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
28int 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
62out:
63	++pobj->in_gart;
64	dma_resv_unlock(obj->resv);
65
66	return 0;
67
68err_dma_resv_unlock:
69	dma_resv_unlock(obj->resv);
70	return ret;
71}
72
73void 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
105out:
106	dma_resv_unlock(obj->resv);
107}
108
109static vm_fault_t psb_gem_fault(struct vm_fault *vmf);
110
111static 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
127static 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
133static 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
138struct psb_gem_object *
139psb_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
182err_release_resource:
183	release_resource(&pobj->resource);
184err_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 */
199int 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
233err_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 */
254static 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);
298fail:
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. */
309static 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
330int 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
364err_mutex_destroy:
365	mutex_destroy(&dev_priv->mmap_mutex);
366	return ret;
367}
368
369void 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. */
379static 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
405int 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