vmwgfx_gmr.c

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/**************************************************************************
 *
 * Copyright © 2009-2011 VMware, Inc., Palo Alto, CA., USA
 * 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, 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 "vmwgfx_drv.h"
#include <drm/drmP.h>
#include <drm/ttm/ttm_bo_driver.h>

#define VMW_PPN_SIZE sizeof(unsigned long)

static int vmw_gmr2_bind(struct vmw_private *dev_priv,
             struct page *pages[],
             unsigned long num_pages,
             int gmr_id)
{
    SVGAFifoCmdDefineGMR2 define_cmd;
    SVGAFifoCmdRemapGMR2 remap_cmd;
    uint32_t define_size = sizeof(define_cmd) + 4;
    uint32_t remap_size = VMW_PPN_SIZE * num_pages + sizeof(remap_cmd) + 4;
    uint32_t *cmd;
    uint32_t *cmd_orig;
    uint32_t i;

    cmd_orig = cmd = vmw_fifo_reserve(dev_priv, define_size + remap_size);
    if (unlikely(cmd == NULL))
        return -ENOMEM;

    define_cmd.gmrId = gmr_id;
    define_cmd.numPages = num_pages;

    remap_cmd.gmrId = gmr_id;
    remap_cmd.flags = (VMW_PPN_SIZE > sizeof(*cmd)) ?
        SVGA_REMAP_GMR2_PPN64 : SVGA_REMAP_GMR2_PPN32;
    remap_cmd.offsetPages = 0;
    remap_cmd.numPages = num_pages;

    *cmd++ = SVGA_CMD_DEFINE_GMR2;
    memcpy(cmd, &define_cmd, sizeof(define_cmd));
    cmd += sizeof(define_cmd) / sizeof(uint32);

    *cmd++ = SVGA_CMD_REMAP_GMR2;
    memcpy(cmd, &remap_cmd, sizeof(remap_cmd));
    cmd += sizeof(remap_cmd) / sizeof(uint32);

    for (i = 0; i < num_pages; ++i) {
        if (VMW_PPN_SIZE <= 4)
            *cmd = page_to_pfn(*pages++);
        else
            *((uint64_t *)cmd) = page_to_pfn(*pages++);

        cmd += VMW_PPN_SIZE / sizeof(*cmd);
    }

    vmw_fifo_commit(dev_priv, define_size + remap_size);

    return 0;
}

static void vmw_gmr2_unbind(struct vmw_private *dev_priv,
                int gmr_id)
{
    SVGAFifoCmdDefineGMR2 define_cmd;
    uint32_t define_size = sizeof(define_cmd) + 4;
    uint32_t *cmd;

    cmd = vmw_fifo_reserve(dev_priv, define_size);
    if (unlikely(cmd == NULL)) {
        DRM_ERROR("GMR2 unbind failed.\n");
        return;
    }
    define_cmd.gmrId = gmr_id;
    define_cmd.numPages = 0;

    *cmd++ = SVGA_CMD_DEFINE_GMR2;
    memcpy(cmd, &define_cmd, sizeof(define_cmd));

    vmw_fifo_commit(dev_priv, define_size);
}

static int vmw_gmr_build_descriptors(struct list_head *desc_pages,
                     struct page *pages[],
                     unsigned long num_pages)
{
    struct page *page, *next;
    struct svga_guest_mem_descriptor *page_virtual = NULL;
    struct svga_guest_mem_descriptor *desc_virtual = NULL;
    unsigned int desc_per_page;
    unsigned long prev_pfn;
    unsigned long pfn;
    int ret;

    desc_per_page = PAGE_SIZE /
        sizeof(struct svga_guest_mem_descriptor) - 1;

    while (likely(num_pages != 0)) {
        page = alloc_page(__GFP_HIGHMEM);
        if (unlikely(page == NULL)) {
            ret = -ENOMEM;
            goto out_err;
        }

        list_add_tail(&page->lru, desc_pages);

        /*
         * Point previous page terminating descriptor to this
         * page before unmapping it.
         */

        if (likely(page_virtual != NULL)) {
            desc_virtual->ppn = page_to_pfn(page);
            kunmap_atomic(page_virtual);
        }

        page_virtual = kmap_atomic(page);
        desc_virtual = page_virtual - 1;
        prev_pfn = ~(0UL);

        while (likely(num_pages != 0)) {
            pfn = page_to_pfn(*pages);

            if (pfn != prev_pfn + 1) {

                if (desc_virtual - page_virtual ==
                    desc_per_page - 1)
                    break;

                (++desc_virtual)->ppn = cpu_to_le32(pfn);
                desc_virtual->num_pages = cpu_to_le32(1);
            } else {
                uint32_t tmp =
                    le32_to_cpu(desc_virtual->num_pages);
                desc_virtual->num_pages = cpu_to_le32(tmp + 1);
            }
            prev_pfn = pfn;
            --num_pages;
            ++pages;
        }

        (++desc_virtual)->ppn = cpu_to_le32(0);
        desc_virtual->num_pages = cpu_to_le32(0);
    }

    if (likely(page_virtual != NULL))
        kunmap_atomic(page_virtual);

    return 0;
out_err:
    list_for_each_entry_safe(page, next, desc_pages, lru) {
        list_del_init(&page->lru);
        __free_page(page);
    }
    return ret;
}

static inline void vmw_gmr_free_descriptors(struct list_head *desc_pages)
{
    struct page *page, *next;

    list_for_each_entry_safe(page, next, desc_pages, lru) {
        list_del_init(&page->lru);
        __free_page(page);
    }
}

static void vmw_gmr_fire_descriptors(struct vmw_private *dev_priv,
                     int gmr_id, struct list_head *desc_pages)
{
    struct page *page;

    if (unlikely(list_empty(desc_pages)))
        return;

    page = list_entry(desc_pages->next, struct page, lru);

    mutex_lock(&dev_priv->hw_mutex);

    vmw_write(dev_priv, SVGA_REG_GMR_ID, gmr_id);
    wmb();
    vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, page_to_pfn(page));
    mb();

    mutex_unlock(&dev_priv->hw_mutex);

}

static unsigned long vmw_gmr_count_descriptors(struct page *pages[],
                    unsigned long num_pages)
{
    unsigned long prev_pfn = ~(0UL);
    unsigned long pfn;
    unsigned long descriptors = 0;

    while (num_pages--) {
        pfn = page_to_pfn(*pages++);
        if (prev_pfn + 1 != pfn)
            ++descriptors;
        prev_pfn = pfn;
    }

    return descriptors;
}

int vmw_gmr_bind(struct vmw_private *dev_priv,
         struct page *pages[],
         unsigned long num_pages,
         int gmr_id)
{
    struct list_head desc_pages;
    int ret;

    if (likely(dev_priv->capabilities & SVGA_CAP_GMR2))
        return vmw_gmr2_bind(dev_priv, pages, num_pages, gmr_id);

    if (unlikely(!(dev_priv->capabilities & SVGA_CAP_GMR)))
        return -EINVAL;

    if (vmw_gmr_count_descriptors(pages, num_pages) >
        dev_priv->max_gmr_descriptors)
        return -EINVAL;

    INIT_LIST_HEAD(&desc_pages);

    ret = vmw_gmr_build_descriptors(&desc_pages, pages, num_pages);
    if (unlikely(ret != 0))
        return ret;

    vmw_gmr_fire_descriptors(dev_priv, gmr_id, &desc_pages);
    vmw_gmr_free_descriptors(&desc_pages);

    return 0;
}


void vmw_gmr_unbind(struct vmw_private *dev_priv, int gmr_id)
{
    if (likely(dev_priv->capabilities & SVGA_CAP_GMR2)) {
        vmw_gmr2_unbind(dev_priv, gmr_id);
        return;
    }

    mutex_lock(&dev_priv->hw_mutex);
    vmw_write(dev_priv, SVGA_REG_GMR_ID, gmr_id);
    wmb();
    vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, 0);
    mb();
    mutex_unlock(&dev_priv->hw_mutex);
}