/*
 * 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:
 *    Kevin Tian <kevin.tian@intel.com>
 *    Dexuan Cui
 *
 * Contributors:
 *    Pei Zhang <pei.zhang@intel.com>
 *    Min He <min.he@intel.com>
 *    Niu Bing <bing.niu@intel.com>
 *    Yulei Zhang <yulei.zhang@intel.com>
 *    Zhenyu Wang <zhenyuw@linux.intel.com>
 *    Zhi Wang <zhi.a.wang@intel.com>
 *
 */

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

static int alloc_gm(struct intel_vgpu *vgpu, bool high_gm)
{
        struct intel_gvt *gvt = vgpu->gvt;
        struct drm_i915_private *dev_priv = gvt->dev_priv;
        unsigned int flags;
        u64 start, end, size;
        struct drm_mm_node *node;
        int ret;

        if (high_gm) {
                node = &vgpu->gm.high_gm_node;
                size = vgpu_hidden_sz(vgpu);
                start = ALIGN(gvt_hidden_gmadr_base(gvt), I915_GTT_PAGE_SIZE);
                end = ALIGN(gvt_hidden_gmadr_end(gvt), I915_GTT_PAGE_SIZE);
                flags = PIN_HIGH;
        } else {
                node = &vgpu->gm.low_gm_node;
                size = vgpu_aperture_sz(vgpu);
                start = ALIGN(gvt_aperture_gmadr_base(gvt), I915_GTT_PAGE_SIZE);
                end = ALIGN(gvt_aperture_gmadr_end(gvt), I915_GTT_PAGE_SIZE);
                flags = PIN_MAPPABLE;
        }

        mutex_lock(&dev_priv->drm.struct_mutex);
        mmio_hw_access_pre(dev_priv);
        ret = i915_gem_gtt_insert(&dev_priv->ggtt.vm, node,
                                  size, I915_GTT_PAGE_SIZE,
                                  I915_COLOR_UNEVICTABLE,
                                  start, end, flags);
        mmio_hw_access_post(dev_priv);
        mutex_unlock(&dev_priv->drm.struct_mutex);
        if (ret)
                gvt_err("fail to alloc %s gm space from host\n",
                        high_gm ? "high" : "low");

        return ret;
}

static int alloc_vgpu_gm(struct intel_vgpu *vgpu)
{
        struct intel_gvt *gvt = vgpu->gvt;
        struct drm_i915_private *dev_priv = gvt->dev_priv;
        int ret;

        ret = alloc_gm(vgpu, false);
        if (ret)
                return ret;

        ret = alloc_gm(vgpu, true);
        if (ret)
                goto out_free_aperture;

        gvt_dbg_core("vgpu%d: alloc low GM start %llx size %llx\n", vgpu->id,
                     vgpu_aperture_offset(vgpu), vgpu_aperture_sz(vgpu));

        gvt_dbg_core("vgpu%d: alloc high GM start %llx size %llx\n", vgpu->id,
                     vgpu_hidden_offset(vgpu), vgpu_hidden_sz(vgpu));

        return 0;
out_free_aperture:
        mutex_lock(&dev_priv->drm.struct_mutex);
        drm_mm_remove_node(&vgpu->gm.low_gm_node);
        mutex_unlock(&dev_priv->drm.struct_mutex);
        return ret;
}

static void free_vgpu_gm(struct intel_vgpu *vgpu)
{
        struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;

        mutex_lock(&dev_priv->drm.struct_mutex);
        drm_mm_remove_node(&vgpu->gm.low_gm_node);
        drm_mm_remove_node(&vgpu->gm.high_gm_node);
        mutex_unlock(&dev_priv->drm.struct_mutex);
}

/**
 * intel_vgpu_write_fence - write fence registers owned by a vGPU
 * @vgpu: vGPU instance
 * @fence: vGPU fence register number
 * @value: Fence register value to be written
 *
 * This function is used to write fence registers owned by a vGPU. The vGPU
 * fence register number will be translated into HW fence register number.
 *
 */
void intel_vgpu_write_fence(struct intel_vgpu *vgpu,
                u32 fence, u64 value)
{
        struct intel_gvt *gvt = vgpu->gvt;
        struct drm_i915_private *dev_priv = gvt->dev_priv;
        struct drm_i915_fence_reg *reg;
        i915_reg_t fence_reg_lo, fence_reg_hi;

        assert_rpm_wakelock_held(dev_priv);

        if (WARN_ON(fence >= vgpu_fence_sz(vgpu)))
                return;

        reg = vgpu->fence.regs[fence];
        if (WARN_ON(!reg))
                return;

        fence_reg_lo = FENCE_REG_GEN6_LO(reg->id);
        fence_reg_hi = FENCE_REG_GEN6_HI(reg->id);

        I915_WRITE(fence_reg_lo, 0);
        POSTING_READ(fence_reg_lo);

        I915_WRITE(fence_reg_hi, upper_32_bits(value));
        I915_WRITE(fence_reg_lo, lower_32_bits(value));
        POSTING_READ(fence_reg_lo);
}

static void _clear_vgpu_fence(struct intel_vgpu *vgpu)
{
        int i;

        for (i = 0; i < vgpu_fence_sz(vgpu); i++)
                intel_vgpu_write_fence(vgpu, i, 0);
}

static void free_vgpu_fence(struct intel_vgpu *vgpu)
{
        struct intel_gvt *gvt = vgpu->gvt;
        struct drm_i915_private *dev_priv = gvt->dev_priv;
        struct drm_i915_fence_reg *reg;
        u32 i;

        if (WARN_ON(!vgpu_fence_sz(vgpu)))
                return;

        intel_runtime_pm_get(dev_priv);

        mutex_lock(&dev_priv->drm.struct_mutex);
        _clear_vgpu_fence(vgpu);
        for (i = 0; i < vgpu_fence_sz(vgpu); i++) {
                reg = vgpu->fence.regs[i];
                i915_unreserve_fence(reg);
                vgpu->fence.regs[i] = NULL;
        }
        mutex_unlock(&dev_priv->drm.struct_mutex);

        intel_runtime_pm_put_unchecked(dev_priv);
}

static int alloc_vgpu_fence(struct intel_vgpu *vgpu)
{
        struct intel_gvt *gvt = vgpu->gvt;
        struct drm_i915_private *dev_priv = gvt->dev_priv;
        struct drm_i915_fence_reg *reg;
        int i;

        intel_runtime_pm_get(dev_priv);

        /* Request fences from host */
        mutex_lock(&dev_priv->drm.struct_mutex);

        for (i = 0; i < vgpu_fence_sz(vgpu); i++) {
                reg = i915_reserve_fence(dev_priv);
                if (IS_ERR(reg))
                        goto out_free_fence;

                vgpu->fence.regs[i] = reg;
        }

        _clear_vgpu_fence(vgpu);

        mutex_unlock(&dev_priv->drm.struct_mutex);
        intel_runtime_pm_put_unchecked(dev_priv);
        return 0;
out_free_fence:
        gvt_vgpu_err("Failed to alloc fences\n");
        /* Return fences to host, if fail */
        for (i = 0; i < vgpu_fence_sz(vgpu); i++) {
                reg = vgpu->fence.regs[i];
                if (!reg)
                        continue;
                i915_unreserve_fence(reg);
                vgpu->fence.regs[i] = NULL;
        }
        mutex_unlock(&dev_priv->drm.struct_mutex);
        intel_runtime_pm_put_unchecked(dev_priv);
        return -ENOSPC;
}

static void free_resource(struct intel_vgpu *vgpu)
{
        struct intel_gvt *gvt = vgpu->gvt;

        gvt->gm.vgpu_allocated_low_gm_size -= vgpu_aperture_sz(vgpu);
        gvt->gm.vgpu_allocated_high_gm_size -= vgpu_hidden_sz(vgpu);
        gvt->fence.vgpu_allocated_fence_num -= vgpu_fence_sz(vgpu);
}

static int alloc_resource(struct intel_vgpu *vgpu,
                struct intel_vgpu_creation_params *param)
{
        struct intel_gvt *gvt = vgpu->gvt;
        unsigned long request, avail, max, taken;
        const char *item;

        if (!param->low_gm_sz || !param->high_gm_sz || !param->fence_sz) {
                gvt_vgpu_err("Invalid vGPU creation params\n");
                return -EINVAL;
        }

        item = "low GM space";
        max = gvt_aperture_sz(gvt) - HOST_LOW_GM_SIZE;
        taken = gvt->gm.vgpu_allocated_low_gm_size;
        avail = max - taken;
        request = MB_TO_BYTES(param->low_gm_sz);

        if (request > avail)
                goto no_enough_resource;

        vgpu_aperture_sz(vgpu) = ALIGN(request, I915_GTT_PAGE_SIZE);

        item = "high GM space";
        max = gvt_hidden_sz(gvt) - HOST_HIGH_GM_SIZE;
        taken = gvt->gm.vgpu_allocated_high_gm_size;
        avail = max - taken;
        request = MB_TO_BYTES(param->high_gm_sz);

        if (request > avail)
                goto no_enough_resource;

        vgpu_hidden_sz(vgpu) = ALIGN(request, I915_GTT_PAGE_SIZE);

        item = "fence";
        max = gvt_fence_sz(gvt) - HOST_FENCE;
        taken = gvt->fence.vgpu_allocated_fence_num;
        avail = max - taken;
        request = param->fence_sz;

        if (request > avail)
                goto no_enough_resource;

        vgpu_fence_sz(vgpu) = request;

        gvt->gm.vgpu_allocated_low_gm_size += MB_TO_BYTES(param->low_gm_sz);
        gvt->gm.vgpu_allocated_high_gm_size += MB_TO_BYTES(param->high_gm_sz);
        gvt->fence.vgpu_allocated_fence_num += param->fence_sz;
        return 0;

no_enough_resource:
        gvt_err("fail to allocate resource %s\n", item);
        gvt_err("request %luMB avail %luMB max %luMB taken %luMB\n",
                BYTES_TO_MB(request), BYTES_TO_MB(avail),
                BYTES_TO_MB(max), BYTES_TO_MB(taken));
        return -ENOSPC;
}

/**
 * inte_gvt_free_vgpu_resource - free HW resource owned by a vGPU
 * @vgpu: a vGPU
 *
 * This function is used to free the HW resource owned by a vGPU.
 *
 */
void intel_vgpu_free_resource(struct intel_vgpu *vgpu)
{
        free_vgpu_gm(vgpu);
        free_vgpu_fence(vgpu);
        free_resource(vgpu);
}

/**
 * intel_vgpu_reset_resource - reset resource state owned by a vGPU
 * @vgpu: a vGPU
 *
 * This function is used to reset resource state owned by a vGPU.
 *
 */
void intel_vgpu_reset_resource(struct intel_vgpu *vgpu)
{
        struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;

        intel_runtime_pm_get(dev_priv);
        _clear_vgpu_fence(vgpu);
        intel_runtime_pm_put_unchecked(dev_priv);
}

/**
 * intel_alloc_vgpu_resource - allocate HW resource for a vGPU
 * @vgpu: vGPU
 * @param: vGPU creation params
 *
 * This function is used to allocate HW resource for a vGPU. User specifies
 * the resource configuration through the creation params.
 *
 * Returns:
 * zero on success, negative error code if failed.
 *
 */
int intel_vgpu_alloc_resource(struct intel_vgpu *vgpu,
                struct intel_vgpu_creation_params *param)
{
        int ret;

        ret = alloc_resource(vgpu, param);
        if (ret)
                return ret;

        ret = alloc_vgpu_gm(vgpu);
        if (ret)
                goto out_free_resource;

        ret = alloc_vgpu_fence(vgpu);
        if (ret)
                goto out_free_vgpu_gm;

        return 0;

out_free_vgpu_gm:
        free_vgpu_gm(vgpu);
out_free_resource:
        free_resource(vgpu);
        return ret;
}