/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright © 2019 Intel Corporation
 */

#include "i915_drv.h"
#include "intel_lrc_reg.h"
#include "intel_sseu.h"

void intel_sseu_set_info(struct sseu_dev_info *sseu, u8 max_slices,
                         u8 max_subslices, u8 max_eus_per_subslice)
{
        sseu->max_slices = max_slices;
        sseu->max_subslices = max_subslices;
        sseu->max_eus_per_subslice = max_eus_per_subslice;

        sseu->ss_stride = GEN_SSEU_STRIDE(sseu->max_subslices);
        GEM_BUG_ON(sseu->ss_stride > GEN_MAX_SUBSLICE_STRIDE);
        sseu->eu_stride = GEN_SSEU_STRIDE(sseu->max_eus_per_subslice);
        GEM_BUG_ON(sseu->eu_stride > GEN_MAX_EU_STRIDE);
}

unsigned int
intel_sseu_subslice_total(const struct sseu_dev_info *sseu)
{
        unsigned int i, total = 0;

        for (i = 0; i < ARRAY_SIZE(sseu->subslice_mask); i++)
                total += hweight8(sseu->subslice_mask[i]);

        return total;
}

u32 intel_sseu_get_subslices(const struct sseu_dev_info *sseu, u8 slice)
{
        int i, offset = slice * sseu->ss_stride;
        u32 mask = 0;

        GEM_BUG_ON(slice >= sseu->max_slices);

        for (i = 0; i < sseu->ss_stride; i++)
                mask |= (u32)sseu->subslice_mask[offset + i] <<
                        i * BITS_PER_BYTE;

        return mask;
}

void intel_sseu_set_subslices(struct sseu_dev_info *sseu, int slice,
                              u32 ss_mask)
{
        int offset = slice * sseu->ss_stride;

        memcpy(&sseu->subslice_mask[offset], &ss_mask, sseu->ss_stride);
}

unsigned int
intel_sseu_subslices_per_slice(const struct sseu_dev_info *sseu, u8 slice)
{
        return hweight32(intel_sseu_get_subslices(sseu, slice));
}

static int sseu_eu_idx(const struct sseu_dev_info *sseu, int slice,
                       int subslice)
{
        int slice_stride = sseu->max_subslices * sseu->eu_stride;

        return slice * slice_stride + subslice * sseu->eu_stride;
}

static u16 sseu_get_eus(const struct sseu_dev_info *sseu, int slice,
                        int subslice)
{
        int i, offset = sseu_eu_idx(sseu, slice, subslice);
        u16 eu_mask = 0;

        for (i = 0; i < sseu->eu_stride; i++)
                eu_mask |=
                        ((u16)sseu->eu_mask[offset + i]) << (i * BITS_PER_BYTE);

        return eu_mask;
}

static void sseu_set_eus(struct sseu_dev_info *sseu, int slice, int subslice,
                         u16 eu_mask)
{
        int i, offset = sseu_eu_idx(sseu, slice, subslice);

        for (i = 0; i < sseu->eu_stride; i++)
                sseu->eu_mask[offset + i] =
                        (eu_mask >> (BITS_PER_BYTE * i)) & 0xff;
}

static u16 compute_eu_total(const struct sseu_dev_info *sseu)
{
        u16 i, total = 0;

        for (i = 0; i < ARRAY_SIZE(sseu->eu_mask); i++)
                total += hweight8(sseu->eu_mask[i]);

        return total;
}

static void gen11_compute_sseu_info(struct sseu_dev_info *sseu,
                                    u8 s_en, u32 ss_en, u16 eu_en)
{
        int s, ss;

        /* ss_en represents entire subslice mask across all slices */
        GEM_BUG_ON(sseu->max_slices * sseu->max_subslices >
                   sizeof(ss_en) * BITS_PER_BYTE);

        for (s = 0; s < sseu->max_slices; s++) {
                if ((s_en & BIT(s)) == 0)
                        continue;

                sseu->slice_mask |= BIT(s);

                intel_sseu_set_subslices(sseu, s, ss_en);

                for (ss = 0; ss < sseu->max_subslices; ss++)
                        if (intel_sseu_has_subslice(sseu, s, ss))
                                sseu_set_eus(sseu, s, ss, eu_en);
        }
        sseu->eu_per_subslice = hweight16(eu_en);
        sseu->eu_total = compute_eu_total(sseu);
}

static void gen12_sseu_info_init(struct intel_gt *gt)
{
        struct sseu_dev_info *sseu = &gt->info.sseu;
        struct intel_uncore *uncore = gt->uncore;
        u32 dss_en;
        u16 eu_en = 0;
        u8 eu_en_fuse;
        u8 s_en;
        int eu;

        /*
         * Gen12 has Dual-Subslices, which behave similarly to 2 gen11 SS.
         * Instead of splitting these, provide userspace with an array
         * of DSS to more closely represent the hardware resource.
         */
        intel_sseu_set_info(sseu, 1, 6, 16);

        s_en = intel_uncore_read(uncore, GEN11_GT_SLICE_ENABLE) &
                GEN11_GT_S_ENA_MASK;

        dss_en = intel_uncore_read(uncore, GEN12_GT_DSS_ENABLE);

        /* one bit per pair of EUs */
        eu_en_fuse = ~(intel_uncore_read(uncore, GEN11_EU_DISABLE) &
                       GEN11_EU_DIS_MASK);
        for (eu = 0; eu < sseu->max_eus_per_subslice / 2; eu++)
                if (eu_en_fuse & BIT(eu))
                        eu_en |= BIT(eu * 2) | BIT(eu * 2 + 1);

        gen11_compute_sseu_info(sseu, s_en, dss_en, eu_en);

        /* TGL only supports slice-level power gating */
        sseu->has_slice_pg = 1;
}

static void gen11_sseu_info_init(struct intel_gt *gt)
{
        struct sseu_dev_info *sseu = &gt->info.sseu;
        struct intel_uncore *uncore = gt->uncore;
        u32 ss_en;
        u8 eu_en;
        u8 s_en;

        if (IS_JSL_EHL(gt->i915))
                intel_sseu_set_info(sseu, 1, 4, 8);
        else
                intel_sseu_set_info(sseu, 1, 8, 8);

        s_en = intel_uncore_read(uncore, GEN11_GT_SLICE_ENABLE) &
                GEN11_GT_S_ENA_MASK;
        ss_en = ~intel_uncore_read(uncore, GEN11_GT_SUBSLICE_DISABLE);

        eu_en = ~(intel_uncore_read(uncore, GEN11_EU_DISABLE) &
                  GEN11_EU_DIS_MASK);

        gen11_compute_sseu_info(sseu, s_en, ss_en, eu_en);

        /* ICL has no power gating restrictions. */
        sseu->has_slice_pg = 1;
        sseu->has_subslice_pg = 1;
        sseu->has_eu_pg = 1;
}

static void gen10_sseu_info_init(struct intel_gt *gt)
{
        struct intel_uncore *uncore = gt->uncore;
        struct sseu_dev_info *sseu = &gt->info.sseu;
        const u32 fuse2 = intel_uncore_read(uncore, GEN8_FUSE2);
        const int eu_mask = 0xff;
        u32 subslice_mask, eu_en;
        int s, ss;

        intel_sseu_set_info(sseu, 6, 4, 8);

        sseu->slice_mask = (fuse2 & GEN10_F2_S_ENA_MASK) >>
                GEN10_F2_S_ENA_SHIFT;

        /* Slice0 */
        eu_en = ~intel_uncore_read(uncore, GEN8_EU_DISABLE0);
        for (ss = 0; ss < sseu->max_subslices; ss++)
                sseu_set_eus(sseu, 0, ss, (eu_en >> (8 * ss)) & eu_mask);
        /* Slice1 */
        sseu_set_eus(sseu, 1, 0, (eu_en >> 24) & eu_mask);
        eu_en = ~intel_uncore_read(uncore, GEN8_EU_DISABLE1);
        sseu_set_eus(sseu, 1, 1, eu_en & eu_mask);
        /* Slice2 */
        sseu_set_eus(sseu, 2, 0, (eu_en >> 8) & eu_mask);
        sseu_set_eus(sseu, 2, 1, (eu_en >> 16) & eu_mask);
        /* Slice3 */
        sseu_set_eus(sseu, 3, 0, (eu_en >> 24) & eu_mask);
        eu_en = ~intel_uncore_read(uncore, GEN8_EU_DISABLE2);
        sseu_set_eus(sseu, 3, 1, eu_en & eu_mask);
        /* Slice4 */
        sseu_set_eus(sseu, 4, 0, (eu_en >> 8) & eu_mask);
        sseu_set_eus(sseu, 4, 1, (eu_en >> 16) & eu_mask);
        /* Slice5 */
        sseu_set_eus(sseu, 5, 0, (eu_en >> 24) & eu_mask);
        eu_en = ~intel_uncore_read(uncore, GEN10_EU_DISABLE3);
        sseu_set_eus(sseu, 5, 1, eu_en & eu_mask);

        subslice_mask = (1 << 4) - 1;
        subslice_mask &= ~((fuse2 & GEN10_F2_SS_DIS_MASK) >>
                           GEN10_F2_SS_DIS_SHIFT);

        for (s = 0; s < sseu->max_slices; s++) {
                u32 subslice_mask_with_eus = subslice_mask;

                for (ss = 0; ss < sseu->max_subslices; ss++) {
                        if (sseu_get_eus(sseu, s, ss) == 0)
                                subslice_mask_with_eus &= ~BIT(ss);
                }

                /*
                 * Slice0 can have up to 3 subslices, but there are only 2 in
                 * slice1/2.
                 */
                intel_sseu_set_subslices(sseu, s, s == 0 ?
                                         subslice_mask_with_eus :
                                         subslice_mask_with_eus & 0x3);
        }

        sseu->eu_total = compute_eu_total(sseu);

        /*
         * CNL 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.
         */
        sseu->eu_per_subslice =
                intel_sseu_subslice_total(sseu) ?
                DIV_ROUND_UP(sseu->eu_total, intel_sseu_subslice_total(sseu)) :
                0;

        /* No restrictions on Power Gating */
        sseu->has_slice_pg = 1;
        sseu->has_subslice_pg = 1;
        sseu->has_eu_pg = 1;
}

static void cherryview_sseu_info_init(struct intel_gt *gt)
{
        struct sseu_dev_info *sseu = &gt->info.sseu;
        u32 fuse;
        u8 subslice_mask = 0;

        fuse = intel_uncore_read(gt->uncore, CHV_FUSE_GT);

        sseu->slice_mask = BIT(0);
        intel_sseu_set_info(sseu, 1, 2, 8);

        if (!(fuse & CHV_FGT_DISABLE_SS0)) {
                u8 disabled_mask =
                        ((fuse & CHV_FGT_EU_DIS_SS0_R0_MASK) >>
                         CHV_FGT_EU_DIS_SS0_R0_SHIFT) |
                        (((fuse & CHV_FGT_EU_DIS_SS0_R1_MASK) >>
                          CHV_FGT_EU_DIS_SS0_R1_SHIFT) << 4);

                subslice_mask |= BIT(0);
                sseu_set_eus(sseu, 0, 0, ~disabled_mask);
        }

        if (!(fuse & CHV_FGT_DISABLE_SS1)) {
                u8 disabled_mask =
                        ((fuse & CHV_FGT_EU_DIS_SS1_R0_MASK) >>
                         CHV_FGT_EU_DIS_SS1_R0_SHIFT) |
                        (((fuse & CHV_FGT_EU_DIS_SS1_R1_MASK) >>
                          CHV_FGT_EU_DIS_SS1_R1_SHIFT) << 4);

                subslice_mask |= BIT(1);
                sseu_set_eus(sseu, 0, 1, ~disabled_mask);
        }

        intel_sseu_set_subslices(sseu, 0, subslice_mask);

        sseu->eu_total = compute_eu_total(sseu);

        /*
         * CHV expected to always have a uniform distribution of EU
         * across subslices.
         */
        sseu->eu_per_subslice = intel_sseu_subslice_total(sseu) ?
                sseu->eu_total /
                intel_sseu_subslice_total(sseu) :
                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.
         */
        sseu->has_slice_pg = 0;
        sseu->has_subslice_pg = intel_sseu_subslice_total(sseu) > 1;
        sseu->has_eu_pg = (sseu->eu_per_subslice > 2);
}

static void gen9_sseu_info_init(struct intel_gt *gt)
{
        struct drm_i915_private *i915 = gt->i915;
        struct intel_device_info *info = mkwrite_device_info(i915);
        struct sseu_dev_info *sseu = &gt->info.sseu;
        struct intel_uncore *uncore = gt->uncore;
        u32 fuse2, eu_disable, subslice_mask;
        const u8 eu_mask = 0xff;
        int s, ss;

        fuse2 = intel_uncore_read(uncore, GEN8_FUSE2);
        sseu->slice_mask = (fuse2 & GEN8_F2_S_ENA_MASK) >> GEN8_F2_S_ENA_SHIFT;

        /* BXT has a single slice and at most 3 subslices. */
        intel_sseu_set_info(sseu, IS_GEN9_LP(i915) ? 1 : 3,
                            IS_GEN9_LP(i915) ? 3 : 4, 8);

        /*
         * The subslice disable field is global, i.e. it applies
         * to each of the enabled slices.
         */
        subslice_mask = (1 << sseu->max_subslices) - 1;
        subslice_mask &= ~((fuse2 & GEN9_F2_SS_DIS_MASK) >>
                           GEN9_F2_SS_DIS_SHIFT);

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

                intel_sseu_set_subslices(sseu, s, subslice_mask);

                eu_disable = intel_uncore_read(uncore, GEN9_EU_DISABLE(s));
                for (ss = 0; ss < sseu->max_subslices; ss++) {
                        int eu_per_ss;
                        u8 eu_disabled_mask;

                        if (!intel_sseu_has_subslice(sseu, s, ss))
                                /* skip disabled subslice */
                                continue;

                        eu_disabled_mask = (eu_disable >> (ss * 8)) & eu_mask;

                        sseu_set_eus(sseu, s, ss, ~eu_disabled_mask);

                        eu_per_ss = sseu->max_eus_per_subslice -
                                hweight8(eu_disabled_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)
                                sseu->subslice_7eu[s] |= BIT(ss);
                }
        }

        sseu->eu_total = compute_eu_total(sseu);

        /*
         * 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.
         */
        sseu->eu_per_subslice =
                intel_sseu_subslice_total(sseu) ?
                DIV_ROUND_UP(sseu->eu_total, intel_sseu_subslice_total(sseu)) :
                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.
         */
        sseu->has_slice_pg =
                !IS_GEN9_LP(i915) && hweight8(sseu->slice_mask) > 1;
        sseu->has_subslice_pg =
                IS_GEN9_LP(i915) && intel_sseu_subslice_total(sseu) > 1;
        sseu->has_eu_pg = sseu->eu_per_subslice > 2;

        if (IS_GEN9_LP(i915)) {
#define IS_SS_DISABLED(ss)      (!(sseu->subslice_mask[0] & BIT(ss)))
                info->has_pooled_eu = hweight8(sseu->subslice_mask[0]) == 3;

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

static void bdw_sseu_info_init(struct intel_gt *gt)
{
        struct sseu_dev_info *sseu = &gt->info.sseu;
        struct intel_uncore *uncore = gt->uncore;
        int s, ss;
        u32 fuse2, subslice_mask, eu_disable[3]; /* s_max */
        u32 eu_disable0, eu_disable1, eu_disable2;

        fuse2 = intel_uncore_read(uncore, GEN8_FUSE2);
        sseu->slice_mask = (fuse2 & GEN8_F2_S_ENA_MASK) >> GEN8_F2_S_ENA_SHIFT;
        intel_sseu_set_info(sseu, 3, 3, 8);

        /*
         * The subslice disable field is global, i.e. it applies
         * to each of the enabled slices.
         */
        subslice_mask = GENMASK(sseu->max_subslices - 1, 0);
        subslice_mask &= ~((fuse2 & GEN8_F2_SS_DIS_MASK) >>
                           GEN8_F2_SS_DIS_SHIFT);
        eu_disable0 = intel_uncore_read(uncore, GEN8_EU_DISABLE0);
        eu_disable1 = intel_uncore_read(uncore, GEN8_EU_DISABLE1);
        eu_disable2 = intel_uncore_read(uncore, GEN8_EU_DISABLE2);
        eu_disable[0] = eu_disable0 & GEN8_EU_DIS0_S0_MASK;
        eu_disable[1] = (eu_disable0 >> GEN8_EU_DIS0_S1_SHIFT) |
                ((eu_disable1 & GEN8_EU_DIS1_S1_MASK) <<
                 (32 - GEN8_EU_DIS0_S1_SHIFT));
        eu_disable[2] = (eu_disable1 >> GEN8_EU_DIS1_S2_SHIFT) |
                ((eu_disable2 & GEN8_EU_DIS2_S2_MASK) <<
                 (32 - GEN8_EU_DIS1_S2_SHIFT));

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

                intel_sseu_set_subslices(sseu, s, subslice_mask);

                for (ss = 0; ss < sseu->max_subslices; ss++) {
                        u8 eu_disabled_mask;
                        u32 n_disabled;

                        if (!intel_sseu_has_subslice(sseu, s, ss))
                                /* skip disabled subslice */
                                continue;

                        eu_disabled_mask =
                                eu_disable[s] >> (ss * sseu->max_eus_per_subslice);

                        sseu_set_eus(sseu, s, ss, ~eu_disabled_mask);

                        n_disabled = hweight8(eu_disabled_mask);

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

        sseu->eu_total = compute_eu_total(sseu);

        /*
         * 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.
         */
        sseu->eu_per_subslice =
                intel_sseu_subslice_total(sseu) ?
                DIV_ROUND_UP(sseu->eu_total, intel_sseu_subslice_total(sseu)) :
                0;

        /*
         * BDW supports slice power gating on devices with more than
         * one slice.
         */
        sseu->has_slice_pg = hweight8(sseu->slice_mask) > 1;
        sseu->has_subslice_pg = 0;
        sseu->has_eu_pg = 0;
}

static void hsw_sseu_info_init(struct intel_gt *gt)
{
        struct drm_i915_private *i915 = gt->i915;
        struct sseu_dev_info *sseu = &gt->info.sseu;
        u32 fuse1;
        u8 subslice_mask = 0;
        int s, ss;

        /*
         * There isn't a register to tell us how many slices/subslices. We
         * work off the PCI-ids here.
         */
        switch (INTEL_INFO(i915)->gt) {
        default:
                MISSING_CASE(INTEL_INFO(i915)->gt);
                fallthrough;
        case 1:
                sseu->slice_mask = BIT(0);
                subslice_mask = BIT(0);
                break;
        case 2:
                sseu->slice_mask = BIT(0);
                subslice_mask = BIT(0) | BIT(1);
                break;
        case 3:
                sseu->slice_mask = BIT(0) | BIT(1);
                subslice_mask = BIT(0) | BIT(1);
                break;
        }

        fuse1 = intel_uncore_read(gt->uncore, HSW_PAVP_FUSE1);
        switch ((fuse1 & HSW_F1_EU_DIS_MASK) >> HSW_F1_EU_DIS_SHIFT) {
        default:
                MISSING_CASE((fuse1 & HSW_F1_EU_DIS_MASK) >>
                             HSW_F1_EU_DIS_SHIFT);
                fallthrough;
        case HSW_F1_EU_DIS_10EUS:
                sseu->eu_per_subslice = 10;
                break;
        case HSW_F1_EU_DIS_8EUS:
                sseu->eu_per_subslice = 8;
                break;
        case HSW_F1_EU_DIS_6EUS:
                sseu->eu_per_subslice = 6;
                break;
        }

        intel_sseu_set_info(sseu, hweight8(sseu->slice_mask),
                            hweight8(subslice_mask),
                            sseu->eu_per_subslice);

        for (s = 0; s < sseu->max_slices; s++) {
                intel_sseu_set_subslices(sseu, s, subslice_mask);

                for (ss = 0; ss < sseu->max_subslices; ss++) {
                        sseu_set_eus(sseu, s, ss,
                                     (1UL << sseu->eu_per_subslice) - 1);
                }
        }

        sseu->eu_total = compute_eu_total(sseu);

        /* No powergating for you. */
        sseu->has_slice_pg = 0;
        sseu->has_subslice_pg = 0;
        sseu->has_eu_pg = 0;
}

void intel_sseu_info_init(struct intel_gt *gt)
{
        struct drm_i915_private *i915 = gt->i915;

        if (IS_HASWELL(i915))
                hsw_sseu_info_init(gt);
        else if (IS_CHERRYVIEW(i915))
                cherryview_sseu_info_init(gt);
        else if (IS_BROADWELL(i915))
                bdw_sseu_info_init(gt);
        else if (IS_GEN(i915, 9))
                gen9_sseu_info_init(gt);
        else if (IS_GEN(i915, 10))
                gen10_sseu_info_init(gt);
        else if (IS_GEN(i915, 11))
                gen11_sseu_info_init(gt);
        else if (INTEL_GEN(i915) >= 12)
                gen12_sseu_info_init(gt);
}

u32 intel_sseu_make_rpcs(struct intel_gt *gt,
                         const struct intel_sseu *req_sseu)
{
        struct drm_i915_private *i915 = gt->i915;
        const struct sseu_dev_info *sseu = &gt->info.sseu;
        bool subslice_pg = sseu->has_subslice_pg;
        u8 slices, subslices;
        u32 rpcs = 0;

        /*
         * No explicit RPCS request is needed to ensure full
         * slice/subslice/EU enablement prior to Gen9.
         */
        if (INTEL_GEN(i915) < 9)
                return 0;

        /*
         * If i915/perf is active, we want a stable powergating configuration
         * on the system. Use the configuration pinned by i915/perf.
         */
        if (i915->perf.exclusive_stream)
                req_sseu = &i915->perf.sseu;

        slices = hweight8(req_sseu->slice_mask);
        subslices = hweight8(req_sseu->subslice_mask);

        /*
         * Since the SScount bitfield in GEN8_R_PWR_CLK_STATE is only three bits
         * wide and Icelake has up to eight subslices, specfial programming is
         * needed in order to correctly enable all subslices.
         *
         * According to documentation software must consider the configuration
         * as 2x4x8 and hardware will translate this to 1x8x8.
         *
         * Furthemore, even though SScount is three bits, maximum documented
         * value for it is four. From this some rules/restrictions follow:
         *
         * 1.
         * If enabled subslice count is greater than four, two whole slices must
         * be enabled instead.
         *
         * 2.
         * When more than one slice is enabled, hardware ignores the subslice
         * count altogether.
         *
         * From these restrictions it follows that it is not possible to enable
         * a count of subslices between the SScount maximum of four restriction,
         * and the maximum available number on a particular SKU. Either all
         * subslices are enabled, or a count between one and four on the first
         * slice.
         */
        if (IS_GEN(i915, 11) &&
            slices == 1 &&
            subslices > min_t(u8, 4, hweight8(sseu->subslice_mask[0]) / 2)) {
                GEM_BUG_ON(subslices & 1);

                subslice_pg = false;
                slices *= 2;
        }

        /*
         * Starting in Gen9, render power gating can leave
         * slice/subslice/EU in a partially enabled state. We
         * must make an explicit request through RPCS for full
         * enablement.
         */
        if (sseu->has_slice_pg) {
                u32 mask, val = slices;

                if (INTEL_GEN(i915) >= 11) {
                        mask = GEN11_RPCS_S_CNT_MASK;
                        val <<= GEN11_RPCS_S_CNT_SHIFT;
                } else {
                        mask = GEN8_RPCS_S_CNT_MASK;
                        val <<= GEN8_RPCS_S_CNT_SHIFT;
                }

                GEM_BUG_ON(val & ~mask);
                val &= mask;

                rpcs |= GEN8_RPCS_ENABLE | GEN8_RPCS_S_CNT_ENABLE | val;
        }

        if (subslice_pg) {
                u32 val = subslices;

                val <<= GEN8_RPCS_SS_CNT_SHIFT;

                GEM_BUG_ON(val & ~GEN8_RPCS_SS_CNT_MASK);
                val &= GEN8_RPCS_SS_CNT_MASK;

                rpcs |= GEN8_RPCS_ENABLE | GEN8_RPCS_SS_CNT_ENABLE | val;
        }

        if (sseu->has_eu_pg) {
                u32 val;

                val = req_sseu->min_eus_per_subslice << GEN8_RPCS_EU_MIN_SHIFT;
                GEM_BUG_ON(val & ~GEN8_RPCS_EU_MIN_MASK);
                val &= GEN8_RPCS_EU_MIN_MASK;

                rpcs |= val;

                val = req_sseu->max_eus_per_subslice << GEN8_RPCS_EU_MAX_SHIFT;
                GEM_BUG_ON(val & ~GEN8_RPCS_EU_MAX_MASK);
                val &= GEN8_RPCS_EU_MAX_MASK;

                rpcs |= val;

                rpcs |= GEN8_RPCS_ENABLE;
        }

        return rpcs;
}

void intel_sseu_dump(const struct sseu_dev_info *sseu, struct drm_printer *p)
{
        int s;

        drm_printf(p, "slice total: %u, mask=%04x\n",
                   hweight8(sseu->slice_mask), sseu->slice_mask);
        drm_printf(p, "subslice total: %u\n", intel_sseu_subslice_total(sseu));
        for (s = 0; s < sseu->max_slices; s++) {
                drm_printf(p, "slice%d: %u subslices, mask=%08x\n",
                           s, intel_sseu_subslices_per_slice(sseu, s),
                           intel_sseu_get_subslices(sseu, s));
        }
        drm_printf(p, "EU total: %u\n", sseu->eu_total);
        drm_printf(p, "EU per subslice: %u\n", sseu->eu_per_subslice);
        drm_printf(p, "has slice power gating: %s\n",
                   yesno(sseu->has_slice_pg));
        drm_printf(p, "has subslice power gating: %s\n",
                   yesno(sseu->has_subslice_pg));
        drm_printf(p, "has EU power gating: %s\n", yesno(sseu->has_eu_pg));
}

void intel_sseu_print_topology(const struct sseu_dev_info *sseu,
                               struct drm_printer *p)
{
        int s, ss;

        if (sseu->max_slices == 0) {
                drm_printf(p, "Unavailable\n");
                return;
        }

        for (s = 0; s < sseu->max_slices; s++) {
                drm_printf(p, "slice%d: %u subslice(s) (0x%08x):\n",
                           s, intel_sseu_subslices_per_slice(sseu, s),
                           intel_sseu_get_subslices(sseu, s));

                for (ss = 0; ss < sseu->max_subslices; ss++) {
                        u16 enabled_eus = sseu_get_eus(sseu, s, ss);

                        drm_printf(p, "\tsubslice%d: %u EUs (0x%hx)\n",
                                   ss, hweight16(enabled_eus), enabled_eus);
                }
        }
}