/*
 * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
 *
 * 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.
 *
 * Authors:
 *    Eddie Dong <eddie.dong@intel.com>
 *    Kevin Tian <kevin.tian@intel.com>
 *
 * Contributors:
 *    Zhi Wang <zhi.a.wang@intel.com>
 *    Changbin Du <changbin.du@intel.com>
 *    Zhenyu Wang <zhenyuw@linux.intel.com>
 *    Tina Zhang <tina.zhang@intel.com>
 *    Bing Niu <bing.niu@intel.com>
 *
 */

#include "i915_drv.h"
#include "gvt.h"
#include "trace.h"

#define GEN9_MOCS_SIZE          64

/* Raw offset is appened to each line for convenience. */
static struct engine_mmio gen8_engine_mmio_list[] __cacheline_aligned = {
        {RCS, GFX_MODE_GEN7, 0xffff, false}, /* 0x229c */
        {RCS, GEN9_CTX_PREEMPT_REG, 0x0, false}, /* 0x2248 */
        {RCS, HWSTAM, 0x0, false}, /* 0x2098 */
        {RCS, INSTPM, 0xffff, true}, /* 0x20c0 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 0), 0, false}, /* 0x24d0 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 1), 0, false}, /* 0x24d4 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 2), 0, false}, /* 0x24d8 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 3), 0, false}, /* 0x24dc */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 4), 0, false}, /* 0x24e0 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 5), 0, false}, /* 0x24e4 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 6), 0, false}, /* 0x24e8 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 7), 0, false}, /* 0x24ec */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 8), 0, false}, /* 0x24f0 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 9), 0, false}, /* 0x24f4 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 10), 0, false}, /* 0x24f8 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 11), 0, false}, /* 0x24fc */
        {RCS, CACHE_MODE_1, 0xffff, true}, /* 0x7004 */
        {RCS, GEN7_GT_MODE, 0xffff, true}, /* 0x7008 */
        {RCS, CACHE_MODE_0_GEN7, 0xffff, true}, /* 0x7000 */
        {RCS, GEN7_COMMON_SLICE_CHICKEN1, 0xffff, true}, /* 0x7010 */
        {RCS, HDC_CHICKEN0, 0xffff, true}, /* 0x7300 */
        {RCS, VF_GUARDBAND, 0xffff, true}, /* 0x83a4 */

        {BCS, RING_GFX_MODE(BLT_RING_BASE), 0xffff, false}, /* 0x2229c */
        {BCS, RING_MI_MODE(BLT_RING_BASE), 0xffff, false}, /* 0x2209c */
        {BCS, RING_INSTPM(BLT_RING_BASE), 0xffff, false}, /* 0x220c0 */
        {BCS, RING_HWSTAM(BLT_RING_BASE), 0x0, false}, /* 0x22098 */
        {BCS, RING_EXCC(BLT_RING_BASE), 0x0, false}, /* 0x22028 */
        {RCS, INVALID_MMIO_REG, 0, false } /* Terminated */
};

static struct engine_mmio gen9_engine_mmio_list[] __cacheline_aligned = {
        {RCS, GFX_MODE_GEN7, 0xffff, false}, /* 0x229c */
        {RCS, GEN9_CTX_PREEMPT_REG, 0x0, false}, /* 0x2248 */
        {RCS, HWSTAM, 0x0, false}, /* 0x2098 */
        {RCS, INSTPM, 0xffff, true}, /* 0x20c0 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 0), 0, false}, /* 0x24d0 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 1), 0, false}, /* 0x24d4 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 2), 0, false}, /* 0x24d8 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 3), 0, false}, /* 0x24dc */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 4), 0, false}, /* 0x24e0 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 5), 0, false}, /* 0x24e4 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 6), 0, false}, /* 0x24e8 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 7), 0, false}, /* 0x24ec */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 8), 0, false}, /* 0x24f0 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 9), 0, false}, /* 0x24f4 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 10), 0, false}, /* 0x24f8 */
        {RCS, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 11), 0, false}, /* 0x24fc */
        {RCS, CACHE_MODE_1, 0xffff, true}, /* 0x7004 */
        {RCS, GEN7_GT_MODE, 0xffff, true}, /* 0x7008 */
        {RCS, CACHE_MODE_0_GEN7, 0xffff, true}, /* 0x7000 */
        {RCS, GEN7_COMMON_SLICE_CHICKEN1, 0xffff, true}, /* 0x7010 */
        {RCS, HDC_CHICKEN0, 0xffff, true}, /* 0x7300 */
        {RCS, VF_GUARDBAND, 0xffff, true}, /* 0x83a4 */

        {RCS, GEN8_PRIVATE_PAT_LO, 0, false}, /* 0x40e0 */
        {RCS, GEN8_PRIVATE_PAT_HI, 0, false}, /* 0x40e4 */
        {RCS, GEN8_CS_CHICKEN1, 0xffff, true}, /* 0x2580 */
        {RCS, COMMON_SLICE_CHICKEN2, 0xffff, true}, /* 0x7014 */
        {RCS, GEN9_CS_DEBUG_MODE1, 0xffff, false}, /* 0x20ec */
        {RCS, GEN8_L3SQCREG4, 0, false}, /* 0xb118 */
        {RCS, GEN7_HALF_SLICE_CHICKEN1, 0xffff, true}, /* 0xe100 */
        {RCS, HALF_SLICE_CHICKEN2, 0xffff, true}, /* 0xe180 */
        {RCS, HALF_SLICE_CHICKEN3, 0xffff, true}, /* 0xe184 */
        {RCS, GEN9_HALF_SLICE_CHICKEN5, 0xffff, true}, /* 0xe188 */
        {RCS, GEN9_HALF_SLICE_CHICKEN7, 0xffff, true}, /* 0xe194 */
        {RCS, GEN8_ROW_CHICKEN, 0xffff, true}, /* 0xe4f0 */
        {RCS, TRVATTL3PTRDW(0), 0, false}, /* 0x4de0 */
        {RCS, TRVATTL3PTRDW(1), 0, false}, /* 0x4de4 */
        {RCS, TRNULLDETCT, 0, false}, /* 0x4de8 */
        {RCS, TRINVTILEDETCT, 0, false}, /* 0x4dec */
        {RCS, TRVADR, 0, false}, /* 0x4df0 */
        {RCS, TRTTE, 0, false}, /* 0x4df4 */

        {BCS, RING_GFX_MODE(BLT_RING_BASE), 0xffff, false}, /* 0x2229c */
        {BCS, RING_MI_MODE(BLT_RING_BASE), 0xffff, false}, /* 0x2209c */
        {BCS, RING_INSTPM(BLT_RING_BASE), 0xffff, false}, /* 0x220c0 */
        {BCS, RING_HWSTAM(BLT_RING_BASE), 0x0, false}, /* 0x22098 */
        {BCS, RING_EXCC(BLT_RING_BASE), 0x0, false}, /* 0x22028 */

        {VCS2, RING_EXCC(GEN8_BSD2_RING_BASE), 0xffff, false}, /* 0x1c028 */

        {VECS, RING_EXCC(VEBOX_RING_BASE), 0xffff, false}, /* 0x1a028 */

        {RCS, GEN8_HDC_CHICKEN1, 0xffff, true}, /* 0x7304 */
        {RCS, GEN9_CTX_PREEMPT_REG, 0x0, false}, /* 0x2248 */
        {RCS, GEN7_UCGCTL4, 0x0, false}, /* 0x940c */
        {RCS, GAMT_CHKN_BIT_REG, 0x0, false}, /* 0x4ab8 */

        {RCS, GEN9_GAMT_ECO_REG_RW_IA, 0x0, false}, /* 0x4ab0 */
        {RCS, GEN9_CSFE_CHICKEN1_RCS, 0xffff, false}, /* 0x20d4 */
        {RCS, _MMIO(0x20D8), 0xffff, true}, /* 0x20d8 */

        {RCS, GEN8_GARBCNTL, 0x0, false}, /* 0xb004 */
        {RCS, GEN7_FF_THREAD_MODE, 0x0, false}, /* 0x20a0 */
        {RCS, FF_SLICE_CS_CHICKEN2, 0xffff, false}, /* 0x20e4 */
        {RCS, INVALID_MMIO_REG, 0, false } /* Terminated */
};

static struct {
        bool initialized;
        u32 control_table[I915_NUM_ENGINES][GEN9_MOCS_SIZE];
        u32 l3cc_table[GEN9_MOCS_SIZE / 2];
} gen9_render_mocs;

static void load_render_mocs(struct drm_i915_private *dev_priv)
{
        i915_reg_t offset;
        u32 regs[] = {
                [RCS] = 0xc800,
                [VCS] = 0xc900,
                [VCS2] = 0xca00,
                [BCS] = 0xcc00,
                [VECS] = 0xcb00,
        };
        int ring_id, i;

        for (ring_id = 0; ring_id < ARRAY_SIZE(regs); ring_id++) {
                if (!HAS_ENGINE(dev_priv, ring_id))
                        continue;
                offset.reg = regs[ring_id];
                for (i = 0; i < GEN9_MOCS_SIZE; i++) {
                        gen9_render_mocs.control_table[ring_id][i] =
                                I915_READ_FW(offset);
                        offset.reg += 4;
                }
        }

        offset.reg = 0xb020;
        for (i = 0; i < GEN9_MOCS_SIZE / 2; i++) {
                gen9_render_mocs.l3cc_table[i] =
                        I915_READ_FW(offset);
                offset.reg += 4;
        }
        gen9_render_mocs.initialized = true;
}

static int
restore_context_mmio_for_inhibit(struct intel_vgpu *vgpu,
                                 struct i915_request *req)
{
        u32 *cs;
        int ret;
        struct engine_mmio *mmio;
        struct intel_gvt *gvt = vgpu->gvt;
        int ring_id = req->engine->id;
        int count = gvt->engine_mmio_list.ctx_mmio_count[ring_id];

        if (count == 0)
                return 0;

        ret = req->engine->emit_flush(req, EMIT_BARRIER);
        if (ret)
                return ret;

        cs = intel_ring_begin(req, count * 2 + 2);
        if (IS_ERR(cs))
                return PTR_ERR(cs);

        *cs++ = MI_LOAD_REGISTER_IMM(count);
        for (mmio = gvt->engine_mmio_list.mmio;
             i915_mmio_reg_valid(mmio->reg); mmio++) {
                if (mmio->ring_id != ring_id ||
                    !mmio->in_context)
                        continue;

                *cs++ = i915_mmio_reg_offset(mmio->reg);
                *cs++ = vgpu_vreg_t(vgpu, mmio->reg) |
                                (mmio->mask << 16);
                gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
                              *(cs-2), *(cs-1), vgpu->id, ring_id);
        }

        *cs++ = MI_NOOP;
        intel_ring_advance(req, cs);

        ret = req->engine->emit_flush(req, EMIT_BARRIER);
        if (ret)
                return ret;

        return 0;
}

static int
restore_render_mocs_control_for_inhibit(struct intel_vgpu *vgpu,
                                        struct i915_request *req)
{
        unsigned int index;
        u32 *cs;

        cs = intel_ring_begin(req, 2 * GEN9_MOCS_SIZE + 2);
        if (IS_ERR(cs))
                return PTR_ERR(cs);

        *cs++ = MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE);

        for (index = 0; index < GEN9_MOCS_SIZE; index++) {
                *cs++ = i915_mmio_reg_offset(GEN9_GFX_MOCS(index));
                *cs++ = vgpu_vreg_t(vgpu, GEN9_GFX_MOCS(index));
                gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
                              *(cs-2), *(cs-1), vgpu->id, req->engine->id);

        }

        *cs++ = MI_NOOP;
        intel_ring_advance(req, cs);

        return 0;
}

static int
restore_render_mocs_l3cc_for_inhibit(struct intel_vgpu *vgpu,
                                     struct i915_request *req)
{
        unsigned int index;
        u32 *cs;

        cs = intel_ring_begin(req, 2 * GEN9_MOCS_SIZE / 2 + 2);
        if (IS_ERR(cs))
                return PTR_ERR(cs);

        *cs++ = MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE / 2);

        for (index = 0; index < GEN9_MOCS_SIZE / 2; index++) {
                *cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(index));
                *cs++ = vgpu_vreg_t(vgpu, GEN9_LNCFCMOCS(index));
                gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
                              *(cs-2), *(cs-1), vgpu->id, req->engine->id);

        }

        *cs++ = MI_NOOP;
        intel_ring_advance(req, cs);

        return 0;
}

/*
 * Use lri command to initialize the mmio which is in context state image for
 * inhibit context, it contains tracked engine mmio, render_mocs and
 * render_mocs_l3cc.
 */
int intel_vgpu_restore_inhibit_context(struct intel_vgpu *vgpu,
                                       struct i915_request *req)
{
        int ret;
        u32 *cs;

        cs = intel_ring_begin(req, 2);
        if (IS_ERR(cs))
                return PTR_ERR(cs);

        *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
        *cs++ = MI_NOOP;
        intel_ring_advance(req, cs);

        ret = restore_context_mmio_for_inhibit(vgpu, req);
        if (ret)
                goto out;

        /* no MOCS register in context except render engine */
        if (req->engine->id != RCS)
                goto out;

        ret = restore_render_mocs_control_for_inhibit(vgpu, req);
        if (ret)
                goto out;

        ret = restore_render_mocs_l3cc_for_inhibit(vgpu, req);
        if (ret)
                goto out;

out:
        cs = intel_ring_begin(req, 2);
        if (IS_ERR(cs))
                return PTR_ERR(cs);

        *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
        *cs++ = MI_NOOP;
        intel_ring_advance(req, cs);

        return ret;
}

static void handle_tlb_pending_event(struct intel_vgpu *vgpu, int ring_id)
{
        struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
        struct intel_vgpu_submission *s = &vgpu->submission;
        enum forcewake_domains fw;
        i915_reg_t reg;
        u32 regs[] = {
                [RCS] = 0x4260,
                [VCS] = 0x4264,
                [VCS2] = 0x4268,
                [BCS] = 0x426c,
                [VECS] = 0x4270,
        };

        if (WARN_ON(ring_id >= ARRAY_SIZE(regs)))
                return;

        if (!test_and_clear_bit(ring_id, (void *)s->tlb_handle_pending))
                return;

        reg = _MMIO(regs[ring_id]);

        /* WaForceWakeRenderDuringMmioTLBInvalidate:skl
         * we need to put a forcewake when invalidating RCS TLB caches,
         * otherwise device can go to RC6 state and interrupt invalidation
         * process
         */
        fw = intel_uncore_forcewake_for_reg(dev_priv, reg,
                                            FW_REG_READ | FW_REG_WRITE);
        if (ring_id == RCS && (INTEL_GEN(dev_priv) >= 9))
                fw |= FORCEWAKE_RENDER;

        intel_uncore_forcewake_get(dev_priv, fw);

        I915_WRITE_FW(reg, 0x1);

        if (wait_for_atomic((I915_READ_FW(reg) == 0), 50))
                gvt_vgpu_err("timeout in invalidate ring (%d) tlb\n", ring_id);
        else
                vgpu_vreg_t(vgpu, reg) = 0;

        intel_uncore_forcewake_put(dev_priv, fw);

        gvt_dbg_core("invalidate TLB for ring %d\n", ring_id);
}

static void switch_mocs(struct intel_vgpu *pre, struct intel_vgpu *next,
                        int ring_id)
{
        struct drm_i915_private *dev_priv;
        i915_reg_t offset, l3_offset;
        u32 old_v, new_v;

        u32 regs[] = {
                [RCS] = 0xc800,
                [VCS] = 0xc900,
                [VCS2] = 0xca00,
                [BCS] = 0xcc00,
                [VECS] = 0xcb00,
        };
        int i;

        dev_priv = pre ? pre->gvt->dev_priv : next->gvt->dev_priv;
        if (WARN_ON(ring_id >= ARRAY_SIZE(regs)))
                return;

        if ((IS_KABYLAKE(dev_priv)  || IS_BROXTON(dev_priv)
                || IS_COFFEELAKE(dev_priv)) && ring_id == RCS)
                return;

        if (!pre && !gen9_render_mocs.initialized)
                load_render_mocs(dev_priv);

        offset.reg = regs[ring_id];
        for (i = 0; i < GEN9_MOCS_SIZE; i++) {
                if (pre)
                        old_v = vgpu_vreg_t(pre, offset);
                else
                        old_v = gen9_render_mocs.control_table[ring_id][i];
                if (next)
                        new_v = vgpu_vreg_t(next, offset);
                else
                        new_v = gen9_render_mocs.control_table[ring_id][i];

                if (old_v != new_v)
                        I915_WRITE_FW(offset, new_v);

                offset.reg += 4;
        }

        if (ring_id == RCS) {
                l3_offset.reg = 0xb020;
                for (i = 0; i < GEN9_MOCS_SIZE / 2; i++) {
                        if (pre)
                                old_v = vgpu_vreg_t(pre, l3_offset);
                        else
                                old_v = gen9_render_mocs.l3cc_table[i];
                        if (next)
                                new_v = vgpu_vreg_t(next, l3_offset);
                        else
                                new_v = gen9_render_mocs.l3cc_table[i];

                        if (old_v != new_v)
                                I915_WRITE_FW(l3_offset, new_v);

                        l3_offset.reg += 4;
                }
        }
}

#define CTX_CONTEXT_CONTROL_VAL 0x03

bool is_inhibit_context(struct intel_context *ce)
{
        const u32 *reg_state = ce->lrc_reg_state;
        u32 inhibit_mask =
                _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT);

        return inhibit_mask ==
                (reg_state[CTX_CONTEXT_CONTROL_VAL] & inhibit_mask);
}

/* Switch ring mmio values (context). */
static void switch_mmio(struct intel_vgpu *pre,
                        struct intel_vgpu *next,
                        int ring_id)
{
        struct drm_i915_private *dev_priv;
        struct intel_vgpu_submission *s;
        struct engine_mmio *mmio;
        u32 old_v, new_v;

        dev_priv = pre ? pre->gvt->dev_priv : next->gvt->dev_priv;
        if (INTEL_GEN(dev_priv) >= 9)
                switch_mocs(pre, next, ring_id);

        for (mmio = dev_priv->gvt->engine_mmio_list.mmio;
             i915_mmio_reg_valid(mmio->reg); mmio++) {
                if (mmio->ring_id != ring_id)
                        continue;
                /*
                 * No need to do save or restore of the mmio which is in context
                 * state image on kabylake, it's initialized by lri command and
                 * save or restore with context together.
                 */
                if ((IS_KABYLAKE(dev_priv) || IS_BROXTON(dev_priv)
                        || IS_COFFEELAKE(dev_priv)) && mmio->in_context)
                        continue;

                // save
                if (pre) {
                        vgpu_vreg_t(pre, mmio->reg) = I915_READ_FW(mmio->reg);
                        if (mmio->mask)
                                vgpu_vreg_t(pre, mmio->reg) &=
                                                ~(mmio->mask << 16);
                        old_v = vgpu_vreg_t(pre, mmio->reg);
                } else
                        old_v = mmio->value = I915_READ_FW(mmio->reg);

                // restore
                if (next) {
                        s = &next->submission;
                        /*
                         * No need to restore the mmio which is in context state
                         * image if it's not inhibit context, it will restore
                         * itself.
                         */
                        if (mmio->in_context &&
                            !is_inhibit_context(&s->shadow_ctx->__engine[ring_id]))
                                continue;

                        if (mmio->mask)
                                new_v = vgpu_vreg_t(next, mmio->reg) |
                                                        (mmio->mask << 16);
                        else
                                new_v = vgpu_vreg_t(next, mmio->reg);
                } else {
                        if (mmio->in_context)
                                continue;
                        if (mmio->mask)
                                new_v = mmio->value | (mmio->mask << 16);
                        else
                                new_v = mmio->value;
                }

                I915_WRITE_FW(mmio->reg, new_v);

                trace_render_mmio(pre ? pre->id : 0,
                                  next ? next->id : 0,
                                  "switch",
                                  i915_mmio_reg_offset(mmio->reg),
                                  old_v, new_v);
        }

        if (next)
                handle_tlb_pending_event(next, ring_id);
}

/**
 * intel_gvt_switch_render_mmio - switch mmio context of specific engine
 * @pre: the last vGPU that own the engine
 * @next: the vGPU to switch to
 * @ring_id: specify the engine
 *
 * If pre is null indicates that host own the engine. If next is null
 * indicates that we are switching to host workload.
 */
void intel_gvt_switch_mmio(struct intel_vgpu *pre,
                           struct intel_vgpu *next, int ring_id)
{
        struct drm_i915_private *dev_priv;

        if (WARN_ON(!pre && !next))
                return;

        gvt_dbg_render("switch ring %d from %s to %s\n", ring_id,
                       pre ? "vGPU" : "host", next ? "vGPU" : "HOST");

        dev_priv = pre ? pre->gvt->dev_priv : next->gvt->dev_priv;

        /**
         * We are using raw mmio access wrapper to improve the
         * performace for batch mmio read/write, so we need
         * handle forcewake mannually.
         */
        intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
        switch_mmio(pre, next, ring_id);
        intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
}

/**
 * intel_gvt_init_engine_mmio_context - Initiate the engine mmio list
 * @gvt: GVT device
 *
 */
void intel_gvt_init_engine_mmio_context(struct intel_gvt *gvt)
{
        struct engine_mmio *mmio;

        if (INTEL_GEN(gvt->dev_priv) >= 9)
                gvt->engine_mmio_list.mmio = gen9_engine_mmio_list;
        else
                gvt->engine_mmio_list.mmio = gen8_engine_mmio_list;

        for (mmio = gvt->engine_mmio_list.mmio;
             i915_mmio_reg_valid(mmio->reg); mmio++) {
                if (mmio->in_context) {
                        gvt->engine_mmio_list.ctx_mmio_count[mmio->ring_id]++;
                        intel_gvt_mmio_set_in_ctx(gvt, mmio->reg.reg);
                }
        }
}