xref: /openbmc/linux/drivers/gpu/drm/i915/gt/gen6_ppgtt.c (revision 0eb76ba2)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020 Intel Corporation
4  */
5 
6 #include <linux/log2.h>
7 
8 #include "gen6_ppgtt.h"
9 #include "i915_scatterlist.h"
10 #include "i915_trace.h"
11 #include "i915_vgpu.h"
12 #include "intel_gt.h"
13 
14 /* Write pde (index) from the page directory @pd to the page table @pt */
15 static inline void gen6_write_pde(const struct gen6_ppgtt *ppgtt,
16 				  const unsigned int pde,
17 				  const struct i915_page_table *pt)
18 {
19 	dma_addr_t addr = pt ? px_dma(pt) : px_dma(ppgtt->base.vm.scratch[1]);
20 
21 	/* Caller needs to make sure the write completes if necessary */
22 	iowrite32(GEN6_PDE_ADDR_ENCODE(addr) | GEN6_PDE_VALID,
23 		  ppgtt->pd_addr + pde);
24 }
25 
26 void gen7_ppgtt_enable(struct intel_gt *gt)
27 {
28 	struct drm_i915_private *i915 = gt->i915;
29 	struct intel_uncore *uncore = gt->uncore;
30 	struct intel_engine_cs *engine;
31 	enum intel_engine_id id;
32 	u32 ecochk;
33 
34 	intel_uncore_rmw(uncore, GAC_ECO_BITS, 0, ECOBITS_PPGTT_CACHE64B);
35 
36 	ecochk = intel_uncore_read(uncore, GAM_ECOCHK);
37 	if (IS_HASWELL(i915)) {
38 		ecochk |= ECOCHK_PPGTT_WB_HSW;
39 	} else {
40 		ecochk |= ECOCHK_PPGTT_LLC_IVB;
41 		ecochk &= ~ECOCHK_PPGTT_GFDT_IVB;
42 	}
43 	intel_uncore_write(uncore, GAM_ECOCHK, ecochk);
44 
45 	for_each_engine(engine, gt, id) {
46 		/* GFX_MODE is per-ring on gen7+ */
47 		ENGINE_WRITE(engine,
48 			     RING_MODE_GEN7,
49 			     _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
50 	}
51 }
52 
53 void gen6_ppgtt_enable(struct intel_gt *gt)
54 {
55 	struct intel_uncore *uncore = gt->uncore;
56 
57 	intel_uncore_rmw(uncore,
58 			 GAC_ECO_BITS,
59 			 0,
60 			 ECOBITS_SNB_BIT | ECOBITS_PPGTT_CACHE64B);
61 
62 	intel_uncore_rmw(uncore,
63 			 GAB_CTL,
64 			 0,
65 			 GAB_CTL_CONT_AFTER_PAGEFAULT);
66 
67 	intel_uncore_rmw(uncore,
68 			 GAM_ECOCHK,
69 			 0,
70 			 ECOCHK_SNB_BIT | ECOCHK_PPGTT_CACHE64B);
71 
72 	if (HAS_PPGTT(uncore->i915)) /* may be disabled for VT-d */
73 		intel_uncore_write(uncore,
74 				   GFX_MODE,
75 				   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
76 }
77 
78 /* PPGTT support for Sandybdrige/Gen6 and later */
79 static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
80 				   u64 start, u64 length)
81 {
82 	struct gen6_ppgtt * const ppgtt = to_gen6_ppgtt(i915_vm_to_ppgtt(vm));
83 	const unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
84 	const gen6_pte_t scratch_pte = vm->scratch[0]->encode;
85 	unsigned int pde = first_entry / GEN6_PTES;
86 	unsigned int pte = first_entry % GEN6_PTES;
87 	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
88 
89 	while (num_entries) {
90 		struct i915_page_table * const pt =
91 			i915_pt_entry(ppgtt->base.pd, pde++);
92 		const unsigned int count = min(num_entries, GEN6_PTES - pte);
93 		gen6_pte_t *vaddr;
94 
95 		num_entries -= count;
96 
97 		GEM_BUG_ON(count > atomic_read(&pt->used));
98 		if (!atomic_sub_return(count, &pt->used))
99 			ppgtt->scan_for_unused_pt = true;
100 
101 		/*
102 		 * Note that the hw doesn't support removing PDE on the fly
103 		 * (they are cached inside the context with no means to
104 		 * invalidate the cache), so we can only reset the PTE
105 		 * entries back to scratch.
106 		 */
107 
108 		vaddr = kmap_atomic_px(pt);
109 		memset32(vaddr + pte, scratch_pte, count);
110 		kunmap_atomic(vaddr);
111 
112 		pte = 0;
113 	}
114 }
115 
116 static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
117 				      struct i915_vma *vma,
118 				      enum i915_cache_level cache_level,
119 				      u32 flags)
120 {
121 	struct i915_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
122 	struct i915_page_directory * const pd = ppgtt->pd;
123 	unsigned int first_entry = vma->node.start / I915_GTT_PAGE_SIZE;
124 	unsigned int act_pt = first_entry / GEN6_PTES;
125 	unsigned int act_pte = first_entry % GEN6_PTES;
126 	const u32 pte_encode = vm->pte_encode(0, cache_level, flags);
127 	struct sgt_dma iter = sgt_dma(vma);
128 	gen6_pte_t *vaddr;
129 
130 	GEM_BUG_ON(!pd->entry[act_pt]);
131 
132 	vaddr = kmap_atomic_px(i915_pt_entry(pd, act_pt));
133 	do {
134 		GEM_BUG_ON(sg_dma_len(iter.sg) < I915_GTT_PAGE_SIZE);
135 		vaddr[act_pte] = pte_encode | GEN6_PTE_ADDR_ENCODE(iter.dma);
136 
137 		iter.dma += I915_GTT_PAGE_SIZE;
138 		if (iter.dma == iter.max) {
139 			iter.sg = __sg_next(iter.sg);
140 			if (!iter.sg || sg_dma_len(iter.sg) == 0)
141 				break;
142 
143 			iter.dma = sg_dma_address(iter.sg);
144 			iter.max = iter.dma + sg_dma_len(iter.sg);
145 		}
146 
147 		if (++act_pte == GEN6_PTES) {
148 			kunmap_atomic(vaddr);
149 			vaddr = kmap_atomic_px(i915_pt_entry(pd, ++act_pt));
150 			act_pte = 0;
151 		}
152 	} while (1);
153 	kunmap_atomic(vaddr);
154 
155 	vma->page_sizes.gtt = I915_GTT_PAGE_SIZE;
156 }
157 
158 static void gen6_flush_pd(struct gen6_ppgtt *ppgtt, u64 start, u64 end)
159 {
160 	struct i915_page_directory * const pd = ppgtt->base.pd;
161 	struct i915_page_table *pt;
162 	unsigned int pde;
163 
164 	start = round_down(start, SZ_64K);
165 	end = round_up(end, SZ_64K) - start;
166 
167 	mutex_lock(&ppgtt->flush);
168 
169 	gen6_for_each_pde(pt, pd, start, end, pde)
170 		gen6_write_pde(ppgtt, pde, pt);
171 
172 	mb();
173 	ioread32(ppgtt->pd_addr + pde - 1);
174 	gen6_ggtt_invalidate(ppgtt->base.vm.gt->ggtt);
175 	mb();
176 
177 	mutex_unlock(&ppgtt->flush);
178 }
179 
180 static void gen6_alloc_va_range(struct i915_address_space *vm,
181 				struct i915_vm_pt_stash *stash,
182 				u64 start, u64 length)
183 {
184 	struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(i915_vm_to_ppgtt(vm));
185 	struct i915_page_directory * const pd = ppgtt->base.pd;
186 	struct i915_page_table *pt;
187 	bool flush = false;
188 	u64 from = start;
189 	unsigned int pde;
190 
191 	spin_lock(&pd->lock);
192 	gen6_for_each_pde(pt, pd, start, length, pde) {
193 		const unsigned int count = gen6_pte_count(start, length);
194 
195 		if (!pt) {
196 			spin_unlock(&pd->lock);
197 
198 			pt = stash->pt[0];
199 			__i915_gem_object_pin_pages(pt->base);
200 			i915_gem_object_make_unshrinkable(pt->base);
201 
202 			fill32_px(pt, vm->scratch[0]->encode);
203 
204 			spin_lock(&pd->lock);
205 			if (!pd->entry[pde]) {
206 				stash->pt[0] = pt->stash;
207 				atomic_set(&pt->used, 0);
208 				pd->entry[pde] = pt;
209 			} else {
210 				pt = pd->entry[pde];
211 			}
212 
213 			flush = true;
214 		}
215 
216 		atomic_add(count, &pt->used);
217 	}
218 	spin_unlock(&pd->lock);
219 
220 	if (flush && i915_vma_is_bound(ppgtt->vma, I915_VMA_GLOBAL_BIND)) {
221 		intel_wakeref_t wakeref;
222 
223 		with_intel_runtime_pm(&vm->i915->runtime_pm, wakeref)
224 			gen6_flush_pd(ppgtt, from, start);
225 	}
226 }
227 
228 static int gen6_ppgtt_init_scratch(struct gen6_ppgtt *ppgtt)
229 {
230 	struct i915_address_space * const vm = &ppgtt->base.vm;
231 	int ret;
232 
233 	ret = setup_scratch_page(vm);
234 	if (ret)
235 		return ret;
236 
237 	vm->scratch[0]->encode =
238 		vm->pte_encode(px_dma(vm->scratch[0]),
239 			       I915_CACHE_NONE, PTE_READ_ONLY);
240 
241 	vm->scratch[1] = vm->alloc_pt_dma(vm, I915_GTT_PAGE_SIZE_4K);
242 	if (IS_ERR(vm->scratch[1])) {
243 		ret = PTR_ERR(vm->scratch[1]);
244 		goto err_scratch0;
245 	}
246 
247 	ret = pin_pt_dma(vm, vm->scratch[1]);
248 	if (ret)
249 		goto err_scratch1;
250 
251 	fill32_px(vm->scratch[1], vm->scratch[0]->encode);
252 
253 	return 0;
254 
255 err_scratch1:
256 	i915_gem_object_put(vm->scratch[1]);
257 err_scratch0:
258 	i915_gem_object_put(vm->scratch[0]);
259 	return ret;
260 }
261 
262 static void gen6_ppgtt_free_pd(struct gen6_ppgtt *ppgtt)
263 {
264 	struct i915_page_directory * const pd = ppgtt->base.pd;
265 	struct i915_page_table *pt;
266 	u32 pde;
267 
268 	gen6_for_all_pdes(pt, pd, pde)
269 		if (pt)
270 			free_pt(&ppgtt->base.vm, pt);
271 }
272 
273 static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
274 {
275 	struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(i915_vm_to_ppgtt(vm));
276 
277 	__i915_vma_put(ppgtt->vma);
278 
279 	gen6_ppgtt_free_pd(ppgtt);
280 	free_scratch(vm);
281 
282 	mutex_destroy(&ppgtt->flush);
283 	mutex_destroy(&ppgtt->pin_mutex);
284 
285 	free_pd(&ppgtt->base.vm, ppgtt->base.pd);
286 }
287 
288 static int pd_vma_set_pages(struct i915_vma *vma)
289 {
290 	vma->pages = ERR_PTR(-ENODEV);
291 	return 0;
292 }
293 
294 static void pd_vma_clear_pages(struct i915_vma *vma)
295 {
296 	GEM_BUG_ON(!vma->pages);
297 
298 	vma->pages = NULL;
299 }
300 
301 static void pd_vma_bind(struct i915_address_space *vm,
302 			struct i915_vm_pt_stash *stash,
303 			struct i915_vma *vma,
304 			enum i915_cache_level cache_level,
305 			u32 unused)
306 {
307 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
308 	struct gen6_ppgtt *ppgtt = vma->private;
309 	u32 ggtt_offset = i915_ggtt_offset(vma) / I915_GTT_PAGE_SIZE;
310 
311 	ppgtt->pp_dir = ggtt_offset * sizeof(gen6_pte_t) << 10;
312 	ppgtt->pd_addr = (gen6_pte_t __iomem *)ggtt->gsm + ggtt_offset;
313 
314 	gen6_flush_pd(ppgtt, 0, ppgtt->base.vm.total);
315 }
316 
317 static void pd_vma_unbind(struct i915_address_space *vm, struct i915_vma *vma)
318 {
319 	struct gen6_ppgtt *ppgtt = vma->private;
320 	struct i915_page_directory * const pd = ppgtt->base.pd;
321 	struct i915_page_table *pt;
322 	unsigned int pde;
323 
324 	if (!ppgtt->scan_for_unused_pt)
325 		return;
326 
327 	/* Free all no longer used page tables */
328 	gen6_for_all_pdes(pt, ppgtt->base.pd, pde) {
329 		if (!pt || atomic_read(&pt->used))
330 			continue;
331 
332 		free_pt(&ppgtt->base.vm, pt);
333 		pd->entry[pde] = NULL;
334 	}
335 
336 	ppgtt->scan_for_unused_pt = false;
337 }
338 
339 static const struct i915_vma_ops pd_vma_ops = {
340 	.set_pages = pd_vma_set_pages,
341 	.clear_pages = pd_vma_clear_pages,
342 	.bind_vma = pd_vma_bind,
343 	.unbind_vma = pd_vma_unbind,
344 };
345 
346 static struct i915_vma *pd_vma_create(struct gen6_ppgtt *ppgtt, int size)
347 {
348 	struct i915_ggtt *ggtt = ppgtt->base.vm.gt->ggtt;
349 	struct i915_vma *vma;
350 
351 	GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_PAGE_SIZE));
352 	GEM_BUG_ON(size > ggtt->vm.total);
353 
354 	vma = i915_vma_alloc();
355 	if (!vma)
356 		return ERR_PTR(-ENOMEM);
357 
358 	i915_active_init(&vma->active, NULL, NULL);
359 
360 	kref_init(&vma->ref);
361 	mutex_init(&vma->pages_mutex);
362 	vma->vm = i915_vm_get(&ggtt->vm);
363 	vma->ops = &pd_vma_ops;
364 	vma->private = ppgtt;
365 
366 	vma->size = size;
367 	vma->fence_size = size;
368 	atomic_set(&vma->flags, I915_VMA_GGTT);
369 	vma->ggtt_view.type = I915_GGTT_VIEW_ROTATED; /* prevent fencing */
370 
371 	INIT_LIST_HEAD(&vma->obj_link);
372 	INIT_LIST_HEAD(&vma->closed_link);
373 
374 	return vma;
375 }
376 
377 int gen6_ppgtt_pin(struct i915_ppgtt *base, struct i915_gem_ww_ctx *ww)
378 {
379 	struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(base);
380 	int err;
381 
382 	GEM_BUG_ON(!atomic_read(&ppgtt->base.vm.open));
383 
384 	/*
385 	 * Workaround the limited maximum vma->pin_count and the aliasing_ppgtt
386 	 * which will be pinned into every active context.
387 	 * (When vma->pin_count becomes atomic, I expect we will naturally
388 	 * need a larger, unpacked, type and kill this redundancy.)
389 	 */
390 	if (atomic_add_unless(&ppgtt->pin_count, 1, 0))
391 		return 0;
392 
393 	if (mutex_lock_interruptible(&ppgtt->pin_mutex))
394 		return -EINTR;
395 
396 	/*
397 	 * PPGTT PDEs reside in the GGTT and consists of 512 entries. The
398 	 * allocator works in address space sizes, so it's multiplied by page
399 	 * size. We allocate at the top of the GTT to avoid fragmentation.
400 	 */
401 	err = 0;
402 	if (!atomic_read(&ppgtt->pin_count))
403 		err = i915_ggtt_pin(ppgtt->vma, ww, GEN6_PD_ALIGN, PIN_HIGH);
404 	if (!err)
405 		atomic_inc(&ppgtt->pin_count);
406 	mutex_unlock(&ppgtt->pin_mutex);
407 
408 	return err;
409 }
410 
411 void gen6_ppgtt_unpin(struct i915_ppgtt *base)
412 {
413 	struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(base);
414 
415 	GEM_BUG_ON(!atomic_read(&ppgtt->pin_count));
416 	if (atomic_dec_and_test(&ppgtt->pin_count))
417 		i915_vma_unpin(ppgtt->vma);
418 }
419 
420 void gen6_ppgtt_unpin_all(struct i915_ppgtt *base)
421 {
422 	struct gen6_ppgtt *ppgtt = to_gen6_ppgtt(base);
423 
424 	if (!atomic_read(&ppgtt->pin_count))
425 		return;
426 
427 	i915_vma_unpin(ppgtt->vma);
428 	atomic_set(&ppgtt->pin_count, 0);
429 }
430 
431 struct i915_ppgtt *gen6_ppgtt_create(struct intel_gt *gt)
432 {
433 	struct i915_ggtt * const ggtt = gt->ggtt;
434 	struct gen6_ppgtt *ppgtt;
435 	int err;
436 
437 	ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
438 	if (!ppgtt)
439 		return ERR_PTR(-ENOMEM);
440 
441 	mutex_init(&ppgtt->flush);
442 	mutex_init(&ppgtt->pin_mutex);
443 
444 	ppgtt_init(&ppgtt->base, gt);
445 	ppgtt->base.vm.pd_shift = ilog2(SZ_4K * SZ_4K / sizeof(gen6_pte_t));
446 	ppgtt->base.vm.top = 1;
447 
448 	ppgtt->base.vm.bind_async_flags = I915_VMA_LOCAL_BIND;
449 	ppgtt->base.vm.allocate_va_range = gen6_alloc_va_range;
450 	ppgtt->base.vm.clear_range = gen6_ppgtt_clear_range;
451 	ppgtt->base.vm.insert_entries = gen6_ppgtt_insert_entries;
452 	ppgtt->base.vm.cleanup = gen6_ppgtt_cleanup;
453 
454 	ppgtt->base.vm.alloc_pt_dma = alloc_pt_dma;
455 	ppgtt->base.vm.pte_encode = ggtt->vm.pte_encode;
456 
457 	ppgtt->base.pd = __alloc_pd(I915_PDES);
458 	if (!ppgtt->base.pd) {
459 		err = -ENOMEM;
460 		goto err_free;
461 	}
462 
463 	err = gen6_ppgtt_init_scratch(ppgtt);
464 	if (err)
465 		goto err_pd;
466 
467 	ppgtt->vma = pd_vma_create(ppgtt, GEN6_PD_SIZE);
468 	if (IS_ERR(ppgtt->vma)) {
469 		err = PTR_ERR(ppgtt->vma);
470 		goto err_scratch;
471 	}
472 
473 	return &ppgtt->base;
474 
475 err_scratch:
476 	free_scratch(&ppgtt->base.vm);
477 err_pd:
478 	free_pd(&ppgtt->base.vm, ppgtt->base.pd);
479 err_free:
480 	mutex_destroy(&ppgtt->pin_mutex);
481 	kfree(ppgtt);
482 	return ERR_PTR(err);
483 }
484