/* mga_dma.c -- DMA support for mga g200/g400 -*- linux-c -*-
 * Created: Mon Dec 13 01:50:01 1999 by jhartmann@precisioninsight.com
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * 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
 * PRECISION INSIGHT 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.
 */

/**
 * \file mga_dma.c
 * DMA support for MGA G200 / G400.
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Jeff Hartmann <jhartmann@valinux.com>
 * \author Keith Whitwell <keith@tungstengraphics.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

#include <drm/drmP.h>
#include <drm/mga_drm.h>
#include "mga_drv.h"

#define MGA_DEFAULT_USEC_TIMEOUT        10000
#define MGA_FREELIST_DEBUG              0

#define MINIMAL_CLEANUP 0
#define FULL_CLEANUP 1
static int mga_do_cleanup_dma(struct drm_device *dev, int full_cleanup);

/* ================================================================
 * Engine control
 */

int mga_do_wait_for_idle(drm_mga_private_t *dev_priv)
{
        u32 status = 0;
        int i;
        DRM_DEBUG("\n");

        for (i = 0; i < dev_priv->usec_timeout; i++) {
                status = MGA_READ(MGA_STATUS) & MGA_ENGINE_IDLE_MASK;
                if (status == MGA_ENDPRDMASTS) {
                        MGA_WRITE8(MGA_CRTC_INDEX, 0);
                        return 0;
                }
                DRM_UDELAY(1);
        }

#if MGA_DMA_DEBUG
        DRM_ERROR("failed!\n");
        DRM_INFO("   status=0x%08x\n", status);
#endif
        return -EBUSY;
}

static int mga_do_dma_reset(drm_mga_private_t *dev_priv)
{
        drm_mga_sarea_t *sarea_priv = dev_priv->sarea_priv;
        drm_mga_primary_buffer_t *primary = &dev_priv->prim;

        DRM_DEBUG("\n");

        /* The primary DMA stream should look like new right about now.
         */
        primary->tail = 0;
        primary->space = primary->size;
        primary->last_flush = 0;

        sarea_priv->last_wrap = 0;

        /* FIXME: Reset counters, buffer ages etc...
         */

        /* FIXME: What else do we need to reinitialize?  WARP stuff?
         */

        return 0;
}

/* ================================================================
 * Primary DMA stream
 */

void mga_do_dma_flush(drm_mga_private_t *dev_priv)
{
        drm_mga_primary_buffer_t *primary = &dev_priv->prim;
        u32 head, tail;
        u32 status = 0;
        int i;
        DMA_LOCALS;
        DRM_DEBUG("\n");

        /* We need to wait so that we can do an safe flush */
        for (i = 0; i < dev_priv->usec_timeout; i++) {
                status = MGA_READ(MGA_STATUS) & MGA_ENGINE_IDLE_MASK;
                if (status == MGA_ENDPRDMASTS)
                        break;
                DRM_UDELAY(1);
        }

        if (primary->tail == primary->last_flush) {
                DRM_DEBUG("   bailing out...\n");
                return;
        }

        tail = primary->tail + dev_priv->primary->offset;

        /* We need to pad the stream between flushes, as the card
         * actually (partially?) reads the first of these commands.
         * See page 4-16 in the G400 manual, middle of the page or so.
         */
        BEGIN_DMA(1);

        DMA_BLOCK(MGA_DMAPAD, 0x00000000,
                  MGA_DMAPAD, 0x00000000,
                  MGA_DMAPAD, 0x00000000, MGA_DMAPAD, 0x00000000);

        ADVANCE_DMA();

        primary->last_flush = primary->tail;

        head = MGA_READ(MGA_PRIMADDRESS);

        if (head <= tail)
                primary->space = primary->size - primary->tail;
        else
                primary->space = head - tail;

        DRM_DEBUG("   head = 0x%06lx\n", (unsigned long)(head - dev_priv->primary->offset));
        DRM_DEBUG("   tail = 0x%06lx\n", (unsigned long)(tail - dev_priv->primary->offset));
        DRM_DEBUG("  space = 0x%06x\n", primary->space);

        mga_flush_write_combine();
        MGA_WRITE(MGA_PRIMEND, tail | dev_priv->dma_access);

        DRM_DEBUG("done.\n");
}

void mga_do_dma_wrap_start(drm_mga_private_t *dev_priv)
{
        drm_mga_primary_buffer_t *primary = &dev_priv->prim;
        u32 head, tail;
        DMA_LOCALS;
        DRM_DEBUG("\n");

        BEGIN_DMA_WRAP();

        DMA_BLOCK(MGA_DMAPAD, 0x00000000,
                  MGA_DMAPAD, 0x00000000,
                  MGA_DMAPAD, 0x00000000, MGA_DMAPAD, 0x00000000);

        ADVANCE_DMA();

        tail = primary->tail + dev_priv->primary->offset;

        primary->tail = 0;
        primary->last_flush = 0;
        primary->last_wrap++;

        head = MGA_READ(MGA_PRIMADDRESS);

        if (head == dev_priv->primary->offset)
                primary->space = primary->size;
        else
                primary->space = head - dev_priv->primary->offset;

        DRM_DEBUG("   head = 0x%06lx\n", (unsigned long)(head - dev_priv->primary->offset));
        DRM_DEBUG("   tail = 0x%06x\n", primary->tail);
        DRM_DEBUG("   wrap = %d\n", primary->last_wrap);
        DRM_DEBUG("  space = 0x%06x\n", primary->space);

        mga_flush_write_combine();
        MGA_WRITE(MGA_PRIMEND, tail | dev_priv->dma_access);

        set_bit(0, &primary->wrapped);
        DRM_DEBUG("done.\n");
}

void mga_do_dma_wrap_end(drm_mga_private_t *dev_priv)
{
        drm_mga_primary_buffer_t *primary = &dev_priv->prim;
        drm_mga_sarea_t *sarea_priv = dev_priv->sarea_priv;
        u32 head = dev_priv->primary->offset;
        DRM_DEBUG("\n");

        sarea_priv->last_wrap++;
        DRM_DEBUG("   wrap = %d\n", sarea_priv->last_wrap);

        mga_flush_write_combine();
        MGA_WRITE(MGA_PRIMADDRESS, head | MGA_DMA_GENERAL);

        clear_bit(0, &primary->wrapped);
        DRM_DEBUG("done.\n");
}

/* ================================================================
 * Freelist management
 */

#define MGA_BUFFER_USED         (~0)
#define MGA_BUFFER_FREE         0

#if MGA_FREELIST_DEBUG
static void mga_freelist_print(struct drm_device *dev)
{
        drm_mga_private_t *dev_priv = dev->dev_private;
        drm_mga_freelist_t *entry;

        DRM_INFO("\n");
        DRM_INFO("current dispatch: last=0x%x done=0x%x\n",
                 dev_priv->sarea_priv->last_dispatch,
                 (unsigned int)(MGA_READ(MGA_PRIMADDRESS) -
                                dev_priv->primary->offset));
        DRM_INFO("current freelist:\n");

        for (entry = dev_priv->head->next; entry; entry = entry->next) {
                DRM_INFO("   %p   idx=%2d  age=0x%x 0x%06lx\n",
                         entry, entry->buf->idx, entry->age.head,
                         (unsigned long)(entry->age.head - dev_priv->primary->offset));
        }
        DRM_INFO("\n");
}
#endif

static int mga_freelist_init(struct drm_device *dev, drm_mga_private_t *dev_priv)
{
        struct drm_device_dma *dma = dev->dma;
        struct drm_buf *buf;
        drm_mga_buf_priv_t *buf_priv;
        drm_mga_freelist_t *entry;
        int i;
        DRM_DEBUG("count=%d\n", dma->buf_count);

        dev_priv->head = kzalloc(sizeof(drm_mga_freelist_t), GFP_KERNEL);
        if (dev_priv->head == NULL)
                return -ENOMEM;

        SET_AGE(&dev_priv->head->age, MGA_BUFFER_USED, 0);

        for (i = 0; i < dma->buf_count; i++) {
                buf = dma->buflist[i];
                buf_priv = buf->dev_private;

                entry = kzalloc(sizeof(drm_mga_freelist_t), GFP_KERNEL);
                if (entry == NULL)
                        return -ENOMEM;

                entry->next = dev_priv->head->next;
                entry->prev = dev_priv->head;
                SET_AGE(&entry->age, MGA_BUFFER_FREE, 0);
                entry->buf = buf;

                if (dev_priv->head->next != NULL)
                        dev_priv->head->next->prev = entry;
                if (entry->next == NULL)
                        dev_priv->tail = entry;

                buf_priv->list_entry = entry;
                buf_priv->discard = 0;
                buf_priv->dispatched = 0;

                dev_priv->head->next = entry;
        }

        return 0;
}

static void mga_freelist_cleanup(struct drm_device *dev)
{
        drm_mga_private_t *dev_priv = dev->dev_private;
        drm_mga_freelist_t *entry;
        drm_mga_freelist_t *next;
        DRM_DEBUG("\n");

        entry = dev_priv->head;
        while (entry) {
                next = entry->next;
                kfree(entry);
                entry = next;
        }

        dev_priv->head = dev_priv->tail = NULL;
}

#if 0
/* FIXME: Still needed?
 */
static void mga_freelist_reset(struct drm_device *dev)
{
        struct drm_device_dma *dma = dev->dma;
        struct drm_buf *buf;
        drm_mga_buf_priv_t *buf_priv;
        int i;

        for (i = 0; i < dma->buf_count; i++) {
                buf = dma->buflist[i];
                buf_priv = buf->dev_private;
                SET_AGE(&buf_priv->list_entry->age, MGA_BUFFER_FREE, 0);
        }
}
#endif

static struct drm_buf *mga_freelist_get(struct drm_device * dev)
{
        drm_mga_private_t *dev_priv = dev->dev_private;
        drm_mga_freelist_t *next;
        drm_mga_freelist_t *prev;
        drm_mga_freelist_t *tail = dev_priv->tail;
        u32 head, wrap;
        DRM_DEBUG("\n");

        head = MGA_READ(MGA_PRIMADDRESS);
        wrap = dev_priv->sarea_priv->last_wrap;

        DRM_DEBUG("   tail=0x%06lx %d\n",
                  tail->age.head ?
                  (unsigned long)(tail->age.head - dev_priv->primary->offset) : 0,
                  tail->age.wrap);
        DRM_DEBUG("   head=0x%06lx %d\n",
                  (unsigned long)(head - dev_priv->primary->offset), wrap);

        if (TEST_AGE(&tail->age, head, wrap)) {
                prev = dev_priv->tail->prev;
                next = dev_priv->tail;
                prev->next = NULL;
                next->prev = next->next = NULL;
                dev_priv->tail = prev;
                SET_AGE(&next->age, MGA_BUFFER_USED, 0);
                return next->buf;
        }

        DRM_DEBUG("returning NULL!\n");
        return NULL;
}

int mga_freelist_put(struct drm_device *dev, struct drm_buf *buf)
{
        drm_mga_private_t *dev_priv = dev->dev_private;
        drm_mga_buf_priv_t *buf_priv = buf->dev_private;
        drm_mga_freelist_t *head, *entry, *prev;

        DRM_DEBUG("age=0x%06lx wrap=%d\n",
                  (unsigned long)(buf_priv->list_entry->age.head -
                                  dev_priv->primary->offset),
                  buf_priv->list_entry->age.wrap);

        entry = buf_priv->list_entry;
        head = dev_priv->head;

        if (buf_priv->list_entry->age.head == MGA_BUFFER_USED) {
                SET_AGE(&entry->age, MGA_BUFFER_FREE, 0);
                prev = dev_priv->tail;
                prev->next = entry;
                entry->prev = prev;
                entry->next = NULL;
        } else {
                prev = head->next;
                head->next = entry;
                prev->prev = entry;
                entry->prev = head;
                entry->next = prev;
        }

        return 0;
}

/* ================================================================
 * DMA initialization, cleanup
 */

int mga_driver_load(struct drm_device *dev, unsigned long flags)
{
        drm_mga_private_t *dev_priv;
        int ret;

        dev_priv = kzalloc(sizeof(drm_mga_private_t), GFP_KERNEL);
        if (!dev_priv)
                return -ENOMEM;

        dev->dev_private = (void *)dev_priv;

        dev_priv->usec_timeout = MGA_DEFAULT_USEC_TIMEOUT;
        dev_priv->chipset = flags;

        pci_set_master(dev->pdev);

        dev_priv->mmio_base = pci_resource_start(dev->pdev, 1);
        dev_priv->mmio_size = pci_resource_len(dev->pdev, 1);

        ret = drm_vblank_init(dev, 1);

        if (ret) {
                (void) mga_driver_unload(dev);
                return ret;
        }

        return 0;
}

#if IS_ENABLED(CONFIG_AGP)
/**
 * Bootstrap the driver for AGP DMA.
 *
 * \todo
 * Investigate whether there is any benefit to storing the WARP microcode in
 * AGP memory.  If not, the microcode may as well always be put in PCI
 * memory.
 *
 * \todo
 * This routine needs to set dma_bs->agp_mode to the mode actually configured
 * in the hardware.  Looking just at the Linux AGP driver code, I don't see
 * an easy way to determine this.
 *
 * \sa mga_do_dma_bootstrap, mga_do_pci_dma_bootstrap
 */
static int mga_do_agp_dma_bootstrap(struct drm_device *dev,
                                    drm_mga_dma_bootstrap_t *dma_bs)
{
        drm_mga_private_t *const dev_priv =
            (drm_mga_private_t *) dev->dev_private;
        unsigned int warp_size = MGA_WARP_UCODE_SIZE;
        int err;
        unsigned offset;
        const unsigned secondary_size = dma_bs->secondary_bin_count
            * dma_bs->secondary_bin_size;
        const unsigned agp_size = (dma_bs->agp_size << 20);
        struct drm_buf_desc req;
        struct drm_agp_mode mode;
        struct drm_agp_info info;
        struct drm_agp_buffer agp_req;
        struct drm_agp_binding bind_req;

        /* Acquire AGP. */
        err = drm_agp_acquire(dev);
        if (err) {
                DRM_ERROR("Unable to acquire AGP: %d\n", err);
                return err;
        }

        err = drm_agp_info(dev, &info);
        if (err) {
                DRM_ERROR("Unable to get AGP info: %d\n", err);
                return err;
        }

        mode.mode = (info.mode & ~0x07) | dma_bs->agp_mode;
        err = drm_agp_enable(dev, mode);
        if (err) {
                DRM_ERROR("Unable to enable AGP (mode = 0x%lx)\n", mode.mode);
                return err;
        }

        /* In addition to the usual AGP mode configuration, the G200 AGP cards
         * need to have the AGP mode "manually" set.
         */

        if (dev_priv->chipset == MGA_CARD_TYPE_G200) {
                if (mode.mode & 0x02)
                        MGA_WRITE(MGA_AGP_PLL, MGA_AGP2XPLL_ENABLE);
                else
                        MGA_WRITE(MGA_AGP_PLL, MGA_AGP2XPLL_DISABLE);
        }

        /* Allocate and bind AGP memory. */
        agp_req.size = agp_size;
        agp_req.type = 0;
        err = drm_agp_alloc(dev, &agp_req);
        if (err) {
                dev_priv->agp_size = 0;
                DRM_ERROR("Unable to allocate %uMB AGP memory\n",
                          dma_bs->agp_size);
                return err;
        }

        dev_priv->agp_size = agp_size;
        dev_priv->agp_handle = agp_req.handle;

        bind_req.handle = agp_req.handle;
        bind_req.offset = 0;
        err = drm_agp_bind(dev, &bind_req);
        if (err) {
                DRM_ERROR("Unable to bind AGP memory: %d\n", err);
                return err;
        }

        /* Make drm_legacy_addbufs happy by not trying to create a mapping for
         * less than a page.
         */
        if (warp_size < PAGE_SIZE)
                warp_size = PAGE_SIZE;

        offset = 0;
        err = drm_legacy_addmap(dev, offset, warp_size,
                                _DRM_AGP, _DRM_READ_ONLY, &dev_priv->warp);
        if (err) {
                DRM_ERROR("Unable to map WARP microcode: %d\n", err);
                return err;
        }

        offset += warp_size;
        err = drm_legacy_addmap(dev, offset, dma_bs->primary_size,
                                _DRM_AGP, _DRM_READ_ONLY, &dev_priv->primary);
        if (err) {
                DRM_ERROR("Unable to map primary DMA region: %d\n", err);
                return err;
        }

        offset += dma_bs->primary_size;
        err = drm_legacy_addmap(dev, offset, secondary_size,
                                _DRM_AGP, 0, &dev->agp_buffer_map);
        if (err) {
                DRM_ERROR("Unable to map secondary DMA region: %d\n", err);
                return err;
        }

        (void)memset(&req, 0, sizeof(req));
        req.count = dma_bs->secondary_bin_count;
        req.size = dma_bs->secondary_bin_size;
        req.flags = _DRM_AGP_BUFFER;
        req.agp_start = offset;

        err = drm_legacy_addbufs_agp(dev, &req);
        if (err) {
                DRM_ERROR("Unable to add secondary DMA buffers: %d\n", err);
                return err;
        }

        {
                struct drm_map_list *_entry;
                unsigned long agp_token = 0;

                list_for_each_entry(_entry, &dev->maplist, head) {
                        if (_entry->map == dev->agp_buffer_map)
                                agp_token = _entry->user_token;
                }
                if (!agp_token)
                        return -EFAULT;

                dev->agp_buffer_token = agp_token;
        }

        offset += secondary_size;
        err = drm_legacy_addmap(dev, offset, agp_size - offset,
                                _DRM_AGP, 0, &dev_priv->agp_textures);
        if (err) {
                DRM_ERROR("Unable to map AGP texture region %d\n", err);
                return err;
        }

        drm_legacy_ioremap(dev_priv->warp, dev);
        drm_legacy_ioremap(dev_priv->primary, dev);
        drm_legacy_ioremap(dev->agp_buffer_map, dev);

        if (!dev_priv->warp->handle ||
            !dev_priv->primary->handle || !dev->agp_buffer_map->handle) {
                DRM_ERROR("failed to ioremap agp regions! (%p, %p, %p)\n",
                          dev_priv->warp->handle, dev_priv->primary->handle,
                          dev->agp_buffer_map->handle);
                return -ENOMEM;
        }

        dev_priv->dma_access = MGA_PAGPXFER;
        dev_priv->wagp_enable = MGA_WAGP_ENABLE;

        DRM_INFO("Initialized card for AGP DMA.\n");
        return 0;
}
#else
static int mga_do_agp_dma_bootstrap(struct drm_device *dev,
                                    drm_mga_dma_bootstrap_t *dma_bs)
{
        return -EINVAL;
}
#endif

/**
 * Bootstrap the driver for PCI DMA.
 *
 * \todo
 * The algorithm for decreasing the size of the primary DMA buffer could be
 * better.  The size should be rounded up to the nearest page size, then
 * decrease the request size by a single page each pass through the loop.
 *
 * \todo
 * Determine whether the maximum address passed to drm_pci_alloc is correct.
 * The same goes for drm_legacy_addbufs_pci.
 *
 * \sa mga_do_dma_bootstrap, mga_do_agp_dma_bootstrap
 */
static int mga_do_pci_dma_bootstrap(struct drm_device *dev,
                                    drm_mga_dma_bootstrap_t *dma_bs)
{
        drm_mga_private_t *const dev_priv =
            (drm_mga_private_t *) dev->dev_private;
        unsigned int warp_size = MGA_WARP_UCODE_SIZE;
        unsigned int primary_size;
        unsigned int bin_count;
        int err;
        struct drm_buf_desc req;

        if (dev->dma == NULL) {
                DRM_ERROR("dev->dma is NULL\n");
                return -EFAULT;
        }

        /* Make drm_legacy_addbufs happy by not trying to create a mapping for
         * less than a page.
         */
        if (warp_size < PAGE_SIZE)
                warp_size = PAGE_SIZE;

        /* The proper alignment is 0x100 for this mapping */
        err = drm_legacy_addmap(dev, 0, warp_size, _DRM_CONSISTENT,
                                _DRM_READ_ONLY, &dev_priv->warp);
        if (err != 0) {
                DRM_ERROR("Unable to create mapping for WARP microcode: %d\n",
                          err);
                return err;
        }

        /* Other than the bottom two bits being used to encode other
         * information, there don't appear to be any restrictions on the
         * alignment of the primary or secondary DMA buffers.
         */

        for (primary_size = dma_bs->primary_size; primary_size != 0;
             primary_size >>= 1) {
                /* The proper alignment for this mapping is 0x04 */
                err = drm_legacy_addmap(dev, 0, primary_size, _DRM_CONSISTENT,
                                        _DRM_READ_ONLY, &dev_priv->primary);
                if (!err)
                        break;
        }

        if (err != 0) {
                DRM_ERROR("Unable to allocate primary DMA region: %d\n", err);
                return -ENOMEM;
        }

        if (dev_priv->primary->size != dma_bs->primary_size) {
                DRM_INFO("Primary DMA buffer size reduced from %u to %u.\n",
                         dma_bs->primary_size,
                         (unsigned)dev_priv->primary->size);
                dma_bs->primary_size = dev_priv->primary->size;
        }

        for (bin_count = dma_bs->secondary_bin_count; bin_count > 0;
             bin_count--) {
                (void)memset(&req, 0, sizeof(req));
                req.count = bin_count;
                req.size = dma_bs->secondary_bin_size;

                err = drm_legacy_addbufs_pci(dev, &req);
                if (!err)
                        break;
        }

        if (bin_count == 0) {
                DRM_ERROR("Unable to add secondary DMA buffers: %d\n", err);
                return err;
        }

        if (bin_count != dma_bs->secondary_bin_count) {
                DRM_INFO("Secondary PCI DMA buffer bin count reduced from %u "
                         "to %u.\n", dma_bs->secondary_bin_count, bin_count);

                dma_bs->secondary_bin_count = bin_count;
        }

        dev_priv->dma_access = 0;
        dev_priv->wagp_enable = 0;

        dma_bs->agp_mode = 0;

        DRM_INFO("Initialized card for PCI DMA.\n");
        return 0;
}

static int mga_do_dma_bootstrap(struct drm_device *dev,
                                drm_mga_dma_bootstrap_t *dma_bs)
{
        const int is_agp = (dma_bs->agp_mode != 0) && drm_pci_device_is_agp(dev);
        int err;
        drm_mga_private_t *const dev_priv =
            (drm_mga_private_t *) dev->dev_private;

        dev_priv->used_new_dma_init = 1;

        /* The first steps are the same for both PCI and AGP based DMA.  Map
         * the cards MMIO registers and map a status page.
         */
        err = drm_legacy_addmap(dev, dev_priv->mmio_base, dev_priv->mmio_size,
                                _DRM_REGISTERS, _DRM_READ_ONLY,
                                &dev_priv->mmio);
        if (err) {
                DRM_ERROR("Unable to map MMIO region: %d\n", err);
                return err;
        }

        err = drm_legacy_addmap(dev, 0, SAREA_MAX, _DRM_SHM,
                                _DRM_READ_ONLY | _DRM_LOCKED | _DRM_KERNEL,
                         &dev_priv->status);
        if (err) {
                DRM_ERROR("Unable to map status region: %d\n", err);
                return err;
        }

        /* The DMA initialization procedure is slightly different for PCI and
         * AGP cards.  AGP cards just allocate a large block of AGP memory and
         * carve off portions of it for internal uses.  The remaining memory
         * is returned to user-mode to be used for AGP textures.
         */
        if (is_agp)
                err = mga_do_agp_dma_bootstrap(dev, dma_bs);

        /* If we attempted to initialize the card for AGP DMA but failed,
         * clean-up any mess that may have been created.
         */

        if (err)
                mga_do_cleanup_dma(dev, MINIMAL_CLEANUP);

        /* Not only do we want to try and initialized PCI cards for PCI DMA,
         * but we also try to initialized AGP cards that could not be
         * initialized for AGP DMA.  This covers the case where we have an AGP
         * card in a system with an unsupported AGP chipset.  In that case the
         * card will be detected as AGP, but we won't be able to allocate any
         * AGP memory, etc.
         */

        if (!is_agp || err)
                err = mga_do_pci_dma_bootstrap(dev, dma_bs);

        return err;
}

int mga_dma_bootstrap(struct drm_device *dev, void *data,
                      struct drm_file *file_priv)
{
        drm_mga_dma_bootstrap_t *bootstrap = data;
        int err;
        static const int modes[] = { 0, 1, 2, 2, 4, 4, 4, 4 };
        const drm_mga_private_t *const dev_priv =
                (drm_mga_private_t *) dev->dev_private;

        err = mga_do_dma_bootstrap(dev, bootstrap);
        if (err) {
                mga_do_cleanup_dma(dev, FULL_CLEANUP);
                return err;
        }

        if (dev_priv->agp_textures != NULL) {
                bootstrap->texture_handle = dev_priv->agp_textures->offset;
                bootstrap->texture_size = dev_priv->agp_textures->size;
        } else {
                bootstrap->texture_handle = 0;
                bootstrap->texture_size = 0;
        }

        bootstrap->agp_mode = modes[bootstrap->agp_mode & 0x07];

        return err;
}

static int mga_do_init_dma(struct drm_device *dev, drm_mga_init_t *init)
{
        drm_mga_private_t *dev_priv;
        int ret;
        DRM_DEBUG("\n");

        dev_priv = dev->dev_private;

        if (init->sgram)
                dev_priv->clear_cmd = MGA_DWGCTL_CLEAR | MGA_ATYPE_BLK;
        else
                dev_priv->clear_cmd = MGA_DWGCTL_CLEAR | MGA_ATYPE_RSTR;
        dev_priv->maccess = init->maccess;

        dev_priv->fb_cpp = init->fb_cpp;
        dev_priv->front_offset = init->front_offset;
        dev_priv->front_pitch = init->front_pitch;
        dev_priv->back_offset = init->back_offset;
        dev_priv->back_pitch = init->back_pitch;

        dev_priv->depth_cpp = init->depth_cpp;
        dev_priv->depth_offset = init->depth_offset;
        dev_priv->depth_pitch = init->depth_pitch;

        /* FIXME: Need to support AGP textures...
         */
        dev_priv->texture_offset = init->texture_offset[0];
        dev_priv->texture_size = init->texture_size[0];

        dev_priv->sarea = drm_legacy_getsarea(dev);
        if (!dev_priv->sarea) {
                DRM_ERROR("failed to find sarea!\n");
                return -EINVAL;
        }

        if (!dev_priv->used_new_dma_init) {

                dev_priv->dma_access = MGA_PAGPXFER;
                dev_priv->wagp_enable = MGA_WAGP_ENABLE;

                dev_priv->status = drm_legacy_findmap(dev, init->status_offset);
                if (!dev_priv->status) {
                        DRM_ERROR("failed to find status page!\n");
                        return -EINVAL;
                }
                dev_priv->mmio = drm_legacy_findmap(dev, init->mmio_offset);
                if (!dev_priv->mmio) {
                        DRM_ERROR("failed to find mmio region!\n");
                        return -EINVAL;
                }
                dev_priv->warp = drm_legacy_findmap(dev, init->warp_offset);
                if (!dev_priv->warp) {
                        DRM_ERROR("failed to find warp microcode region!\n");
                        return -EINVAL;
                }
                dev_priv->primary = drm_legacy_findmap(dev, init->primary_offset);
                if (!dev_priv->primary) {
                        DRM_ERROR("failed to find primary dma region!\n");
                        return -EINVAL;
                }
                dev->agp_buffer_token = init->buffers_offset;
                dev->agp_buffer_map =
                    drm_legacy_findmap(dev, init->buffers_offset);
                if (!dev->agp_buffer_map) {
                        DRM_ERROR("failed to find dma buffer region!\n");
                        return -EINVAL;
                }

                drm_legacy_ioremap(dev_priv->warp, dev);
                drm_legacy_ioremap(dev_priv->primary, dev);
                drm_legacy_ioremap(dev->agp_buffer_map, dev);
        }

        dev_priv->sarea_priv =
            (drm_mga_sarea_t *) ((u8 *) dev_priv->sarea->handle +
                                 init->sarea_priv_offset);

        if (!dev_priv->warp->handle ||
            !dev_priv->primary->handle ||
            ((dev_priv->dma_access != 0) &&
             ((dev->agp_buffer_map == NULL) ||
              (dev->agp_buffer_map->handle == NULL)))) {
                DRM_ERROR("failed to ioremap agp regions!\n");
                return -ENOMEM;
        }

        ret = mga_warp_install_microcode(dev_priv);
        if (ret < 0) {
                DRM_ERROR("failed to install WARP ucode!: %d\n", ret);
                return ret;
        }

        ret = mga_warp_init(dev_priv);
        if (ret < 0) {
                DRM_ERROR("failed to init WARP engine!: %d\n", ret);
                return ret;
        }

        dev_priv->prim.status = (u32 *) dev_priv->status->handle;

        mga_do_wait_for_idle(dev_priv);

        /* Init the primary DMA registers.
         */
        MGA_WRITE(MGA_PRIMADDRESS, dev_priv->primary->offset | MGA_DMA_GENERAL);
#if 0
        MGA_WRITE(MGA_PRIMPTR, virt_to_bus((void *)dev_priv->prim.status) | MGA_PRIMPTREN0 |    /* Soft trap, SECEND, SETUPEND */
                  MGA_PRIMPTREN1);      /* DWGSYNC */
#endif

        dev_priv->prim.start = (u8 *) dev_priv->primary->handle;
        dev_priv->prim.end = ((u8 *) dev_priv->primary->handle
                              + dev_priv->primary->size);
        dev_priv->prim.size = dev_priv->primary->size;

        dev_priv->prim.tail = 0;
        dev_priv->prim.space = dev_priv->prim.size;
        dev_priv->prim.wrapped = 0;

        dev_priv->prim.last_flush = 0;
        dev_priv->prim.last_wrap = 0;

        dev_priv->prim.high_mark = 256 * DMA_BLOCK_SIZE;

        dev_priv->prim.status[0] = dev_priv->primary->offset;
        dev_priv->prim.status[1] = 0;

        dev_priv->sarea_priv->last_wrap = 0;
        dev_priv->sarea_priv->last_frame.head = 0;
        dev_priv->sarea_priv->last_frame.wrap = 0;

        if (mga_freelist_init(dev, dev_priv) < 0) {
                DRM_ERROR("could not initialize freelist\n");
                return -ENOMEM;
        }

        return 0;
}

static int mga_do_cleanup_dma(struct drm_device *dev, int full_cleanup)
{
        int err = 0;
        DRM_DEBUG("\n");

        /* Make sure interrupts are disabled here because the uninstall ioctl
         * may not have been called from userspace and after dev_private
         * is freed, it's too late.
         */
        if (dev->irq_enabled)
                drm_irq_uninstall(dev);

        if (dev->dev_private) {
                drm_mga_private_t *dev_priv = dev->dev_private;

                if ((dev_priv->warp != NULL)
                    && (dev_priv->warp->type != _DRM_CONSISTENT))
                        drm_legacy_ioremapfree(dev_priv->warp, dev);

                if ((dev_priv->primary != NULL)
                    && (dev_priv->primary->type != _DRM_CONSISTENT))
                        drm_legacy_ioremapfree(dev_priv->primary, dev);

                if (dev->agp_buffer_map != NULL)
                        drm_legacy_ioremapfree(dev->agp_buffer_map, dev);

                if (dev_priv->used_new_dma_init) {
#if IS_ENABLED(CONFIG_AGP)
                        if (dev_priv->agp_handle != 0) {
                                struct drm_agp_binding unbind_req;
                                struct drm_agp_buffer free_req;

                                unbind_req.handle = dev_priv->agp_handle;
                                drm_agp_unbind(dev, &unbind_req);

                                free_req.handle = dev_priv->agp_handle;
                                drm_agp_free(dev, &free_req);

                                dev_priv->agp_textures = NULL;
                                dev_priv->agp_size = 0;
                                dev_priv->agp_handle = 0;
                        }

                        if ((dev->agp != NULL) && dev->agp->acquired)
                                err = drm_agp_release(dev);
#endif
                }

                dev_priv->warp = NULL;
                dev_priv->primary = NULL;
                dev_priv->sarea = NULL;
                dev_priv->sarea_priv = NULL;
                dev->agp_buffer_map = NULL;

                if (full_cleanup) {
                        dev_priv->mmio = NULL;
                        dev_priv->status = NULL;
                        dev_priv->used_new_dma_init = 0;
                }

                memset(&dev_priv->prim, 0, sizeof(dev_priv->prim));
                dev_priv->warp_pipe = 0;
                memset(dev_priv->warp_pipe_phys, 0,
                       sizeof(dev_priv->warp_pipe_phys));

                if (dev_priv->head != NULL)
                        mga_freelist_cleanup(dev);
        }

        return err;
}

int mga_dma_init(struct drm_device *dev, void *data,
                 struct drm_file *file_priv)
{
        drm_mga_init_t *init = data;
        int err;

        LOCK_TEST_WITH_RETURN(dev, file_priv);

        switch (init->func) {
        case MGA_INIT_DMA:
                err = mga_do_init_dma(dev, init);
                if (err)
                        (void)mga_do_cleanup_dma(dev, FULL_CLEANUP);
                return err;
        case MGA_CLEANUP_DMA:
                return mga_do_cleanup_dma(dev, FULL_CLEANUP);
        }

        return -EINVAL;
}

/* ================================================================
 * Primary DMA stream management
 */

int mga_dma_flush(struct drm_device *dev, void *data,
                  struct drm_file *file_priv)
{
        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
        struct drm_lock *lock = data;

        LOCK_TEST_WITH_RETURN(dev, file_priv);

        DRM_DEBUG("%s%s%s\n",
                  (lock->flags & _DRM_LOCK_FLUSH) ? "flush, " : "",
                  (lock->flags & _DRM_LOCK_FLUSH_ALL) ? "flush all, " : "",
                  (lock->flags & _DRM_LOCK_QUIESCENT) ? "idle, " : "");

        WRAP_WAIT_WITH_RETURN(dev_priv);

        if (lock->flags & (_DRM_LOCK_FLUSH | _DRM_LOCK_FLUSH_ALL))
                mga_do_dma_flush(dev_priv);

        if (lock->flags & _DRM_LOCK_QUIESCENT) {
#if MGA_DMA_DEBUG
                int ret = mga_do_wait_for_idle(dev_priv);
                if (ret < 0)
                        DRM_INFO("-EBUSY\n");
                return ret;
#else
                return mga_do_wait_for_idle(dev_priv);
#endif
        } else {
                return 0;
        }
}

int mga_dma_reset(struct drm_device *dev, void *data,
                  struct drm_file *file_priv)
{
        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;

        LOCK_TEST_WITH_RETURN(dev, file_priv);

        return mga_do_dma_reset(dev_priv);
}

/* ================================================================
 * DMA buffer management
 */

static int mga_dma_get_buffers(struct drm_device *dev,
                               struct drm_file *file_priv, struct drm_dma *d)
{
        struct drm_buf *buf;
        int i;

        for (i = d->granted_count; i < d->request_count; i++) {
                buf = mga_freelist_get(dev);
                if (!buf)
                        return -EAGAIN;

                buf->file_priv = file_priv;

                if (copy_to_user(&d->request_indices[i],
                                     &buf->idx, sizeof(buf->idx)))
                        return -EFAULT;
                if (copy_to_user(&d->request_sizes[i],
                                     &buf->total, sizeof(buf->total)))
                        return -EFAULT;

                d->granted_count++;
        }
        return 0;
}

int mga_dma_buffers(struct drm_device *dev, void *data,
                    struct drm_file *file_priv)
{
        struct drm_device_dma *dma = dev->dma;
        drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
        struct drm_dma *d = data;
        int ret = 0;

        LOCK_TEST_WITH_RETURN(dev, file_priv);

        /* Please don't send us buffers.
         */
        if (d->send_count != 0) {
                DRM_ERROR("Process %d trying to send %d buffers via drmDMA\n",
                          DRM_CURRENTPID, d->send_count);
                return -EINVAL;
        }

        /* We'll send you buffers.
         */
        if (d->request_count < 0 || d->request_count > dma->buf_count) {
                DRM_ERROR("Process %d trying to get %d buffers (of %d max)\n",
                          DRM_CURRENTPID, d->request_count, dma->buf_count);
                return -EINVAL;
        }

        WRAP_TEST_WITH_RETURN(dev_priv);

        d->granted_count = 0;

        if (d->request_count)
                ret = mga_dma_get_buffers(dev, file_priv, d);

        return ret;
}

/**
 * Called just before the module is unloaded.
 */
int mga_driver_unload(struct drm_device *dev)
{
        kfree(dev->dev_private);
        dev->dev_private = NULL;

        return 0;
}

/**
 * Called when the last opener of the device is closed.
 */
void mga_driver_lastclose(struct drm_device *dev)
{
        mga_do_cleanup_dma(dev, FULL_CLEANUP);
}

int mga_driver_dma_quiescent(struct drm_device *dev)
{
        drm_mga_private_t *dev_priv = dev->dev_private;
        return mga_do_wait_for_idle(dev_priv);
}