xref: /openbmc/linux/drivers/gpu/drm/gma500/gtt.c (revision 8e74a48d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2007, Intel Corporation.
4  * All Rights Reserved.
5  *
6  * Authors: Thomas Hellstrom <thomas-at-tungstengraphics.com>
7  *	    Alan Cox <alan@linux.intel.com>
8  */
9 
10 #include "gem.h" /* TODO: for struct psb_gem_object, see psb_gtt_restore() */
11 #include "psb_drv.h"
12 
13 
14 /*
15  *	GTT resource allocator - manage page mappings in GTT space
16  */
17 
18 int psb_gtt_allocate_resource(struct drm_psb_private *pdev, struct resource *res,
19 			      const char *name, resource_size_t size, resource_size_t align,
20 			      bool stolen, u32 *offset)
21 {
22 	struct resource *root = pdev->gtt_mem;
23 	resource_size_t start, end;
24 	int ret;
25 
26 	if (stolen) {
27 		/* The start of the GTT is backed by stolen pages. */
28 		start = root->start;
29 		end = root->start + pdev->gtt.stolen_size - 1;
30 	} else {
31 		/* The rest is backed by system pages. */
32 		start = root->start + pdev->gtt.stolen_size;
33 		end = root->end;
34 	}
35 
36 	res->name = name;
37 	ret = allocate_resource(root, res, size, start, end, align, NULL, NULL);
38 	if (ret)
39 		return ret;
40 	*offset = res->start - root->start;
41 
42 	return 0;
43 }
44 
45 /**
46  *	psb_gtt_mask_pte	-	generate GTT pte entry
47  *	@pfn: page number to encode
48  *	@type: type of memory in the GTT
49  *
50  *	Set the GTT entry for the appropriate memory type.
51  */
52 static inline uint32_t psb_gtt_mask_pte(uint32_t pfn, int type)
53 {
54 	uint32_t mask = PSB_PTE_VALID;
55 
56 	/* Ensure we explode rather than put an invalid low mapping of
57 	   a high mapping page into the gtt */
58 	BUG_ON(pfn & ~(0xFFFFFFFF >> PAGE_SHIFT));
59 
60 	if (type & PSB_MMU_CACHED_MEMORY)
61 		mask |= PSB_PTE_CACHED;
62 	if (type & PSB_MMU_RO_MEMORY)
63 		mask |= PSB_PTE_RO;
64 	if (type & PSB_MMU_WO_MEMORY)
65 		mask |= PSB_PTE_WO;
66 
67 	return (pfn << PAGE_SHIFT) | mask;
68 }
69 
70 static u32 __iomem *psb_gtt_entry(struct drm_psb_private *pdev, const struct resource *res)
71 {
72 	unsigned long offset = res->start - pdev->gtt_mem->start;
73 
74 	return pdev->gtt_map + (offset >> PAGE_SHIFT);
75 }
76 
77 /*
78  * Take our preallocated GTT range and insert the GEM object into
79  * the GTT. This is protected via the gtt mutex which the caller
80  * must hold.
81  */
82 void psb_gtt_insert_pages(struct drm_psb_private *pdev, const struct resource *res,
83 			  struct page **pages)
84 {
85 	resource_size_t npages, i;
86 	u32 __iomem *gtt_slot;
87 	u32 pte;
88 
89 	/* Write our page entries into the GTT itself */
90 
91 	npages = resource_size(res) >> PAGE_SHIFT;
92 	gtt_slot = psb_gtt_entry(pdev, res);
93 
94 	for (i = 0; i < npages; ++i, ++gtt_slot) {
95 		pte = psb_gtt_mask_pte(page_to_pfn(pages[i]), PSB_MMU_CACHED_MEMORY);
96 		iowrite32(pte, gtt_slot);
97 	}
98 
99 	/* Make sure all the entries are set before we return */
100 	ioread32(gtt_slot - 1);
101 }
102 
103 /*
104  * Remove a preallocated GTT range from the GTT. Overwrite all the
105  * page table entries with the dummy page. This is protected via the gtt
106  * mutex which the caller must hold.
107  */
108 void psb_gtt_remove_pages(struct drm_psb_private *pdev, const struct resource *res)
109 {
110 	resource_size_t npages, i;
111 	u32 __iomem *gtt_slot;
112 	u32 pte;
113 
114 	/* Install scratch page for the resource */
115 
116 	pte = psb_gtt_mask_pte(page_to_pfn(pdev->scratch_page), PSB_MMU_CACHED_MEMORY);
117 
118 	npages = resource_size(res) >> PAGE_SHIFT;
119 	gtt_slot = psb_gtt_entry(pdev, res);
120 
121 	for (i = 0; i < npages; ++i, ++gtt_slot)
122 		iowrite32(pte, gtt_slot);
123 
124 	/* Make sure all the entries are set before we return */
125 	ioread32(gtt_slot - 1);
126 }
127 
128 static void psb_gtt_alloc(struct drm_device *dev)
129 {
130 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
131 	init_rwsem(&dev_priv->gtt.sem);
132 }
133 
134 void psb_gtt_takedown(struct drm_device *dev)
135 {
136 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
137 	struct pci_dev *pdev = to_pci_dev(dev->dev);
138 
139 	if (dev_priv->gtt_map) {
140 		iounmap(dev_priv->gtt_map);
141 		dev_priv->gtt_map = NULL;
142 	}
143 	if (dev_priv->gtt_initialized) {
144 		pci_write_config_word(pdev, PSB_GMCH_CTRL,
145 				      dev_priv->gmch_ctrl);
146 		PSB_WVDC32(dev_priv->pge_ctl, PSB_PGETBL_CTL);
147 		(void) PSB_RVDC32(PSB_PGETBL_CTL);
148 	}
149 	if (dev_priv->vram_addr)
150 		iounmap(dev_priv->gtt_map);
151 }
152 
153 int psb_gtt_init(struct drm_device *dev, int resume)
154 {
155 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
156 	struct pci_dev *pdev = to_pci_dev(dev->dev);
157 	unsigned gtt_pages;
158 	unsigned long stolen_size, vram_stolen_size;
159 	unsigned i, num_pages;
160 	unsigned pfn_base;
161 	struct psb_gtt *pg;
162 
163 	int ret = 0;
164 	uint32_t pte;
165 
166 	if (!resume) {
167 		mutex_init(&dev_priv->gtt_mutex);
168 		mutex_init(&dev_priv->mmap_mutex);
169 		psb_gtt_alloc(dev);
170 	}
171 
172 	pg = &dev_priv->gtt;
173 
174 	/* Enable the GTT */
175 	pci_read_config_word(pdev, PSB_GMCH_CTRL, &dev_priv->gmch_ctrl);
176 	pci_write_config_word(pdev, PSB_GMCH_CTRL,
177 			      dev_priv->gmch_ctrl | _PSB_GMCH_ENABLED);
178 
179 	dev_priv->pge_ctl = PSB_RVDC32(PSB_PGETBL_CTL);
180 	PSB_WVDC32(dev_priv->pge_ctl | _PSB_PGETBL_ENABLED, PSB_PGETBL_CTL);
181 	(void) PSB_RVDC32(PSB_PGETBL_CTL);
182 
183 	/* The root resource we allocate address space from */
184 	dev_priv->gtt_initialized = 1;
185 
186 	pg->gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;
187 
188 	/*
189 	 *	The video mmu has a hw bug when accessing 0x0D0000000.
190 	 *	Make gatt start at 0x0e000,0000. This doesn't actually
191 	 *	matter for us but may do if the video acceleration ever
192 	 *	gets opened up.
193 	 */
194 	pg->mmu_gatt_start = 0xE0000000;
195 
196 	pg->gtt_start = pci_resource_start(pdev, PSB_GTT_RESOURCE);
197 	gtt_pages = pci_resource_len(pdev, PSB_GTT_RESOURCE)
198 								>> PAGE_SHIFT;
199 	/* CDV doesn't report this. In which case the system has 64 gtt pages */
200 	if (pg->gtt_start == 0 || gtt_pages == 0) {
201 		dev_dbg(dev->dev, "GTT PCI BAR not initialized.\n");
202 		gtt_pages = 64;
203 		pg->gtt_start = dev_priv->pge_ctl;
204 	}
205 
206 	pg->gatt_start = pci_resource_start(pdev, PSB_GATT_RESOURCE);
207 	pg->gatt_pages = pci_resource_len(pdev, PSB_GATT_RESOURCE)
208 								>> PAGE_SHIFT;
209 	dev_priv->gtt_mem = &pdev->resource[PSB_GATT_RESOURCE];
210 
211 	if (pg->gatt_pages == 0 || pg->gatt_start == 0) {
212 		static struct resource fudge;	/* Preferably peppermint */
213 		/* This can occur on CDV systems. Fudge it in this case.
214 		   We really don't care what imaginary space is being allocated
215 		   at this point */
216 		dev_dbg(dev->dev, "GATT PCI BAR not initialized.\n");
217 		pg->gatt_start = 0x40000000;
218 		pg->gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
219 		/* This is a little confusing but in fact the GTT is providing
220 		   a view from the GPU into memory and not vice versa. As such
221 		   this is really allocating space that is not the same as the
222 		   CPU address space on CDV */
223 		fudge.start = 0x40000000;
224 		fudge.end = 0x40000000 + 128 * 1024 * 1024 - 1;
225 		fudge.name = "fudge";
226 		fudge.flags = IORESOURCE_MEM;
227 		dev_priv->gtt_mem = &fudge;
228 	}
229 
230 	pci_read_config_dword(pdev, PSB_BSM, &dev_priv->stolen_base);
231 	vram_stolen_size = pg->gtt_phys_start - dev_priv->stolen_base
232 								- PAGE_SIZE;
233 
234 	stolen_size = vram_stolen_size;
235 
236 	dev_dbg(dev->dev, "Stolen memory base 0x%x, size %luK\n",
237 			dev_priv->stolen_base, vram_stolen_size / 1024);
238 
239 	if (resume && (gtt_pages != pg->gtt_pages) &&
240 	    (stolen_size != pg->stolen_size)) {
241 		dev_err(dev->dev, "GTT resume error.\n");
242 		ret = -EINVAL;
243 		goto out_err;
244 	}
245 
246 	pg->gtt_pages = gtt_pages;
247 	pg->stolen_size = stolen_size;
248 	dev_priv->vram_stolen_size = vram_stolen_size;
249 
250 	/*
251 	 *	Map the GTT and the stolen memory area
252 	 */
253 	if (!resume)
254 		dev_priv->gtt_map = ioremap(pg->gtt_phys_start,
255 						gtt_pages << PAGE_SHIFT);
256 	if (!dev_priv->gtt_map) {
257 		dev_err(dev->dev, "Failure to map gtt.\n");
258 		ret = -ENOMEM;
259 		goto out_err;
260 	}
261 
262 	if (!resume)
263 		dev_priv->vram_addr = ioremap_wc(dev_priv->stolen_base,
264 						 stolen_size);
265 
266 	if (!dev_priv->vram_addr) {
267 		dev_err(dev->dev, "Failure to map stolen base.\n");
268 		ret = -ENOMEM;
269 		goto out_err;
270 	}
271 
272 	/*
273 	 * Insert vram stolen pages into the GTT
274 	 */
275 
276 	pfn_base = dev_priv->stolen_base >> PAGE_SHIFT;
277 	num_pages = vram_stolen_size >> PAGE_SHIFT;
278 	dev_dbg(dev->dev, "Set up %d stolen pages starting at 0x%08x, GTT offset %dK\n",
279 		num_pages, pfn_base << PAGE_SHIFT, 0);
280 	for (i = 0; i < num_pages; ++i) {
281 		pte = psb_gtt_mask_pte(pfn_base + i, PSB_MMU_CACHED_MEMORY);
282 		iowrite32(pte, dev_priv->gtt_map + i);
283 	}
284 
285 	/*
286 	 * Init rest of GTT to the scratch page to avoid accidents or scribbles
287 	 */
288 
289 	pfn_base = page_to_pfn(dev_priv->scratch_page);
290 	pte = psb_gtt_mask_pte(pfn_base, PSB_MMU_CACHED_MEMORY);
291 	for (; i < gtt_pages; ++i)
292 		iowrite32(pte, dev_priv->gtt_map + i);
293 
294 	(void) ioread32(dev_priv->gtt_map + i - 1);
295 	return 0;
296 
297 out_err:
298 	psb_gtt_takedown(dev);
299 	return ret;
300 }
301 
302 int psb_gtt_restore(struct drm_device *dev)
303 {
304 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
305 	struct resource *r = dev_priv->gtt_mem->child;
306 	struct psb_gem_object *pobj;
307 	unsigned int restored = 0, total = 0, size = 0;
308 
309 	/* On resume, the gtt_mutex is already initialized */
310 	mutex_lock(&dev_priv->gtt_mutex);
311 	psb_gtt_init(dev, 1);
312 
313 	while (r != NULL) {
314 		/*
315 		 * TODO: GTT restoration needs a refactoring, so that we don't have to touch
316 		 *       struct psb_gem_object here. The type represents a GEM object and is
317 		 *       not related to the GTT itself.
318 		 */
319 		pobj = container_of(r, struct psb_gem_object, resource);
320 		if (pobj->pages) {
321 			psb_gtt_insert_pages(dev_priv, &pobj->resource, pobj->pages);
322 			size += pobj->resource.end - pobj->resource.start;
323 			restored++;
324 		}
325 		r = r->sibling;
326 		total++;
327 	}
328 	mutex_unlock(&dev_priv->gtt_mutex);
329 	DRM_DEBUG_DRIVER("Restored %u of %u gtt ranges (%u KB)", restored,
330 			 total, (size / 1024));
331 
332 	return 0;
333 }
334