gem.c

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