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      1 /*	$NetBSD: intel_fbc.c,v 1.3 2021/12/19 12:32:15 riastradh Exp $	*/
      2 
      3 /*
      4  * Copyright  2014 Intel Corporation
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the "Software"),
      8  * to deal in the Software without restriction, including without limitation
      9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     10  * and/or sell copies of the Software, and to permit persons to whom the
     11  * Software is furnished to do so, subject to the following conditions:
     12  *
     13  * The above copyright notice and this permission notice (including the next
     14  * paragraph) shall be included in all copies or substantial portions of the
     15  * Software.
     16  *
     17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     23  * DEALINGS IN THE SOFTWARE.
     24  */
     25 
     26 /**
     27  * DOC: Frame Buffer Compression (FBC)
     28  *
     29  * FBC tries to save memory bandwidth (and so power consumption) by
     30  * compressing the amount of memory used by the display. It is total
     31  * transparent to user space and completely handled in the kernel.
     32  *
     33  * The benefits of FBC are mostly visible with solid backgrounds and
     34  * variation-less patterns. It comes from keeping the memory footprint small
     35  * and having fewer memory pages opened and accessed for refreshing the display.
     36  *
     37  * i915 is responsible to reserve stolen memory for FBC and configure its
     38  * offset on proper registers. The hardware takes care of all
     39  * compress/decompress. However there are many known cases where we have to
     40  * forcibly disable it to allow proper screen updates.
     41  */
     42 
     43 #include <sys/cdefs.h>
     44 __KERNEL_RCSID(0, "$NetBSD: intel_fbc.c,v 1.3 2021/12/19 12:32:15 riastradh Exp $");
     45 
     46 #include <drm/drm_fourcc.h>
     47 
     48 #include "i915_drv.h"
     49 #include "intel_display_types.h"
     50 #include "intel_fbc.h"
     51 #include "intel_frontbuffer.h"
     52 
     53 #include <linux/nbsd-namespace.h>
     54 
     55 static inline bool fbc_supported(struct drm_i915_private *dev_priv)
     56 {
     57 	return HAS_FBC(dev_priv);
     58 }
     59 
     60 /*
     61  * In some platforms where the CRTC's x:0/y:0 coordinates doesn't match the
     62  * frontbuffer's x:0/y:0 coordinates we lie to the hardware about the plane's
     63  * origin so the x and y offsets can actually fit the registers. As a
     64  * consequence, the fence doesn't really start exactly at the display plane
     65  * address we program because it starts at the real start of the buffer, so we
     66  * have to take this into consideration here.
     67  */
     68 static unsigned int get_crtc_fence_y_offset(struct intel_fbc *fbc)
     69 {
     70 	return fbc->state_cache.plane.y - fbc->state_cache.plane.adjusted_y;
     71 }
     72 
     73 /*
     74  * For SKL+, the plane source size used by the hardware is based on the value we
     75  * write to the PLANE_SIZE register. For BDW-, the hardware looks at the value
     76  * we wrote to PIPESRC.
     77  */
     78 static void intel_fbc_get_plane_source_size(const struct intel_fbc_state_cache *cache,
     79 					    int *width, int *height)
     80 {
     81 	if (width)
     82 		*width = cache->plane.src_w;
     83 	if (height)
     84 		*height = cache->plane.src_h;
     85 }
     86 
     87 static int intel_fbc_calculate_cfb_size(struct drm_i915_private *dev_priv,
     88 					const struct intel_fbc_state_cache *cache)
     89 {
     90 	int lines;
     91 
     92 	intel_fbc_get_plane_source_size(cache, NULL, &lines);
     93 	if (IS_GEN(dev_priv, 7))
     94 		lines = min(lines, 2048);
     95 	else if (INTEL_GEN(dev_priv) >= 8)
     96 		lines = min(lines, 2560);
     97 
     98 	/* Hardware needs the full buffer stride, not just the active area. */
     99 	return lines * cache->fb.stride;
    100 }
    101 
    102 static void i8xx_fbc_deactivate(struct drm_i915_private *dev_priv)
    103 {
    104 	u32 fbc_ctl;
    105 
    106 	/* Disable compression */
    107 	fbc_ctl = I915_READ(FBC_CONTROL);
    108 	if ((fbc_ctl & FBC_CTL_EN) == 0)
    109 		return;
    110 
    111 	fbc_ctl &= ~FBC_CTL_EN;
    112 	I915_WRITE(FBC_CONTROL, fbc_ctl);
    113 
    114 	/* Wait for compressing bit to clear */
    115 	if (intel_de_wait_for_clear(dev_priv, FBC_STATUS,
    116 				    FBC_STAT_COMPRESSING, 10)) {
    117 		DRM_DEBUG_KMS("FBC idle timed out\n");
    118 		return;
    119 	}
    120 }
    121 
    122 static void i8xx_fbc_activate(struct drm_i915_private *dev_priv)
    123 {
    124 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
    125 	int cfb_pitch;
    126 	int i;
    127 	u32 fbc_ctl;
    128 
    129 	/* Note: fbc.threshold == 1 for i8xx */
    130 	cfb_pitch = params->cfb_size / FBC_LL_SIZE;
    131 	if (params->fb.stride < cfb_pitch)
    132 		cfb_pitch = params->fb.stride;
    133 
    134 	/* FBC_CTL wants 32B or 64B units */
    135 	if (IS_GEN(dev_priv, 2))
    136 		cfb_pitch = (cfb_pitch / 32) - 1;
    137 	else
    138 		cfb_pitch = (cfb_pitch / 64) - 1;
    139 
    140 	/* Clear old tags */
    141 	for (i = 0; i < (FBC_LL_SIZE / 32) + 1; i++)
    142 		I915_WRITE(FBC_TAG(i), 0);
    143 
    144 	if (IS_GEN(dev_priv, 4)) {
    145 		u32 fbc_ctl2;
    146 
    147 		/* Set it up... */
    148 		fbc_ctl2 = FBC_CTL_FENCE_DBL | FBC_CTL_IDLE_IMM;
    149 		fbc_ctl2 |= FBC_CTL_PLANE(params->crtc.i9xx_plane);
    150 		if (params->fence_id >= 0)
    151 			fbc_ctl2 |= FBC_CTL_CPU_FENCE;
    152 		I915_WRITE(FBC_CONTROL2, fbc_ctl2);
    153 		I915_WRITE(FBC_FENCE_OFF, params->crtc.fence_y_offset);
    154 	}
    155 
    156 	/* enable it... */
    157 	fbc_ctl = I915_READ(FBC_CONTROL);
    158 	fbc_ctl &= 0x3fff << FBC_CTL_INTERVAL_SHIFT;
    159 	fbc_ctl |= FBC_CTL_EN | FBC_CTL_PERIODIC;
    160 	if (IS_I945GM(dev_priv))
    161 		fbc_ctl |= FBC_CTL_C3_IDLE; /* 945 needs special SR handling */
    162 	fbc_ctl |= (cfb_pitch & 0xff) << FBC_CTL_STRIDE_SHIFT;
    163 	if (params->fence_id >= 0)
    164 		fbc_ctl |= params->fence_id;
    165 	I915_WRITE(FBC_CONTROL, fbc_ctl);
    166 }
    167 
    168 static bool i8xx_fbc_is_active(struct drm_i915_private *dev_priv)
    169 {
    170 	return I915_READ(FBC_CONTROL) & FBC_CTL_EN;
    171 }
    172 
    173 static void g4x_fbc_activate(struct drm_i915_private *dev_priv)
    174 {
    175 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
    176 	u32 dpfc_ctl;
    177 
    178 	dpfc_ctl = DPFC_CTL_PLANE(params->crtc.i9xx_plane) | DPFC_SR_EN;
    179 	if (params->fb.format->cpp[0] == 2)
    180 		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
    181 	else
    182 		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
    183 
    184 	if (params->fence_id >= 0) {
    185 		dpfc_ctl |= DPFC_CTL_FENCE_EN | params->fence_id;
    186 		I915_WRITE(DPFC_FENCE_YOFF, params->crtc.fence_y_offset);
    187 	} else {
    188 		I915_WRITE(DPFC_FENCE_YOFF, 0);
    189 	}
    190 
    191 	/* enable it... */
    192 	I915_WRITE(DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
    193 }
    194 
    195 static void g4x_fbc_deactivate(struct drm_i915_private *dev_priv)
    196 {
    197 	u32 dpfc_ctl;
    198 
    199 	/* Disable compression */
    200 	dpfc_ctl = I915_READ(DPFC_CONTROL);
    201 	if (dpfc_ctl & DPFC_CTL_EN) {
    202 		dpfc_ctl &= ~DPFC_CTL_EN;
    203 		I915_WRITE(DPFC_CONTROL, dpfc_ctl);
    204 	}
    205 }
    206 
    207 static bool g4x_fbc_is_active(struct drm_i915_private *dev_priv)
    208 {
    209 	return I915_READ(DPFC_CONTROL) & DPFC_CTL_EN;
    210 }
    211 
    212 /* This function forces a CFB recompression through the nuke operation. */
    213 static void intel_fbc_recompress(struct drm_i915_private *dev_priv)
    214 {
    215 	I915_WRITE(MSG_FBC_REND_STATE, FBC_REND_NUKE);
    216 	POSTING_READ(MSG_FBC_REND_STATE);
    217 }
    218 
    219 static void ilk_fbc_activate(struct drm_i915_private *dev_priv)
    220 {
    221 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
    222 	u32 dpfc_ctl;
    223 	int threshold = dev_priv->fbc.threshold;
    224 
    225 	dpfc_ctl = DPFC_CTL_PLANE(params->crtc.i9xx_plane);
    226 	if (params->fb.format->cpp[0] == 2)
    227 		threshold++;
    228 
    229 	switch (threshold) {
    230 	case 4:
    231 	case 3:
    232 		dpfc_ctl |= DPFC_CTL_LIMIT_4X;
    233 		break;
    234 	case 2:
    235 		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
    236 		break;
    237 	case 1:
    238 		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
    239 		break;
    240 	}
    241 
    242 	if (params->fence_id >= 0) {
    243 		dpfc_ctl |= DPFC_CTL_FENCE_EN;
    244 		if (IS_GEN(dev_priv, 5))
    245 			dpfc_ctl |= params->fence_id;
    246 		if (IS_GEN(dev_priv, 6)) {
    247 			I915_WRITE(SNB_DPFC_CTL_SA,
    248 				   SNB_CPU_FENCE_ENABLE |
    249 				   params->fence_id);
    250 			I915_WRITE(DPFC_CPU_FENCE_OFFSET,
    251 				   params->crtc.fence_y_offset);
    252 		}
    253 	} else {
    254 		if (IS_GEN(dev_priv, 6)) {
    255 			I915_WRITE(SNB_DPFC_CTL_SA, 0);
    256 			I915_WRITE(DPFC_CPU_FENCE_OFFSET, 0);
    257 		}
    258 	}
    259 
    260 	I915_WRITE(ILK_DPFC_FENCE_YOFF, params->crtc.fence_y_offset);
    261 	/* enable it... */
    262 	I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
    263 
    264 	intel_fbc_recompress(dev_priv);
    265 }
    266 
    267 static void ilk_fbc_deactivate(struct drm_i915_private *dev_priv)
    268 {
    269 	u32 dpfc_ctl;
    270 
    271 	/* Disable compression */
    272 	dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
    273 	if (dpfc_ctl & DPFC_CTL_EN) {
    274 		dpfc_ctl &= ~DPFC_CTL_EN;
    275 		I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl);
    276 	}
    277 }
    278 
    279 static bool ilk_fbc_is_active(struct drm_i915_private *dev_priv)
    280 {
    281 	return I915_READ(ILK_DPFC_CONTROL) & DPFC_CTL_EN;
    282 }
    283 
    284 static void gen7_fbc_activate(struct drm_i915_private *dev_priv)
    285 {
    286 	struct intel_fbc_reg_params *params = &dev_priv->fbc.params;
    287 	u32 dpfc_ctl;
    288 	int threshold = dev_priv->fbc.threshold;
    289 
    290 	/* Display WA #0529: skl, kbl, bxt. */
    291 	if (IS_GEN9_BC(dev_priv) || IS_BROXTON(dev_priv)) {
    292 		u32 val = I915_READ(CHICKEN_MISC_4);
    293 
    294 		val &= ~(FBC_STRIDE_OVERRIDE | FBC_STRIDE_MASK);
    295 
    296 		if (params->gen9_wa_cfb_stride)
    297 			val |= FBC_STRIDE_OVERRIDE | params->gen9_wa_cfb_stride;
    298 
    299 		I915_WRITE(CHICKEN_MISC_4, val);
    300 	}
    301 
    302 	dpfc_ctl = 0;
    303 	if (IS_IVYBRIDGE(dev_priv))
    304 		dpfc_ctl |= IVB_DPFC_CTL_PLANE(params->crtc.i9xx_plane);
    305 
    306 	if (params->fb.format->cpp[0] == 2)
    307 		threshold++;
    308 
    309 	switch (threshold) {
    310 	case 4:
    311 	case 3:
    312 		dpfc_ctl |= DPFC_CTL_LIMIT_4X;
    313 		break;
    314 	case 2:
    315 		dpfc_ctl |= DPFC_CTL_LIMIT_2X;
    316 		break;
    317 	case 1:
    318 		dpfc_ctl |= DPFC_CTL_LIMIT_1X;
    319 		break;
    320 	}
    321 
    322 	if (params->fence_id >= 0) {
    323 		dpfc_ctl |= IVB_DPFC_CTL_FENCE_EN;
    324 		I915_WRITE(SNB_DPFC_CTL_SA,
    325 			   SNB_CPU_FENCE_ENABLE |
    326 			   params->fence_id);
    327 		I915_WRITE(DPFC_CPU_FENCE_OFFSET, params->crtc.fence_y_offset);
    328 	} else {
    329 		I915_WRITE(SNB_DPFC_CTL_SA,0);
    330 		I915_WRITE(DPFC_CPU_FENCE_OFFSET, 0);
    331 	}
    332 
    333 	if (dev_priv->fbc.false_color)
    334 		dpfc_ctl |= FBC_CTL_FALSE_COLOR;
    335 
    336 	if (IS_IVYBRIDGE(dev_priv)) {
    337 		/* WaFbcAsynchFlipDisableFbcQueue:ivb */
    338 		I915_WRITE(ILK_DISPLAY_CHICKEN1,
    339 			   I915_READ(ILK_DISPLAY_CHICKEN1) |
    340 			   ILK_FBCQ_DIS);
    341 	} else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
    342 		/* WaFbcAsynchFlipDisableFbcQueue:hsw,bdw */
    343 		I915_WRITE(CHICKEN_PIPESL_1(params->crtc.pipe),
    344 			   I915_READ(CHICKEN_PIPESL_1(params->crtc.pipe)) |
    345 			   HSW_FBCQ_DIS);
    346 	}
    347 
    348 	if (INTEL_GEN(dev_priv) >= 11)
    349 		/* Wa_1409120013:icl,ehl,tgl */
    350 		I915_WRITE(ILK_DPFC_CHICKEN, ILK_DPFC_CHICKEN_COMP_DUMMY_PIXEL);
    351 
    352 	I915_WRITE(ILK_DPFC_CONTROL, dpfc_ctl | DPFC_CTL_EN);
    353 
    354 	intel_fbc_recompress(dev_priv);
    355 }
    356 
    357 static bool intel_fbc_hw_is_active(struct drm_i915_private *dev_priv)
    358 {
    359 	if (INTEL_GEN(dev_priv) >= 5)
    360 		return ilk_fbc_is_active(dev_priv);
    361 	else if (IS_GM45(dev_priv))
    362 		return g4x_fbc_is_active(dev_priv);
    363 	else
    364 		return i8xx_fbc_is_active(dev_priv);
    365 }
    366 
    367 static void intel_fbc_hw_activate(struct drm_i915_private *dev_priv)
    368 {
    369 	struct intel_fbc *fbc = &dev_priv->fbc;
    370 
    371 	fbc->active = true;
    372 	fbc->activated = true;
    373 
    374 	if (INTEL_GEN(dev_priv) >= 7)
    375 		gen7_fbc_activate(dev_priv);
    376 	else if (INTEL_GEN(dev_priv) >= 5)
    377 		ilk_fbc_activate(dev_priv);
    378 	else if (IS_GM45(dev_priv))
    379 		g4x_fbc_activate(dev_priv);
    380 	else
    381 		i8xx_fbc_activate(dev_priv);
    382 }
    383 
    384 static void intel_fbc_hw_deactivate(struct drm_i915_private *dev_priv)
    385 {
    386 	struct intel_fbc *fbc = &dev_priv->fbc;
    387 
    388 	fbc->active = false;
    389 
    390 	if (INTEL_GEN(dev_priv) >= 5)
    391 		ilk_fbc_deactivate(dev_priv);
    392 	else if (IS_GM45(dev_priv))
    393 		g4x_fbc_deactivate(dev_priv);
    394 	else
    395 		i8xx_fbc_deactivate(dev_priv);
    396 }
    397 
    398 /**
    399  * intel_fbc_is_active - Is FBC active?
    400  * @dev_priv: i915 device instance
    401  *
    402  * This function is used to verify the current state of FBC.
    403  *
    404  * FIXME: This should be tracked in the plane config eventually
    405  * instead of queried at runtime for most callers.
    406  */
    407 bool intel_fbc_is_active(struct drm_i915_private *dev_priv)
    408 {
    409 	return dev_priv->fbc.active;
    410 }
    411 
    412 static void intel_fbc_deactivate(struct drm_i915_private *dev_priv,
    413 				 const char *reason)
    414 {
    415 	struct intel_fbc *fbc = &dev_priv->fbc;
    416 
    417 	WARN_ON(!mutex_is_locked(&fbc->lock));
    418 
    419 	if (fbc->active)
    420 		intel_fbc_hw_deactivate(dev_priv);
    421 
    422 	fbc->no_fbc_reason = reason;
    423 }
    424 
    425 static int find_compression_threshold(struct drm_i915_private *dev_priv,
    426 				      struct drm_mm_node *node,
    427 				      unsigned int size,
    428 				      unsigned int fb_cpp)
    429 {
    430 	int compression_threshold = 1;
    431 	int ret;
    432 	u64 end;
    433 
    434 	/* The FBC hardware for BDW/SKL doesn't have access to the stolen
    435 	 * reserved range size, so it always assumes the maximum (8mb) is used.
    436 	 * If we enable FBC using a CFB on that memory range we'll get FIFO
    437 	 * underruns, even if that range is not reserved by the BIOS. */
    438 	if (IS_BROADWELL(dev_priv) || IS_GEN9_BC(dev_priv))
    439 		end = resource_size(&dev_priv->dsm) - 8 * 1024 * 1024;
    440 	else
    441 		end = U64_MAX;
    442 
    443 	/* HACK: This code depends on what we will do in *_enable_fbc. If that
    444 	 * code changes, this code needs to change as well.
    445 	 *
    446 	 * The enable_fbc code will attempt to use one of our 2 compression
    447 	 * thresholds, therefore, in that case, we only have 1 resort.
    448 	 */
    449 
    450 	/* Try to over-allocate to reduce reallocations and fragmentation. */
    451 	ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size <<= 1,
    452 						   4096, 0, end);
    453 	if (ret == 0)
    454 		return compression_threshold;
    455 
    456 again:
    457 	/* HW's ability to limit the CFB is 1:4 */
    458 	if (compression_threshold > 4 ||
    459 	    (fb_cpp == 2 && compression_threshold == 2))
    460 		return 0;
    461 
    462 	ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size >>= 1,
    463 						   4096, 0, end);
    464 	if (ret && INTEL_GEN(dev_priv) <= 4) {
    465 		return 0;
    466 	} else if (ret) {
    467 		compression_threshold <<= 1;
    468 		goto again;
    469 	} else {
    470 		return compression_threshold;
    471 	}
    472 }
    473 
    474 static int intel_fbc_alloc_cfb(struct drm_i915_private *dev_priv,
    475 			       unsigned int size, unsigned int fb_cpp)
    476 {
    477 	struct intel_fbc *fbc = &dev_priv->fbc;
    478 	struct drm_mm_node *uninitialized_var(compressed_llb);
    479 	int ret;
    480 
    481 	WARN_ON(drm_mm_node_allocated(&fbc->compressed_fb));
    482 
    483 	ret = find_compression_threshold(dev_priv, &fbc->compressed_fb,
    484 					 size, fb_cpp);
    485 	if (!ret)
    486 		goto err_llb;
    487 	else if (ret > 1) {
    488 		DRM_INFO("Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.\n");
    489 
    490 	}
    491 
    492 	fbc->threshold = ret;
    493 
    494 	if (INTEL_GEN(dev_priv) >= 5)
    495 		I915_WRITE(ILK_DPFC_CB_BASE, fbc->compressed_fb.start);
    496 	else if (IS_GM45(dev_priv)) {
    497 		I915_WRITE(DPFC_CB_BASE, fbc->compressed_fb.start);
    498 	} else {
    499 		compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
    500 		if (!compressed_llb)
    501 			goto err_fb;
    502 
    503 		ret = i915_gem_stolen_insert_node(dev_priv, compressed_llb,
    504 						  4096, 4096);
    505 		if (ret)
    506 			goto err_fb;
    507 
    508 		fbc->compressed_llb = compressed_llb;
    509 
    510 		GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
    511 					     fbc->compressed_fb.start,
    512 					     U32_MAX));
    513 		GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
    514 					     fbc->compressed_llb->start,
    515 					     U32_MAX));
    516 		I915_WRITE(FBC_CFB_BASE,
    517 			   dev_priv->dsm.start + fbc->compressed_fb.start);
    518 		I915_WRITE(FBC_LL_BASE,
    519 			   dev_priv->dsm.start + compressed_llb->start);
    520 	}
    521 
    522 	DRM_DEBUG_KMS("reserved %"PRIu64" bytes of contiguous stolen space for FBC, threshold: %d\n",
    523 		      fbc->compressed_fb.size, fbc->threshold);
    524 
    525 	return 0;
    526 
    527 err_fb:
    528 	kfree(compressed_llb);
    529 	i915_gem_stolen_remove_node(dev_priv, &fbc->compressed_fb);
    530 err_llb:
    531 	if (drm_mm_initialized(&dev_priv->mm.stolen))
    532 		pr_info_once("drm: not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size);
    533 	return -ENOSPC;
    534 }
    535 
    536 static void __intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
    537 {
    538 	struct intel_fbc *fbc = &dev_priv->fbc;
    539 
    540 	if (drm_mm_node_allocated(&fbc->compressed_fb))
    541 		i915_gem_stolen_remove_node(dev_priv, &fbc->compressed_fb);
    542 
    543 	if (fbc->compressed_llb) {
    544 		i915_gem_stolen_remove_node(dev_priv, fbc->compressed_llb);
    545 		kfree(fbc->compressed_llb);
    546 	}
    547 }
    548 
    549 void intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
    550 {
    551 	struct intel_fbc *fbc = &dev_priv->fbc;
    552 
    553 	if (!fbc_supported(dev_priv))
    554 		return;
    555 
    556 	mutex_lock(&fbc->lock);
    557 	__intel_fbc_cleanup_cfb(dev_priv);
    558 	mutex_unlock(&fbc->lock);
    559 }
    560 
    561 static bool stride_is_valid(struct drm_i915_private *dev_priv,
    562 			    unsigned int stride)
    563 {
    564 	/* This should have been caught earlier. */
    565 	if (WARN_ON_ONCE((stride & (64 - 1)) != 0))
    566 		return false;
    567 
    568 	/* Below are the additional FBC restrictions. */
    569 	if (stride < 512)
    570 		return false;
    571 
    572 	if (IS_GEN(dev_priv, 2) || IS_GEN(dev_priv, 3))
    573 		return stride == 4096 || stride == 8192;
    574 
    575 	if (IS_GEN(dev_priv, 4) && !IS_G4X(dev_priv) && stride < 2048)
    576 		return false;
    577 
    578 	if (stride > 16384)
    579 		return false;
    580 
    581 	return true;
    582 }
    583 
    584 static bool pixel_format_is_valid(struct drm_i915_private *dev_priv,
    585 				  u32 pixel_format)
    586 {
    587 	switch (pixel_format) {
    588 	case DRM_FORMAT_XRGB8888:
    589 	case DRM_FORMAT_XBGR8888:
    590 		return true;
    591 	case DRM_FORMAT_XRGB1555:
    592 	case DRM_FORMAT_RGB565:
    593 		/* 16bpp not supported on gen2 */
    594 		if (IS_GEN(dev_priv, 2))
    595 			return false;
    596 		/* WaFbcOnly1to1Ratio:ctg */
    597 		if (IS_G4X(dev_priv))
    598 			return false;
    599 		return true;
    600 	default:
    601 		return false;
    602 	}
    603 }
    604 
    605 /*
    606  * For some reason, the hardware tracking starts looking at whatever we
    607  * programmed as the display plane base address register. It does not look at
    608  * the X and Y offset registers. That's why we look at the crtc->adjusted{x,y}
    609  * variables instead of just looking at the pipe/plane size.
    610  */
    611 static bool intel_fbc_hw_tracking_covers_screen(struct intel_crtc *crtc)
    612 {
    613 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
    614 	struct intel_fbc *fbc = &dev_priv->fbc;
    615 	unsigned int effective_w, effective_h, max_w, max_h;
    616 
    617 	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) {
    618 		max_w = 5120;
    619 		max_h = 4096;
    620 	} else if (INTEL_GEN(dev_priv) >= 8 || IS_HASWELL(dev_priv)) {
    621 		max_w = 4096;
    622 		max_h = 4096;
    623 	} else if (IS_G4X(dev_priv) || INTEL_GEN(dev_priv) >= 5) {
    624 		max_w = 4096;
    625 		max_h = 2048;
    626 	} else {
    627 		max_w = 2048;
    628 		max_h = 1536;
    629 	}
    630 
    631 	intel_fbc_get_plane_source_size(&fbc->state_cache, &effective_w,
    632 					&effective_h);
    633 	effective_w += fbc->state_cache.plane.adjusted_x;
    634 	effective_h += fbc->state_cache.plane.adjusted_y;
    635 
    636 	return effective_w <= max_w && effective_h <= max_h;
    637 }
    638 
    639 static void intel_fbc_update_state_cache(struct intel_crtc *crtc,
    640 					 const struct intel_crtc_state *crtc_state,
    641 					 const struct intel_plane_state *plane_state)
    642 {
    643 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
    644 	struct intel_fbc *fbc = &dev_priv->fbc;
    645 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
    646 	struct drm_framebuffer *fb = plane_state->hw.fb;
    647 
    648 	cache->plane.visible = plane_state->uapi.visible;
    649 	if (!cache->plane.visible)
    650 		return;
    651 
    652 	cache->crtc.mode_flags = crtc_state->hw.adjusted_mode.flags;
    653 	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
    654 		cache->crtc.hsw_bdw_pixel_rate = crtc_state->pixel_rate;
    655 
    656 	cache->plane.rotation = plane_state->hw.rotation;
    657 	/*
    658 	 * Src coordinates are already rotated by 270 degrees for
    659 	 * the 90/270 degree plane rotation cases (to match the
    660 	 * GTT mapping), hence no need to account for rotation here.
    661 	 */
    662 	cache->plane.src_w = drm_rect_width(&plane_state->uapi.src) >> 16;
    663 	cache->plane.src_h = drm_rect_height(&plane_state->uapi.src) >> 16;
    664 	cache->plane.adjusted_x = plane_state->color_plane[0].x;
    665 	cache->plane.adjusted_y = plane_state->color_plane[0].y;
    666 	cache->plane.y = plane_state->uapi.src.y1 >> 16;
    667 
    668 	cache->plane.pixel_blend_mode = plane_state->hw.pixel_blend_mode;
    669 
    670 	cache->fb.format = fb->format;
    671 	cache->fb.stride = fb->pitches[0];
    672 
    673 	WARN_ON(plane_state->flags & PLANE_HAS_FENCE &&
    674 		!plane_state->vma->fence);
    675 
    676 	if (plane_state->flags & PLANE_HAS_FENCE &&
    677 	    plane_state->vma->fence)
    678 		cache->fence_id = plane_state->vma->fence->id;
    679 	else
    680 		cache->fence_id = -1;
    681 }
    682 
    683 static bool intel_fbc_cfb_size_changed(struct drm_i915_private *dev_priv)
    684 {
    685 	struct intel_fbc *fbc = &dev_priv->fbc;
    686 
    687 	return intel_fbc_calculate_cfb_size(dev_priv, &fbc->state_cache) >
    688 		fbc->compressed_fb.size * fbc->threshold;
    689 }
    690 
    691 static bool intel_fbc_can_activate(struct intel_crtc *crtc)
    692 {
    693 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
    694 	struct intel_fbc *fbc = &dev_priv->fbc;
    695 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
    696 
    697 	if (!cache->plane.visible) {
    698 		fbc->no_fbc_reason = "primary plane not visible";
    699 		return false;
    700 	}
    701 
    702 	/* We don't need to use a state cache here since this information is
    703 	 * global for all CRTC.
    704 	 */
    705 	if (fbc->underrun_detected) {
    706 		fbc->no_fbc_reason = "underrun detected";
    707 		return false;
    708 	}
    709 
    710 	if (cache->crtc.mode_flags & DRM_MODE_FLAG_INTERLACE) {
    711 		fbc->no_fbc_reason = "incompatible mode";
    712 		return false;
    713 	}
    714 
    715 	if (!intel_fbc_hw_tracking_covers_screen(crtc)) {
    716 		fbc->no_fbc_reason = "mode too large for compression";
    717 		return false;
    718 	}
    719 
    720 	/* The use of a CPU fence is mandatory in order to detect writes
    721 	 * by the CPU to the scanout and trigger updates to the FBC.
    722 	 *
    723 	 * Note that is possible for a tiled surface to be unmappable (and
    724 	 * so have no fence associated with it) due to aperture constaints
    725 	 * at the time of pinning.
    726 	 *
    727 	 * FIXME with 90/270 degree rotation we should use the fence on
    728 	 * the normal GTT view (the rotated view doesn't even have a
    729 	 * fence). Would need changes to the FBC fence Y offset as well.
    730 	 * For now this will effecively disable FBC with 90/270 degree
    731 	 * rotation.
    732 	 */
    733 	if (cache->fence_id < 0) {
    734 		fbc->no_fbc_reason = "framebuffer not tiled or fenced";
    735 		return false;
    736 	}
    737 	if (INTEL_GEN(dev_priv) <= 4 && !IS_G4X(dev_priv) &&
    738 	    cache->plane.rotation != DRM_MODE_ROTATE_0) {
    739 		fbc->no_fbc_reason = "rotation unsupported";
    740 		return false;
    741 	}
    742 
    743 	if (!stride_is_valid(dev_priv, cache->fb.stride)) {
    744 		fbc->no_fbc_reason = "framebuffer stride not supported";
    745 		return false;
    746 	}
    747 
    748 	if (!pixel_format_is_valid(dev_priv, cache->fb.format->format)) {
    749 		fbc->no_fbc_reason = "pixel format is invalid";
    750 		return false;
    751 	}
    752 
    753 	if (cache->plane.pixel_blend_mode != DRM_MODE_BLEND_PIXEL_NONE &&
    754 	    cache->fb.format->has_alpha) {
    755 		fbc->no_fbc_reason = "per-pixel alpha blending is incompatible with FBC";
    756 		return false;
    757 	}
    758 
    759 	/* WaFbcExceedCdClockThreshold:hsw,bdw */
    760 	if ((IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) &&
    761 	    cache->crtc.hsw_bdw_pixel_rate >= dev_priv->cdclk.hw.cdclk * 95 / 100) {
    762 		fbc->no_fbc_reason = "pixel rate is too big";
    763 		return false;
    764 	}
    765 
    766 	/* It is possible for the required CFB size change without a
    767 	 * crtc->disable + crtc->enable since it is possible to change the
    768 	 * stride without triggering a full modeset. Since we try to
    769 	 * over-allocate the CFB, there's a chance we may keep FBC enabled even
    770 	 * if this happens, but if we exceed the current CFB size we'll have to
    771 	 * disable FBC. Notice that it would be possible to disable FBC, wait
    772 	 * for a frame, free the stolen node, then try to reenable FBC in case
    773 	 * we didn't get any invalidate/deactivate calls, but this would require
    774 	 * a lot of tracking just for a specific case. If we conclude it's an
    775 	 * important case, we can implement it later. */
    776 	if (intel_fbc_cfb_size_changed(dev_priv)) {
    777 		fbc->no_fbc_reason = "CFB requirements changed";
    778 		return false;
    779 	}
    780 
    781 	/*
    782 	 * Work around a problem on GEN9+ HW, where enabling FBC on a plane
    783 	 * having a Y offset that isn't divisible by 4 causes FIFO underrun
    784 	 * and screen flicker.
    785 	 */
    786 	if (INTEL_GEN(dev_priv) >= 9 &&
    787 	    (fbc->state_cache.plane.adjusted_y & 3)) {
    788 		fbc->no_fbc_reason = "plane Y offset is misaligned";
    789 		return false;
    790 	}
    791 
    792 	return true;
    793 }
    794 
    795 static bool intel_fbc_can_enable(struct drm_i915_private *dev_priv)
    796 {
    797 	struct intel_fbc *fbc = &dev_priv->fbc;
    798 
    799 	if (intel_vgpu_active(dev_priv)) {
    800 		fbc->no_fbc_reason = "VGPU is active";
    801 		return false;
    802 	}
    803 
    804 	if (!i915_modparams.enable_fbc) {
    805 		fbc->no_fbc_reason = "disabled per module param or by default";
    806 		return false;
    807 	}
    808 
    809 	if (fbc->underrun_detected) {
    810 		fbc->no_fbc_reason = "underrun detected";
    811 		return false;
    812 	}
    813 
    814 	return true;
    815 }
    816 
    817 static void intel_fbc_get_reg_params(struct intel_crtc *crtc,
    818 				     struct intel_fbc_reg_params *params)
    819 {
    820 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
    821 	struct intel_fbc *fbc = &dev_priv->fbc;
    822 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
    823 
    824 	/* Since all our fields are integer types, use memset here so the
    825 	 * comparison function can rely on memcmp because the padding will be
    826 	 * zero. */
    827 	memset(params, 0, sizeof(*params));
    828 
    829 	params->fence_id = cache->fence_id;
    830 
    831 	params->crtc.pipe = crtc->pipe;
    832 	params->crtc.i9xx_plane = to_intel_plane(crtc->base.primary)->i9xx_plane;
    833 	params->crtc.fence_y_offset = get_crtc_fence_y_offset(fbc);
    834 
    835 	params->fb.format = cache->fb.format;
    836 	params->fb.stride = cache->fb.stride;
    837 
    838 	params->cfb_size = intel_fbc_calculate_cfb_size(dev_priv, cache);
    839 
    840 	params->gen9_wa_cfb_stride = cache->gen9_wa_cfb_stride;
    841 
    842 	params->plane_visible = cache->plane.visible;
    843 }
    844 
    845 static bool intel_fbc_can_flip_nuke(const struct intel_crtc_state *crtc_state)
    846 {
    847 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
    848 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
    849 	const struct intel_fbc *fbc = &dev_priv->fbc;
    850 	const struct intel_fbc_state_cache *cache = &fbc->state_cache;
    851 	const struct intel_fbc_reg_params *params = &fbc->params;
    852 
    853 	if (drm_atomic_crtc_needs_modeset(&crtc_state->uapi))
    854 		return false;
    855 
    856 	if (!params->plane_visible)
    857 		return false;
    858 
    859 	if (!intel_fbc_can_activate(crtc))
    860 		return false;
    861 
    862 	if (params->fb.format != cache->fb.format)
    863 		return false;
    864 
    865 	if (params->fb.stride != cache->fb.stride)
    866 		return false;
    867 
    868 	if (params->cfb_size != intel_fbc_calculate_cfb_size(dev_priv, cache))
    869 		return false;
    870 
    871 	if (params->gen9_wa_cfb_stride != cache->gen9_wa_cfb_stride)
    872 		return false;
    873 
    874 	return true;
    875 }
    876 
    877 bool intel_fbc_pre_update(struct intel_crtc *crtc,
    878 			  const struct intel_crtc_state *crtc_state,
    879 			  const struct intel_plane_state *plane_state)
    880 {
    881 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
    882 	struct intel_fbc *fbc = &dev_priv->fbc;
    883 	const char *reason = "update pending";
    884 	bool need_vblank_wait = false;
    885 
    886 	if (!fbc_supported(dev_priv))
    887 		return need_vblank_wait;
    888 
    889 	mutex_lock(&fbc->lock);
    890 
    891 	if (fbc->crtc != crtc)
    892 		goto unlock;
    893 
    894 	intel_fbc_update_state_cache(crtc, crtc_state, plane_state);
    895 	fbc->flip_pending = true;
    896 
    897 	if (!intel_fbc_can_flip_nuke(crtc_state)) {
    898 		intel_fbc_deactivate(dev_priv, reason);
    899 
    900 		/*
    901 		 * Display WA #1198: glk+
    902 		 * Need an extra vblank wait between FBC disable and most plane
    903 		 * updates. Bspec says this is only needed for plane disable, but
    904 		 * that is not true. Touching most plane registers will cause the
    905 		 * corruption to appear. Also SKL/derivatives do not seem to be
    906 		 * affected.
    907 		 *
    908 		 * TODO: could optimize this a bit by sampling the frame
    909 		 * counter when we disable FBC (if it was already done earlier)
    910 		 * and skipping the extra vblank wait before the plane update
    911 		 * if at least one frame has already passed.
    912 		 */
    913 		if (fbc->activated &&
    914 		    (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)))
    915 			need_vblank_wait = true;
    916 		fbc->activated = false;
    917 	}
    918 unlock:
    919 	mutex_unlock(&fbc->lock);
    920 
    921 	return need_vblank_wait;
    922 }
    923 
    924 /**
    925  * __intel_fbc_disable - disable FBC
    926  * @dev_priv: i915 device instance
    927  *
    928  * This is the low level function that actually disables FBC. Callers should
    929  * grab the FBC lock.
    930  */
    931 static void __intel_fbc_disable(struct drm_i915_private *dev_priv)
    932 {
    933 	struct intel_fbc *fbc = &dev_priv->fbc;
    934 	struct intel_crtc *crtc = fbc->crtc;
    935 
    936 	WARN_ON(!mutex_is_locked(&fbc->lock));
    937 	WARN_ON(!fbc->crtc);
    938 	WARN_ON(fbc->active);
    939 
    940 	DRM_DEBUG_KMS("Disabling FBC on pipe %c\n", pipe_name(crtc->pipe));
    941 
    942 	__intel_fbc_cleanup_cfb(dev_priv);
    943 
    944 	fbc->crtc = NULL;
    945 }
    946 
    947 static void __intel_fbc_post_update(struct intel_crtc *crtc)
    948 {
    949 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
    950 	struct intel_fbc *fbc = &dev_priv->fbc;
    951 
    952 	WARN_ON(!mutex_is_locked(&fbc->lock));
    953 
    954 	if (fbc->crtc != crtc)
    955 		return;
    956 
    957 	fbc->flip_pending = false;
    958 
    959 	if (!i915_modparams.enable_fbc) {
    960 		intel_fbc_deactivate(dev_priv, "disabled at runtime per module param");
    961 		__intel_fbc_disable(dev_priv);
    962 
    963 		return;
    964 	}
    965 
    966 	intel_fbc_get_reg_params(crtc, &fbc->params);
    967 
    968 	if (!intel_fbc_can_activate(crtc))
    969 		return;
    970 
    971 	if (!fbc->busy_bits)
    972 		intel_fbc_hw_activate(dev_priv);
    973 	else
    974 		intel_fbc_deactivate(dev_priv, "frontbuffer write");
    975 }
    976 
    977 void intel_fbc_post_update(struct intel_crtc *crtc)
    978 {
    979 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
    980 	struct intel_fbc *fbc = &dev_priv->fbc;
    981 
    982 	if (!fbc_supported(dev_priv))
    983 		return;
    984 
    985 	mutex_lock(&fbc->lock);
    986 	__intel_fbc_post_update(crtc);
    987 	mutex_unlock(&fbc->lock);
    988 }
    989 
    990 static unsigned int intel_fbc_get_frontbuffer_bit(struct intel_fbc *fbc)
    991 {
    992 	if (fbc->crtc)
    993 		return to_intel_plane(fbc->crtc->base.primary)->frontbuffer_bit;
    994 	else
    995 		return fbc->possible_framebuffer_bits;
    996 }
    997 
    998 void intel_fbc_invalidate(struct drm_i915_private *dev_priv,
    999 			  unsigned int frontbuffer_bits,
   1000 			  enum fb_op_origin origin)
   1001 {
   1002 	struct intel_fbc *fbc = &dev_priv->fbc;
   1003 
   1004 	if (!fbc_supported(dev_priv))
   1005 		return;
   1006 
   1007 	if (origin == ORIGIN_GTT || origin == ORIGIN_FLIP)
   1008 		return;
   1009 
   1010 	mutex_lock(&fbc->lock);
   1011 
   1012 	fbc->busy_bits |= intel_fbc_get_frontbuffer_bit(fbc) & frontbuffer_bits;
   1013 
   1014 	if (fbc->crtc && fbc->busy_bits)
   1015 		intel_fbc_deactivate(dev_priv, "frontbuffer write");
   1016 
   1017 	mutex_unlock(&fbc->lock);
   1018 }
   1019 
   1020 void intel_fbc_flush(struct drm_i915_private *dev_priv,
   1021 		     unsigned int frontbuffer_bits, enum fb_op_origin origin)
   1022 {
   1023 	struct intel_fbc *fbc = &dev_priv->fbc;
   1024 
   1025 	if (!fbc_supported(dev_priv))
   1026 		return;
   1027 
   1028 	mutex_lock(&fbc->lock);
   1029 
   1030 	fbc->busy_bits &= ~frontbuffer_bits;
   1031 
   1032 	if (origin == ORIGIN_GTT || origin == ORIGIN_FLIP)
   1033 		goto out;
   1034 
   1035 	if (!fbc->busy_bits && fbc->crtc &&
   1036 	    (frontbuffer_bits & intel_fbc_get_frontbuffer_bit(fbc))) {
   1037 		if (fbc->active)
   1038 			intel_fbc_recompress(dev_priv);
   1039 		else if (!fbc->flip_pending)
   1040 			__intel_fbc_post_update(fbc->crtc);
   1041 	}
   1042 
   1043 out:
   1044 	mutex_unlock(&fbc->lock);
   1045 }
   1046 
   1047 /**
   1048  * intel_fbc_choose_crtc - select a CRTC to enable FBC on
   1049  * @dev_priv: i915 device instance
   1050  * @state: the atomic state structure
   1051  *
   1052  * This function looks at the proposed state for CRTCs and planes, then chooses
   1053  * which pipe is going to have FBC by setting intel_crtc_state->enable_fbc to
   1054  * true.
   1055  *
   1056  * Later, intel_fbc_enable is going to look for state->enable_fbc and then maybe
   1057  * enable FBC for the chosen CRTC. If it does, it will set dev_priv->fbc.crtc.
   1058  */
   1059 void intel_fbc_choose_crtc(struct drm_i915_private *dev_priv,
   1060 			   struct intel_atomic_state *state)
   1061 {
   1062 	struct intel_fbc *fbc = &dev_priv->fbc;
   1063 	struct intel_plane *plane;
   1064 	struct intel_plane_state *plane_state;
   1065 	bool crtc_chosen = false;
   1066 	int i;
   1067 
   1068 	mutex_lock(&fbc->lock);
   1069 
   1070 	/* Does this atomic commit involve the CRTC currently tied to FBC? */
   1071 	if (fbc->crtc &&
   1072 	    !intel_atomic_get_new_crtc_state(state, fbc->crtc))
   1073 		goto out;
   1074 
   1075 	if (!intel_fbc_can_enable(dev_priv))
   1076 		goto out;
   1077 
   1078 	/* Simply choose the first CRTC that is compatible and has a visible
   1079 	 * plane. We could go for fancier schemes such as checking the plane
   1080 	 * size, but this would just affect the few platforms that don't tie FBC
   1081 	 * to pipe or plane A. */
   1082 	for_each_new_intel_plane_in_state(state, plane, plane_state, i) {
   1083 		struct intel_crtc_state *crtc_state;
   1084 		struct intel_crtc *crtc = to_intel_crtc(plane_state->hw.crtc);
   1085 
   1086 		if (!plane->has_fbc)
   1087 			continue;
   1088 
   1089 		if (!plane_state->uapi.visible)
   1090 			continue;
   1091 
   1092 		crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
   1093 
   1094 		crtc_state->enable_fbc = true;
   1095 		crtc_chosen = true;
   1096 		break;
   1097 	}
   1098 
   1099 	if (!crtc_chosen)
   1100 		fbc->no_fbc_reason = "no suitable CRTC for FBC";
   1101 
   1102 out:
   1103 	mutex_unlock(&fbc->lock);
   1104 }
   1105 
   1106 /**
   1107  * intel_fbc_enable: tries to enable FBC on the CRTC
   1108  * @crtc: the CRTC
   1109  * @crtc_state: corresponding &drm_crtc_state for @crtc
   1110  * @plane_state: corresponding &drm_plane_state for the primary plane of @crtc
   1111  *
   1112  * This function checks if the given CRTC was chosen for FBC, then enables it if
   1113  * possible. Notice that it doesn't activate FBC. It is valid to call
   1114  * intel_fbc_enable multiple times for the same pipe without an
   1115  * intel_fbc_disable in the middle, as long as it is deactivated.
   1116  */
   1117 void intel_fbc_enable(struct intel_crtc *crtc,
   1118 		      const struct intel_crtc_state *crtc_state,
   1119 		      const struct intel_plane_state *plane_state)
   1120 {
   1121 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
   1122 	struct intel_fbc *fbc = &dev_priv->fbc;
   1123 	struct intel_fbc_state_cache *cache = &fbc->state_cache;
   1124 	const struct drm_framebuffer *fb = plane_state->hw.fb;
   1125 
   1126 	if (!fbc_supported(dev_priv))
   1127 		return;
   1128 
   1129 	mutex_lock(&fbc->lock);
   1130 
   1131 	if (fbc->crtc) {
   1132 		if (fbc->crtc != crtc ||
   1133 		    !intel_fbc_cfb_size_changed(dev_priv))
   1134 			goto out;
   1135 
   1136 		__intel_fbc_disable(dev_priv);
   1137 	}
   1138 
   1139 	WARN_ON(fbc->active);
   1140 
   1141 	intel_fbc_update_state_cache(crtc, crtc_state, plane_state);
   1142 
   1143 	/* FIXME crtc_state->enable_fbc lies :( */
   1144 	if (!cache->plane.visible)
   1145 		goto out;
   1146 
   1147 	if (intel_fbc_alloc_cfb(dev_priv,
   1148 				intel_fbc_calculate_cfb_size(dev_priv, cache),
   1149 				fb->format->cpp[0])) {
   1150 		cache->plane.visible = false;
   1151 		fbc->no_fbc_reason = "not enough stolen memory";
   1152 		goto out;
   1153 	}
   1154 
   1155 	if ((IS_GEN9_BC(dev_priv) || IS_BROXTON(dev_priv)) &&
   1156 	    fb->modifier != I915_FORMAT_MOD_X_TILED)
   1157 		cache->gen9_wa_cfb_stride =
   1158 			DIV_ROUND_UP(cache->plane.src_w, 32 * fbc->threshold) * 8;
   1159 	else
   1160 		cache->gen9_wa_cfb_stride = 0;
   1161 
   1162 	DRM_DEBUG_KMS("Enabling FBC on pipe %c\n", pipe_name(crtc->pipe));
   1163 	fbc->no_fbc_reason = "FBC enabled but not active yet\n";
   1164 
   1165 	fbc->crtc = crtc;
   1166 out:
   1167 	mutex_unlock(&fbc->lock);
   1168 }
   1169 
   1170 /**
   1171  * intel_fbc_disable - disable FBC if it's associated with crtc
   1172  * @crtc: the CRTC
   1173  *
   1174  * This function disables FBC if it's associated with the provided CRTC.
   1175  */
   1176 void intel_fbc_disable(struct intel_crtc *crtc)
   1177 {
   1178 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
   1179 	struct intel_fbc *fbc = &dev_priv->fbc;
   1180 
   1181 	if (!fbc_supported(dev_priv))
   1182 		return;
   1183 
   1184 	mutex_lock(&fbc->lock);
   1185 	if (fbc->crtc == crtc)
   1186 		__intel_fbc_disable(dev_priv);
   1187 	mutex_unlock(&fbc->lock);
   1188 }
   1189 
   1190 /**
   1191  * intel_fbc_global_disable - globally disable FBC
   1192  * @dev_priv: i915 device instance
   1193  *
   1194  * This function disables FBC regardless of which CRTC is associated with it.
   1195  */
   1196 void intel_fbc_global_disable(struct drm_i915_private *dev_priv)
   1197 {
   1198 	struct intel_fbc *fbc = &dev_priv->fbc;
   1199 
   1200 	if (!fbc_supported(dev_priv))
   1201 		return;
   1202 
   1203 	mutex_lock(&fbc->lock);
   1204 	if (fbc->crtc) {
   1205 		WARN_ON(fbc->crtc->active);
   1206 		__intel_fbc_disable(dev_priv);
   1207 	}
   1208 	mutex_unlock(&fbc->lock);
   1209 }
   1210 
   1211 static void intel_fbc_underrun_work_fn(struct work_struct *work)
   1212 {
   1213 	struct drm_i915_private *dev_priv =
   1214 		container_of(work, struct drm_i915_private, fbc.underrun_work);
   1215 	struct intel_fbc *fbc = &dev_priv->fbc;
   1216 
   1217 	mutex_lock(&fbc->lock);
   1218 
   1219 	/* Maybe we were scheduled twice. */
   1220 	if (fbc->underrun_detected || !fbc->crtc)
   1221 		goto out;
   1222 
   1223 	DRM_DEBUG_KMS("Disabling FBC due to FIFO underrun.\n");
   1224 	fbc->underrun_detected = true;
   1225 
   1226 	intel_fbc_deactivate(dev_priv, "FIFO underrun");
   1227 out:
   1228 	mutex_unlock(&fbc->lock);
   1229 }
   1230 
   1231 /*
   1232  * intel_fbc_reset_underrun - reset FBC fifo underrun status.
   1233  * @dev_priv: i915 device instance
   1234  *
   1235  * See intel_fbc_handle_fifo_underrun_irq(). For automated testing we
   1236  * want to re-enable FBC after an underrun to increase test coverage.
   1237  */
   1238 int intel_fbc_reset_underrun(struct drm_i915_private *dev_priv)
   1239 {
   1240 	int ret;
   1241 
   1242 	cancel_work_sync(&dev_priv->fbc.underrun_work);
   1243 
   1244 	ret = mutex_lock_interruptible(&dev_priv->fbc.lock);
   1245 	if (ret)
   1246 		return ret;
   1247 
   1248 	if (dev_priv->fbc.underrun_detected) {
   1249 		DRM_DEBUG_KMS("Re-allowing FBC after fifo underrun\n");
   1250 		dev_priv->fbc.no_fbc_reason = "FIFO underrun cleared";
   1251 	}
   1252 
   1253 	dev_priv->fbc.underrun_detected = false;
   1254 	mutex_unlock(&dev_priv->fbc.lock);
   1255 
   1256 	return 0;
   1257 }
   1258 
   1259 /**
   1260  * intel_fbc_handle_fifo_underrun_irq - disable FBC when we get a FIFO underrun
   1261  * @dev_priv: i915 device instance
   1262  *
   1263  * Without FBC, most underruns are harmless and don't really cause too many
   1264  * problems, except for an annoying message on dmesg. With FBC, underruns can
   1265  * become black screens or even worse, especially when paired with bad
   1266  * watermarks. So in order for us to be on the safe side, completely disable FBC
   1267  * in case we ever detect a FIFO underrun on any pipe. An underrun on any pipe
   1268  * already suggests that watermarks may be bad, so try to be as safe as
   1269  * possible.
   1270  *
   1271  * This function is called from the IRQ handler.
   1272  */
   1273 void intel_fbc_handle_fifo_underrun_irq(struct drm_i915_private *dev_priv)
   1274 {
   1275 	struct intel_fbc *fbc = &dev_priv->fbc;
   1276 
   1277 	if (!fbc_supported(dev_priv))
   1278 		return;
   1279 
   1280 	/* There's no guarantee that underrun_detected won't be set to true
   1281 	 * right after this check and before the work is scheduled, but that's
   1282 	 * not a problem since we'll check it again under the work function
   1283 	 * while FBC is locked. This check here is just to prevent us from
   1284 	 * unnecessarily scheduling the work, and it relies on the fact that we
   1285 	 * never switch underrun_detect back to false after it's true. */
   1286 	if (READ_ONCE(fbc->underrun_detected))
   1287 		return;
   1288 
   1289 	schedule_work(&fbc->underrun_work);
   1290 }
   1291 
   1292 /*
   1293  * The DDX driver changes its behavior depending on the value it reads from
   1294  * i915.enable_fbc, so sanitize it by translating the default value into either
   1295  * 0 or 1 in order to allow it to know what's going on.
   1296  *
   1297  * Notice that this is done at driver initialization and we still allow user
   1298  * space to change the value during runtime without sanitizing it again. IGT
   1299  * relies on being able to change i915.enable_fbc at runtime.
   1300  */
   1301 static int intel_sanitize_fbc_option(struct drm_i915_private *dev_priv)
   1302 {
   1303 	if (i915_modparams.enable_fbc >= 0)
   1304 		return !!i915_modparams.enable_fbc;
   1305 
   1306 	if (!HAS_FBC(dev_priv))
   1307 		return 0;
   1308 
   1309 	if (IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) >= 9)
   1310 		return 1;
   1311 
   1312 	return 0;
   1313 }
   1314 
   1315 static bool need_fbc_vtd_wa(struct drm_i915_private *dev_priv)
   1316 {
   1317 	/* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl,bxt */
   1318 	if (intel_vtd_active() &&
   1319 	    (IS_SKYLAKE(dev_priv) || IS_BROXTON(dev_priv))) {
   1320 		DRM_INFO("Disabling framebuffer compression (FBC) to prevent screen flicker with VT-d enabled\n");
   1321 		return true;
   1322 	}
   1323 
   1324 	return false;
   1325 }
   1326 
   1327 /**
   1328  * intel_fbc_init - Initialize FBC
   1329  * @dev_priv: the i915 device
   1330  *
   1331  * This function might be called during PM init process.
   1332  */
   1333 void intel_fbc_init(struct drm_i915_private *dev_priv)
   1334 {
   1335 	struct intel_fbc *fbc = &dev_priv->fbc;
   1336 
   1337 	INIT_WORK(&fbc->underrun_work, intel_fbc_underrun_work_fn);
   1338 	mutex_init(&fbc->lock);
   1339 	fbc->active = false;
   1340 
   1341 	if (!drm_mm_initialized(&dev_priv->mm.stolen))
   1342 		mkwrite_device_info(dev_priv)->display.has_fbc = false;
   1343 
   1344 	if (need_fbc_vtd_wa(dev_priv))
   1345 		mkwrite_device_info(dev_priv)->display.has_fbc = false;
   1346 
   1347 	i915_modparams.enable_fbc = intel_sanitize_fbc_option(dev_priv);
   1348 	DRM_DEBUG_KMS("Sanitized enable_fbc value: %d\n",
   1349 		      i915_modparams.enable_fbc);
   1350 
   1351 	if (!HAS_FBC(dev_priv)) {
   1352 		fbc->no_fbc_reason = "unsupported by this chipset";
   1353 		return;
   1354 	}
   1355 
   1356 	/* This value was pulled out of someone's hat */
   1357 	if (INTEL_GEN(dev_priv) <= 4 && !IS_GM45(dev_priv))
   1358 		I915_WRITE(FBC_CONTROL, 500 << FBC_CTL_INTERVAL_SHIFT);
   1359 
   1360 	/* We still don't have any sort of hardware state readout for FBC, so
   1361 	 * deactivate it in case the BIOS activated it to make sure software
   1362 	 * matches the hardware state. */
   1363 	if (intel_fbc_hw_is_active(dev_priv))
   1364 		intel_fbc_hw_deactivate(dev_priv);
   1365 }
   1366 
   1367 void
   1368 intel_fbc_cleanup(struct drm_i915_private *dev_priv)
   1369 {
   1370 	struct intel_fbc *fbc = &dev_priv->fbc;
   1371 
   1372 	mutex_destroy(&fbc->lock);
   1373 }
   1374