1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2021 Intel Corporation
4  */
5 
6 /**
7  * DOC: display pinning helpers
8  */
9 
10 #include "intel_display_types.h"
11 #include "intel_fb_pin.h"
12 #include "intel_fb.h"
13 
14 #include "intel_dpt.h"
15 
16 #include "gem/i915_gem_object.h"
17 
18 static struct i915_vma *
19 intel_pin_fb_obj_dpt(struct drm_framebuffer *fb,
20 		     const struct i915_ggtt_view *view,
21 		     bool uses_fence,
22 		     unsigned long *out_flags,
23 		     struct i915_address_space *vm)
24 {
25 	struct drm_device *dev = fb->dev;
26 	struct drm_i915_private *dev_priv = to_i915(dev);
27 	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
28 	struct i915_vma *vma;
29 	u32 alignment;
30 	int ret;
31 
32 	if (WARN_ON(!i915_gem_object_is_framebuffer(obj)))
33 		return ERR_PTR(-EINVAL);
34 
35 	alignment = 4096 * 512;
36 
37 	atomic_inc(&dev_priv->gpu_error.pending_fb_pin);
38 
39 	ret = i915_gem_object_set_cache_level(obj, I915_CACHE_NONE);
40 	if (ret) {
41 		vma = ERR_PTR(ret);
42 		goto err;
43 	}
44 
45 	vma = i915_vma_instance(obj, vm, view);
46 	if (IS_ERR(vma))
47 		goto err;
48 
49 	if (i915_vma_misplaced(vma, 0, alignment, 0)) {
50 		ret = i915_vma_unbind(vma);
51 		if (ret) {
52 			vma = ERR_PTR(ret);
53 			goto err;
54 		}
55 	}
56 
57 	ret = i915_vma_pin(vma, 0, alignment, PIN_GLOBAL);
58 	if (ret) {
59 		vma = ERR_PTR(ret);
60 		goto err;
61 	}
62 
63 	vma->display_alignment = max_t(u64, vma->display_alignment, alignment);
64 
65 	i915_gem_object_flush_if_display(obj);
66 
67 	i915_vma_get(vma);
68 err:
69 	atomic_dec(&dev_priv->gpu_error.pending_fb_pin);
70 
71 	return vma;
72 }
73 
74 struct i915_vma *
75 intel_pin_and_fence_fb_obj(struct drm_framebuffer *fb,
76 			   bool phys_cursor,
77 			   const struct i915_ggtt_view *view,
78 			   bool uses_fence,
79 			   unsigned long *out_flags)
80 {
81 	struct drm_device *dev = fb->dev;
82 	struct drm_i915_private *dev_priv = to_i915(dev);
83 	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
84 	intel_wakeref_t wakeref;
85 	struct i915_gem_ww_ctx ww;
86 	struct i915_vma *vma;
87 	unsigned int pinctl;
88 	u32 alignment;
89 	int ret;
90 
91 	if (drm_WARN_ON(dev, !i915_gem_object_is_framebuffer(obj)))
92 		return ERR_PTR(-EINVAL);
93 
94 	if (phys_cursor)
95 		alignment = intel_cursor_alignment(dev_priv);
96 	else
97 		alignment = intel_surf_alignment(fb, 0);
98 	if (drm_WARN_ON(dev, alignment && !is_power_of_2(alignment)))
99 		return ERR_PTR(-EINVAL);
100 
101 	/* Note that the w/a also requires 64 PTE of padding following the
102 	 * bo. We currently fill all unused PTE with the shadow page and so
103 	 * we should always have valid PTE following the scanout preventing
104 	 * the VT-d warning.
105 	 */
106 	if (intel_scanout_needs_vtd_wa(dev_priv) && alignment < 256 * 1024)
107 		alignment = 256 * 1024;
108 
109 	/*
110 	 * Global gtt pte registers are special registers which actually forward
111 	 * writes to a chunk of system memory. Which means that there is no risk
112 	 * that the register values disappear as soon as we call
113 	 * intel_runtime_pm_put(), so it is correct to wrap only the
114 	 * pin/unpin/fence and not more.
115 	 */
116 	wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);
117 
118 	atomic_inc(&dev_priv->gpu_error.pending_fb_pin);
119 
120 	/*
121 	 * Valleyview is definitely limited to scanning out the first
122 	 * 512MiB. Lets presume this behaviour was inherited from the
123 	 * g4x display engine and that all earlier gen are similarly
124 	 * limited. Testing suggests that it is a little more
125 	 * complicated than this. For example, Cherryview appears quite
126 	 * happy to scanout from anywhere within its global aperture.
127 	 */
128 	pinctl = 0;
129 	if (HAS_GMCH(dev_priv))
130 		pinctl |= PIN_MAPPABLE;
131 
132 	i915_gem_ww_ctx_init(&ww, true);
133 retry:
134 	ret = i915_gem_object_lock(obj, &ww);
135 	if (!ret && phys_cursor)
136 		ret = i915_gem_object_attach_phys(obj, alignment);
137 	else if (!ret && HAS_LMEM(dev_priv))
138 		ret = i915_gem_object_migrate(obj, &ww, INTEL_REGION_LMEM);
139 	/* TODO: Do we need to sync when migration becomes async? */
140 	if (!ret)
141 		ret = i915_gem_object_pin_pages(obj);
142 	if (ret)
143 		goto err;
144 
145 	if (!ret) {
146 		vma = i915_gem_object_pin_to_display_plane(obj, &ww, alignment,
147 							   view, pinctl);
148 		if (IS_ERR(vma)) {
149 			ret = PTR_ERR(vma);
150 			goto err_unpin;
151 		}
152 	}
153 
154 	if (uses_fence && i915_vma_is_map_and_fenceable(vma)) {
155 		/*
156 		 * Install a fence for tiled scan-out. Pre-i965 always needs a
157 		 * fence, whereas 965+ only requires a fence if using
158 		 * framebuffer compression.  For simplicity, we always, when
159 		 * possible, install a fence as the cost is not that onerous.
160 		 *
161 		 * If we fail to fence the tiled scanout, then either the
162 		 * modeset will reject the change (which is highly unlikely as
163 		 * the affected systems, all but one, do not have unmappable
164 		 * space) or we will not be able to enable full powersaving
165 		 * techniques (also likely not to apply due to various limits
166 		 * FBC and the like impose on the size of the buffer, which
167 		 * presumably we violated anyway with this unmappable buffer).
168 		 * Anyway, it is presumably better to stumble onwards with
169 		 * something and try to run the system in a "less than optimal"
170 		 * mode that matches the user configuration.
171 		 */
172 		ret = i915_vma_pin_fence(vma);
173 		if (ret != 0 && DISPLAY_VER(dev_priv) < 4) {
174 			i915_vma_unpin(vma);
175 			goto err_unpin;
176 		}
177 		ret = 0;
178 
179 		if (vma->fence)
180 			*out_flags |= PLANE_HAS_FENCE;
181 	}
182 
183 	i915_vma_get(vma);
184 
185 err_unpin:
186 	i915_gem_object_unpin_pages(obj);
187 err:
188 	if (ret == -EDEADLK) {
189 		ret = i915_gem_ww_ctx_backoff(&ww);
190 		if (!ret)
191 			goto retry;
192 	}
193 	i915_gem_ww_ctx_fini(&ww);
194 	if (ret)
195 		vma = ERR_PTR(ret);
196 
197 	atomic_dec(&dev_priv->gpu_error.pending_fb_pin);
198 	intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
199 	return vma;
200 }
201 
202 void intel_unpin_fb_vma(struct i915_vma *vma, unsigned long flags)
203 {
204 	if (flags & PLANE_HAS_FENCE)
205 		i915_vma_unpin_fence(vma);
206 	i915_vma_unpin(vma);
207 	i915_vma_put(vma);
208 }
209 
210 int intel_plane_pin_fb(struct intel_plane_state *plane_state)
211 {
212 	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
213 	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
214 	struct drm_framebuffer *fb = plane_state->hw.fb;
215 	struct i915_vma *vma;
216 	bool phys_cursor =
217 		plane->id == PLANE_CURSOR &&
218 		INTEL_INFO(dev_priv)->display.cursor_needs_physical;
219 
220 	if (!intel_fb_uses_dpt(fb)) {
221 		vma = intel_pin_and_fence_fb_obj(fb, phys_cursor,
222 						 &plane_state->view.gtt,
223 						 intel_plane_uses_fence(plane_state),
224 						 &plane_state->flags);
225 		if (IS_ERR(vma))
226 			return PTR_ERR(vma);
227 
228 		plane_state->ggtt_vma = vma;
229 	} else {
230 		struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
231 
232 		vma = intel_dpt_pin(intel_fb->dpt_vm);
233 		if (IS_ERR(vma))
234 			return PTR_ERR(vma);
235 
236 		plane_state->ggtt_vma = vma;
237 
238 		vma = intel_pin_fb_obj_dpt(fb, &plane_state->view.gtt, false,
239 					   &plane_state->flags, intel_fb->dpt_vm);
240 		if (IS_ERR(vma)) {
241 			intel_dpt_unpin(intel_fb->dpt_vm);
242 			plane_state->ggtt_vma = NULL;
243 			return PTR_ERR(vma);
244 		}
245 
246 		plane_state->dpt_vma = vma;
247 
248 		WARN_ON(plane_state->ggtt_vma == plane_state->dpt_vma);
249 	}
250 
251 	return 0;
252 }
253 
254 void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state)
255 {
256 	struct drm_framebuffer *fb = old_plane_state->hw.fb;
257 	struct i915_vma *vma;
258 
259 	if (!intel_fb_uses_dpt(fb)) {
260 		vma = fetch_and_zero(&old_plane_state->ggtt_vma);
261 		if (vma)
262 			intel_unpin_fb_vma(vma, old_plane_state->flags);
263 	} else {
264 		struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
265 
266 		vma = fetch_and_zero(&old_plane_state->dpt_vma);
267 		if (vma)
268 			intel_unpin_fb_vma(vma, old_plane_state->flags);
269 
270 		vma = fetch_and_zero(&old_plane_state->ggtt_vma);
271 		if (vma)
272 			intel_dpt_unpin(intel_fb->dpt_vm);
273 	}
274 }
275