1 /*
2  * Copyright © 2014 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  * Please try to maintain the following order within this file unless it makes
24  * sense to do otherwise. From top to bottom:
25  * 1. typedefs
26  * 2. #defines, and macros
27  * 3. structure definitions
28  * 4. function prototypes
29  *
30  * Within each section, please try to order by generation in ascending order,
31  * from top to bottom (ie. gen6 on the top, gen8 on the bottom).
32  */
33 
34 #ifndef __I915_GEM_GTT_H__
35 #define __I915_GEM_GTT_H__
36 
37 #include <linux/io-mapping.h>
38 
39 struct drm_i915_file_private;
40 
41 typedef uint32_t gen6_pte_t;
42 typedef uint64_t gen8_pte_t;
43 typedef uint64_t gen8_pde_t;
44 typedef uint64_t gen8_ppgtt_pdpe_t;
45 typedef uint64_t gen8_ppgtt_pml4e_t;
46 
47 #define ggtt_total_entries(ggtt) ((ggtt)->base.total >> PAGE_SHIFT)
48 
49 /* gen6-hsw has bit 11-4 for physical addr bit 39-32 */
50 #define GEN6_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0xff0))
51 #define GEN6_PTE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
52 #define GEN6_PDE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
53 #define GEN6_PTE_CACHE_LLC		(2 << 1)
54 #define GEN6_PTE_UNCACHED		(1 << 1)
55 #define GEN6_PTE_VALID			(1 << 0)
56 
57 #define I915_PTES(pte_len)		(PAGE_SIZE / (pte_len))
58 #define I915_PTE_MASK(pte_len)		(I915_PTES(pte_len) - 1)
59 #define I915_PDES			512
60 #define I915_PDE_MASK			(I915_PDES - 1)
61 #define NUM_PTE(pde_shift)     (1 << (pde_shift - PAGE_SHIFT))
62 
63 #define GEN6_PTES			I915_PTES(sizeof(gen6_pte_t))
64 #define GEN6_PD_SIZE		        (I915_PDES * PAGE_SIZE)
65 #define GEN6_PD_ALIGN			(PAGE_SIZE * 16)
66 #define GEN6_PDE_SHIFT			22
67 #define GEN6_PDE_VALID			(1 << 0)
68 
69 #define GEN7_PTE_CACHE_L3_LLC		(3 << 1)
70 
71 #define BYT_PTE_SNOOPED_BY_CPU_CACHES	(1 << 2)
72 #define BYT_PTE_WRITEABLE		(1 << 1)
73 
74 /* Cacheability Control is a 4-bit value. The low three bits are stored in bits
75  * 3:1 of the PTE, while the fourth bit is stored in bit 11 of the PTE.
76  */
77 #define HSW_CACHEABILITY_CONTROL(bits)	((((bits) & 0x7) << 1) | \
78 					 (((bits) & 0x8) << (11 - 3)))
79 #define HSW_WB_LLC_AGE3			HSW_CACHEABILITY_CONTROL(0x2)
80 #define HSW_WB_LLC_AGE0			HSW_CACHEABILITY_CONTROL(0x3)
81 #define HSW_WB_ELLC_LLC_AGE3		HSW_CACHEABILITY_CONTROL(0x8)
82 #define HSW_WB_ELLC_LLC_AGE0		HSW_CACHEABILITY_CONTROL(0xb)
83 #define HSW_WT_ELLC_LLC_AGE3		HSW_CACHEABILITY_CONTROL(0x7)
84 #define HSW_WT_ELLC_LLC_AGE0		HSW_CACHEABILITY_CONTROL(0x6)
85 #define HSW_PTE_UNCACHED		(0)
86 #define HSW_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0x7f0))
87 #define HSW_PTE_ADDR_ENCODE(addr)	HSW_GTT_ADDR_ENCODE(addr)
88 
89 /* GEN8 legacy style address is defined as a 3 level page table:
90  * 31:30 | 29:21 | 20:12 |  11:0
91  * PDPE  |  PDE  |  PTE  | offset
92  * The difference as compared to normal x86 3 level page table is the PDPEs are
93  * programmed via register.
94  *
95  * GEN8 48b legacy style address is defined as a 4 level page table:
96  * 47:39 | 38:30 | 29:21 | 20:12 |  11:0
97  * PML4E | PDPE  |  PDE  |  PTE  | offset
98  */
99 #define GEN8_PML4ES_PER_PML4		512
100 #define GEN8_PML4E_SHIFT		39
101 #define GEN8_PML4E_MASK			(GEN8_PML4ES_PER_PML4 - 1)
102 #define GEN8_PDPE_SHIFT			30
103 /* NB: GEN8_PDPE_MASK is untrue for 32b platforms, but it has no impact on 32b page
104  * tables */
105 #define GEN8_PDPE_MASK			0x1ff
106 #define GEN8_PDE_SHIFT			21
107 #define GEN8_PDE_MASK			0x1ff
108 #define GEN8_PTE_SHIFT			12
109 #define GEN8_PTE_MASK			0x1ff
110 #define GEN8_LEGACY_PDPES		4
111 #define GEN8_PTES			I915_PTES(sizeof(gen8_pte_t))
112 
113 #define I915_PDPES_PER_PDP(dev) (USES_FULL_48BIT_PPGTT(dev) ?\
114 				 GEN8_PML4ES_PER_PML4 : GEN8_LEGACY_PDPES)
115 
116 #define PPAT_UNCACHED_INDEX		(_PAGE_PWT | _PAGE_PCD)
117 #define PPAT_CACHED_PDE_INDEX		0 /* WB LLC */
118 #define PPAT_CACHED_INDEX		_PAGE_PAT /* WB LLCeLLC */
119 #define PPAT_DISPLAY_ELLC_INDEX		_PAGE_PCD /* WT eLLC */
120 
121 #define CHV_PPAT_SNOOP			(1<<6)
122 #define GEN8_PPAT_AGE(x)		(x<<4)
123 #define GEN8_PPAT_LLCeLLC		(3<<2)
124 #define GEN8_PPAT_LLCELLC		(2<<2)
125 #define GEN8_PPAT_LLC			(1<<2)
126 #define GEN8_PPAT_WB			(3<<0)
127 #define GEN8_PPAT_WT			(2<<0)
128 #define GEN8_PPAT_WC			(1<<0)
129 #define GEN8_PPAT_UC			(0<<0)
130 #define GEN8_PPAT_ELLC_OVERRIDE		(0<<2)
131 #define GEN8_PPAT(i, x)			((uint64_t) (x) << ((i) * 8))
132 
133 enum i915_ggtt_view_type {
134 	I915_GGTT_VIEW_NORMAL = 0,
135 	I915_GGTT_VIEW_ROTATED,
136 	I915_GGTT_VIEW_PARTIAL,
137 };
138 
139 struct intel_rotation_info {
140 	unsigned int uv_offset;
141 	uint32_t pixel_format;
142 	unsigned int uv_start_page;
143 	struct {
144 		/* tiles */
145 		unsigned int width, height;
146 	} plane[2];
147 };
148 
149 struct i915_ggtt_view {
150 	enum i915_ggtt_view_type type;
151 
152 	union {
153 		struct {
154 			u64 offset;
155 			unsigned int size;
156 		} partial;
157 		struct intel_rotation_info rotated;
158 	} params;
159 
160 	struct sg_table *pages;
161 };
162 
163 extern const struct i915_ggtt_view i915_ggtt_view_normal;
164 extern const struct i915_ggtt_view i915_ggtt_view_rotated;
165 
166 enum i915_cache_level;
167 
168 /**
169  * A VMA represents a GEM BO that is bound into an address space. Therefore, a
170  * VMA's presence cannot be guaranteed before binding, or after unbinding the
171  * object into/from the address space.
172  *
173  * To make things as simple as possible (ie. no refcounting), a VMA's lifetime
174  * will always be <= an objects lifetime. So object refcounting should cover us.
175  */
176 struct i915_vma {
177 	struct drm_mm_node node;
178 	struct drm_i915_gem_object *obj;
179 	struct i915_address_space *vm;
180 	void __iomem *iomap;
181 
182 	/** Flags and address space this VMA is bound to */
183 #define GLOBAL_BIND	(1<<0)
184 #define LOCAL_BIND	(1<<1)
185 	unsigned int bound : 4;
186 	bool is_ggtt : 1;
187 
188 	/**
189 	 * Support different GGTT views into the same object.
190 	 * This means there can be multiple VMA mappings per object and per VM.
191 	 * i915_ggtt_view_type is used to distinguish between those entries.
192 	 * The default one of zero (I915_GGTT_VIEW_NORMAL) is default and also
193 	 * assumed in GEM functions which take no ggtt view parameter.
194 	 */
195 	struct i915_ggtt_view ggtt_view;
196 
197 	/** This object's place on the active/inactive lists */
198 	struct list_head vm_link;
199 
200 	struct list_head obj_link; /* Link in the object's VMA list */
201 
202 	/** This vma's place in the batchbuffer or on the eviction list */
203 	struct list_head exec_list;
204 
205 	/**
206 	 * Used for performing relocations during execbuffer insertion.
207 	 */
208 	struct hlist_node exec_node;
209 	unsigned long exec_handle;
210 	struct drm_i915_gem_exec_object2 *exec_entry;
211 
212 	/**
213 	 * How many users have pinned this object in GTT space. The following
214 	 * users can each hold at most one reference: pwrite/pread, execbuffer
215 	 * (objects are not allowed multiple times for the same batchbuffer),
216 	 * and the framebuffer code. When switching/pageflipping, the
217 	 * framebuffer code has at most two buffers pinned per crtc.
218 	 *
219 	 * In the worst case this is 1 + 1 + 1 + 2*2 = 7. That would fit into 3
220 	 * bits with absolutely no headroom. So use 4 bits. */
221 	unsigned int pin_count:4;
222 #define DRM_I915_GEM_OBJECT_MAX_PIN_COUNT 0xf
223 };
224 
225 struct i915_page_dma {
226 	struct page *page;
227 	union {
228 		dma_addr_t daddr;
229 
230 		/* For gen6/gen7 only. This is the offset in the GGTT
231 		 * where the page directory entries for PPGTT begin
232 		 */
233 		uint32_t ggtt_offset;
234 	};
235 };
236 
237 #define px_base(px) (&(px)->base)
238 #define px_page(px) (px_base(px)->page)
239 #define px_dma(px) (px_base(px)->daddr)
240 
241 struct i915_page_scratch {
242 	struct i915_page_dma base;
243 };
244 
245 struct i915_page_table {
246 	struct i915_page_dma base;
247 
248 	unsigned long *used_ptes;
249 };
250 
251 struct i915_page_directory {
252 	struct i915_page_dma base;
253 
254 	unsigned long *used_pdes;
255 	struct i915_page_table *page_table[I915_PDES]; /* PDEs */
256 };
257 
258 struct i915_page_directory_pointer {
259 	struct i915_page_dma base;
260 
261 	unsigned long *used_pdpes;
262 	struct i915_page_directory **page_directory;
263 };
264 
265 struct i915_pml4 {
266 	struct i915_page_dma base;
267 
268 	DECLARE_BITMAP(used_pml4es, GEN8_PML4ES_PER_PML4);
269 	struct i915_page_directory_pointer *pdps[GEN8_PML4ES_PER_PML4];
270 };
271 
272 struct i915_address_space {
273 	struct drm_mm mm;
274 	struct drm_device *dev;
275 	/* Every address space belongs to a struct file - except for the global
276 	 * GTT that is owned by the driver (and so @file is set to NULL). In
277 	 * principle, no information should leak from one context to another
278 	 * (or between files/processes etc) unless explicitly shared by the
279 	 * owner. Tracking the owner is important in order to free up per-file
280 	 * objects along with the file, to aide resource tracking, and to
281 	 * assign blame.
282 	 */
283 	struct drm_i915_file_private *file;
284 	struct list_head global_link;
285 	u64 start;		/* Start offset always 0 for dri2 */
286 	u64 total;		/* size addr space maps (ex. 2GB for ggtt) */
287 
288 	struct i915_page_scratch *scratch_page;
289 	struct i915_page_table *scratch_pt;
290 	struct i915_page_directory *scratch_pd;
291 	struct i915_page_directory_pointer *scratch_pdp; /* GEN8+ & 48b PPGTT */
292 
293 	/**
294 	 * List of objects currently involved in rendering.
295 	 *
296 	 * Includes buffers having the contents of their GPU caches
297 	 * flushed, not necessarily primitives. last_read_req
298 	 * represents when the rendering involved will be completed.
299 	 *
300 	 * A reference is held on the buffer while on this list.
301 	 */
302 	struct list_head active_list;
303 
304 	/**
305 	 * LRU list of objects which are not in the ringbuffer and
306 	 * are ready to unbind, but are still in the GTT.
307 	 *
308 	 * last_read_req is NULL while an object is in this list.
309 	 *
310 	 * A reference is not held on the buffer while on this list,
311 	 * as merely being GTT-bound shouldn't prevent its being
312 	 * freed, and we'll pull it off the list in the free path.
313 	 */
314 	struct list_head inactive_list;
315 
316 	/* FIXME: Need a more generic return type */
317 	gen6_pte_t (*pte_encode)(dma_addr_t addr,
318 				 enum i915_cache_level level,
319 				 bool valid, u32 flags); /* Create a valid PTE */
320 	/* flags for pte_encode */
321 #define PTE_READ_ONLY	(1<<0)
322 	int (*allocate_va_range)(struct i915_address_space *vm,
323 				 uint64_t start,
324 				 uint64_t length);
325 	void (*clear_range)(struct i915_address_space *vm,
326 			    uint64_t start,
327 			    uint64_t length,
328 			    bool use_scratch);
329 	void (*insert_page)(struct i915_address_space *vm,
330 			    dma_addr_t addr,
331 			    uint64_t offset,
332 			    enum i915_cache_level cache_level,
333 			    u32 flags);
334 	void (*insert_entries)(struct i915_address_space *vm,
335 			       struct sg_table *st,
336 			       uint64_t start,
337 			       enum i915_cache_level cache_level, u32 flags);
338 	void (*cleanup)(struct i915_address_space *vm);
339 	/** Unmap an object from an address space. This usually consists of
340 	 * setting the valid PTE entries to a reserved scratch page. */
341 	void (*unbind_vma)(struct i915_vma *vma);
342 	/* Map an object into an address space with the given cache flags. */
343 	int (*bind_vma)(struct i915_vma *vma,
344 			enum i915_cache_level cache_level,
345 			u32 flags);
346 };
347 
348 #define i915_is_ggtt(V) (!(V)->file)
349 
350 /* The Graphics Translation Table is the way in which GEN hardware translates a
351  * Graphics Virtual Address into a Physical Address. In addition to the normal
352  * collateral associated with any va->pa translations GEN hardware also has a
353  * portion of the GTT which can be mapped by the CPU and remain both coherent
354  * and correct (in cases like swizzling). That region is referred to as GMADR in
355  * the spec.
356  */
357 struct i915_ggtt {
358 	struct i915_address_space base;
359 
360 	size_t stolen_size;		/* Total size of stolen memory */
361 	size_t stolen_usable_size;	/* Total size minus BIOS reserved */
362 	size_t stolen_reserved_base;
363 	size_t stolen_reserved_size;
364 	u64 mappable_end;		/* End offset that we can CPU map */
365 	struct io_mapping *mappable;	/* Mapping to our CPU mappable region */
366 	phys_addr_t mappable_base;	/* PA of our GMADR */
367 
368 	/** "Graphics Stolen Memory" holds the global PTEs */
369 	void __iomem *gsm;
370 
371 	bool do_idle_maps;
372 
373 	int mtrr;
374 };
375 
376 struct i915_hw_ppgtt {
377 	struct i915_address_space base;
378 	struct kref ref;
379 	struct drm_mm_node node;
380 	unsigned long pd_dirty_rings;
381 	union {
382 		struct i915_pml4 pml4;		/* GEN8+ & 48b PPGTT */
383 		struct i915_page_directory_pointer pdp;	/* GEN8+ */
384 		struct i915_page_directory pd;		/* GEN6-7 */
385 	};
386 
387 	gen6_pte_t __iomem *pd_addr;
388 
389 	int (*enable)(struct i915_hw_ppgtt *ppgtt);
390 	int (*switch_mm)(struct i915_hw_ppgtt *ppgtt,
391 			 struct drm_i915_gem_request *req);
392 	void (*debug_dump)(struct i915_hw_ppgtt *ppgtt, struct seq_file *m);
393 };
394 
395 /*
396  * gen6_for_each_pde() iterates over every pde from start until start+length.
397  * If start and start+length are not perfectly divisible, the macro will round
398  * down and up as needed. Start=0 and length=2G effectively iterates over
399  * every PDE in the system. The macro modifies ALL its parameters except 'pd',
400  * so each of the other parameters should preferably be a simple variable, or
401  * at most an lvalue with no side-effects!
402  */
403 #define gen6_for_each_pde(pt, pd, start, length, iter)			\
404 	for (iter = gen6_pde_index(start);				\
405 	     length > 0 && iter < I915_PDES &&				\
406 		(pt = (pd)->page_table[iter], true);			\
407 	     ({ u32 temp = ALIGN(start+1, 1 << GEN6_PDE_SHIFT);		\
408 		    temp = min(temp - start, length);			\
409 		    start += temp, length -= temp; }), ++iter)
410 
411 #define gen6_for_all_pdes(pt, pd, iter)					\
412 	for (iter = 0;							\
413 	     iter < I915_PDES &&					\
414 		(pt = (pd)->page_table[iter], true);			\
415 	     ++iter)
416 
417 static inline uint32_t i915_pte_index(uint64_t address, uint32_t pde_shift)
418 {
419 	const uint32_t mask = NUM_PTE(pde_shift) - 1;
420 
421 	return (address >> PAGE_SHIFT) & mask;
422 }
423 
424 /* Helper to counts the number of PTEs within the given length. This count
425  * does not cross a page table boundary, so the max value would be
426  * GEN6_PTES for GEN6, and GEN8_PTES for GEN8.
427 */
428 static inline uint32_t i915_pte_count(uint64_t addr, size_t length,
429 				      uint32_t pde_shift)
430 {
431 	const uint64_t mask = ~((1ULL << pde_shift) - 1);
432 	uint64_t end;
433 
434 	WARN_ON(length == 0);
435 	WARN_ON(offset_in_page(addr|length));
436 
437 	end = addr + length;
438 
439 	if ((addr & mask) != (end & mask))
440 		return NUM_PTE(pde_shift) - i915_pte_index(addr, pde_shift);
441 
442 	return i915_pte_index(end, pde_shift) - i915_pte_index(addr, pde_shift);
443 }
444 
445 static inline uint32_t i915_pde_index(uint64_t addr, uint32_t shift)
446 {
447 	return (addr >> shift) & I915_PDE_MASK;
448 }
449 
450 static inline uint32_t gen6_pte_index(uint32_t addr)
451 {
452 	return i915_pte_index(addr, GEN6_PDE_SHIFT);
453 }
454 
455 static inline size_t gen6_pte_count(uint32_t addr, uint32_t length)
456 {
457 	return i915_pte_count(addr, length, GEN6_PDE_SHIFT);
458 }
459 
460 static inline uint32_t gen6_pde_index(uint32_t addr)
461 {
462 	return i915_pde_index(addr, GEN6_PDE_SHIFT);
463 }
464 
465 /* Equivalent to the gen6 version, For each pde iterates over every pde
466  * between from start until start + length. On gen8+ it simply iterates
467  * over every page directory entry in a page directory.
468  */
469 #define gen8_for_each_pde(pt, pd, start, length, iter)			\
470 	for (iter = gen8_pde_index(start);				\
471 	     length > 0 && iter < I915_PDES &&				\
472 		(pt = (pd)->page_table[iter], true);			\
473 	     ({ u64 temp = ALIGN(start+1, 1 << GEN8_PDE_SHIFT);		\
474 		    temp = min(temp - start, length);			\
475 		    start += temp, length -= temp; }), ++iter)
476 
477 #define gen8_for_each_pdpe(pd, pdp, start, length, iter)		\
478 	for (iter = gen8_pdpe_index(start);				\
479 	     length > 0 && iter < I915_PDPES_PER_PDP(dev) &&		\
480 		(pd = (pdp)->page_directory[iter], true);		\
481 	     ({ u64 temp = ALIGN(start+1, 1 << GEN8_PDPE_SHIFT);	\
482 		    temp = min(temp - start, length);			\
483 		    start += temp, length -= temp; }), ++iter)
484 
485 #define gen8_for_each_pml4e(pdp, pml4, start, length, iter)		\
486 	for (iter = gen8_pml4e_index(start);				\
487 	     length > 0 && iter < GEN8_PML4ES_PER_PML4 &&		\
488 		(pdp = (pml4)->pdps[iter], true);			\
489 	     ({ u64 temp = ALIGN(start+1, 1ULL << GEN8_PML4E_SHIFT);	\
490 		    temp = min(temp - start, length);			\
491 		    start += temp, length -= temp; }), ++iter)
492 
493 static inline uint32_t gen8_pte_index(uint64_t address)
494 {
495 	return i915_pte_index(address, GEN8_PDE_SHIFT);
496 }
497 
498 static inline uint32_t gen8_pde_index(uint64_t address)
499 {
500 	return i915_pde_index(address, GEN8_PDE_SHIFT);
501 }
502 
503 static inline uint32_t gen8_pdpe_index(uint64_t address)
504 {
505 	return (address >> GEN8_PDPE_SHIFT) & GEN8_PDPE_MASK;
506 }
507 
508 static inline uint32_t gen8_pml4e_index(uint64_t address)
509 {
510 	return (address >> GEN8_PML4E_SHIFT) & GEN8_PML4E_MASK;
511 }
512 
513 static inline size_t gen8_pte_count(uint64_t address, uint64_t length)
514 {
515 	return i915_pte_count(address, length, GEN8_PDE_SHIFT);
516 }
517 
518 static inline dma_addr_t
519 i915_page_dir_dma_addr(const struct i915_hw_ppgtt *ppgtt, const unsigned n)
520 {
521 	return test_bit(n, ppgtt->pdp.used_pdpes) ?
522 		px_dma(ppgtt->pdp.page_directory[n]) :
523 		px_dma(ppgtt->base.scratch_pd);
524 }
525 
526 int i915_ggtt_probe_hw(struct drm_i915_private *dev_priv);
527 int i915_ggtt_init_hw(struct drm_i915_private *dev_priv);
528 int i915_ggtt_enable_hw(struct drm_i915_private *dev_priv);
529 int i915_gem_init_ggtt(struct drm_i915_private *dev_priv);
530 void i915_ggtt_cleanup_hw(struct drm_i915_private *dev_priv);
531 
532 int i915_ppgtt_init_hw(struct drm_device *dev);
533 void i915_ppgtt_release(struct kref *kref);
534 struct i915_hw_ppgtt *i915_ppgtt_create(struct drm_i915_private *dev_priv,
535 					struct drm_i915_file_private *fpriv);
536 static inline void i915_ppgtt_get(struct i915_hw_ppgtt *ppgtt)
537 {
538 	if (ppgtt)
539 		kref_get(&ppgtt->ref);
540 }
541 static inline void i915_ppgtt_put(struct i915_hw_ppgtt *ppgtt)
542 {
543 	if (ppgtt)
544 		kref_put(&ppgtt->ref, i915_ppgtt_release);
545 }
546 
547 void i915_check_and_clear_faults(struct drm_i915_private *dev_priv);
548 void i915_gem_suspend_gtt_mappings(struct drm_device *dev);
549 void i915_gem_restore_gtt_mappings(struct drm_device *dev);
550 
551 int __must_check i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj);
552 void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj);
553 
554 static inline bool
555 i915_ggtt_view_equal(const struct i915_ggtt_view *a,
556                      const struct i915_ggtt_view *b)
557 {
558 	if (WARN_ON(!a || !b))
559 		return false;
560 
561 	if (a->type != b->type)
562 		return false;
563 	if (a->type != I915_GGTT_VIEW_NORMAL)
564 		return !memcmp(&a->params, &b->params, sizeof(a->params));
565 	return true;
566 }
567 
568 size_t
569 i915_ggtt_view_size(struct drm_i915_gem_object *obj,
570 		    const struct i915_ggtt_view *view);
571 
572 /**
573  * i915_vma_pin_iomap - calls ioremap_wc to map the GGTT VMA via the aperture
574  * @vma: VMA to iomap
575  *
576  * The passed in VMA has to be pinned in the global GTT mappable region.
577  * An extra pinning of the VMA is acquired for the return iomapping,
578  * the caller must call i915_vma_unpin_iomap to relinquish the pinning
579  * after the iomapping is no longer required.
580  *
581  * Callers must hold the struct_mutex.
582  *
583  * Returns a valid iomapped pointer or ERR_PTR.
584  */
585 void __iomem *i915_vma_pin_iomap(struct i915_vma *vma);
586 #define IO_ERR_PTR(x) ((void __iomem *)ERR_PTR(x))
587 
588 /**
589  * i915_vma_unpin_iomap - unpins the mapping returned from i915_vma_iomap
590  * @vma: VMA to unpin
591  *
592  * Unpins the previously iomapped VMA from i915_vma_pin_iomap().
593  *
594  * Callers must hold the struct_mutex. This function is only valid to be
595  * called on a VMA previously iomapped by the caller with i915_vma_pin_iomap().
596  */
597 static inline void i915_vma_unpin_iomap(struct i915_vma *vma)
598 {
599 	lockdep_assert_held(&vma->vm->dev->struct_mutex);
600 	GEM_BUG_ON(vma->pin_count == 0);
601 	GEM_BUG_ON(vma->iomap == NULL);
602 	vma->pin_count--;
603 }
604 
605 #endif
606