1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  psb GEM interface
4  *
5  * Copyright (c) 2011, Intel Corporation.
6  *
7  * Authors: Alan Cox
8  *
9  * TODO:
10  *	-	we need to work out if the MMU is relevant (eg for
11  *		accelerated operations on a GEM object)
12  */
13 
14 #include <linux/pagemap.h>
15 
16 #include <asm/set_memory.h>
17 
18 #include <drm/drm.h>
19 #include <drm/drm_vma_manager.h>
20 
21 #include "gem.h"
22 #include "psb_drv.h"
23 
24 /*
25  * PSB GEM object
26  */
27 
psb_gem_pin(struct psb_gem_object * pobj)28 int psb_gem_pin(struct psb_gem_object *pobj)
29 {
30 	struct drm_gem_object *obj = &pobj->base;
31 	struct drm_device *dev = obj->dev;
32 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
33 	u32 gpu_base = dev_priv->gtt.gatt_start;
34 	struct page **pages;
35 	unsigned int npages;
36 	int ret;
37 
38 	ret = dma_resv_lock(obj->resv, NULL);
39 	if (drm_WARN_ONCE(dev, ret, "dma_resv_lock() failed, ret=%d\n", ret))
40 		return ret;
41 
42 	if (pobj->in_gart || pobj->stolen)
43 		goto out; /* already mapped */
44 
45 	pages = drm_gem_get_pages(obj);
46 	if (IS_ERR(pages)) {
47 		ret = PTR_ERR(pages);
48 		goto err_dma_resv_unlock;
49 	}
50 
51 	npages = obj->size / PAGE_SIZE;
52 
53 	set_pages_array_wc(pages, npages);
54 
55 	psb_gtt_insert_pages(dev_priv, &pobj->resource, pages);
56 	psb_mmu_insert_pages(psb_mmu_get_default_pd(dev_priv->mmu), pages,
57 			     (gpu_base + pobj->offset), npages, 0, 0,
58 			     PSB_MMU_CACHED_MEMORY);
59 
60 	pobj->pages = pages;
61 
62 out:
63 	++pobj->in_gart;
64 	dma_resv_unlock(obj->resv);
65 
66 	return 0;
67 
68 err_dma_resv_unlock:
69 	dma_resv_unlock(obj->resv);
70 	return ret;
71 }
72 
psb_gem_unpin(struct psb_gem_object * pobj)73 void psb_gem_unpin(struct psb_gem_object *pobj)
74 {
75 	struct drm_gem_object *obj = &pobj->base;
76 	struct drm_device *dev = obj->dev;
77 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
78 	u32 gpu_base = dev_priv->gtt.gatt_start;
79 	unsigned long npages;
80 	int ret;
81 
82 	ret = dma_resv_lock(obj->resv, NULL);
83 	if (drm_WARN_ONCE(dev, ret, "dma_resv_lock() failed, ret=%d\n", ret))
84 		return;
85 
86 	WARN_ON(!pobj->in_gart);
87 
88 	--pobj->in_gart;
89 
90 	if (pobj->in_gart || pobj->stolen)
91 		goto out;
92 
93 	npages = obj->size / PAGE_SIZE;
94 
95 	psb_mmu_remove_pages(psb_mmu_get_default_pd(dev_priv->mmu),
96 			     (gpu_base + pobj->offset), npages, 0, 0);
97 	psb_gtt_remove_pages(dev_priv, &pobj->resource);
98 
99 	/* Reset caching flags */
100 	set_pages_array_wb(pobj->pages, npages);
101 
102 	drm_gem_put_pages(obj, pobj->pages, true, false);
103 	pobj->pages = NULL;
104 
105 out:
106 	dma_resv_unlock(obj->resv);
107 }
108 
109 static vm_fault_t psb_gem_fault(struct vm_fault *vmf);
110 
psb_gem_free_object(struct drm_gem_object * obj)111 static void psb_gem_free_object(struct drm_gem_object *obj)
112 {
113 	struct psb_gem_object *pobj = to_psb_gem_object(obj);
114 
115 	/* Undo the mmap pin if we are destroying the object */
116 	if (pobj->mmapping)
117 		psb_gem_unpin(pobj);
118 
119 	drm_gem_object_release(obj);
120 
121 	WARN_ON(pobj->in_gart && !pobj->stolen);
122 
123 	release_resource(&pobj->resource);
124 	kfree(pobj);
125 }
126 
127 static const struct vm_operations_struct psb_gem_vm_ops = {
128 	.fault = psb_gem_fault,
129 	.open = drm_gem_vm_open,
130 	.close = drm_gem_vm_close,
131 };
132 
133 static const struct drm_gem_object_funcs psb_gem_object_funcs = {
134 	.free = psb_gem_free_object,
135 	.vm_ops = &psb_gem_vm_ops,
136 };
137 
138 struct psb_gem_object *
psb_gem_create(struct drm_device * dev,u64 size,const char * name,bool stolen,u32 align)139 psb_gem_create(struct drm_device *dev, u64 size, const char *name, bool stolen, u32 align)
140 {
141 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
142 	struct psb_gem_object *pobj;
143 	struct drm_gem_object *obj;
144 	int ret;
145 
146 	size = roundup(size, PAGE_SIZE);
147 
148 	pobj = kzalloc(sizeof(*pobj), GFP_KERNEL);
149 	if (!pobj)
150 		return ERR_PTR(-ENOMEM);
151 	obj = &pobj->base;
152 
153 	/* GTT resource */
154 
155 	ret = psb_gtt_allocate_resource(dev_priv, &pobj->resource, name, size, align, stolen,
156 					&pobj->offset);
157 	if (ret)
158 		goto err_kfree;
159 
160 	if (stolen) {
161 		pobj->stolen = true;
162 		pobj->in_gart = 1;
163 	}
164 
165 	/* GEM object */
166 
167 	obj->funcs = &psb_gem_object_funcs;
168 
169 	if (stolen) {
170 		drm_gem_private_object_init(dev, obj, size);
171 	} else {
172 		ret = drm_gem_object_init(dev, obj, size);
173 		if (ret)
174 			goto err_release_resource;
175 
176 		/* Limit the object to 32-bit mappings */
177 		mapping_set_gfp_mask(obj->filp->f_mapping, GFP_KERNEL | __GFP_DMA32);
178 	}
179 
180 	return pobj;
181 
182 err_release_resource:
183 	release_resource(&pobj->resource);
184 err_kfree:
185 	kfree(pobj);
186 	return ERR_PTR(ret);
187 }
188 
189 /**
190  *	psb_gem_dumb_create	-	create a dumb buffer
191  *	@file: our client file
192  *	@dev: our device
193  *	@args: the requested arguments copied from userspace
194  *
195  *	Allocate a buffer suitable for use for a frame buffer of the
196  *	form described by user space. Give userspace a handle by which
197  *	to reference it.
198  */
psb_gem_dumb_create(struct drm_file * file,struct drm_device * dev,struct drm_mode_create_dumb * args)199 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
200 			struct drm_mode_create_dumb *args)
201 {
202 	size_t pitch, size;
203 	struct psb_gem_object *pobj;
204 	struct drm_gem_object *obj;
205 	u32 handle;
206 	int ret;
207 
208 	pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
209 	pitch = ALIGN(pitch, 64);
210 
211 	size = pitch * args->height;
212 	size = roundup(size, PAGE_SIZE);
213 	if (!size)
214 		return -EINVAL;
215 
216 	pobj = psb_gem_create(dev, size, "gem", false, PAGE_SIZE);
217 	if (IS_ERR(pobj))
218 		return PTR_ERR(pobj);
219 	obj = &pobj->base;
220 
221 	ret = drm_gem_handle_create(file, obj, &handle);
222 	if (ret)
223 		goto err_drm_gem_object_put;
224 
225 	drm_gem_object_put(obj);
226 
227 	args->pitch = pitch;
228 	args->size = size;
229 	args->handle = handle;
230 
231 	return 0;
232 
233 err_drm_gem_object_put:
234 	drm_gem_object_put(obj);
235 	return ret;
236 }
237 
238 /**
239  *	psb_gem_fault		-	pagefault handler for GEM objects
240  *	@vmf: fault detail
241  *
242  *	Invoked when a fault occurs on an mmap of a GEM managed area. GEM
243  *	does most of the work for us including the actual map/unmap calls
244  *	but we need to do the actual page work.
245  *
246  *	This code eventually needs to handle faulting objects in and out
247  *	of the GTT and repacking it when we run out of space. We can put
248  *	that off for now and for our simple uses
249  *
250  *	The VMA was set up by GEM. In doing so it also ensured that the
251  *	vma->vm_private_data points to the GEM object that is backing this
252  *	mapping.
253  */
psb_gem_fault(struct vm_fault * vmf)254 static vm_fault_t psb_gem_fault(struct vm_fault *vmf)
255 {
256 	struct vm_area_struct *vma = vmf->vma;
257 	struct drm_gem_object *obj;
258 	struct psb_gem_object *pobj;
259 	int err;
260 	vm_fault_t ret;
261 	unsigned long pfn;
262 	pgoff_t page_offset;
263 	struct drm_device *dev;
264 	struct drm_psb_private *dev_priv;
265 
266 	obj = vma->vm_private_data;	/* GEM object */
267 	dev = obj->dev;
268 	dev_priv = to_drm_psb_private(dev);
269 
270 	pobj = to_psb_gem_object(obj);
271 
272 	/* Make sure we don't parallel update on a fault, nor move or remove
273 	   something from beneath our feet */
274 	mutex_lock(&dev_priv->mmap_mutex);
275 
276 	/* For now the mmap pins the object and it stays pinned. As things
277 	   stand that will do us no harm */
278 	if (pobj->mmapping == 0) {
279 		err = psb_gem_pin(pobj);
280 		if (err < 0) {
281 			dev_err(dev->dev, "gma500: pin failed: %d\n", err);
282 			ret = vmf_error(err);
283 			goto fail;
284 		}
285 		pobj->mmapping = 1;
286 	}
287 
288 	/* Page relative to the VMA start - we must calculate this ourselves
289 	   because vmf->pgoff is the fake GEM offset */
290 	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
291 
292 	/* CPU view of the page, don't go via the GART for CPU writes */
293 	if (pobj->stolen)
294 		pfn = (dev_priv->stolen_base + pobj->offset) >> PAGE_SHIFT;
295 	else
296 		pfn = page_to_pfn(pobj->pages[page_offset]);
297 	ret = vmf_insert_pfn(vma, vmf->address, pfn);
298 fail:
299 	mutex_unlock(&dev_priv->mmap_mutex);
300 
301 	return ret;
302 }
303 
304 /*
305  * Memory management
306  */
307 
308 /* Insert vram stolen pages into the GTT. */
psb_gem_mm_populate_stolen(struct drm_psb_private * pdev)309 static void psb_gem_mm_populate_stolen(struct drm_psb_private *pdev)
310 {
311 	struct drm_device *dev = &pdev->dev;
312 	unsigned int pfn_base;
313 	unsigned int i, num_pages;
314 	uint32_t pte;
315 
316 	pfn_base = pdev->stolen_base >> PAGE_SHIFT;
317 	num_pages = pdev->vram_stolen_size >> PAGE_SHIFT;
318 
319 	drm_dbg(dev, "Set up %u stolen pages starting at 0x%08x, GTT offset %dK\n",
320 		num_pages, pfn_base << PAGE_SHIFT, 0);
321 
322 	for (i = 0; i < num_pages; ++i) {
323 		pte = psb_gtt_mask_pte(pfn_base + i, PSB_MMU_CACHED_MEMORY);
324 		iowrite32(pte, pdev->gtt_map + i);
325 	}
326 
327 	(void)ioread32(pdev->gtt_map + i - 1);
328 }
329 
psb_gem_mm_init(struct drm_device * dev)330 int psb_gem_mm_init(struct drm_device *dev)
331 {
332 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
333 	struct pci_dev *pdev = to_pci_dev(dev->dev);
334 	unsigned long stolen_size, vram_stolen_size;
335 	struct psb_gtt *pg;
336 	int ret;
337 
338 	mutex_init(&dev_priv->mmap_mutex);
339 
340 	pg = &dev_priv->gtt;
341 
342 	pci_read_config_dword(pdev, PSB_BSM, &dev_priv->stolen_base);
343 	vram_stolen_size = pg->gtt_phys_start - dev_priv->stolen_base - PAGE_SIZE;
344 
345 	stolen_size = vram_stolen_size;
346 
347 	dev_dbg(dev->dev, "Stolen memory base 0x%x, size %luK\n",
348 		dev_priv->stolen_base, vram_stolen_size / 1024);
349 
350 	pg->stolen_size = stolen_size;
351 	dev_priv->vram_stolen_size = vram_stolen_size;
352 
353 	dev_priv->vram_addr = ioremap_wc(dev_priv->stolen_base, stolen_size);
354 	if (!dev_priv->vram_addr) {
355 		dev_err(dev->dev, "Failure to map stolen base.\n");
356 		ret = -ENOMEM;
357 		goto err_mutex_destroy;
358 	}
359 
360 	psb_gem_mm_populate_stolen(dev_priv);
361 
362 	return 0;
363 
364 err_mutex_destroy:
365 	mutex_destroy(&dev_priv->mmap_mutex);
366 	return ret;
367 }
368 
psb_gem_mm_fini(struct drm_device * dev)369 void psb_gem_mm_fini(struct drm_device *dev)
370 {
371 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
372 
373 	iounmap(dev_priv->vram_addr);
374 
375 	mutex_destroy(&dev_priv->mmap_mutex);
376 }
377 
378 /* Re-insert all pinned GEM objects into GTT. */
psb_gem_mm_populate_resources(struct drm_psb_private * pdev)379 static void psb_gem_mm_populate_resources(struct drm_psb_private *pdev)
380 {
381 	unsigned int restored = 0, total = 0, size = 0;
382 	struct resource *r = pdev->gtt_mem->child;
383 	struct drm_device *dev = &pdev->dev;
384 	struct psb_gem_object *pobj;
385 
386 	while (r) {
387 		/*
388 		 * TODO: GTT restoration needs a refactoring, so that we don't have to touch
389 		 *       struct psb_gem_object here. The type represents a GEM object and is
390 		 *       not related to the GTT itself.
391 		 */
392 		pobj = container_of(r, struct psb_gem_object, resource);
393 		if (pobj->pages) {
394 			psb_gtt_insert_pages(pdev, &pobj->resource, pobj->pages);
395 			size += resource_size(&pobj->resource);
396 			++restored;
397 		}
398 		r = r->sibling;
399 		++total;
400 	}
401 
402 	drm_dbg(dev, "Restored %u of %u gtt ranges (%u KB)", restored, total, (size / 1024));
403 }
404 
psb_gem_mm_resume(struct drm_device * dev)405 int psb_gem_mm_resume(struct drm_device *dev)
406 {
407 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
408 	struct pci_dev *pdev = to_pci_dev(dev->dev);
409 	unsigned long stolen_size, vram_stolen_size;
410 	struct psb_gtt *pg;
411 
412 	pg = &dev_priv->gtt;
413 
414 	pci_read_config_dword(pdev, PSB_BSM, &dev_priv->stolen_base);
415 	vram_stolen_size = pg->gtt_phys_start - dev_priv->stolen_base - PAGE_SIZE;
416 
417 	stolen_size = vram_stolen_size;
418 
419 	dev_dbg(dev->dev, "Stolen memory base 0x%x, size %luK\n", dev_priv->stolen_base,
420 		vram_stolen_size / 1024);
421 
422 	if (stolen_size != pg->stolen_size) {
423 		dev_err(dev->dev, "GTT resume error.\n");
424 		return -EINVAL;
425 	}
426 
427 	psb_gem_mm_populate_stolen(dev_priv);
428 	psb_gem_mm_populate_resources(dev_priv);
429 
430 	return 0;
431 }
432