// SPDX-License-Identifier: GPL-2.0 OR MIT
/**************************************************************************
 *
 * Copyright 2009-2020 VMware, Inc., Palo Alto, CA., USA
 *
 * 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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/sched/signal.h>

#include <drm/ttm/ttm_placement.h>

#include "vmwgfx_drv.h"
#include "vmwgfx_devcaps.h"

bool vmw_supports_3d(struct vmw_private *dev_priv)
{
        uint32_t fifo_min, hwversion;
        const struct vmw_fifo_state *fifo = dev_priv->fifo;

        if (!(dev_priv->capabilities & SVGA_CAP_3D))
                return false;

        if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS) {
                uint32_t result;

                if (!dev_priv->has_mob)
                        return false;

                result = vmw_devcap_get(dev_priv, SVGA3D_DEVCAP_3D);

                return (result != 0);
        }

        if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
                return false;

        BUG_ON(vmw_is_svga_v3(dev_priv));

        fifo_min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
        if (fifo_min <= SVGA_FIFO_3D_HWVERSION * sizeof(unsigned int))
                return false;

        hwversion = vmw_fifo_mem_read(dev_priv,
                                      ((fifo->capabilities &
                                        SVGA_FIFO_CAP_3D_HWVERSION_REVISED) ?
                                               SVGA_FIFO_3D_HWVERSION_REVISED :
                                               SVGA_FIFO_3D_HWVERSION));

        if (hwversion == 0)
                return false;

        if (hwversion < SVGA3D_HWVERSION_WS8_B1)
                return false;

        /* Legacy Display Unit does not support surfaces */
        if (dev_priv->active_display_unit == vmw_du_legacy)
                return false;

        return true;
}

bool vmw_fifo_have_pitchlock(struct vmw_private *dev_priv)
{
        uint32_t caps;

        if (!(dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO))
                return false;

        caps = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_CAPABILITIES);
        if (caps & SVGA_FIFO_CAP_PITCHLOCK)
                return true;

        return false;
}

struct vmw_fifo_state *vmw_fifo_create(struct vmw_private *dev_priv)
{
        struct vmw_fifo_state *fifo;
        uint32_t max;
        uint32_t min;

        if (!dev_priv->fifo_mem)
                return NULL;

        fifo = kzalloc(sizeof(*fifo), GFP_KERNEL);
        if (!fifo)
                return ERR_PTR(-ENOMEM);
        fifo->static_buffer_size = VMWGFX_FIFO_STATIC_SIZE;
        fifo->static_buffer = vmalloc(fifo->static_buffer_size);
        if (unlikely(fifo->static_buffer == NULL)) {
                kfree(fifo);
                return ERR_PTR(-ENOMEM);
        }

        fifo->dynamic_buffer = NULL;
        fifo->reserved_size = 0;
        fifo->using_bounce_buffer = false;

        mutex_init(&fifo->fifo_mutex);
        init_rwsem(&fifo->rwsem);
        min = 4;
        if (dev_priv->capabilities & SVGA_CAP_EXTENDED_FIFO)
                min = vmw_read(dev_priv, SVGA_REG_MEM_REGS);
        min <<= 2;

        if (min < PAGE_SIZE)
                min = PAGE_SIZE;

        vmw_fifo_mem_write(dev_priv, SVGA_FIFO_MIN, min);
        vmw_fifo_mem_write(dev_priv, SVGA_FIFO_MAX, dev_priv->fifo_mem_size);
        wmb();
        vmw_fifo_mem_write(dev_priv, SVGA_FIFO_NEXT_CMD, min);
        vmw_fifo_mem_write(dev_priv, SVGA_FIFO_STOP, min);
        vmw_fifo_mem_write(dev_priv, SVGA_FIFO_BUSY, 0);
        mb();

        vmw_write(dev_priv, SVGA_REG_CONFIG_DONE, 1);

        max = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MAX);
        min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
        fifo->capabilities = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_CAPABILITIES);

        drm_info(&dev_priv->drm,
                 "Fifo max 0x%08x min 0x%08x cap 0x%08x\n",
                 (unsigned int) max,
                 (unsigned int) min,
                 (unsigned int) fifo->capabilities);

        if (unlikely(min >= max)) {
                drm_warn(&dev_priv->drm,
                         "FIFO memory is not usable. Driver failed to initialize.");
                return ERR_PTR(-ENXIO);
        }

        return fifo;
}

void vmw_fifo_ping_host(struct vmw_private *dev_priv, uint32_t reason)
{
        u32 *fifo_mem = dev_priv->fifo_mem;
        if (fifo_mem && cmpxchg(fifo_mem + SVGA_FIFO_BUSY, 0, 1) == 0)
                vmw_write(dev_priv, SVGA_REG_SYNC, reason);

}

void vmw_fifo_destroy(struct vmw_private *dev_priv)
{
        struct vmw_fifo_state *fifo = dev_priv->fifo;

        if (!fifo)
                return;

        if (likely(fifo->static_buffer != NULL)) {
                vfree(fifo->static_buffer);
                fifo->static_buffer = NULL;
        }

        if (likely(fifo->dynamic_buffer != NULL)) {
                vfree(fifo->dynamic_buffer);
                fifo->dynamic_buffer = NULL;
        }
        kfree(fifo);
        dev_priv->fifo = NULL;
}

static bool vmw_fifo_is_full(struct vmw_private *dev_priv, uint32_t bytes)
{
        uint32_t max = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MAX);
        uint32_t next_cmd = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_NEXT_CMD);
        uint32_t min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
        uint32_t stop = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_STOP);

        return ((max - next_cmd) + (stop - min) <= bytes);
}

static int vmw_fifo_wait_noirq(struct vmw_private *dev_priv,
                               uint32_t bytes, bool interruptible,
                               unsigned long timeout)
{
        int ret = 0;
        unsigned long end_jiffies = jiffies + timeout;
        DEFINE_WAIT(__wait);

        DRM_INFO("Fifo wait noirq.\n");

        for (;;) {
                prepare_to_wait(&dev_priv->fifo_queue, &__wait,
                                (interruptible) ?
                                TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
                if (!vmw_fifo_is_full(dev_priv, bytes))
                        break;
                if (time_after_eq(jiffies, end_jiffies)) {
                        ret = -EBUSY;
                        DRM_ERROR("SVGA device lockup.\n");
                        break;
                }
                schedule_timeout(1);
                if (interruptible && signal_pending(current)) {
                        ret = -ERESTARTSYS;
                        break;
                }
        }
        finish_wait(&dev_priv->fifo_queue, &__wait);
        wake_up_all(&dev_priv->fifo_queue);
        DRM_INFO("Fifo noirq exit.\n");
        return ret;
}

static int vmw_fifo_wait(struct vmw_private *dev_priv,
                         uint32_t bytes, bool interruptible,
                         unsigned long timeout)
{
        long ret = 1L;

        if (likely(!vmw_fifo_is_full(dev_priv, bytes)))
                return 0;

        vmw_fifo_ping_host(dev_priv, SVGA_SYNC_FIFOFULL);
        if (!(dev_priv->capabilities & SVGA_CAP_IRQMASK))
                return vmw_fifo_wait_noirq(dev_priv, bytes,
                                           interruptible, timeout);

        vmw_generic_waiter_add(dev_priv, SVGA_IRQFLAG_FIFO_PROGRESS,
                               &dev_priv->fifo_queue_waiters);

        if (interruptible)
                ret = wait_event_interruptible_timeout
                    (dev_priv->fifo_queue,
                     !vmw_fifo_is_full(dev_priv, bytes), timeout);
        else
                ret = wait_event_timeout
                    (dev_priv->fifo_queue,
                     !vmw_fifo_is_full(dev_priv, bytes), timeout);

        if (unlikely(ret == 0))
                ret = -EBUSY;
        else if (likely(ret > 0))
                ret = 0;

        vmw_generic_waiter_remove(dev_priv, SVGA_IRQFLAG_FIFO_PROGRESS,
                                  &dev_priv->fifo_queue_waiters);

        return ret;
}

/*
 * Reserve @bytes number of bytes in the fifo.
 *
 * This function will return NULL (error) on two conditions:
 *  If it timeouts waiting for fifo space, or if @bytes is larger than the
 *   available fifo space.
 *
 * Returns:
 *   Pointer to the fifo, or null on error (possible hardware hang).
 */
static void *vmw_local_fifo_reserve(struct vmw_private *dev_priv,
                                    uint32_t bytes)
{
        struct vmw_fifo_state *fifo_state = dev_priv->fifo;
        u32  *fifo_mem = dev_priv->fifo_mem;
        uint32_t max;
        uint32_t min;
        uint32_t next_cmd;
        uint32_t reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;
        int ret;

        mutex_lock(&fifo_state->fifo_mutex);
        max = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MAX);
        min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
        next_cmd = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_NEXT_CMD);

        if (unlikely(bytes >= (max - min)))
                goto out_err;

        BUG_ON(fifo_state->reserved_size != 0);
        BUG_ON(fifo_state->dynamic_buffer != NULL);

        fifo_state->reserved_size = bytes;

        while (1) {
                uint32_t stop = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_STOP);
                bool need_bounce = false;
                bool reserve_in_place = false;

                if (next_cmd >= stop) {
                        if (likely((next_cmd + bytes < max ||
                                    (next_cmd + bytes == max && stop > min))))
                                reserve_in_place = true;

                        else if (vmw_fifo_is_full(dev_priv, bytes)) {
                                ret = vmw_fifo_wait(dev_priv, bytes,
                                                    false, 3 * HZ);
                                if (unlikely(ret != 0))
                                        goto out_err;
                        } else
                                need_bounce = true;

                } else {

                        if (likely((next_cmd + bytes < stop)))
                                reserve_in_place = true;
                        else {
                                ret = vmw_fifo_wait(dev_priv, bytes,
                                                    false, 3 * HZ);
                                if (unlikely(ret != 0))
                                        goto out_err;
                        }
                }

                if (reserve_in_place) {
                        if (reserveable || bytes <= sizeof(uint32_t)) {
                                fifo_state->using_bounce_buffer = false;

                                if (reserveable)
                                        vmw_fifo_mem_write(dev_priv,
                                                           SVGA_FIFO_RESERVED,
                                                           bytes);
                                return (void __force *) (fifo_mem +
                                                         (next_cmd >> 2));
                        } else {
                                need_bounce = true;
                        }
                }

                if (need_bounce) {
                        fifo_state->using_bounce_buffer = true;
                        if (bytes < fifo_state->static_buffer_size)
                                return fifo_state->static_buffer;
                        else {
                                fifo_state->dynamic_buffer = vmalloc(bytes);
                                if (!fifo_state->dynamic_buffer)
                                        goto out_err;
                                return fifo_state->dynamic_buffer;
                        }
                }
        }
out_err:
        fifo_state->reserved_size = 0;
        mutex_unlock(&fifo_state->fifo_mutex);

        return NULL;
}

void *vmw_cmd_ctx_reserve(struct vmw_private *dev_priv, uint32_t bytes,
                          int ctx_id)
{
        void *ret;

        if (dev_priv->cman)
                ret = vmw_cmdbuf_reserve(dev_priv->cman, bytes,
                                         ctx_id, false, NULL);
        else if (ctx_id == SVGA3D_INVALID_ID)
                ret = vmw_local_fifo_reserve(dev_priv, bytes);
        else {
                WARN(1, "Command buffer has not been allocated.\n");
                ret = NULL;
        }
        if (IS_ERR_OR_NULL(ret))
                return NULL;

        return ret;
}

static void vmw_fifo_res_copy(struct vmw_fifo_state *fifo_state,
                              struct vmw_private *vmw,
                              uint32_t next_cmd,
                              uint32_t max, uint32_t min, uint32_t bytes)
{
        u32 *fifo_mem = vmw->fifo_mem;
        uint32_t chunk_size = max - next_cmd;
        uint32_t rest;
        uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
            fifo_state->dynamic_buffer : fifo_state->static_buffer;

        if (bytes < chunk_size)
                chunk_size = bytes;

        vmw_fifo_mem_write(vmw, SVGA_FIFO_RESERVED, bytes);
        mb();
        memcpy(fifo_mem + (next_cmd >> 2), buffer, chunk_size);
        rest = bytes - chunk_size;
        if (rest)
                memcpy(fifo_mem + (min >> 2), buffer + (chunk_size >> 2), rest);
}

static void vmw_fifo_slow_copy(struct vmw_fifo_state *fifo_state,
                               struct vmw_private *vmw,
                               uint32_t next_cmd,
                               uint32_t max, uint32_t min, uint32_t bytes)
{
        uint32_t *buffer = (fifo_state->dynamic_buffer != NULL) ?
            fifo_state->dynamic_buffer : fifo_state->static_buffer;

        while (bytes > 0) {
                vmw_fifo_mem_write(vmw, (next_cmd >> 2), *buffer++);
                next_cmd += sizeof(uint32_t);
                if (unlikely(next_cmd == max))
                        next_cmd = min;
                mb();
                vmw_fifo_mem_write(vmw, SVGA_FIFO_NEXT_CMD, next_cmd);
                mb();
                bytes -= sizeof(uint32_t);
        }
}

static void vmw_local_fifo_commit(struct vmw_private *dev_priv, uint32_t bytes)
{
        struct vmw_fifo_state *fifo_state = dev_priv->fifo;
        uint32_t next_cmd = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_NEXT_CMD);
        uint32_t max = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MAX);
        uint32_t min = vmw_fifo_mem_read(dev_priv, SVGA_FIFO_MIN);
        bool reserveable = fifo_state->capabilities & SVGA_FIFO_CAP_RESERVE;

        BUG_ON((bytes & 3) != 0);
        BUG_ON(bytes > fifo_state->reserved_size);

        fifo_state->reserved_size = 0;

        if (fifo_state->using_bounce_buffer) {
                if (reserveable)
                        vmw_fifo_res_copy(fifo_state, dev_priv,
                                          next_cmd, max, min, bytes);
                else
                        vmw_fifo_slow_copy(fifo_state, dev_priv,
                                           next_cmd, max, min, bytes);

                if (fifo_state->dynamic_buffer) {
                        vfree(fifo_state->dynamic_buffer);
                        fifo_state->dynamic_buffer = NULL;
                }

        }

        down_write(&fifo_state->rwsem);
        if (fifo_state->using_bounce_buffer || reserveable) {
                next_cmd += bytes;
                if (next_cmd >= max)
                        next_cmd -= max - min;
                mb();
                vmw_fifo_mem_write(dev_priv, SVGA_FIFO_NEXT_CMD, next_cmd);
        }

        if (reserveable)
                vmw_fifo_mem_write(dev_priv, SVGA_FIFO_RESERVED, 0);
        mb();
        up_write(&fifo_state->rwsem);
        vmw_fifo_ping_host(dev_priv, SVGA_SYNC_GENERIC);
        mutex_unlock(&fifo_state->fifo_mutex);
}

void vmw_cmd_commit(struct vmw_private *dev_priv, uint32_t bytes)
{
        if (dev_priv->cman)
                vmw_cmdbuf_commit(dev_priv->cman, bytes, NULL, false);
        else
                vmw_local_fifo_commit(dev_priv, bytes);
}


/**
 * vmw_cmd_commit_flush - Commit fifo space and flush any buffered commands.
 *
 * @dev_priv: Pointer to device private structure.
 * @bytes: Number of bytes to commit.
 */
void vmw_cmd_commit_flush(struct vmw_private *dev_priv, uint32_t bytes)
{
        if (dev_priv->cman)
                vmw_cmdbuf_commit(dev_priv->cman, bytes, NULL, true);
        else
                vmw_local_fifo_commit(dev_priv, bytes);
}

/**
 * vmw_cmd_flush - Flush any buffered commands and make sure command processing
 * starts.
 *
 * @dev_priv: Pointer to device private structure.
 * @interruptible: Whether to wait interruptible if function needs to sleep.
 */
int vmw_cmd_flush(struct vmw_private *dev_priv, bool interruptible)
{
        might_sleep();

        if (dev_priv->cman)
                return vmw_cmdbuf_cur_flush(dev_priv->cman, interruptible);
        else
                return 0;
}

int vmw_cmd_send_fence(struct vmw_private *dev_priv, uint32_t *seqno)
{
        struct svga_fifo_cmd_fence *cmd_fence;
        u32 *fm;
        int ret = 0;
        uint32_t bytes = sizeof(u32) + sizeof(*cmd_fence);

        fm = VMW_CMD_RESERVE(dev_priv, bytes);
        if (unlikely(fm == NULL)) {
                *seqno = atomic_read(&dev_priv->marker_seq);
                ret = -ENOMEM;
                (void)vmw_fallback_wait(dev_priv, false, true, *seqno,
                                        false, 3*HZ);
                goto out_err;
        }

        do {
                *seqno = atomic_add_return(1, &dev_priv->marker_seq);
        } while (*seqno == 0);

        if (!(vmw_fifo_caps(dev_priv) & SVGA_FIFO_CAP_FENCE)) {

                /*
                 * Don't request hardware to send a fence. The
                 * waiting code in vmwgfx_irq.c will emulate this.
                 */

                vmw_cmd_commit(dev_priv, 0);
                return 0;
        }

        *fm++ = SVGA_CMD_FENCE;
        cmd_fence = (struct svga_fifo_cmd_fence *) fm;
        cmd_fence->fence = *seqno;
        vmw_cmd_commit_flush(dev_priv, bytes);
        vmw_update_seqno(dev_priv);

out_err:
        return ret;
}

/**
 * vmw_cmd_emit_dummy_legacy_query - emits a dummy query to the fifo using
 * legacy query commands.
 *
 * @dev_priv: The device private structure.
 * @cid: The hardware context id used for the query.
 *
 * See the vmw_cmd_emit_dummy_query documentation.
 */
static int vmw_cmd_emit_dummy_legacy_query(struct vmw_private *dev_priv,
                                            uint32_t cid)
{
        /*
         * A query wait without a preceding query end will
         * actually finish all queries for this cid
         * without writing to the query result structure.
         */

        struct ttm_buffer_object *bo = &dev_priv->dummy_query_bo->base;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdWaitForQuery body;
        } *cmd;

        cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
        if (unlikely(cmd == NULL))
                return -ENOMEM;

        cmd->header.id = SVGA_3D_CMD_WAIT_FOR_QUERY;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.cid = cid;
        cmd->body.type = SVGA3D_QUERYTYPE_OCCLUSION;

        if (bo->resource->mem_type == TTM_PL_VRAM) {
                cmd->body.guestResult.gmrId = SVGA_GMR_FRAMEBUFFER;
                cmd->body.guestResult.offset = bo->resource->start << PAGE_SHIFT;
        } else {
                cmd->body.guestResult.gmrId = bo->resource->start;
                cmd->body.guestResult.offset = 0;
        }

        vmw_cmd_commit(dev_priv, sizeof(*cmd));

        return 0;
}

/**
 * vmw_cmd_emit_dummy_gb_query - emits a dummy query to the fifo using
 * guest-backed resource query commands.
 *
 * @dev_priv: The device private structure.
 * @cid: The hardware context id used for the query.
 *
 * See the vmw_cmd_emit_dummy_query documentation.
 */
static int vmw_cmd_emit_dummy_gb_query(struct vmw_private *dev_priv,
                                       uint32_t cid)
{
        /*
         * A query wait without a preceding query end will
         * actually finish all queries for this cid
         * without writing to the query result structure.
         */

        struct ttm_buffer_object *bo = &dev_priv->dummy_query_bo->base;
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdWaitForGBQuery body;
        } *cmd;

        cmd = VMW_CMD_RESERVE(dev_priv, sizeof(*cmd));
        if (unlikely(cmd == NULL))
                return -ENOMEM;

        cmd->header.id = SVGA_3D_CMD_WAIT_FOR_GB_QUERY;
        cmd->header.size = sizeof(cmd->body);
        cmd->body.cid = cid;
        cmd->body.type = SVGA3D_QUERYTYPE_OCCLUSION;
        BUG_ON(bo->resource->mem_type != VMW_PL_MOB);
        cmd->body.mobid = bo->resource->start;
        cmd->body.offset = 0;

        vmw_cmd_commit(dev_priv, sizeof(*cmd));

        return 0;
}


/**
 * vmw_cmd_emit_dummy_query - emits a dummy query to the fifo using
 * appropriate resource query commands.
 *
 * @dev_priv: The device private structure.
 * @cid: The hardware context id used for the query.
 *
 * This function is used to emit a dummy occlusion query with
 * no primitives rendered between query begin and query end.
 * It's used to provide a query barrier, in order to know that when
 * this query is finished, all preceding queries are also finished.
 *
 * A Query results structure should have been initialized at the start
 * of the dev_priv->dummy_query_bo buffer object. And that buffer object
 * must also be either reserved or pinned when this function is called.
 *
 * Returns -ENOMEM on failure to reserve fifo space.
 */
int vmw_cmd_emit_dummy_query(struct vmw_private *dev_priv,
                              uint32_t cid)
{
        if (dev_priv->has_mob)
                return vmw_cmd_emit_dummy_gb_query(dev_priv, cid);

        return vmw_cmd_emit_dummy_legacy_query(dev_priv, cid);
}


/**
 * vmw_cmd_supported - returns true if the given device supports
 * command queues.
 *
 * @vmw: The device private structure.
 *
 * Returns true if we can issue commands.
 */
bool vmw_cmd_supported(struct vmw_private *vmw)
{
        if ((vmw->capabilities & (SVGA_CAP_COMMAND_BUFFERS |
                                  SVGA_CAP_CMD_BUFFERS_2)) != 0)
                return true;
        /*
         * We have FIFO cmd's
         */
        return vmw->fifo_mem != NULL;
}