drivers/gpu/drm/i915/intel_device_info.c

/*
 * Copyright © 2016 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

#include "i915_drv.h"

void intel_device_info_dump(struct drm_i915_private *dev_priv)
{
	const struct intel_device_info *info = &dev_priv->info;

#define PRINT_S(name) "%s"
#define SEP_EMPTY
#define PRINT_FLAG(name) info->name ? #name "," : ""
#define SEP_COMMA ,
	DRM_DEBUG_DRIVER("i915 device info: gen=%i, pciid=0x%04x rev=0x%02x flags="
			 DEV_INFO_FOR_EACH_FLAG(PRINT_S, SEP_EMPTY),
			 info->gen,
			 dev_priv->drm.pdev->device,
			 dev_priv->drm.pdev->revision,
			 DEV_INFO_FOR_EACH_FLAG(PRINT_FLAG, SEP_COMMA));
#undef PRINT_S
#undef SEP_EMPTY
#undef PRINT_FLAG
#undef SEP_COMMA
}

static void cherryview_sseu_info_init(struct drm_i915_private *dev_priv)
{
	struct intel_device_info *info = mkwrite_device_info(dev_priv);
	u32 fuse, eu_dis;

	fuse = I915_READ(CHV_FUSE_GT);

	info->slice_total = 1;

	if (!(fuse & CHV_FGT_DISABLE_SS0)) {
		info->subslice_per_slice++;
		eu_dis = fuse & (CHV_FGT_EU_DIS_SS0_R0_MASK |
				 CHV_FGT_EU_DIS_SS0_R1_MASK);
		info->eu_total += 8 - hweight32(eu_dis);
	}

	if (!(fuse & CHV_FGT_DISABLE_SS1)) {
		info->subslice_per_slice++;
		eu_dis = fuse & (CHV_FGT_EU_DIS_SS1_R0_MASK |
				 CHV_FGT_EU_DIS_SS1_R1_MASK);
		info->eu_total += 8 - hweight32(eu_dis);
	}

	info->subslice_total = info->subslice_per_slice;
	/*
	 * CHV expected to always have a uniform distribution of EU
	 * across subslices.
	*/
	info->eu_per_subslice = info->subslice_total ?
				info->eu_total / info->subslice_total :
				0;
	/*
	 * CHV supports subslice power gating on devices with more than
	 * one subslice, and supports EU power gating on devices with
	 * more than one EU pair per subslice.
	*/
	info->has_slice_pg = 0;
	info->has_subslice_pg = (info->subslice_total > 1);
	info->has_eu_pg = (info->eu_per_subslice > 2);
}

static void gen9_sseu_info_init(struct drm_i915_private *dev_priv)
{
	struct intel_device_info *info = mkwrite_device_info(dev_priv);
	int s_max = 3, ss_max = 4, eu_max = 8;
	int s, ss;
	u32 fuse2, s_enable, ss_disable, eu_disable;
	u8 eu_mask = 0xff;

	fuse2 = I915_READ(GEN8_FUSE2);
	s_enable = (fuse2 & GEN8_F2_S_ENA_MASK) >> GEN8_F2_S_ENA_SHIFT;
	ss_disable = (fuse2 & GEN9_F2_SS_DIS_MASK) >> GEN9_F2_SS_DIS_SHIFT;

	info->slice_total = hweight32(s_enable);
	/*
	 * The subslice disable field is global, i.e. it applies
	 * to each of the enabled slices.
	*/
	info->subslice_per_slice = ss_max - hweight32(ss_disable);
	info->subslice_total = info->slice_total * info->subslice_per_slice;

	/*
	 * Iterate through enabled slices and subslices to
	 * count the total enabled EU.
	*/
	for (s = 0; s < s_max; s++) {
		if (!(s_enable & BIT(s)))
			/* skip disabled slice */
			continue;

		eu_disable = I915_READ(GEN9_EU_DISABLE(s));
		for (ss = 0; ss < ss_max; ss++) {
			int eu_per_ss;

			if (ss_disable & BIT(ss))
				/* skip disabled subslice */
				continue;

			eu_per_ss = eu_max - hweight8((eu_disable >> (ss*8)) &
						      eu_mask);

			/*
			 * Record which subslice(s) has(have) 7 EUs. we
			 * can tune the hash used to spread work among
			 * subslices if they are unbalanced.
			 */
			if (eu_per_ss == 7)
				info->subslice_7eu[s] |= BIT(ss);

			info->eu_total += eu_per_ss;
		}
	}

	/*
	 * SKL is expected to always have a uniform distribution
	 * of EU across subslices with the exception that any one
	 * EU in any one subslice may be fused off for die
	 * recovery. BXT is expected to be perfectly uniform in EU
	 * distribution.
	*/
	info->eu_per_subslice = info->subslice_total ?
				DIV_ROUND_UP(info->eu_total,
					     info->subslice_total) : 0;
	/*
	 * SKL supports slice power gating on devices with more than
	 * one slice, and supports EU power gating on devices with
	 * more than one EU pair per subslice. BXT supports subslice
	 * power gating on devices with more than one subslice, and
	 * supports EU power gating on devices with more than one EU
	 * pair per subslice.
	*/
	info->has_slice_pg =
		(IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv)) &&
		info->slice_total > 1;
	info->has_subslice_pg =
		IS_BROXTON(dev_priv) && info->subslice_total > 1;
	info->has_eu_pg = info->eu_per_subslice > 2;

	if (IS_BROXTON(dev_priv)) {
#define IS_SS_DISABLED(_ss_disable, ss)    (_ss_disable & BIT(ss))
		/*
		 * There is a HW issue in 2x6 fused down parts that requires
		 * Pooled EU to be enabled as a WA. The pool configuration
		 * changes depending upon which subslice is fused down. This
		 * doesn't affect if the device has all 3 subslices enabled.
		 */
		/* WaEnablePooledEuFor2x6:bxt */
		info->has_pooled_eu = ((info->subslice_per_slice == 3) ||
				       (info->subslice_per_slice == 2 &&
					INTEL_REVID(dev_priv) < BXT_REVID_C0));

		info->min_eu_in_pool = 0;
		if (info->has_pooled_eu) {
			if (IS_SS_DISABLED(ss_disable, 0) ||
			    IS_SS_DISABLED(ss_disable, 2))
				info->min_eu_in_pool = 3;
			else if (IS_SS_DISABLED(ss_disable, 1))
				info->min_eu_in_pool = 6;
			else
				info->min_eu_in_pool = 9;
		}
#undef IS_SS_DISABLED
	}
}

static void broadwell_sseu_info_init(struct drm_i915_private *dev_priv)
{
	struct intel_device_info *info = mkwrite_device_info(dev_priv);
	const int s_max = 3, ss_max = 3, eu_max = 8;
	int s, ss;
	u32 fuse2, eu_disable[s_max], s_enable, ss_disable;

	fuse2 = I915_READ(GEN8_FUSE2);
	s_enable = (fuse2 & GEN8_F2_S_ENA_MASK) >> GEN8_F2_S_ENA_SHIFT;
	ss_disable = (fuse2 & GEN8_F2_SS_DIS_MASK) >> GEN8_F2_SS_DIS_SHIFT;

	eu_disable[0] = I915_READ(GEN8_EU_DISABLE0) & GEN8_EU_DIS0_S0_MASK;
	eu_disable[1] = (I915_READ(GEN8_EU_DISABLE0) >> GEN8_EU_DIS0_S1_SHIFT) |
			((I915_READ(GEN8_EU_DISABLE1) & GEN8_EU_DIS1_S1_MASK) <<
			 (32 - GEN8_EU_DIS0_S1_SHIFT));
	eu_disable[2] = (I915_READ(GEN8_EU_DISABLE1) >> GEN8_EU_DIS1_S2_SHIFT) |
			((I915_READ(GEN8_EU_DISABLE2) & GEN8_EU_DIS2_S2_MASK) <<
			 (32 - GEN8_EU_DIS1_S2_SHIFT));

	info->slice_total = hweight32(s_enable);

	/*
	 * The subslice disable field is global, i.e. it applies
	 * to each of the enabled slices.
	 */
	info->subslice_per_slice = ss_max - hweight32(ss_disable);
	info->subslice_total = info->slice_total * info->subslice_per_slice;

	/*
	 * Iterate through enabled slices and subslices to
	 * count the total enabled EU.
	 */
	for (s = 0; s < s_max; s++) {
		if (!(s_enable & (0x1 << s)))
			/* skip disabled slice */
			continue;

		for (ss = 0; ss < ss_max; ss++) {
			u32 n_disabled;

			if (ss_disable & (0x1 << ss))
				/* skip disabled subslice */
				continue;

			n_disabled = hweight8(eu_disable[s] >> (ss * eu_max));

			/*
			 * Record which subslices have 7 EUs.
			 */
			if (eu_max - n_disabled == 7)
				info->subslice_7eu[s] |= 1 << ss;

			info->eu_total += eu_max - n_disabled;
		}
	}

	/*
	 * BDW is expected to always have a uniform distribution of EU across
	 * subslices with the exception that any one EU in any one subslice may
	 * be fused off for die recovery.
	 */
	info->eu_per_subslice = info->subslice_total ?
		DIV_ROUND_UP(info->eu_total, info->subslice_total) : 0;

	/*
	 * BDW supports slice power gating on devices with more than
	 * one slice.
	 */
	info->has_slice_pg = (info->slice_total > 1);
	info->has_subslice_pg = 0;
	info->has_eu_pg = 0;
}

/*
 * Determine various intel_device_info fields at runtime.
 *
 * Use it when either:
 *   - it's judged too laborious to fill n static structures with the limit
 *     when a simple if statement does the job,
 *   - run-time checks (eg read fuse/strap registers) are needed.
 *
 * This function needs to be called:
 *   - after the MMIO has been setup as we are reading registers,
 *   - after the PCH has been detected,
 *   - before the first usage of the fields it can tweak.
 */
void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
{
	struct intel_device_info *info = mkwrite_device_info(dev_priv);
	enum pipe pipe;

	/*
	 * Skylake and Broxton currently don't expose the topmost plane as its
	 * use is exclusive with the legacy cursor and we only want to expose
	 * one of those, not both. Until we can safely expose the topmost plane
	 * as a DRM_PLANE_TYPE_CURSOR with all the features exposed/supported,
	 * we don't expose the topmost plane at all to prevent ABI breakage
	 * down the line.
	 */
	if (IS_BROXTON(dev_priv)) {
		info->num_sprites[PIPE_A] = 2;
		info->num_sprites[PIPE_B] = 2;
		info->num_sprites[PIPE_C] = 1;
	} else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
		for_each_pipe(dev_priv, pipe)
			info->num_sprites[pipe] = 2;
	else
		for_each_pipe(dev_priv, pipe)
			info->num_sprites[pipe] = 1;

	if (i915.disable_display) {
		DRM_INFO("Display disabled (module parameter)\n");
		info->num_pipes = 0;
	} else if (info->num_pipes > 0 &&
		   (IS_GEN7(dev_priv) || IS_GEN8(dev_priv)) &&
		   HAS_PCH_SPLIT(dev_priv)) {
		u32 fuse_strap = I915_READ(FUSE_STRAP);
		u32 sfuse_strap = I915_READ(SFUSE_STRAP);

		/*
		 * SFUSE_STRAP is supposed to have a bit signalling the display
		 * is fused off. Unfortunately it seems that, at least in
		 * certain cases, fused off display means that PCH display
		 * reads don't land anywhere. In that case, we read 0s.
		 *
		 * On CPT/PPT, we can detect this case as SFUSE_STRAP_FUSE_LOCK
		 * should be set when taking over after the firmware.
		 */
		if (fuse_strap & ILK_INTERNAL_DISPLAY_DISABLE ||
		    sfuse_strap & SFUSE_STRAP_DISPLAY_DISABLED ||
		    (dev_priv->pch_type == PCH_CPT &&
		     !(sfuse_strap & SFUSE_STRAP_FUSE_LOCK))) {
			DRM_INFO("Display fused off, disabling\n");
			info->num_pipes = 0;
		} else if (fuse_strap & IVB_PIPE_C_DISABLE) {
			DRM_INFO("PipeC fused off\n");
			info->num_pipes -= 1;
		}
	} else if (info->num_pipes > 0 && IS_GEN9(dev_priv)) {
		u32 dfsm = I915_READ(SKL_DFSM);
		u8 disabled_mask = 0;
		bool invalid;
		int num_bits;

		if (dfsm & SKL_DFSM_PIPE_A_DISABLE)
			disabled_mask |= BIT(PIPE_A);
		if (dfsm & SKL_DFSM_PIPE_B_DISABLE)
			disabled_mask |= BIT(PIPE_B);
		if (dfsm & SKL_DFSM_PIPE_C_DISABLE)
			disabled_mask |= BIT(PIPE_C);

		num_bits = hweight8(disabled_mask);

		switch (disabled_mask) {
		case BIT(PIPE_A):
		case BIT(PIPE_B):
		case BIT(PIPE_A) | BIT(PIPE_B):
		case BIT(PIPE_A) | BIT(PIPE_C):
			invalid = true;
			break;
		default:
			invalid = false;
		}

		if (num_bits > info->num_pipes || invalid)
			DRM_ERROR("invalid pipe fuse configuration: 0x%x\n",
				  disabled_mask);
		else
			info->num_pipes -= num_bits;
	}

	/* Initialize slice/subslice/EU info */
	if (IS_CHERRYVIEW(dev_priv))
		cherryview_sseu_info_init(dev_priv);
	else if (IS_BROADWELL(dev_priv))
		broadwell_sseu_info_init(dev_priv);
	else if (INTEL_INFO(dev_priv)->gen >= 9)
		gen9_sseu_info_init(dev_priv);

	info->has_snoop = !info->has_llc;

	/* Snooping is broken on BXT A stepping. */
	if (IS_BXT_REVID(dev_priv, 0, BXT_REVID_A1))
		info->has_snoop = false;

	DRM_DEBUG_DRIVER("slice total: %u\n", info->slice_total);
	DRM_DEBUG_DRIVER("subslice total: %u\n", info->subslice_total);
	DRM_DEBUG_DRIVER("subslice per slice: %u\n", info->subslice_per_slice);
	DRM_DEBUG_DRIVER("EU total: %u\n", info->eu_total);
	DRM_DEBUG_DRIVER("EU per subslice: %u\n", info->eu_per_subslice);
	DRM_DEBUG_DRIVER("has slice power gating: %s\n",
			 info->has_slice_pg ? "y" : "n");
	DRM_DEBUG_DRIVER("has subslice power gating: %s\n",
			 info->has_subslice_pg ? "y" : "n");
	DRM_DEBUG_DRIVER("has EU power gating: %s\n",
			 info->has_eu_pg ? "y" : "n");
}