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1 /*
2  * Copyright (c) 2007, Intel Corporation.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
17  *
18  * Authors: Thomas Hellstrom <thomas-at-tungstengraphics.com>
19  *	    Alan Cox <alan@linux.intel.com>
20  */
21 
22 #include <drm/drmP.h>
23 #include <linux/shmem_fs.h>
24 #include "psb_drv.h"
25 
26 
27 /*
28  *	GTT resource allocator - manage page mappings in GTT space
29  */
30 
31 /**
32  *	psb_gtt_mask_pte	-	generate GTT pte entry
33  *	@pfn: page number to encode
34  *	@type: type of memory in the GTT
35  *
36  *	Set the GTT entry for the appropriate memory type.
37  */
psb_gtt_mask_pte(uint32_t pfn,int type)38 static inline uint32_t psb_gtt_mask_pte(uint32_t pfn, int type)
39 {
40 	uint32_t mask = PSB_PTE_VALID;
41 
42 	/* Ensure we explode rather than put an invalid low mapping of
43 	   a high mapping page into the gtt */
44 	BUG_ON(pfn & ~(0xFFFFFFFF >> PAGE_SHIFT));
45 
46 	if (type & PSB_MMU_CACHED_MEMORY)
47 		mask |= PSB_PTE_CACHED;
48 	if (type & PSB_MMU_RO_MEMORY)
49 		mask |= PSB_PTE_RO;
50 	if (type & PSB_MMU_WO_MEMORY)
51 		mask |= PSB_PTE_WO;
52 
53 	return (pfn << PAGE_SHIFT) | mask;
54 }
55 
56 /**
57  *	psb_gtt_entry		-	find the GTT entries for a gtt_range
58  *	@dev: our DRM device
59  *	@r: our GTT range
60  *
61  *	Given a gtt_range object return the GTT offset of the page table
62  *	entries for this gtt_range
63  */
psb_gtt_entry(struct drm_device * dev,struct gtt_range * r)64 static u32 __iomem *psb_gtt_entry(struct drm_device *dev, struct gtt_range *r)
65 {
66 	struct drm_psb_private *dev_priv = dev->dev_private;
67 	unsigned long offset;
68 
69 	offset = r->resource.start - dev_priv->gtt_mem->start;
70 
71 	return dev_priv->gtt_map + (offset >> PAGE_SHIFT);
72 }
73 
74 /**
75  *	psb_gtt_insert	-	put an object into the GTT
76  *	@dev: our DRM device
77  *	@r: our GTT range
78  *
79  *	Take our preallocated GTT range and insert the GEM object into
80  *	the GTT. This is protected via the gtt mutex which the caller
81  *	must hold.
82  */
psb_gtt_insert(struct drm_device * dev,struct gtt_range * r,int resume)83 static int psb_gtt_insert(struct drm_device *dev, struct gtt_range *r,
84 			  int resume)
85 {
86 	u32 __iomem *gtt_slot;
87 	u32 pte;
88 	struct page **pages;
89 	int i;
90 
91 	if (r->pages == NULL) {
92 		WARN_ON(1);
93 		return -EINVAL;
94 	}
95 
96 	WARN_ON(r->stolen);	/* refcount these maybe ? */
97 
98 	gtt_slot = psb_gtt_entry(dev, r);
99 	pages = r->pages;
100 
101 	if (!resume) {
102 		/* Make sure changes are visible to the GPU */
103 		set_pages_array_wc(pages, r->npage);
104 	}
105 
106 	/* Write our page entries into the GTT itself */
107 	for (i = r->roll; i < r->npage; i++) {
108 		pte = psb_gtt_mask_pte(page_to_pfn(r->pages[i]), 0);
109 		iowrite32(pte, gtt_slot++);
110 	}
111 	for (i = 0; i < r->roll; i++) {
112 		pte = psb_gtt_mask_pte(page_to_pfn(r->pages[i]), 0);
113 		iowrite32(pte, gtt_slot++);
114 	}
115 	/* Make sure all the entries are set before we return */
116 	ioread32(gtt_slot - 1);
117 
118 	return 0;
119 }
120 
121 /**
122  *	psb_gtt_remove	-	remove an object from the GTT
123  *	@dev: our DRM device
124  *	@r: our GTT range
125  *
126  *	Remove a preallocated GTT range from the GTT. Overwrite all the
127  *	page table entries with the dummy page. This is protected via the gtt
128  *	mutex which the caller must hold.
129  */
psb_gtt_remove(struct drm_device * dev,struct gtt_range * r)130 static void psb_gtt_remove(struct drm_device *dev, struct gtt_range *r)
131 {
132 	struct drm_psb_private *dev_priv = dev->dev_private;
133 	u32 __iomem *gtt_slot;
134 	u32 pte;
135 	int i;
136 
137 	WARN_ON(r->stolen);
138 
139 	gtt_slot = psb_gtt_entry(dev, r);
140 	pte = psb_gtt_mask_pte(page_to_pfn(dev_priv->scratch_page), 0);
141 
142 	for (i = 0; i < r->npage; i++)
143 		iowrite32(pte, gtt_slot++);
144 	ioread32(gtt_slot - 1);
145 	set_pages_array_wb(r->pages, r->npage);
146 }
147 
148 /**
149  *	psb_gtt_roll	-	set scrolling position
150  *	@dev: our DRM device
151  *	@r: the gtt mapping we are using
152  *	@roll: roll offset
153  *
154  *	Roll an existing pinned mapping by moving the pages through the GTT.
155  *	This allows us to implement hardware scrolling on the consoles without
156  *	a 2D engine
157  */
psb_gtt_roll(struct drm_device * dev,struct gtt_range * r,int roll)158 void psb_gtt_roll(struct drm_device *dev, struct gtt_range *r, int roll)
159 {
160 	u32 __iomem *gtt_slot;
161 	u32 pte;
162 	int i;
163 
164 	if (roll >= r->npage) {
165 		WARN_ON(1);
166 		return;
167 	}
168 
169 	r->roll = roll;
170 
171 	/* Not currently in the GTT - no worry we will write the mapping at
172 	   the right position when it gets pinned */
173 	if (!r->stolen && !r->in_gart)
174 		return;
175 
176 	gtt_slot = psb_gtt_entry(dev, r);
177 
178 	for (i = r->roll; i < r->npage; i++) {
179 		pte = psb_gtt_mask_pte(page_to_pfn(r->pages[i]), 0);
180 		iowrite32(pte, gtt_slot++);
181 	}
182 	for (i = 0; i < r->roll; i++) {
183 		pte = psb_gtt_mask_pte(page_to_pfn(r->pages[i]), 0);
184 		iowrite32(pte, gtt_slot++);
185 	}
186 	ioread32(gtt_slot - 1);
187 }
188 
189 /**
190  *	psb_gtt_attach_pages	-	attach and pin GEM pages
191  *	@gt: the gtt range
192  *
193  *	Pin and build an in kernel list of the pages that back our GEM object.
194  *	While we hold this the pages cannot be swapped out. This is protected
195  *	via the gtt mutex which the caller must hold.
196  */
psb_gtt_attach_pages(struct gtt_range * gt)197 static int psb_gtt_attach_pages(struct gtt_range *gt)
198 {
199 	struct inode *inode;
200 	struct address_space *mapping;
201 	int i;
202 	struct page *p;
203 	int pages = gt->gem.size / PAGE_SIZE;
204 
205 	WARN_ON(gt->pages);
206 
207 	/* This is the shared memory object that backs the GEM resource */
208 	inode = file_inode(gt->gem.filp);
209 	mapping = inode->i_mapping;
210 
211 	gt->pages = kmalloc(pages * sizeof(struct page *), GFP_KERNEL);
212 	if (gt->pages == NULL)
213 		return -ENOMEM;
214 	gt->npage = pages;
215 
216 	for (i = 0; i < pages; i++) {
217 		p = shmem_read_mapping_page(mapping, i);
218 		if (IS_ERR(p))
219 			goto err;
220 		gt->pages[i] = p;
221 	}
222 	return 0;
223 
224 err:
225 	while (i--)
226 		page_cache_release(gt->pages[i]);
227 	kfree(gt->pages);
228 	gt->pages = NULL;
229 	return PTR_ERR(p);
230 }
231 
232 /**
233  *	psb_gtt_detach_pages	-	attach and pin GEM pages
234  *	@gt: the gtt range
235  *
236  *	Undo the effect of psb_gtt_attach_pages. At this point the pages
237  *	must have been removed from the GTT as they could now be paged out
238  *	and move bus address. This is protected via the gtt mutex which the
239  *	caller must hold.
240  */
psb_gtt_detach_pages(struct gtt_range * gt)241 static void psb_gtt_detach_pages(struct gtt_range *gt)
242 {
243 	int i;
244 	for (i = 0; i < gt->npage; i++) {
245 		/* FIXME: do we need to force dirty */
246 		set_page_dirty(gt->pages[i]);
247 		page_cache_release(gt->pages[i]);
248 	}
249 	kfree(gt->pages);
250 	gt->pages = NULL;
251 }
252 
253 /**
254  *	psb_gtt_pin		-	pin pages into the GTT
255  *	@gt: range to pin
256  *
257  *	Pin a set of pages into the GTT. The pins are refcounted so that
258  *	multiple pins need multiple unpins to undo.
259  *
260  *	Non GEM backed objects treat this as a no-op as they are always GTT
261  *	backed objects.
262  */
psb_gtt_pin(struct gtt_range * gt)263 int psb_gtt_pin(struct gtt_range *gt)
264 {
265 	int ret = 0;
266 	struct drm_device *dev = gt->gem.dev;
267 	struct drm_psb_private *dev_priv = dev->dev_private;
268 
269 	mutex_lock(&dev_priv->gtt_mutex);
270 
271 	if (gt->in_gart == 0 && gt->stolen == 0) {
272 		ret = psb_gtt_attach_pages(gt);
273 		if (ret < 0)
274 			goto out;
275 		ret = psb_gtt_insert(dev, gt, 0);
276 		if (ret < 0) {
277 			psb_gtt_detach_pages(gt);
278 			goto out;
279 		}
280 	}
281 	gt->in_gart++;
282 out:
283 	mutex_unlock(&dev_priv->gtt_mutex);
284 	return ret;
285 }
286 
287 /**
288  *	psb_gtt_unpin		-	Drop a GTT pin requirement
289  *	@gt: range to pin
290  *
291  *	Undoes the effect of psb_gtt_pin. On the last drop the GEM object
292  *	will be removed from the GTT which will also drop the page references
293  *	and allow the VM to clean up or page stuff.
294  *
295  *	Non GEM backed objects treat this as a no-op as they are always GTT
296  *	backed objects.
297  */
psb_gtt_unpin(struct gtt_range * gt)298 void psb_gtt_unpin(struct gtt_range *gt)
299 {
300 	struct drm_device *dev = gt->gem.dev;
301 	struct drm_psb_private *dev_priv = dev->dev_private;
302 
303 	mutex_lock(&dev_priv->gtt_mutex);
304 
305 	WARN_ON(!gt->in_gart);
306 
307 	gt->in_gart--;
308 	if (gt->in_gart == 0 && gt->stolen == 0) {
309 		psb_gtt_remove(dev, gt);
310 		psb_gtt_detach_pages(gt);
311 	}
312 	mutex_unlock(&dev_priv->gtt_mutex);
313 }
314 
315 /*
316  *	GTT resource allocator - allocate and manage GTT address space
317  */
318 
319 /**
320  *	psb_gtt_alloc_range	-	allocate GTT address space
321  *	@dev: Our DRM device
322  *	@len: length (bytes) of address space required
323  *	@name: resource name
324  *	@backed: resource should be backed by stolen pages
325  *
326  *	Ask the kernel core to find us a suitable range of addresses
327  *	to use for a GTT mapping.
328  *
329  *	Returns a gtt_range structure describing the object, or NULL on
330  *	error. On successful return the resource is both allocated and marked
331  *	as in use.
332  */
psb_gtt_alloc_range(struct drm_device * dev,int len,const char * name,int backed)333 struct gtt_range *psb_gtt_alloc_range(struct drm_device *dev, int len,
334 						const char *name, int backed)
335 {
336 	struct drm_psb_private *dev_priv = dev->dev_private;
337 	struct gtt_range *gt;
338 	struct resource *r = dev_priv->gtt_mem;
339 	int ret;
340 	unsigned long start, end;
341 
342 	if (backed) {
343 		/* The start of the GTT is the stolen pages */
344 		start = r->start;
345 		end = r->start + dev_priv->gtt.stolen_size - 1;
346 	} else {
347 		/* The rest we will use for GEM backed objects */
348 		start = r->start + dev_priv->gtt.stolen_size;
349 		end = r->end;
350 	}
351 
352 	gt = kzalloc(sizeof(struct gtt_range), GFP_KERNEL);
353 	if (gt == NULL)
354 		return NULL;
355 	gt->resource.name = name;
356 	gt->stolen = backed;
357 	gt->in_gart = backed;
358 	gt->roll = 0;
359 	/* Ensure this is set for non GEM objects */
360 	gt->gem.dev = dev;
361 	ret = allocate_resource(dev_priv->gtt_mem, &gt->resource,
362 				len, start, end, PAGE_SIZE, NULL, NULL);
363 	if (ret == 0) {
364 		gt->offset = gt->resource.start - r->start;
365 		return gt;
366 	}
367 	kfree(gt);
368 	return NULL;
369 }
370 
371 /**
372  *	psb_gtt_free_range	-	release GTT address space
373  *	@dev: our DRM device
374  *	@gt: a mapping created with psb_gtt_alloc_range
375  *
376  *	Release a resource that was allocated with psb_gtt_alloc_range. If the
377  *	object has been pinned by mmap users we clean this up here currently.
378  */
psb_gtt_free_range(struct drm_device * dev,struct gtt_range * gt)379 void psb_gtt_free_range(struct drm_device *dev, struct gtt_range *gt)
380 {
381 	/* Undo the mmap pin if we are destroying the object */
382 	if (gt->mmapping) {
383 		psb_gtt_unpin(gt);
384 		gt->mmapping = 0;
385 	}
386 	WARN_ON(gt->in_gart && !gt->stolen);
387 	release_resource(&gt->resource);
388 	kfree(gt);
389 }
390 
psb_gtt_alloc(struct drm_device * dev)391 static void psb_gtt_alloc(struct drm_device *dev)
392 {
393 	struct drm_psb_private *dev_priv = dev->dev_private;
394 	init_rwsem(&dev_priv->gtt.sem);
395 }
396 
psb_gtt_takedown(struct drm_device * dev)397 void psb_gtt_takedown(struct drm_device *dev)
398 {
399 	struct drm_psb_private *dev_priv = dev->dev_private;
400 
401 	if (dev_priv->gtt_map) {
402 		iounmap(dev_priv->gtt_map);
403 		dev_priv->gtt_map = NULL;
404 	}
405 	if (dev_priv->gtt_initialized) {
406 		pci_write_config_word(dev->pdev, PSB_GMCH_CTRL,
407 				      dev_priv->gmch_ctrl);
408 		PSB_WVDC32(dev_priv->pge_ctl, PSB_PGETBL_CTL);
409 		(void) PSB_RVDC32(PSB_PGETBL_CTL);
410 	}
411 	if (dev_priv->vram_addr)
412 		iounmap(dev_priv->gtt_map);
413 }
414 
psb_gtt_init(struct drm_device * dev,int resume)415 int psb_gtt_init(struct drm_device *dev, int resume)
416 {
417 	struct drm_psb_private *dev_priv = dev->dev_private;
418 	unsigned gtt_pages;
419 	unsigned long stolen_size, vram_stolen_size;
420 	unsigned i, num_pages;
421 	unsigned pfn_base;
422 	struct psb_gtt *pg;
423 
424 	int ret = 0;
425 	uint32_t pte;
426 
427 	if (!resume) {
428 		mutex_init(&dev_priv->gtt_mutex);
429 		psb_gtt_alloc(dev);
430 	}
431 
432 	pg = &dev_priv->gtt;
433 
434 	/* Enable the GTT */
435 	pci_read_config_word(dev->pdev, PSB_GMCH_CTRL, &dev_priv->gmch_ctrl);
436 	pci_write_config_word(dev->pdev, PSB_GMCH_CTRL,
437 			      dev_priv->gmch_ctrl | _PSB_GMCH_ENABLED);
438 
439 	dev_priv->pge_ctl = PSB_RVDC32(PSB_PGETBL_CTL);
440 	PSB_WVDC32(dev_priv->pge_ctl | _PSB_PGETBL_ENABLED, PSB_PGETBL_CTL);
441 	(void) PSB_RVDC32(PSB_PGETBL_CTL);
442 
443 	/* The root resource we allocate address space from */
444 	dev_priv->gtt_initialized = 1;
445 
446 	pg->gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;
447 
448 	/*
449 	 *	The video mmu has a hw bug when accessing 0x0D0000000.
450 	 *	Make gatt start at 0x0e000,0000. This doesn't actually
451 	 *	matter for us but may do if the video acceleration ever
452 	 *	gets opened up.
453 	 */
454 	pg->mmu_gatt_start = 0xE0000000;
455 
456 	pg->gtt_start = pci_resource_start(dev->pdev, PSB_GTT_RESOURCE);
457 	gtt_pages = pci_resource_len(dev->pdev, PSB_GTT_RESOURCE)
458 								>> PAGE_SHIFT;
459 	/* CDV doesn't report this. In which case the system has 64 gtt pages */
460 	if (pg->gtt_start == 0 || gtt_pages == 0) {
461 		dev_dbg(dev->dev, "GTT PCI BAR not initialized.\n");
462 		gtt_pages = 64;
463 		pg->gtt_start = dev_priv->pge_ctl;
464 	}
465 
466 	pg->gatt_start = pci_resource_start(dev->pdev, PSB_GATT_RESOURCE);
467 	pg->gatt_pages = pci_resource_len(dev->pdev, PSB_GATT_RESOURCE)
468 								>> PAGE_SHIFT;
469 	dev_priv->gtt_mem = &dev->pdev->resource[PSB_GATT_RESOURCE];
470 
471 	if (pg->gatt_pages == 0 || pg->gatt_start == 0) {
472 		static struct resource fudge;	/* Preferably peppermint */
473 		/* This can occur on CDV systems. Fudge it in this case.
474 		   We really don't care what imaginary space is being allocated
475 		   at this point */
476 		dev_dbg(dev->dev, "GATT PCI BAR not initialized.\n");
477 		pg->gatt_start = 0x40000000;
478 		pg->gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
479 		/* This is a little confusing but in fact the GTT is providing
480 		   a view from the GPU into memory and not vice versa. As such
481 		   this is really allocating space that is not the same as the
482 		   CPU address space on CDV */
483 		fudge.start = 0x40000000;
484 		fudge.end = 0x40000000 + 128 * 1024 * 1024 - 1;
485 		fudge.name = "fudge";
486 		fudge.flags = IORESOURCE_MEM;
487 		dev_priv->gtt_mem = &fudge;
488 	}
489 
490 	pci_read_config_dword(dev->pdev, PSB_BSM, &dev_priv->stolen_base);
491 	vram_stolen_size = pg->gtt_phys_start - dev_priv->stolen_base
492 								- PAGE_SIZE;
493 
494 	stolen_size = vram_stolen_size;
495 
496 	dev_dbg(dev->dev, "Stolen memory base 0x%x, size %luK\n",
497 			dev_priv->stolen_base, vram_stolen_size / 1024);
498 
499 	if (resume && (gtt_pages != pg->gtt_pages) &&
500 	    (stolen_size != pg->stolen_size)) {
501 		dev_err(dev->dev, "GTT resume error.\n");
502 		ret = -EINVAL;
503 		goto out_err;
504 	}
505 
506 	pg->gtt_pages = gtt_pages;
507 	pg->stolen_size = stolen_size;
508 	dev_priv->vram_stolen_size = vram_stolen_size;
509 
510 	/*
511 	 *	Map the GTT and the stolen memory area
512 	 */
513 	if (!resume)
514 		dev_priv->gtt_map = ioremap_nocache(pg->gtt_phys_start,
515 						gtt_pages << PAGE_SHIFT);
516 	if (!dev_priv->gtt_map) {
517 		dev_err(dev->dev, "Failure to map gtt.\n");
518 		ret = -ENOMEM;
519 		goto out_err;
520 	}
521 
522 	if (!resume)
523 		dev_priv->vram_addr = ioremap_wc(dev_priv->stolen_base,
524 						 stolen_size);
525 	if (!dev_priv->vram_addr) {
526 		dev_err(dev->dev, "Failure to map stolen base.\n");
527 		ret = -ENOMEM;
528 		goto out_err;
529 	}
530 
531 	/*
532 	 * Insert vram stolen pages into the GTT
533 	 */
534 
535 	pfn_base = dev_priv->stolen_base >> PAGE_SHIFT;
536 	num_pages = vram_stolen_size >> PAGE_SHIFT;
537 	dev_dbg(dev->dev, "Set up %d stolen pages starting at 0x%08x, GTT offset %dK\n",
538 		num_pages, pfn_base << PAGE_SHIFT, 0);
539 	for (i = 0; i < num_pages; ++i) {
540 		pte = psb_gtt_mask_pte(pfn_base + i, 0);
541 		iowrite32(pte, dev_priv->gtt_map + i);
542 	}
543 
544 	/*
545 	 * Init rest of GTT to the scratch page to avoid accidents or scribbles
546 	 */
547 
548 	pfn_base = page_to_pfn(dev_priv->scratch_page);
549 	pte = psb_gtt_mask_pte(pfn_base, 0);
550 	for (; i < gtt_pages; ++i)
551 		iowrite32(pte, dev_priv->gtt_map + i);
552 
553 	(void) ioread32(dev_priv->gtt_map + i - 1);
554 	return 0;
555 
556 out_err:
557 	psb_gtt_takedown(dev);
558 	return ret;
559 }
560 
psb_gtt_restore(struct drm_device * dev)561 int psb_gtt_restore(struct drm_device *dev)
562 {
563 	struct drm_psb_private *dev_priv = dev->dev_private;
564 	struct resource *r = dev_priv->gtt_mem->child;
565 	struct gtt_range *range;
566 	unsigned int restored = 0, total = 0, size = 0;
567 
568 	/* On resume, the gtt_mutex is already initialized */
569 	mutex_lock(&dev_priv->gtt_mutex);
570 	psb_gtt_init(dev, 1);
571 
572 	while (r != NULL) {
573 		range = container_of(r, struct gtt_range, resource);
574 		if (range->pages) {
575 			psb_gtt_insert(dev, range, 1);
576 			size += range->resource.end - range->resource.start;
577 			restored++;
578 		}
579 		r = r->sibling;
580 		total++;
581 	}
582 	mutex_unlock(&dev_priv->gtt_mutex);
583 	DRM_DEBUG_DRIVER("Restored %u of %u gtt ranges (%u KB)", restored,
584 			 total, (size / 1024));
585 
586 	return 0;
587 }
588