1// SPDX-License-Identifier: MIT
  2/*
  3 * Copyright © 2019 Intel Corporation
  4 */
  5
  6#include <linux/prandom.h>
  7
  8#include <uapi/drm/i915_drm.h>
  9
 10#include "intel_memory_region.h"
 11#include "i915_drv.h"
 12#include "i915_ttm_buddy_manager.h"
 13
 14static const struct {
 15	u16 class;
 16	u16 instance;
 17} intel_region_map[] = {
 18	[INTEL_REGION_SMEM] = {
 19		.class = INTEL_MEMORY_SYSTEM,
 20		.instance = 0,
 21	},
 22	[INTEL_REGION_LMEM_0] = {
 23		.class = INTEL_MEMORY_LOCAL,
 24		.instance = 0,
 25	},
 26	[INTEL_REGION_STOLEN_SMEM] = {
 27		.class = INTEL_MEMORY_STOLEN_SYSTEM,
 28		.instance = 0,
 29	},
 30	[INTEL_REGION_STOLEN_LMEM] = {
 31		.class = INTEL_MEMORY_STOLEN_LOCAL,
 32		.instance = 0,
 33	},
 34};
 35
 36static int __iopagetest(struct intel_memory_region *mem,
 37			u8 __iomem *va, int pagesize,
 38			u8 value, resource_size_t offset,
 39			const void *caller)
 40{
 41	int byte = get_random_u32_below(pagesize);
 42	u8 result[3];
 43
 44	memset_io(va, value, pagesize); /* or GPF! */
 45	wmb();
 46
 47	result[0] = ioread8(va);
 48	result[1] = ioread8(va + byte);
 49	result[2] = ioread8(va + pagesize - 1);
 50	if (memchr_inv(result, value, sizeof(result))) {
 51		dev_err(mem->i915->drm.dev,
 52			"Failed to read back from memory region:%pR at [%pa + %pa] for %ps; wrote %x, read (%x, %x, %x)\n",
 53			&mem->region, &mem->io_start, &offset, caller,
 54			value, result[0], result[1], result[2]);
 55		return -EINVAL;
 56	}
 57
 58	return 0;
 59}
 60
 61static int iopagetest(struct intel_memory_region *mem,
 62		      resource_size_t offset,
 63		      const void *caller)
 64{
 65	const u8 val[] = { 0x0, 0xa5, 0xc3, 0xf0 };
 66	void __iomem *va;
 67	int err;
 68	int i;
 69
 70	va = ioremap_wc(mem->io_start + offset, PAGE_SIZE);
 71	if (!va) {
 72		dev_err(mem->i915->drm.dev,
 73			"Failed to ioremap memory region [%pa + %pa] for %ps\n",
 74			&mem->io_start, &offset, caller);
 75		return -EFAULT;
 76	}
 77
 78	for (i = 0; i < ARRAY_SIZE(val); i++) {
 79		err = __iopagetest(mem, va, PAGE_SIZE, val[i], offset, caller);
 80		if (err)
 81			break;
 82
 83		err = __iopagetest(mem, va, PAGE_SIZE, ~val[i], offset, caller);
 84		if (err)
 85			break;
 86	}
 87
 88	iounmap(va);
 89	return err;
 90}
 91
 92static resource_size_t random_page(resource_size_t last)
 93{
 94	/* Limited to low 44b (16TiB), but should suffice for a spot check */
 95	return get_random_u32_below(last >> PAGE_SHIFT) << PAGE_SHIFT;
 96}
 97
 98static int iomemtest(struct intel_memory_region *mem,
 99		     bool test_all,
100		     const void *caller)
101{
102	resource_size_t last, page;
103	int err;
104
105	if (mem->io_size < PAGE_SIZE)
106		return 0;
107
108	last = mem->io_size - PAGE_SIZE;
109
110	/*
111	 * Quick test to check read/write access to the iomap (backing store).
112	 *
113	 * Write a byte, read it back. If the iomapping fails, we expect
114	 * a GPF preventing further execution. If the backing store does not
115	 * exist, the read back will return garbage. We check a couple of pages,
116	 * the first and last of the specified region to confirm the backing
117	 * store + iomap does cover the entire memory region; and we check
118	 * a random offset within as a quick spot check for bad memory.
119	 */
120
121	if (test_all) {
122		for (page = 0; page <= last; page += PAGE_SIZE) {
123			err = iopagetest(mem, page, caller);
124			if (err)
125				return err;
126		}
127	} else {
128		err = iopagetest(mem, 0, caller);
129		if (err)
130			return err;
131
132		err = iopagetest(mem, last, caller);
133		if (err)
134			return err;
135
136		err = iopagetest(mem, random_page(last), caller);
137		if (err)
138			return err;
139	}
140
141	return 0;
142}
143
144struct intel_memory_region *
145intel_memory_region_lookup(struct drm_i915_private *i915,
146			   u16 class, u16 instance)
147{
148	struct intel_memory_region *mr;
149	int id;
150
151	/* XXX: consider maybe converting to an rb tree at some point */
152	for_each_memory_region(mr, i915, id) {
153		if (mr->type == class && mr->instance == instance)
154			return mr;
155	}
156
157	return NULL;
158}
159
160struct intel_memory_region *
161intel_memory_region_by_type(struct drm_i915_private *i915,
162			    enum intel_memory_type mem_type)
163{
164	struct intel_memory_region *mr;
165	int id;
166
167	for_each_memory_region(mr, i915, id)
168		if (mr->type == mem_type)
169			return mr;
170
171	return NULL;
172}
173
174/**
175 * intel_memory_region_reserve - Reserve a memory range
176 * @mem: The region for which we want to reserve a range.
177 * @offset: Start of the range to reserve.
178 * @size: The size of the range to reserve.
179 *
180 * Return: 0 on success, negative error code on failure.
181 */
182int intel_memory_region_reserve(struct intel_memory_region *mem,
183				resource_size_t offset,
184				resource_size_t size)
185{
186	struct ttm_resource_manager *man = mem->region_private;
187
188	GEM_BUG_ON(mem->is_range_manager);
189
190	return i915_ttm_buddy_man_reserve(man, offset, size);
191}
192
193void intel_memory_region_debug(struct intel_memory_region *mr,
194			       struct drm_printer *printer)
195{
196	drm_printf(printer, "%s: ", mr->name);
197
198	if (mr->region_private)
199		ttm_resource_manager_debug(mr->region_private, printer);
200	else
201		drm_printf(printer, "total:%pa bytes\n", &mr->total);
202}
203
204static int intel_memory_region_memtest(struct intel_memory_region *mem,
205				       void *caller)
206{
207	struct drm_i915_private *i915 = mem->i915;
208	int err = 0;
209
210	if (!mem->io_start)
211		return 0;
212
213	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) || i915->params.memtest)
214		err = iomemtest(mem, i915->params.memtest, caller);
215
216	return err;
217}
218
219struct intel_memory_region *
220intel_memory_region_create(struct drm_i915_private *i915,
221			   resource_size_t start,
222			   resource_size_t size,
223			   resource_size_t min_page_size,
224			   resource_size_t io_start,
225			   resource_size_t io_size,
226			   u16 type,
227			   u16 instance,
228			   const struct intel_memory_region_ops *ops)
229{
230	struct intel_memory_region *mem;
231	int err;
232
233	mem = kzalloc(sizeof(*mem), GFP_KERNEL);
234	if (!mem)
235		return ERR_PTR(-ENOMEM);
236
237	mem->i915 = i915;
238	mem->region = (struct resource)DEFINE_RES_MEM(start, size);
239	mem->io_start = io_start;
240	mem->io_size = io_size;
241	mem->min_page_size = min_page_size;
242	mem->ops = ops;
243	mem->total = size;
244	mem->type = type;
245	mem->instance = instance;
246
247	mutex_init(&mem->objects.lock);
248	INIT_LIST_HEAD(&mem->objects.list);
249
250	if (ops->init) {
251		err = ops->init(mem);
252		if (err)
253			goto err_free;
254	}
255
256	err = intel_memory_region_memtest(mem, (void *)_RET_IP_);
257	if (err)
258		goto err_release;
259
260	return mem;
261
262err_release:
263	if (mem->ops->release)
264		mem->ops->release(mem);
265err_free:
266	kfree(mem);
267	return ERR_PTR(err);
268}
269
270void intel_memory_region_set_name(struct intel_memory_region *mem,
271				  const char *fmt, ...)
272{
273	va_list ap;
274
275	va_start(ap, fmt);
276	vsnprintf(mem->name, sizeof(mem->name), fmt, ap);
277	va_end(ap);
278}
279
280void intel_memory_region_avail(struct intel_memory_region *mr,
281			       u64 *avail, u64 *visible_avail)
282{
283	if (mr->type == INTEL_MEMORY_LOCAL) {
284		i915_ttm_buddy_man_avail(mr->region_private,
285					 avail, visible_avail);
286		*avail <<= PAGE_SHIFT;
287		*visible_avail <<= PAGE_SHIFT;
288	} else {
289		*avail = mr->total;
290		*visible_avail = mr->total;
291	}
292}
293
294void intel_memory_region_destroy(struct intel_memory_region *mem)
295{
296	int ret = 0;
297
298	if (mem->ops->release)
299		ret = mem->ops->release(mem);
300
301	GEM_WARN_ON(!list_empty_careful(&mem->objects.list));
302	mutex_destroy(&mem->objects.lock);
303	if (!ret)
304		kfree(mem);
305}
306
307/* Global memory region registration -- only slight layer inversions! */
308
309int intel_memory_regions_hw_probe(struct drm_i915_private *i915)
310{
311	int err, i;
312
313	for (i = 0; i < ARRAY_SIZE(i915->mm.regions); i++) {
314		struct intel_memory_region *mem = ERR_PTR(-ENODEV);
315		u16 type, instance;
316
317		if (!HAS_REGION(i915, BIT(i)))
318			continue;
319
320		type = intel_region_map[i].class;
321		instance = intel_region_map[i].instance;
322		switch (type) {
323		case INTEL_MEMORY_SYSTEM:
324			if (IS_DGFX(i915))
325				mem = i915_gem_ttm_system_setup(i915, type,
326								instance);
327			else
328				mem = i915_gem_shmem_setup(i915, type,
329							   instance);
330			break;
331		case INTEL_MEMORY_STOLEN_LOCAL:
332			mem = i915_gem_stolen_lmem_setup(i915, type, instance);
333			if (!IS_ERR(mem))
334				i915->mm.stolen_region = mem;
335			break;
336		case INTEL_MEMORY_STOLEN_SYSTEM:
337			mem = i915_gem_stolen_smem_setup(i915, type, instance);
338			if (!IS_ERR(mem))
339				i915->mm.stolen_region = mem;
340			break;
341		default:
342			continue;
343		}
344
345		if (IS_ERR(mem)) {
346			err = PTR_ERR(mem);
347			drm_err(&i915->drm,
348				"Failed to setup region(%d) type=%d\n",
349				err, type);
350			goto out_cleanup;
351		}
352
353		mem->id = i;
354		i915->mm.regions[i] = mem;
355	}
356
357	return 0;
358
359out_cleanup:
360	intel_memory_regions_driver_release(i915);
361	return err;
362}
363
364void intel_memory_regions_driver_release(struct drm_i915_private *i915)
365{
366	int i;
367
368	for (i = 0; i < ARRAY_SIZE(i915->mm.regions); i++) {
369		struct intel_memory_region *region =
370			fetch_and_zero(&i915->mm.regions[i]);
371
372		if (region)
373			intel_memory_region_destroy(region);
374	}
375}
376
377#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
378#include "selftests/intel_memory_region.c"
379#include "selftests/mock_region.c"
380#endif