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2332 Serge 1
/*
2
 * Copyright © 2010 Daniel Vetter
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
 */
24
 
3243 Serge 25
 
3480 Serge 26
#define AGP_NORMAL_MEMORY 0
27
 
28
#define AGP_USER_TYPES (1 << 16)
29
#define AGP_USER_MEMORY (AGP_USER_TYPES)
30
#define AGP_USER_CACHED_MEMORY (AGP_USER_TYPES + 1)
31
 
3031 serge 32
#include 
33
#include 
2332 Serge 34
#include "i915_drv.h"
2351 Serge 35
#include "i915_trace.h"
2332 Serge 36
#include "intel_drv.h"
37
 
4104 Serge 38
#define GEN6_PPGTT_PD_ENTRIES 512
39
#define I915_PPGTT_PT_ENTRIES (PAGE_SIZE / sizeof(gen6_gtt_pte_t))
3243 Serge 40
 
41
/* PPGTT stuff */
42
#define GEN6_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0xff0))
4104 Serge 43
#define HSW_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0x7f0))
3243 Serge 44
 
45
#define GEN6_PDE_VALID			(1 << 0)
46
/* gen6+ has bit 11-4 for physical addr bit 39-32 */
47
#define GEN6_PDE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
48
 
49
#define GEN6_PTE_VALID			(1 << 0)
50
#define GEN6_PTE_UNCACHED		(1 << 1)
51
#define HSW_PTE_UNCACHED		(0)
52
#define GEN6_PTE_CACHE_LLC		(2 << 1)
4104 Serge 53
#define GEN7_PTE_CACHE_L3_LLC		(3 << 1)
3243 Serge 54
#define GEN6_PTE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
4104 Serge 55
#define HSW_PTE_ADDR_ENCODE(addr)	HSW_GTT_ADDR_ENCODE(addr)
3243 Serge 56
 
4104 Serge 57
/* Cacheability Control is a 4-bit value. The low three bits are stored in *
58
 * bits 3:1 of the PTE, while the fourth bit is stored in bit 11 of the PTE.
59
 */
60
#define HSW_CACHEABILITY_CONTROL(bits)	((((bits) & 0x7) << 1) | \
61
					 (((bits) & 0x8) << (11 - 3)))
62
#define HSW_WB_LLC_AGE3			HSW_CACHEABILITY_CONTROL(0x2)
63
#define HSW_WB_LLC_AGE0			HSW_CACHEABILITY_CONTROL(0x3)
64
#define HSW_WB_ELLC_LLC_AGE0		HSW_CACHEABILITY_CONTROL(0xb)
65
#define HSW_WT_ELLC_LLC_AGE0		HSW_CACHEABILITY_CONTROL(0x6)
66
 
67
static gen6_gtt_pte_t snb_pte_encode(dma_addr_t addr,
68
				     enum i915_cache_level level)
69
{
70
	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
71
	pte |= GEN6_PTE_ADDR_ENCODE(addr);
72
 
73
	switch (level) {
74
	case I915_CACHE_L3_LLC:
75
	case I915_CACHE_LLC:
76
		pte |= GEN6_PTE_CACHE_LLC;
77
		break;
78
	case I915_CACHE_NONE:
79
		pte |= GEN6_PTE_UNCACHED;
80
		break;
81
	default:
82
		WARN_ON(1);
83
	}
84
 
85
	return pte;
86
}
87
 
88
static gen6_gtt_pte_t ivb_pte_encode(dma_addr_t addr,
3243 Serge 89
				   enum i915_cache_level level)
90
{
3746 Serge 91
	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
3243 Serge 92
	pte |= GEN6_PTE_ADDR_ENCODE(addr);
93
 
94
	switch (level) {
4104 Serge 95
	case I915_CACHE_L3_LLC:
96
		pte |= GEN7_PTE_CACHE_L3_LLC;
3243 Serge 97
		break;
98
	case I915_CACHE_LLC:
99
		pte |= GEN6_PTE_CACHE_LLC;
100
		break;
101
	case I915_CACHE_NONE:
102
			pte |= GEN6_PTE_UNCACHED;
103
		break;
104
	default:
4104 Serge 105
		WARN_ON(1);
3243 Serge 106
	}
107
 
108
	return pte;
109
}
110
 
4104 Serge 111
#define BYT_PTE_WRITEABLE		(1 << 1)
112
#define BYT_PTE_SNOOPED_BY_CPU_CACHES	(1 << 2)
113
 
114
static gen6_gtt_pte_t byt_pte_encode(dma_addr_t addr,
115
				     enum i915_cache_level level)
3746 Serge 116
{
4104 Serge 117
	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
118
	pte |= GEN6_PTE_ADDR_ENCODE(addr);
119
 
120
	/* Mark the page as writeable.  Other platforms don't have a
121
	 * setting for read-only/writable, so this matches that behavior.
122
	 */
123
	pte |= BYT_PTE_WRITEABLE;
124
 
125
	if (level != I915_CACHE_NONE)
126
		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
127
 
128
	return pte;
129
}
130
 
131
static gen6_gtt_pte_t hsw_pte_encode(dma_addr_t addr,
132
				     enum i915_cache_level level)
133
{
134
	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
135
	pte |= HSW_PTE_ADDR_ENCODE(addr);
136
 
137
	if (level != I915_CACHE_NONE)
138
		pte |= HSW_WB_LLC_AGE3;
139
 
140
	return pte;
141
}
142
 
143
static gen6_gtt_pte_t iris_pte_encode(dma_addr_t addr,
144
				      enum i915_cache_level level)
145
{
146
	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
147
	pte |= HSW_PTE_ADDR_ENCODE(addr);
148
 
149
	switch (level) {
150
	case I915_CACHE_NONE:
151
		break;
152
	case I915_CACHE_WT:
153
		pte |= HSW_WT_ELLC_LLC_AGE0;
154
		break;
155
	default:
156
		pte |= HSW_WB_ELLC_LLC_AGE0;
157
		break;
158
	}
159
 
160
	return pte;
161
}
162
 
163
static void gen6_write_pdes(struct i915_hw_ppgtt *ppgtt)
164
{
165
	struct drm_i915_private *dev_priv = ppgtt->base.dev->dev_private;
3746 Serge 166
	gen6_gtt_pte_t __iomem *pd_addr;
167
	uint32_t pd_entry;
168
	int i;
169
 
4104 Serge 170
	WARN_ON(ppgtt->pd_offset & 0x3f);
3746 Serge 171
	pd_addr = (gen6_gtt_pte_t __iomem*)dev_priv->gtt.gsm +
172
		ppgtt->pd_offset / sizeof(gen6_gtt_pte_t);
173
	for (i = 0; i < ppgtt->num_pd_entries; i++) {
174
		dma_addr_t pt_addr;
175
 
176
		pt_addr = ppgtt->pt_dma_addr[i];
177
		pd_entry = GEN6_PDE_ADDR_ENCODE(pt_addr);
178
		pd_entry |= GEN6_PDE_VALID;
179
 
180
		writel(pd_entry, pd_addr + i);
181
	}
182
	readl(pd_addr);
4104 Serge 183
}
3746 Serge 184
 
4104 Serge 185
static int gen6_ppgtt_enable(struct drm_device *dev)
186
{
187
	drm_i915_private_t *dev_priv = dev->dev_private;
188
	uint32_t pd_offset;
189
	struct intel_ring_buffer *ring;
190
	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
191
	int i;
192
 
193
	BUG_ON(ppgtt->pd_offset & 0x3f);
194
 
195
	gen6_write_pdes(ppgtt);
196
 
3746 Serge 197
	pd_offset = ppgtt->pd_offset;
198
	pd_offset /= 64; /* in cachelines, */
199
	pd_offset <<= 16;
200
 
201
	if (INTEL_INFO(dev)->gen == 6) {
202
		uint32_t ecochk, gab_ctl, ecobits;
203
 
204
		ecobits = I915_READ(GAC_ECO_BITS);
205
		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_SNB_BIT |
206
					 ECOBITS_PPGTT_CACHE64B);
207
 
208
		gab_ctl = I915_READ(GAB_CTL);
209
		I915_WRITE(GAB_CTL, gab_ctl | GAB_CTL_CONT_AFTER_PAGEFAULT);
210
 
211
		ecochk = I915_READ(GAM_ECOCHK);
212
		I915_WRITE(GAM_ECOCHK, ecochk | ECOCHK_SNB_BIT |
213
				       ECOCHK_PPGTT_CACHE64B);
214
		I915_WRITE(GFX_MODE, _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
215
	} else if (INTEL_INFO(dev)->gen >= 7) {
216
		uint32_t ecochk, ecobits;
217
 
218
		ecobits = I915_READ(GAC_ECO_BITS);
219
		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_PPGTT_CACHE64B);
220
 
221
		ecochk = I915_READ(GAM_ECOCHK);
222
		if (IS_HASWELL(dev)) {
223
			ecochk |= ECOCHK_PPGTT_WB_HSW;
224
		} else {
225
			ecochk |= ECOCHK_PPGTT_LLC_IVB;
226
			ecochk &= ~ECOCHK_PPGTT_GFDT_IVB;
227
		}
228
		I915_WRITE(GAM_ECOCHK, ecochk);
229
		/* GFX_MODE is per-ring on gen7+ */
230
	}
231
 
232
	for_each_ring(ring, dev_priv, i) {
233
		if (INTEL_INFO(dev)->gen >= 7)
234
			I915_WRITE(RING_MODE_GEN7(ring),
235
				   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
236
 
237
		I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
238
		I915_WRITE(RING_PP_DIR_BASE(ring), pd_offset);
239
	}
240
	return 0;
241
}
242
 
3031 serge 243
/* PPGTT support for Sandybdrige/Gen6 and later */
4104 Serge 244
static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
3031 serge 245
				   unsigned first_entry,
246
				   unsigned num_entries)
247
{
4104 Serge 248
	struct i915_hw_ppgtt *ppgtt =
249
		container_of(vm, struct i915_hw_ppgtt, base);
3746 Serge 250
	gen6_gtt_pte_t *pt_vaddr, scratch_pte;
251
	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
3031 serge 252
	unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
253
	unsigned last_pte, i;
254
 
4104 Serge 255
	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC);
3031 serge 256
 
257
    pt_vaddr = AllocKernelSpace(4096);
258
 
3480 Serge 259
    if(pt_vaddr == NULL)
260
        return;
261
 
262
	while (num_entries) {
3031 serge 263
            last_pte = first_pte + num_entries;
264
            if (last_pte > I915_PPGTT_PT_ENTRIES)
265
                last_pte = I915_PPGTT_PT_ENTRIES;
266
 
3746 Serge 267
            MapPage(pt_vaddr,(addr_t)(ppgtt->pt_pages[act_pt]), 3);
3031 serge 268
 
269
            for (i = first_pte; i < last_pte; i++)
270
                pt_vaddr[i] = scratch_pte;
271
 
272
            num_entries -= last_pte - first_pte;
273
            first_pte = 0;
3746 Serge 274
            act_pt++;
3480 Serge 275
    };
276
 
277
    FreeKernelSpace(pt_vaddr);
278
}
279
 
4104 Serge 280
static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
3480 Serge 281
				      struct sg_table *pages,
282
				      unsigned first_entry,
283
				      enum i915_cache_level cache_level)
284
{
4104 Serge 285
	struct i915_hw_ppgtt *ppgtt =
286
		container_of(vm, struct i915_hw_ppgtt, base);
3746 Serge 287
	gen6_gtt_pte_t *pt_vaddr;
288
	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
289
	unsigned act_pte = first_entry % I915_PPGTT_PT_ENTRIES;
290
	struct sg_page_iter sg_iter;
3480 Serge 291
	dma_addr_t page_addr;
292
 
293
 
294
    pt_vaddr = AllocKernelSpace(4096);
295
 
296
    if(pt_vaddr == NULL)
297
        return;
298
 
3746 Serge 299
    MapPage(pt_vaddr,(addr_t)(ppgtt->pt_pages[act_pt]), 3);
300
	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
301
		dma_addr_t page_addr;
3480 Serge 302
 
3746 Serge 303
		page_addr = sg_page_iter_dma_address(&sg_iter);
4104 Serge 304
		pt_vaddr[act_pte] = vm->pte_encode(page_addr, cache_level);
3746 Serge 305
		if (++act_pte == I915_PPGTT_PT_ENTRIES) {
306
			act_pt++;
307
    		MapPage(pt_vaddr,(addr_t)(ppgtt->pt_pages[act_pt]), 3);
308
			act_pte = 0;
3480 Serge 309
 
4104 Serge 310
			}
3480 Serge 311
		}
4104 Serge 312
    FreeKernelSpace(pt_vaddr);
3031 serge 313
}
314
 
4104 Serge 315
static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
3031 serge 316
{
4104 Serge 317
	struct i915_hw_ppgtt *ppgtt =
318
		container_of(vm, struct i915_hw_ppgtt, base);
3480 Serge 319
	int i;
320
 
4104 Serge 321
	drm_mm_takedown(&ppgtt->base.mm);
322
 
3480 Serge 323
	if (ppgtt->pt_dma_addr) {
324
		for (i = 0; i < ppgtt->num_pd_entries; i++)
4104 Serge 325
			pci_unmap_page(ppgtt->base.dev->pdev,
3480 Serge 326
				       ppgtt->pt_dma_addr[i],
327
				       4096, PCI_DMA_BIDIRECTIONAL);
328
	}
329
 
330
	kfree(ppgtt->pt_dma_addr);
331
	for (i = 0; i < ppgtt->num_pd_entries; i++)
332
		__free_page(ppgtt->pt_pages[i]);
333
	kfree(ppgtt->pt_pages);
334
	kfree(ppgtt);
335
}
336
 
337
static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
338
{
4104 Serge 339
	struct drm_device *dev = ppgtt->base.dev;
3031 serge 340
	struct drm_i915_private *dev_priv = dev->dev_private;
341
	unsigned first_pd_entry_in_global_pt;
342
	int i;
343
	int ret = -ENOMEM;
344
 
345
	/* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
346
	 * entries. For aliasing ppgtt support we just steal them at the end for
347
	 * now. */
3746 Serge 348
       first_pd_entry_in_global_pt = gtt_total_entries(dev_priv->gtt);
3031 serge 349
 
4104 Serge 350
	ppgtt->base.pte_encode = dev_priv->gtt.base.pte_encode;
351
	ppgtt->num_pd_entries = GEN6_PPGTT_PD_ENTRIES;
3746 Serge 352
	ppgtt->enable = gen6_ppgtt_enable;
4104 Serge 353
	ppgtt->base.clear_range = gen6_ppgtt_clear_range;
354
	ppgtt->base.insert_entries = gen6_ppgtt_insert_entries;
355
	ppgtt->base.cleanup = gen6_ppgtt_cleanup;
356
	ppgtt->base.scratch = dev_priv->gtt.base.scratch;
3243 Serge 357
	ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
3031 serge 358
				  GFP_KERNEL);
359
	if (!ppgtt->pt_pages)
3480 Serge 360
		return -ENOMEM;
3031 serge 361
 
362
	for (i = 0; i < ppgtt->num_pd_entries; i++) {
3243 Serge 363
		ppgtt->pt_pages[i] = alloc_page(GFP_KERNEL);
3031 serge 364
		if (!ppgtt->pt_pages[i])
365
			goto err_pt_alloc;
366
	}
367
 
3480 Serge 368
	ppgtt->pt_dma_addr = kzalloc(sizeof(dma_addr_t) *ppgtt->num_pd_entries,
3031 serge 369
					     GFP_KERNEL);
4104 Serge 370
    if (!ppgtt->pt_dma_addr)
371
        goto err_pt_alloc;
3031 serge 372
 
4104 Serge 373
    for (i = 0; i < ppgtt->num_pd_entries; i++) {
374
        dma_addr_t pt_addr;
3031 serge 375
 
3480 Serge 376
		pt_addr = pci_map_page(dev->pdev, ppgtt->pt_pages[i], 0, 4096,
3031 serge 377
					       PCI_DMA_BIDIRECTIONAL);
378
 
4104 Serge 379
        ppgtt->pt_dma_addr[i] = pt_addr;
380
    }
3031 serge 381
 
4104 Serge 382
	ppgtt->base.clear_range(&ppgtt->base, 0,
3031 serge 383
			       ppgtt->num_pd_entries*I915_PPGTT_PT_ENTRIES);
384
 
3746 Serge 385
	ppgtt->pd_offset = first_pd_entry_in_global_pt * sizeof(gen6_gtt_pte_t);
3031 serge 386
 
387
	return 0;
388
 
389
err_pd_pin:
3480 Serge 390
	if (ppgtt->pt_dma_addr) {
391
		for (i--; i >= 0; i--)
392
			pci_unmap_page(dev->pdev, ppgtt->pt_dma_addr[i],
393
				       4096, PCI_DMA_BIDIRECTIONAL);
394
	}
3031 serge 395
err_pt_alloc:
3480 Serge 396
	kfree(ppgtt->pt_dma_addr);
3031 serge 397
	for (i = 0; i < ppgtt->num_pd_entries; i++) {
398
		if (ppgtt->pt_pages[i])
3480 Serge 399
			__free_page(ppgtt->pt_pages[i]);
3031 serge 400
	}
401
	kfree(ppgtt->pt_pages);
402
 
403
	return ret;
404
}
405
 
3480 Serge 406
static int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
3031 serge 407
{
408
	struct drm_i915_private *dev_priv = dev->dev_private;
3480 Serge 409
	struct i915_hw_ppgtt *ppgtt;
410
	int ret;
3031 serge 411
 
3480 Serge 412
	ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
3031 serge 413
	if (!ppgtt)
3480 Serge 414
		return -ENOMEM;
3031 serge 415
 
4104 Serge 416
	ppgtt->base.dev = dev;
3031 serge 417
 
3746 Serge 418
	if (INTEL_INFO(dev)->gen < 8)
3480 Serge 419
	ret = gen6_ppgtt_init(ppgtt);
3746 Serge 420
	else
421
		BUG();
422
 
3480 Serge 423
	if (ret)
4104 Serge 424
        kfree(ppgtt);
425
	else {
3480 Serge 426
		dev_priv->mm.aliasing_ppgtt = ppgtt;
4104 Serge 427
		drm_mm_init(&ppgtt->base.mm, ppgtt->base.start,
428
			    ppgtt->base.total);
429
	}
3480 Serge 430
 
431
	return ret;
3031 serge 432
}
433
 
3480 Serge 434
void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev)
3031 serge 435
{
3480 Serge 436
	struct drm_i915_private *dev_priv = dev->dev_private;
437
	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
3031 serge 438
 
3480 Serge 439
	if (!ppgtt)
3243 Serge 440
		return;
3031 serge 441
 
4104 Serge 442
	ppgtt->base.cleanup(&ppgtt->base);
3746 Serge 443
	dev_priv->mm.aliasing_ppgtt = NULL;
3031 serge 444
}
445
 
446
void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
447
			    struct drm_i915_gem_object *obj,
448
			    enum i915_cache_level cache_level)
449
{
4104 Serge 450
	ppgtt->base.insert_entries(&ppgtt->base, obj->pages,
451
				   i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT,
3243 Serge 452
				     cache_level);
3031 serge 453
}
454
 
455
void i915_ppgtt_unbind_object(struct i915_hw_ppgtt *ppgtt,
456
			      struct drm_i915_gem_object *obj)
457
{
4104 Serge 458
	ppgtt->base.clear_range(&ppgtt->base,
459
				i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT,
3031 serge 460
			       obj->base.size >> PAGE_SHIFT);
461
}
462
 
3480 Serge 463
extern int intel_iommu_gfx_mapped;
464
/* Certain Gen5 chipsets require require idling the GPU before
465
 * unmapping anything from the GTT when VT-d is enabled.
466
 */
467
static inline bool needs_idle_maps(struct drm_device *dev)
468
{
469
#ifdef CONFIG_INTEL_IOMMU
470
	/* Query intel_iommu to see if we need the workaround. Presumably that
471
	 * was loaded first.
472
	 */
473
	if (IS_GEN5(dev) && IS_MOBILE(dev) && intel_iommu_gfx_mapped)
474
		return true;
475
#endif
476
	return false;
477
}
478
 
2344 Serge 479
static bool do_idling(struct drm_i915_private *dev_priv)
480
{
481
	bool ret = dev_priv->mm.interruptible;
482
 
3480 Serge 483
	if (unlikely(dev_priv->gtt.do_idle_maps)) {
2344 Serge 484
		dev_priv->mm.interruptible = false;
485
		if (i915_gpu_idle(dev_priv->dev)) {
486
			DRM_ERROR("Couldn't idle GPU\n");
487
			/* Wait a bit, in hopes it avoids the hang */
488
			udelay(10);
489
		}
490
	}
491
 
492
	return ret;
493
}
494
 
495
static void undo_idling(struct drm_i915_private *dev_priv, bool interruptible)
496
{
3480 Serge 497
	if (unlikely(dev_priv->gtt.do_idle_maps))
2344 Serge 498
		dev_priv->mm.interruptible = interruptible;
499
}
500
 
2332 Serge 501
void i915_gem_restore_gtt_mappings(struct drm_device *dev)
502
{
503
	struct drm_i915_private *dev_priv = dev->dev_private;
504
	struct drm_i915_gem_object *obj;
505
 
506
	/* First fill our portion of the GTT with scratch pages */
4104 Serge 507
	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
508
				       dev_priv->gtt.base.start / PAGE_SIZE,
509
				       dev_priv->gtt.base.total / PAGE_SIZE);
2332 Serge 510
 
4104 Serge 511
	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
512
		i915_gem_clflush_object(obj, obj->pin_display);
3031 serge 513
		i915_gem_gtt_bind_object(obj, obj->cache_level);
2332 Serge 514
	}
515
 
3243 Serge 516
	i915_gem_chipset_flush(dev);
2332 Serge 517
}
518
 
3031 serge 519
int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
2332 Serge 520
{
3243 Serge 521
	if (obj->has_dma_mapping)
522
		return 0;
523
 
3480 Serge 524
	if (!dma_map_sg(&obj->base.dev->pdev->dev,
525
			obj->pages->sgl, obj->pages->nents,
526
			PCI_DMA_BIDIRECTIONAL))
527
		return -ENOSPC;
3243 Serge 528
 
2332 Serge 529
	return 0;
530
}
531
 
3243 Serge 532
/*
533
 * Binds an object into the global gtt with the specified cache level. The object
534
 * will be accessible to the GPU via commands whose operands reference offsets
535
 * within the global GTT as well as accessible by the GPU through the GMADR
536
 * mapped BAR (dev_priv->mm.gtt->gtt).
537
 */
4104 Serge 538
static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
3480 Serge 539
				     struct sg_table *st,
540
				     unsigned int first_entry,
3243 Serge 541
				  enum i915_cache_level level)
542
{
4104 Serge 543
	struct drm_i915_private *dev_priv = vm->dev->dev_private;
3746 Serge 544
	gen6_gtt_pte_t __iomem *gtt_entries =
545
		(gen6_gtt_pte_t __iomem *)dev_priv->gtt.gsm + first_entry;
546
	int i = 0;
547
	struct sg_page_iter sg_iter;
3243 Serge 548
	dma_addr_t addr;
549
 
3746 Serge 550
	for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) {
551
		addr = sg_page_iter_dma_address(&sg_iter);
4104 Serge 552
		iowrite32(vm->pte_encode(addr, level), >t_entries[i]);
3243 Serge 553
			i++;
554
		}
555
 
556
	/* XXX: This serves as a posting read to make sure that the PTE has
557
	 * actually been updated. There is some concern that even though
558
	 * registers and PTEs are within the same BAR that they are potentially
559
	 * of NUMA access patterns. Therefore, even with the way we assume
560
	 * hardware should work, we must keep this posting read for paranoia.
561
	 */
562
	if (i != 0)
4104 Serge 563
		WARN_ON(readl(>t_entries[i-1]) !=
564
			vm->pte_encode(addr, level));
3243 Serge 565
 
566
	/* This next bit makes the above posting read even more important. We
567
	 * want to flush the TLBs only after we're certain all the PTE updates
568
	 * have finished.
569
	 */
570
	I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
571
	POSTING_READ(GFX_FLSH_CNTL_GEN6);
572
}
573
 
4104 Serge 574
static void gen6_ggtt_clear_range(struct i915_address_space *vm,
3480 Serge 575
				  unsigned int first_entry,
576
				  unsigned int num_entries)
577
{
4104 Serge 578
	struct drm_i915_private *dev_priv = vm->dev->dev_private;
3746 Serge 579
	gen6_gtt_pte_t scratch_pte, __iomem *gtt_base =
580
		(gen6_gtt_pte_t __iomem *) dev_priv->gtt.gsm + first_entry;
3480 Serge 581
	const int max_entries = gtt_total_entries(dev_priv->gtt) - first_entry;
582
	int i;
583
 
3746 Serge 584
//   if (WARN(num_entries > max_entries,
585
//        "First entry = %d; Num entries = %d (max=%d)\n",
586
//        first_entry, num_entries, max_entries))
587
   if (num_entries > max_entries)
4104 Serge 588
        num_entries = max_entries;
3480 Serge 589
 
4104 Serge 590
	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC);
3480 Serge 591
	for (i = 0; i < num_entries; i++)
592
		iowrite32(scratch_pte, >t_base[i]);
593
	readl(gtt_base);
594
}
595
 
596
 
4104 Serge 597
static void i915_ggtt_insert_entries(struct i915_address_space *vm,
3480 Serge 598
				     struct sg_table *st,
599
				     unsigned int pg_start,
600
				     enum i915_cache_level cache_level)
601
{
602
	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
603
		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
604
 
605
	intel_gtt_insert_sg_entries(st, pg_start, flags);
606
 
607
}
608
 
4104 Serge 609
static void i915_ggtt_clear_range(struct i915_address_space *vm,
3480 Serge 610
				  unsigned int first_entry,
611
				  unsigned int num_entries)
612
{
613
	intel_gtt_clear_range(first_entry, num_entries);
614
}
615
 
616
 
3031 serge 617
void i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj,
2332 Serge 618
				enum i915_cache_level cache_level)
619
{
620
	struct drm_device *dev = obj->base.dev;
3480 Serge 621
	struct drm_i915_private *dev_priv = dev->dev_private;
4104 Serge 622
	const unsigned long entry = i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT;
3480 Serge 623
 
4104 Serge 624
	dev_priv->gtt.base.insert_entries(&dev_priv->gtt.base, obj->pages,
625
					  entry,
3480 Serge 626
					 cache_level);
2332 Serge 627
 
3031 serge 628
	obj->has_global_gtt_mapping = 1;
2332 Serge 629
}
630
 
631
void i915_gem_gtt_unbind_object(struct drm_i915_gem_object *obj)
632
{
3480 Serge 633
	struct drm_device *dev = obj->base.dev;
634
	struct drm_i915_private *dev_priv = dev->dev_private;
4104 Serge 635
	const unsigned long entry = i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT;
3480 Serge 636
 
4104 Serge 637
	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
638
				       entry,
3031 serge 639
			      obj->base.size >> PAGE_SHIFT);
640
 
641
	obj->has_global_gtt_mapping = 0;
642
}
643
 
644
void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
645
{
2344 Serge 646
	struct drm_device *dev = obj->base.dev;
647
	struct drm_i915_private *dev_priv = dev->dev_private;
648
	bool interruptible;
649
 
650
	interruptible = do_idling(dev_priv);
651
 
3480 Serge 652
	if (!obj->has_dma_mapping)
653
		dma_unmap_sg(&dev->pdev->dev,
654
			     obj->pages->sgl, obj->pages->nents,
655
			     PCI_DMA_BIDIRECTIONAL);
2332 Serge 656
 
3031 serge 657
	undo_idling(dev_priv, interruptible);
658
}
659
 
660
static void i915_gtt_color_adjust(struct drm_mm_node *node,
661
				  unsigned long color,
662
				  unsigned long *start,
663
				  unsigned long *end)
664
{
665
	if (node->color != color)
666
		*start += 4096;
667
 
668
	if (!list_empty(&node->node_list)) {
669
		node = list_entry(node->node_list.next,
670
				  struct drm_mm_node,
671
				  node_list);
672
		if (node->allocated && node->color != color)
673
			*end -= 4096;
2332 Serge 674
	}
3031 serge 675
}
3480 Serge 676
void i915_gem_setup_global_gtt(struct drm_device *dev,
3031 serge 677
			      unsigned long start,
678
			      unsigned long mappable_end,
679
			      unsigned long end)
680
{
3480 Serge 681
	/* Let GEM Manage all of the aperture.
682
	 *
683
	 * However, leave one page at the end still bound to the scratch page.
684
	 * There are a number of places where the hardware apparently prefetches
685
	 * past the end of the object, and we've seen multiple hangs with the
686
	 * GPU head pointer stuck in a batchbuffer bound at the last page of the
687
	 * aperture.  One page should be enough to keep any prefetching inside
688
	 * of the aperture.
689
	 */
4104 Serge 690
	struct drm_i915_private *dev_priv = dev->dev_private;
691
	struct i915_address_space *ggtt_vm = &dev_priv->gtt.base;
3480 Serge 692
	struct drm_mm_node *entry;
693
	struct drm_i915_gem_object *obj;
694
	unsigned long hole_start, hole_end;
3031 serge 695
 
3480 Serge 696
	BUG_ON(mappable_end > end);
697
 
698
	/* Subtract the guard page ... */
4104 Serge 699
	drm_mm_init(&ggtt_vm->mm, start, end - start - PAGE_SIZE);
3031 serge 700
	if (!HAS_LLC(dev))
4104 Serge 701
		dev_priv->gtt.base.mm.color_adjust = i915_gtt_color_adjust;
3031 serge 702
 
3480 Serge 703
	/* Mark any preallocated objects as occupied */
4104 Serge 704
	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
705
		struct i915_vma *vma = i915_gem_obj_to_vma(obj, ggtt_vm);
706
		int ret;
707
		DRM_DEBUG_KMS("reserving preallocated space: %lx + %zx\n",
708
			      i915_gem_obj_ggtt_offset(obj), obj->base.size);
3031 serge 709
 
4104 Serge 710
		WARN_ON(i915_gem_obj_ggtt_bound(obj));
711
		ret = drm_mm_reserve_node(&ggtt_vm->mm, &vma->node);
712
		if (ret)
713
			DRM_DEBUG_KMS("Reservation failed\n");
3480 Serge 714
		obj->has_global_gtt_mapping = 1;
4104 Serge 715
		list_add(&vma->vma_link, &obj->vma_list);
3480 Serge 716
	}
717
 
4104 Serge 718
	dev_priv->gtt.base.start = start;
719
	dev_priv->gtt.base.total = end - start;
3480 Serge 720
 
721
	/* Clear any non-preallocated blocks */
4104 Serge 722
	drm_mm_for_each_hole(entry, &ggtt_vm->mm, hole_start, hole_end) {
723
		const unsigned long count = (hole_end - hole_start) / PAGE_SIZE;
3480 Serge 724
		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
725
			      hole_start, hole_end);
4104 Serge 726
		ggtt_vm->clear_range(ggtt_vm, hole_start / PAGE_SIZE, count);
3480 Serge 727
	}
728
 
729
	/* And finally clear the reserved guard page */
4104 Serge 730
	ggtt_vm->clear_range(ggtt_vm, end / PAGE_SIZE - 1, 1);
2332 Serge 731
}
3243 Serge 732
 
3480 Serge 733
static bool
734
intel_enable_ppgtt(struct drm_device *dev)
735
{
736
	if (i915_enable_ppgtt >= 0)
737
		return i915_enable_ppgtt;
738
 
739
#ifdef CONFIG_INTEL_IOMMU
740
	/* Disable ppgtt on SNB if VT-d is on. */
741
	if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped)
742
		return false;
743
#endif
744
 
745
	return true;
746
}
747
 
748
void i915_gem_init_global_gtt(struct drm_device *dev)
749
{
750
	struct drm_i915_private *dev_priv = dev->dev_private;
751
	unsigned long gtt_size, mappable_size;
752
 
4104 Serge 753
	gtt_size = dev_priv->gtt.base.total;
3480 Serge 754
	mappable_size = dev_priv->gtt.mappable_end;
755
 
3746 Serge 756
#if 0
3480 Serge 757
	if (intel_enable_ppgtt(dev) && HAS_ALIASING_PPGTT(dev)) {
758
		int ret;
3746 Serge 759
 
760
		if (INTEL_INFO(dev)->gen <= 7) {
3480 Serge 761
		/* PPGTT pdes are stolen from global gtt ptes, so shrink the
762
		 * aperture accordingly when using aliasing ppgtt. */
4104 Serge 763
			gtt_size -= GEN6_PPGTT_PD_ENTRIES * PAGE_SIZE;
3746 Serge 764
		}
3480 Serge 765
 
4104 Serge 766
        i915_gem_setup_global_gtt(dev, LFB_SIZE, mappable_size, gtt_size-LFB_SIZE);
3480 Serge 767
 
768
		ret = i915_gem_init_aliasing_ppgtt(dev);
769
		if (!ret)
770
			return;
771
 
772
		DRM_ERROR("Aliased PPGTT setup failed %d\n", ret);
4104 Serge 773
		drm_mm_takedown(&dev_priv->gtt.base.mm);
774
		gtt_size += GEN6_PPGTT_PD_ENTRIES * PAGE_SIZE;
3746 Serge 775
}
776
#endif
777
 
4104 Serge 778
    i915_gem_setup_global_gtt(dev, LFB_SIZE, mappable_size, gtt_size-LFB_SIZE);
3480 Serge 779
}
780
 
3243 Serge 781
static int setup_scratch_page(struct drm_device *dev)
782
{
783
	struct drm_i915_private *dev_priv = dev->dev_private;
784
	struct page *page;
785
	dma_addr_t dma_addr;
786
 
787
	page = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
788
	if (page == NULL)
789
		return -ENOMEM;
4104 Serge 790
    get_page(page);
3480 Serge 791
	set_pages_uc(page, 1);
3243 Serge 792
 
793
#ifdef CONFIG_INTEL_IOMMU
794
	dma_addr = pci_map_page(dev->pdev, page, 0, PAGE_SIZE,
795
				PCI_DMA_BIDIRECTIONAL);
796
	if (pci_dma_mapping_error(dev->pdev, dma_addr))
797
		return -EINVAL;
798
#else
799
	dma_addr = page_to_phys(page);
800
#endif
4104 Serge 801
	dev_priv->gtt.base.scratch.page = page;
802
	dev_priv->gtt.base.scratch.addr = dma_addr;
3243 Serge 803
 
804
	return 0;
805
}
806
 
3480 Serge 807
static void teardown_scratch_page(struct drm_device *dev)
808
{
809
	struct drm_i915_private *dev_priv = dev->dev_private;
4104 Serge 810
	struct page *page = dev_priv->gtt.base.scratch.page;
811
 
812
	set_pages_wb(page, 1);
813
	pci_unmap_page(dev->pdev, dev_priv->gtt.base.scratch.addr,
3480 Serge 814
		       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
4104 Serge 815
	put_page(page);
816
	__free_page(page);
3480 Serge 817
}
3243 Serge 818
 
819
static inline unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
820
{
821
	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
822
	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
823
	return snb_gmch_ctl << 20;
824
}
825
 
3480 Serge 826
static inline size_t gen6_get_stolen_size(u16 snb_gmch_ctl)
3243 Serge 827
{
828
	snb_gmch_ctl >>= SNB_GMCH_GMS_SHIFT;
829
	snb_gmch_ctl &= SNB_GMCH_GMS_MASK;
830
	return snb_gmch_ctl << 25; /* 32 MB units */
831
}
832
 
3480 Serge 833
static int gen6_gmch_probe(struct drm_device *dev,
834
			   size_t *gtt_total,
835
			   size_t *stolen,
836
			   phys_addr_t *mappable_base,
837
			   unsigned long *mappable_end)
3243 Serge 838
{
839
	struct drm_i915_private *dev_priv = dev->dev_private;
840
	phys_addr_t gtt_bus_addr;
3480 Serge 841
	unsigned int gtt_size;
3243 Serge 842
	u16 snb_gmch_ctl;
843
	int ret;
844
 
3480 Serge 845
	*mappable_base = pci_resource_start(dev->pdev, 2);
846
	*mappable_end = pci_resource_len(dev->pdev, 2);
847
 
848
	/* 64/512MB is the current min/max we actually know of, but this is just
849
	 * a coarse sanity check.
3243 Serge 850
	 */
3480 Serge 851
	if ((*mappable_end < (64<<20) || (*mappable_end > (512<<20)))) {
852
		DRM_ERROR("Unknown GMADR size (%lx)\n",
853
			  dev_priv->gtt.mappable_end);
854
		return -ENXIO;
3243 Serge 855
		}
856
 
3480 Serge 857
	if (!pci_set_dma_mask(dev->pdev, DMA_BIT_MASK(40)))
858
		pci_set_consistent_dma_mask(dev->pdev, DMA_BIT_MASK(40));
859
	pci_read_config_word(dev->pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
860
	gtt_size = gen6_get_total_gtt_size(snb_gmch_ctl);
3243 Serge 861
 
4104 Serge 862
	*stolen = gen6_get_stolen_size(snb_gmch_ctl);
3746 Serge 863
	*gtt_total = (gtt_size / sizeof(gen6_gtt_pte_t)) << PAGE_SHIFT;
3243 Serge 864
 
3746 Serge 865
	/* For Modern GENs the PTEs and register space are split in the BAR */
866
	gtt_bus_addr = pci_resource_start(dev->pdev, 0) +
867
		(pci_resource_len(dev->pdev, 0) / 2);
3243 Serge 868
 
3480 Serge 869
	dev_priv->gtt.gsm = ioremap_wc(gtt_bus_addr, gtt_size);
870
	if (!dev_priv->gtt.gsm) {
871
		DRM_ERROR("Failed to map the gtt page table\n");
872
		return -ENOMEM;
3243 Serge 873
	}
874
 
875
	ret = setup_scratch_page(dev);
3480 Serge 876
	if (ret)
3243 Serge 877
		DRM_ERROR("Scratch setup failed\n");
878
 
4104 Serge 879
	dev_priv->gtt.base.clear_range = gen6_ggtt_clear_range;
880
	dev_priv->gtt.base.insert_entries = gen6_ggtt_insert_entries;
3480 Serge 881
 
882
	return ret;
883
}
884
 
4104 Serge 885
static void gen6_gmch_remove(struct i915_address_space *vm)
3480 Serge 886
{
4104 Serge 887
 
888
	struct i915_gtt *gtt = container_of(vm, struct i915_gtt, base);
889
	iounmap(gtt->gsm);
890
	teardown_scratch_page(vm->dev);
3480 Serge 891
}
892
 
893
static int i915_gmch_probe(struct drm_device *dev,
894
			   size_t *gtt_total,
895
			   size_t *stolen,
896
			   phys_addr_t *mappable_base,
897
			   unsigned long *mappable_end)
898
{
899
	struct drm_i915_private *dev_priv = dev->dev_private;
900
	int ret;
901
 
902
	ret = intel_gmch_probe(dev_priv->bridge_dev, dev_priv->dev->pdev, NULL);
903
	if (!ret) {
904
		DRM_ERROR("failed to set up gmch\n");
905
		return -EIO;
3243 Serge 906
	}
907
 
3480 Serge 908
	intel_gtt_get(gtt_total, stolen, mappable_base, mappable_end);
3243 Serge 909
 
3480 Serge 910
	dev_priv->gtt.do_idle_maps = needs_idle_maps(dev_priv->dev);
4104 Serge 911
	dev_priv->gtt.base.clear_range = i915_ggtt_clear_range;
912
	dev_priv->gtt.base.insert_entries = i915_ggtt_insert_entries;
3480 Serge 913
 
3243 Serge 914
	return 0;
3480 Serge 915
}
3243 Serge 916
 
4104 Serge 917
static void i915_gmch_remove(struct i915_address_space *vm)
3480 Serge 918
{
919
//   intel_gmch_remove();
920
}
921
 
922
int i915_gem_gtt_init(struct drm_device *dev)
923
{
924
	struct drm_i915_private *dev_priv = dev->dev_private;
925
	struct i915_gtt *gtt = &dev_priv->gtt;
926
	int ret;
927
 
928
	if (INTEL_INFO(dev)->gen <= 5) {
4104 Serge 929
		gtt->gtt_probe = i915_gmch_probe;
930
		gtt->base.cleanup = i915_gmch_remove;
3480 Serge 931
	} else {
4104 Serge 932
		gtt->gtt_probe = gen6_gmch_probe;
933
		gtt->base.cleanup = gen6_gmch_remove;
934
		if (IS_HASWELL(dev) && dev_priv->ellc_size)
935
			gtt->base.pte_encode = iris_pte_encode;
936
		else if (IS_HASWELL(dev))
937
			gtt->base.pte_encode = hsw_pte_encode;
938
		else if (IS_VALLEYVIEW(dev))
939
			gtt->base.pte_encode = byt_pte_encode;
940
		else if (INTEL_INFO(dev)->gen >= 7)
941
			gtt->base.pte_encode = ivb_pte_encode;
942
		else
943
			gtt->base.pte_encode = snb_pte_encode;
3480 Serge 944
	}
945
 
4104 Serge 946
	ret = gtt->gtt_probe(dev, >t->base.total, >t->stolen_size,
947
			     >t->mappable_base, >t->mappable_end);
3480 Serge 948
	if (ret)
4104 Serge 949
		return ret;
3480 Serge 950
 
4104 Serge 951
	gtt->base.dev = dev;
952
 
3480 Serge 953
	/* GMADR is the PCI mmio aperture into the global GTT. */
954
	DRM_INFO("Memory usable by graphics device = %zdM\n",
4104 Serge 955
		 gtt->base.total >> 20);
956
	DRM_DEBUG_DRIVER("GMADR size = %ldM\n", gtt->mappable_end >> 20);
957
	DRM_DEBUG_DRIVER("GTT stolen size = %zdM\n", gtt->stolen_size >> 20);
3480 Serge 958
 
959
	return 0;
3243 Serge 960
}
961
 
962
struct scatterlist *sg_next(struct scatterlist *sg)
963
{
964
    if (sg_is_last(sg))
965
        return NULL;
966
 
967
    sg++;
968
    if (unlikely(sg_is_chain(sg)))
969
            sg = sg_chain_ptr(sg);
970
 
971
    return sg;
972
}
973
 
974
 
975
void __sg_free_table(struct sg_table *table, unsigned int max_ents,
976
                     sg_free_fn *free_fn)
977
{
978
    struct scatterlist *sgl, *next;
979
 
980
    if (unlikely(!table->sgl))
981
            return;
982
 
983
    sgl = table->sgl;
984
    while (table->orig_nents) {
985
        unsigned int alloc_size = table->orig_nents;
986
        unsigned int sg_size;
987
 
988
        /*
989
         * If we have more than max_ents segments left,
990
         * then assign 'next' to the sg table after the current one.
991
         * sg_size is then one less than alloc size, since the last
992
         * element is the chain pointer.
993
         */
994
        if (alloc_size > max_ents) {
995
                next = sg_chain_ptr(&sgl[max_ents - 1]);
996
                alloc_size = max_ents;
997
                sg_size = alloc_size - 1;
998
        } else {
999
                sg_size = alloc_size;
1000
                next = NULL;
1001
        }
1002
 
1003
        table->orig_nents -= sg_size;
1004
        kfree(sgl);
1005
        sgl = next;
1006
    }
1007
 
1008
    table->sgl = NULL;
1009
}
1010
 
1011
void sg_free_table(struct sg_table *table)
1012
{
1013
    __sg_free_table(table, SG_MAX_SINGLE_ALLOC, NULL);
1014
}
1015
 
1016
int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
1017
{
1018
    struct scatterlist *sg, *prv;
1019
    unsigned int left;
1020
    unsigned int max_ents = SG_MAX_SINGLE_ALLOC;
1021
 
1022
#ifndef ARCH_HAS_SG_CHAIN
1023
    BUG_ON(nents > max_ents);
1024
#endif
1025
 
1026
    memset(table, 0, sizeof(*table));
1027
 
1028
    left = nents;
1029
    prv = NULL;
1030
    do {
1031
        unsigned int sg_size, alloc_size = left;
1032
 
1033
        if (alloc_size > max_ents) {
1034
                alloc_size = max_ents;
1035
                sg_size = alloc_size - 1;
1036
        } else
1037
                sg_size = alloc_size;
1038
 
1039
        left -= sg_size;
1040
 
1041
        sg = kmalloc(alloc_size * sizeof(struct scatterlist), gfp_mask);
1042
        if (unlikely(!sg)) {
1043
                /*
1044
                 * Adjust entry count to reflect that the last
1045
                 * entry of the previous table won't be used for
1046
                 * linkage.  Without this, sg_kfree() may get
1047
                 * confused.
1048
                 */
1049
                if (prv)
1050
                        table->nents = ++table->orig_nents;
1051
 
1052
                goto err;
1053
        }
1054
 
1055
        sg_init_table(sg, alloc_size);
1056
        table->nents = table->orig_nents += sg_size;
1057
 
1058
        /*
1059
         * If this is the first mapping, assign the sg table header.
1060
         * If this is not the first mapping, chain previous part.
1061
         */
1062
        if (prv)
1063
                sg_chain(prv, max_ents, sg);
1064
        else
1065
                table->sgl = sg;
1066
 
1067
        /*
1068
         * If no more entries after this one, mark the end
1069
         */
1070
        if (!left)
1071
                sg_mark_end(&sg[sg_size - 1]);
1072
 
1073
        prv = sg;
1074
    } while (left);
1075
 
1076
    return 0;
1077
 
1078
err:
1079
    __sg_free_table(table, SG_MAX_SINGLE_ALLOC, NULL);
1080
 
1081
    return -ENOMEM;
1082
}
1083
 
1084
 
1085
void sg_init_table(struct scatterlist *sgl, unsigned int nents)
1086
{
1087
    memset(sgl, 0, sizeof(*sgl) * nents);
1088
#ifdef CONFIG_DEBUG_SG
1089
    {
1090
            unsigned int i;
1091
            for (i = 0; i < nents; i++)
1092
                    sgl[i].sg_magic = SG_MAGIC;
1093
    }
1094
#endif
1095
    sg_mark_end(&sgl[nents - 1]);
1096
}
1097
 
3746 Serge 1098
 
1099
void __sg_page_iter_start(struct sg_page_iter *piter,
1100
              struct scatterlist *sglist, unsigned int nents,
1101
              unsigned long pgoffset)
1102
{
1103
    piter->__pg_advance = 0;
1104
    piter->__nents = nents;
1105
 
1106
    piter->sg = sglist;
1107
    piter->sg_pgoffset = pgoffset;
1108
}
1109
 
1110
static int sg_page_count(struct scatterlist *sg)
1111
{
1112
    return PAGE_ALIGN(sg->offset + sg->length) >> PAGE_SHIFT;
1113
}
1114
 
1115
bool __sg_page_iter_next(struct sg_page_iter *piter)
1116
{
1117
    if (!piter->__nents || !piter->sg)
1118
        return false;
1119
 
1120
    piter->sg_pgoffset += piter->__pg_advance;
1121
    piter->__pg_advance = 1;
1122
 
1123
    while (piter->sg_pgoffset >= sg_page_count(piter->sg)) {
1124
        piter->sg_pgoffset -= sg_page_count(piter->sg);
1125
        piter->sg = sg_next(piter->sg);
1126
        if (!--piter->__nents || !piter->sg)
1127
            return false;
1128
    }
1129
 
1130
    return true;
1131
}
1132
EXPORT_SYMBOL(__sg_page_iter_next);
1133