xref: /openbmc/linux/drivers/gpu/drm/gma500/gtt.c (revision 9a29f5fc)
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 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 /* Acquires GTT mutex internally. */
78 void psb_gtt_insert_pages(struct drm_psb_private *pdev, const struct resource *res,
79 			  struct page **pages)
80 {
81 	resource_size_t npages, i;
82 	u32 __iomem *gtt_slot;
83 	u32 pte;
84 
85 	mutex_lock(&pdev->gtt_mutex);
86 
87 	/* Write our page entries into the GTT itself */
88 
89 	npages = resource_size(res) >> PAGE_SHIFT;
90 	gtt_slot = psb_gtt_entry(pdev, res);
91 
92 	for (i = 0; i < npages; ++i, ++gtt_slot) {
93 		pte = psb_gtt_mask_pte(page_to_pfn(pages[i]), PSB_MMU_CACHED_MEMORY);
94 		iowrite32(pte, gtt_slot);
95 	}
96 
97 	/* Make sure all the entries are set before we return */
98 	ioread32(gtt_slot - 1);
99 
100 	mutex_unlock(&pdev->gtt_mutex);
101 }
102 
103 /* Acquires GTT mutex internally. */
104 void psb_gtt_remove_pages(struct drm_psb_private *pdev, const struct resource *res)
105 {
106 	resource_size_t npages, i;
107 	u32 __iomem *gtt_slot;
108 	u32 pte;
109 
110 	mutex_lock(&pdev->gtt_mutex);
111 
112 	/* Install scratch page for the resource */
113 
114 	pte = psb_gtt_mask_pte(page_to_pfn(pdev->scratch_page), PSB_MMU_CACHED_MEMORY);
115 
116 	npages = resource_size(res) >> PAGE_SHIFT;
117 	gtt_slot = psb_gtt_entry(pdev, res);
118 
119 	for (i = 0; i < npages; ++i, ++gtt_slot)
120 		iowrite32(pte, gtt_slot);
121 
122 	/* Make sure all the entries are set before we return */
123 	ioread32(gtt_slot - 1);
124 
125 	mutex_unlock(&pdev->gtt_mutex);
126 }
127 
128 static int psb_gtt_enable(struct drm_psb_private *dev_priv)
129 {
130 	struct drm_device *dev = &dev_priv->dev;
131 	struct pci_dev *pdev = to_pci_dev(dev->dev);
132 	int ret;
133 
134 	ret = pci_read_config_word(pdev, PSB_GMCH_CTRL, &dev_priv->gmch_ctrl);
135 	if (ret)
136 		return pcibios_err_to_errno(ret);
137 	ret = pci_write_config_word(pdev, PSB_GMCH_CTRL, dev_priv->gmch_ctrl | _PSB_GMCH_ENABLED);
138 	if (ret)
139 		return pcibios_err_to_errno(ret);
140 
141 	dev_priv->pge_ctl = PSB_RVDC32(PSB_PGETBL_CTL);
142 	PSB_WVDC32(dev_priv->pge_ctl | _PSB_PGETBL_ENABLED, PSB_PGETBL_CTL);
143 
144 	(void)PSB_RVDC32(PSB_PGETBL_CTL);
145 
146 	return 0;
147 }
148 
149 static void psb_gtt_disable(struct drm_psb_private *dev_priv)
150 {
151 	struct drm_device *dev = &dev_priv->dev;
152 	struct pci_dev *pdev = to_pci_dev(dev->dev);
153 
154 	pci_write_config_word(pdev, PSB_GMCH_CTRL, dev_priv->gmch_ctrl);
155 	PSB_WVDC32(dev_priv->pge_ctl, PSB_PGETBL_CTL);
156 
157 	(void)PSB_RVDC32(PSB_PGETBL_CTL);
158 }
159 
160 void psb_gtt_fini(struct drm_device *dev)
161 {
162 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
163 
164 	iounmap(dev_priv->gtt_map);
165 	psb_gtt_disable(dev_priv);
166 	mutex_destroy(&dev_priv->gtt_mutex);
167 }
168 
169 /* Clear GTT. Use a scratch page to avoid accidents or scribbles. */
170 static void psb_gtt_clear(struct drm_psb_private *pdev)
171 {
172 	resource_size_t pfn_base;
173 	unsigned long i;
174 	uint32_t pte;
175 
176 	pfn_base = page_to_pfn(pdev->scratch_page);
177 	pte = psb_gtt_mask_pte(pfn_base, PSB_MMU_CACHED_MEMORY);
178 
179 	for (i = 0; i < pdev->gtt.gtt_pages; ++i)
180 		iowrite32(pte, pdev->gtt_map + i);
181 
182 	(void)ioread32(pdev->gtt_map + i - 1);
183 }
184 
185 static void psb_gtt_init_ranges(struct drm_psb_private *dev_priv)
186 {
187 	struct drm_device *dev = &dev_priv->dev;
188 	struct pci_dev *pdev = to_pci_dev(dev->dev);
189 	struct psb_gtt *pg = &dev_priv->gtt;
190 	resource_size_t gtt_phys_start, mmu_gatt_start, gtt_start, gtt_pages,
191 			gatt_start, gatt_pages;
192 	struct resource *gtt_mem;
193 
194 	/* The root resource we allocate address space from */
195 	gtt_phys_start = dev_priv->pge_ctl & PAGE_MASK;
196 
197 	/*
198 	 * The video MMU has a HW bug when accessing 0x0d0000000. Make
199 	 * GATT start at 0x0e0000000. This doesn't actually matter for
200 	 * us now, but maybe will if the video acceleration ever gets
201 	 * opened up.
202 	 */
203 	mmu_gatt_start = 0xe0000000;
204 
205 	gtt_start = pci_resource_start(pdev, PSB_GTT_RESOURCE);
206 	gtt_pages = pci_resource_len(pdev, PSB_GTT_RESOURCE) >> PAGE_SHIFT;
207 
208 	/* CDV doesn't report this. In which case the system has 64 gtt pages */
209 	if (!gtt_start || !gtt_pages) {
210 		dev_dbg(dev->dev, "GTT PCI BAR not initialized.\n");
211 		gtt_pages = 64;
212 		gtt_start = dev_priv->pge_ctl;
213 	}
214 
215 	gatt_start = pci_resource_start(pdev, PSB_GATT_RESOURCE);
216 	gatt_pages = pci_resource_len(pdev, PSB_GATT_RESOURCE) >> PAGE_SHIFT;
217 
218 	if (!gatt_pages || !gatt_start) {
219 		static struct resource fudge;	/* Preferably peppermint */
220 
221 		/*
222 		 * This can occur on CDV systems. Fudge it in this case. We
223 		 * really don't care what imaginary space is being allocated
224 		 * at this point.
225 		 */
226 		dev_dbg(dev->dev, "GATT PCI BAR not initialized.\n");
227 		gatt_start = 0x40000000;
228 		gatt_pages = (128 * 1024 * 1024) >> PAGE_SHIFT;
229 
230 		/*
231 		 * This is a little confusing but in fact the GTT is providing
232 		 * a view from the GPU into memory and not vice versa. As such
233 		 * this is really allocating space that is not the same as the
234 		 * CPU address space on CDV.
235 		 */
236 		fudge.start = 0x40000000;
237 		fudge.end = 0x40000000 + 128 * 1024 * 1024 - 1;
238 		fudge.name = "fudge";
239 		fudge.flags = IORESOURCE_MEM;
240 
241 		gtt_mem = &fudge;
242 	} else {
243 		gtt_mem = &pdev->resource[PSB_GATT_RESOURCE];
244 	}
245 
246 	pg->gtt_phys_start = gtt_phys_start;
247 	pg->mmu_gatt_start = mmu_gatt_start;
248 	pg->gtt_start = gtt_start;
249 	pg->gtt_pages = gtt_pages;
250 	pg->gatt_start = gatt_start;
251 	pg->gatt_pages = gatt_pages;
252 	dev_priv->gtt_mem = gtt_mem;
253 }
254 
255 int psb_gtt_init(struct drm_device *dev)
256 {
257 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
258 	struct psb_gtt *pg = &dev_priv->gtt;
259 	int ret;
260 
261 	mutex_init(&dev_priv->gtt_mutex);
262 
263 	ret = psb_gtt_enable(dev_priv);
264 	if (ret)
265 		goto err_mutex_destroy;
266 
267 	psb_gtt_init_ranges(dev_priv);
268 
269 	dev_priv->gtt_map = ioremap(pg->gtt_phys_start, pg->gtt_pages << PAGE_SHIFT);
270 	if (!dev_priv->gtt_map) {
271 		dev_err(dev->dev, "Failure to map gtt.\n");
272 		ret = -ENOMEM;
273 		goto err_psb_gtt_disable;
274 	}
275 
276 	psb_gtt_clear(dev_priv);
277 
278 	return 0;
279 
280 err_psb_gtt_disable:
281 	psb_gtt_disable(dev_priv);
282 err_mutex_destroy:
283 	mutex_destroy(&dev_priv->gtt_mutex);
284 	return ret;
285 }
286 
287 int psb_gtt_resume(struct drm_device *dev)
288 {
289 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
290 	struct psb_gtt *pg = &dev_priv->gtt;
291 	unsigned int old_gtt_pages = pg->gtt_pages;
292 	int ret;
293 
294 	/* Enable the GTT */
295 	ret = psb_gtt_enable(dev_priv);
296 	if (ret)
297 		return ret;
298 
299 	psb_gtt_init_ranges(dev_priv);
300 
301 	if (old_gtt_pages != pg->gtt_pages) {
302 		dev_err(dev->dev, "GTT resume error.\n");
303 		ret = -ENODEV;
304 		goto err_psb_gtt_disable;
305 	}
306 
307 	psb_gtt_clear(dev_priv);
308 
309 err_psb_gtt_disable:
310 	psb_gtt_disable(dev_priv);
311 	return ret;
312 }
313