1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2021 Intel Corporation
4  */
5 
6 /**
7  * DOC: display pinning helpers
8  */
9 
10 #include "gem/i915_gem_domain.h"
11 #include "gem/i915_gem_object.h"
12 
13 #include "i915_drv.h"
14 #include "intel_display_types.h"
15 #include "intel_dpt.h"
16 #include "intel_fb.h"
17 #include "intel_fb_pin.h"
18 
19 static struct i915_vma *
20 intel_pin_fb_obj_dpt(struct drm_framebuffer *fb,
21 		     const struct i915_ggtt_view *view,
22 		     bool uses_fence,
23 		     unsigned long *out_flags,
24 		     struct i915_address_space *vm)
25 {
26 	struct drm_device *dev = fb->dev;
27 	struct drm_i915_private *dev_priv = to_i915(dev);
28 	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
29 	struct i915_vma *vma;
30 	u32 alignment;
31 	int ret;
32 
33 	if (WARN_ON(!i915_gem_object_is_framebuffer(obj)))
34 		return ERR_PTR(-EINVAL);
35 
36 	alignment = 4096 * 512;
37 
38 	atomic_inc(&dev_priv->gpu_error.pending_fb_pin);
39 
40 	ret = i915_gem_object_lock_interruptible(obj, NULL);
41 	if (!ret) {
42 		ret = i915_gem_object_set_cache_level(obj, I915_CACHE_NONE);
43 		i915_gem_object_unlock(obj);
44 	}
45 	if (ret) {
46 		vma = ERR_PTR(ret);
47 		goto err;
48 	}
49 
50 	vma = i915_vma_instance(obj, vm, view);
51 	if (IS_ERR(vma))
52 		goto err;
53 
54 	if (i915_vma_misplaced(vma, 0, alignment, 0)) {
55 		ret = i915_vma_unbind_unlocked(vma);
56 		if (ret) {
57 			vma = ERR_PTR(ret);
58 			goto err;
59 		}
60 	}
61 
62 	ret = i915_vma_pin(vma, 0, alignment, PIN_GLOBAL);
63 	if (ret) {
64 		vma = ERR_PTR(ret);
65 		goto err;
66 	}
67 
68 	vma->display_alignment = max_t(u64, vma->display_alignment, alignment);
69 
70 	i915_gem_object_flush_if_display(obj);
71 
72 	i915_vma_get(vma);
73 err:
74 	atomic_dec(&dev_priv->gpu_error.pending_fb_pin);
75 
76 	return vma;
77 }
78 
79 struct i915_vma *
80 intel_pin_and_fence_fb_obj(struct drm_framebuffer *fb,
81 			   bool phys_cursor,
82 			   const struct i915_ggtt_view *view,
83 			   bool uses_fence,
84 			   unsigned long *out_flags)
85 {
86 	struct drm_device *dev = fb->dev;
87 	struct drm_i915_private *dev_priv = to_i915(dev);
88 	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
89 	intel_wakeref_t wakeref;
90 	struct i915_gem_ww_ctx ww;
91 	struct i915_vma *vma;
92 	unsigned int pinctl;
93 	u32 alignment;
94 	int ret;
95 
96 	if (drm_WARN_ON(dev, !i915_gem_object_is_framebuffer(obj)))
97 		return ERR_PTR(-EINVAL);
98 
99 	if (phys_cursor)
100 		alignment = intel_cursor_alignment(dev_priv);
101 	else
102 		alignment = intel_surf_alignment(fb, 0);
103 	if (drm_WARN_ON(dev, alignment && !is_power_of_2(alignment)))
104 		return ERR_PTR(-EINVAL);
105 
106 	/* Note that the w/a also requires 64 PTE of padding following the
107 	 * bo. We currently fill all unused PTE with the shadow page and so
108 	 * we should always have valid PTE following the scanout preventing
109 	 * the VT-d warning.
110 	 */
111 	if (intel_scanout_needs_vtd_wa(dev_priv) && alignment < 256 * 1024)
112 		alignment = 256 * 1024;
113 
114 	/*
115 	 * Global gtt pte registers are special registers which actually forward
116 	 * writes to a chunk of system memory. Which means that there is no risk
117 	 * that the register values disappear as soon as we call
118 	 * intel_runtime_pm_put(), so it is correct to wrap only the
119 	 * pin/unpin/fence and not more.
120 	 */
121 	wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);
122 
123 	atomic_inc(&dev_priv->gpu_error.pending_fb_pin);
124 
125 	/*
126 	 * Valleyview is definitely limited to scanning out the first
127 	 * 512MiB. Lets presume this behaviour was inherited from the
128 	 * g4x display engine and that all earlier gen are similarly
129 	 * limited. Testing suggests that it is a little more
130 	 * complicated than this. For example, Cherryview appears quite
131 	 * happy to scanout from anywhere within its global aperture.
132 	 */
133 	pinctl = 0;
134 	if (HAS_GMCH(dev_priv))
135 		pinctl |= PIN_MAPPABLE;
136 
137 	i915_gem_ww_ctx_init(&ww, true);
138 retry:
139 	ret = i915_gem_object_lock(obj, &ww);
140 	if (!ret && phys_cursor)
141 		ret = i915_gem_object_attach_phys(obj, alignment);
142 	else if (!ret && HAS_LMEM(dev_priv))
143 		ret = i915_gem_object_migrate(obj, &ww, INTEL_REGION_LMEM_0);
144 	/* TODO: Do we need to sync when migration becomes async? */
145 	if (!ret)
146 		ret = i915_gem_object_pin_pages(obj);
147 	if (ret)
148 		goto err;
149 
150 	vma = i915_gem_object_pin_to_display_plane(obj, &ww, alignment,
151 						   view, pinctl);
152 	if (IS_ERR(vma)) {
153 		ret = PTR_ERR(vma);
154 		goto err_unpin;
155 	}
156 
157 	if (uses_fence && i915_vma_is_map_and_fenceable(vma)) {
158 		/*
159 		 * Install a fence for tiled scan-out. Pre-i965 always needs a
160 		 * fence, whereas 965+ only requires a fence if using
161 		 * framebuffer compression.  For simplicity, we always, when
162 		 * possible, install a fence as the cost is not that onerous.
163 		 *
164 		 * If we fail to fence the tiled scanout, then either the
165 		 * modeset will reject the change (which is highly unlikely as
166 		 * the affected systems, all but one, do not have unmappable
167 		 * space) or we will not be able to enable full powersaving
168 		 * techniques (also likely not to apply due to various limits
169 		 * FBC and the like impose on the size of the buffer, which
170 		 * presumably we violated anyway with this unmappable buffer).
171 		 * Anyway, it is presumably better to stumble onwards with
172 		 * something and try to run the system in a "less than optimal"
173 		 * mode that matches the user configuration.
174 		 */
175 		ret = i915_vma_pin_fence(vma);
176 		if (ret != 0 && DISPLAY_VER(dev_priv) < 4) {
177 			i915_vma_unpin(vma);
178 			goto err_unpin;
179 		}
180 		ret = 0;
181 
182 		if (vma->fence)
183 			*out_flags |= PLANE_HAS_FENCE;
184 	}
185 
186 	i915_vma_get(vma);
187 
188 err_unpin:
189 	i915_gem_object_unpin_pages(obj);
190 err:
191 	if (ret == -EDEADLK) {
192 		ret = i915_gem_ww_ctx_backoff(&ww);
193 		if (!ret)
194 			goto retry;
195 	}
196 	i915_gem_ww_ctx_fini(&ww);
197 	if (ret)
198 		vma = ERR_PTR(ret);
199 
200 	atomic_dec(&dev_priv->gpu_error.pending_fb_pin);
201 	intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
202 	return vma;
203 }
204 
205 void intel_unpin_fb_vma(struct i915_vma *vma, unsigned long flags)
206 {
207 	if (flags & PLANE_HAS_FENCE)
208 		i915_vma_unpin_fence(vma);
209 	i915_vma_unpin(vma);
210 	i915_vma_put(vma);
211 }
212 
213 int intel_plane_pin_fb(struct intel_plane_state *plane_state)
214 {
215 	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
216 	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
217 	struct drm_framebuffer *fb = plane_state->hw.fb;
218 	struct i915_vma *vma;
219 	bool phys_cursor =
220 		plane->id == PLANE_CURSOR &&
221 		INTEL_INFO(dev_priv)->display.cursor_needs_physical;
222 
223 	if (!intel_fb_uses_dpt(fb)) {
224 		vma = intel_pin_and_fence_fb_obj(fb, phys_cursor,
225 						 &plane_state->view.gtt,
226 						 intel_plane_uses_fence(plane_state),
227 						 &plane_state->flags);
228 		if (IS_ERR(vma))
229 			return PTR_ERR(vma);
230 
231 		plane_state->ggtt_vma = vma;
232 	} else {
233 		struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
234 
235 		vma = intel_dpt_pin(intel_fb->dpt_vm);
236 		if (IS_ERR(vma))
237 			return PTR_ERR(vma);
238 
239 		plane_state->ggtt_vma = vma;
240 
241 		vma = intel_pin_fb_obj_dpt(fb, &plane_state->view.gtt, false,
242 					   &plane_state->flags, intel_fb->dpt_vm);
243 		if (IS_ERR(vma)) {
244 			intel_dpt_unpin(intel_fb->dpt_vm);
245 			plane_state->ggtt_vma = NULL;
246 			return PTR_ERR(vma);
247 		}
248 
249 		plane_state->dpt_vma = vma;
250 
251 		WARN_ON(plane_state->ggtt_vma == plane_state->dpt_vma);
252 	}
253 
254 	return 0;
255 }
256 
257 void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state)
258 {
259 	struct drm_framebuffer *fb = old_plane_state->hw.fb;
260 	struct i915_vma *vma;
261 
262 	if (!intel_fb_uses_dpt(fb)) {
263 		vma = fetch_and_zero(&old_plane_state->ggtt_vma);
264 		if (vma)
265 			intel_unpin_fb_vma(vma, old_plane_state->flags);
266 	} else {
267 		struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
268 
269 		vma = fetch_and_zero(&old_plane_state->dpt_vma);
270 		if (vma)
271 			intel_unpin_fb_vma(vma, old_plane_state->flags);
272 
273 		vma = fetch_and_zero(&old_plane_state->ggtt_vma);
274 		if (vma)
275 			intel_dpt_unpin(intel_fb->dpt_vm);
276 	}
277 }
278