/*
 * Copyright(c) 2011-2017 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.
 */
#include <linux/debugfs.h>
#include <linux/list_sort.h>
#include "i915_drv.h"
#include "gvt.h"

struct mmio_diff_param {
        struct intel_vgpu *vgpu;
        int total;
        int diff;
        struct list_head diff_mmio_list;
};

struct diff_mmio {
        struct list_head node;
        u32 offset;
        u32 preg;
        u32 vreg;
};

/* Compare two diff_mmio items. */
static int mmio_offset_compare(void *priv,
        struct list_head *a, struct list_head *b)
{
        struct diff_mmio *ma;
        struct diff_mmio *mb;

        ma = container_of(a, struct diff_mmio, node);
        mb = container_of(b, struct diff_mmio, node);
        if (ma->offset < mb->offset)
                return -1;
        else if (ma->offset > mb->offset)
                return 1;
        return 0;
}

static inline int mmio_diff_handler(struct intel_gvt *gvt,
                                    u32 offset, void *data)
{
        struct drm_i915_private *i915 = gvt->dev_priv;
        struct mmio_diff_param *param = data;
        struct diff_mmio *node;
        u32 preg, vreg;

        preg = intel_uncore_read_notrace(&i915->uncore, _MMIO(offset));
        vreg = vgpu_vreg(param->vgpu, offset);

        if (preg != vreg) {
                node = kmalloc(sizeof(*node), GFP_KERNEL);
                if (!node)
                        return -ENOMEM;

                node->offset = offset;
                node->preg = preg;
                node->vreg = vreg;
                list_add(&node->node, &param->diff_mmio_list);
                param->diff++;
        }
        param->total++;
        return 0;
}

/* Show the all the different values of tracked mmio. */
static int vgpu_mmio_diff_show(struct seq_file *s, void *unused)
{
        struct intel_vgpu *vgpu = s->private;
        struct intel_gvt *gvt = vgpu->gvt;
        struct mmio_diff_param param = {
                .vgpu = vgpu,
                .total = 0,
                .diff = 0,
        };
        struct diff_mmio *node, *next;

        INIT_LIST_HEAD(&param.diff_mmio_list);

        mutex_lock(&gvt->lock);
        spin_lock_bh(&gvt->scheduler.mmio_context_lock);

        mmio_hw_access_pre(gvt->dev_priv);
        /* Recognize all the diff mmios to list. */
        intel_gvt_for_each_tracked_mmio(gvt, mmio_diff_handler, &param);
        mmio_hw_access_post(gvt->dev_priv);

        spin_unlock_bh(&gvt->scheduler.mmio_context_lock);
        mutex_unlock(&gvt->lock);

        /* In an ascending order by mmio offset. */
        list_sort(NULL, &param.diff_mmio_list, mmio_offset_compare);

        seq_printf(s, "%-8s %-8s %-8s %-8s\n", "Offset", "HW", "vGPU", "Diff");
        list_for_each_entry_safe(node, next, &param.diff_mmio_list, node) {
                u32 diff = node->preg ^ node->vreg;

                seq_printf(s, "%08x %08x %08x %*pbl\n",
                           node->offset, node->preg, node->vreg,
                           32, &diff);
                list_del(&node->node);
                kfree(node);
        }
        seq_printf(s, "Total: %d, Diff: %d\n", param.total, param.diff);
        return 0;
}
DEFINE_SHOW_ATTRIBUTE(vgpu_mmio_diff);

static int
vgpu_scan_nonprivbb_get(void *data, u64 *val)
{
        struct intel_vgpu *vgpu = (struct intel_vgpu *)data;
        *val = vgpu->scan_nonprivbb;
        return 0;
}

/*
 * set/unset bit engine_id of vgpu->scan_nonprivbb to turn on/off scanning
 * of non-privileged batch buffer. e.g.
 * if vgpu->scan_nonprivbb=3, then it will scan non-privileged batch buffer
 * on engine 0 and 1.
 */
static int
vgpu_scan_nonprivbb_set(void *data, u64 val)
{
        struct intel_vgpu *vgpu = (struct intel_vgpu *)data;
        struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
        enum intel_engine_id id;
        char buf[128], *s;
        int len;

        val &= (1 << I915_NUM_ENGINES) - 1;

        if (vgpu->scan_nonprivbb == val)
                return 0;

        if (!val)
                goto done;

        len = sprintf(buf,
                "gvt: vgpu %d turns on non-privileged batch buffers scanning on Engines:",
                vgpu->id);

        s = buf + len;

        for (id = 0; id < I915_NUM_ENGINES; id++) {
                struct intel_engine_cs *engine;

                engine = dev_priv->engine[id];
                if (engine && (val & (1 << id))) {
                        len = snprintf(s, 4, "%d, ", engine->id);
                        s += len;
                } else
                        val &=  ~(1 << id);
        }

        if (val)
                sprintf(s, "low performance expected.");

        pr_warn("%s\n", buf);

done:
        vgpu->scan_nonprivbb = val;
        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(vgpu_scan_nonprivbb_fops,
                        vgpu_scan_nonprivbb_get, vgpu_scan_nonprivbb_set,
                        "0x%llx\n");

/**
 * intel_gvt_debugfs_add_vgpu - register debugfs entries for a vGPU
 * @vgpu: a vGPU
 *
 * Returns:
 * Zero on success, negative error code if failed.
 */
int intel_gvt_debugfs_add_vgpu(struct intel_vgpu *vgpu)
{
        struct dentry *ent;
        char name[16] = "";

        snprintf(name, 16, "vgpu%d", vgpu->id);
        vgpu->debugfs = debugfs_create_dir(name, vgpu->gvt->debugfs_root);
        if (!vgpu->debugfs)
                return -ENOMEM;

        ent = debugfs_create_bool("active", 0444, vgpu->debugfs,
                                  &vgpu->active);
        if (!ent)
                return -ENOMEM;

        ent = debugfs_create_file("mmio_diff", 0444, vgpu->debugfs,
                                  vgpu, &vgpu_mmio_diff_fops);
        if (!ent)
                return -ENOMEM;

        ent = debugfs_create_file("scan_nonprivbb", 0644, vgpu->debugfs,
                                 vgpu, &vgpu_scan_nonprivbb_fops);
        if (!ent)
                return -ENOMEM;

        return 0;
}

/**
 * intel_gvt_debugfs_remove_vgpu - remove debugfs entries of a vGPU
 * @vgpu: a vGPU
 */
void intel_gvt_debugfs_remove_vgpu(struct intel_vgpu *vgpu)
{
        debugfs_remove_recursive(vgpu->debugfs);
        vgpu->debugfs = NULL;
}

/**
 * intel_gvt_debugfs_init - register gvt debugfs root entry
 * @gvt: GVT device
 *
 * Returns:
 * zero on success, negative if failed.
 */
int intel_gvt_debugfs_init(struct intel_gvt *gvt)
{
        struct drm_minor *minor = gvt->dev_priv->drm.primary;
        struct dentry *ent;

        gvt->debugfs_root = debugfs_create_dir("gvt", minor->debugfs_root);
        if (!gvt->debugfs_root) {
                gvt_err("Cannot create debugfs dir\n");
                return -ENOMEM;
        }

        ent = debugfs_create_ulong("num_tracked_mmio", 0444, gvt->debugfs_root,
                                   &gvt->mmio.num_tracked_mmio);
        if (!ent)
                return -ENOMEM;

        return 0;
}

/**
 * intel_gvt_debugfs_clean - remove debugfs entries
 * @gvt: GVT device
 */
void intel_gvt_debugfs_clean(struct intel_gvt *gvt)
{
        debugfs_remove_recursive(gvt->debugfs_root);
        gvt->debugfs_root = NULL;
}