE_SPEED_25;
477254848Sdumbbell		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
478254848Sdumbbell			*mask |= DRM_PCIE_SPEED_50;
479254848Sdumbbell		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
480254848Sdumbbell			*mask |= DRM_PCIE_SPEED_80;
481254848Sdumbbell	} else {
482254848Sdumbbell		if (lnkcap & 1)
483254848Sdumbbell			*mask |= DRM_PCIE_SPEED_25;
484254848Sdumbbell		if (lnkcap & 2)
485254848Sdumbbell			*mask |= DRM_PCIE_SPEED_50;
486254848Sdumbbell	}
487254848Sdumbbell
488254848Sdumbbell	DRM_INFO("probing gen 2 caps for device %x:%x = %x/%x\n", pci_get_vendor(root), pci_get_device(root), lnkcap, lnkcap2);
489254848Sdumbbell	return 0;
490254848Sdumbbell}
491282199SdumbbellEXPORT_SYMBOL(drm_pcie_get_speed_cap_mask);
492