drm_vm.c

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/*
 * Created: Mon Jan  4 08:58:31 1999 by [email protected]
 *
 * 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
 * VA LINUX SYSTEMS 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 <drm/drmP.h>
#include <linux/export.h>
#if defined(__ia64__)
#include <linux/efi.h>
#include <linux/slab.h>
#endif

static void drm_vm_open(struct vm_area_struct *vma);
static void drm_vm_close(struct vm_area_struct *vma);

static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
{
    pgprot_t tmp = vm_get_page_prot(vma->vm_flags);

#if defined(__i386__) || defined(__x86_64__)
    if (boot_cpu_data.x86 > 3 && map_type != _DRM_AGP) {
        pgprot_val(tmp) |= _PAGE_PCD;
        pgprot_val(tmp) &= ~_PAGE_PWT;
    }
#elif defined(__powerpc__)
    pgprot_val(tmp) |= _PAGE_NO_CACHE;
    if (map_type == _DRM_REGISTERS)
        pgprot_val(tmp) |= _PAGE_GUARDED;
#elif defined(__ia64__)
    if (efi_range_is_wc(vma->vm_start, vma->vm_end -
                    vma->vm_start))
        tmp = pgprot_writecombine(tmp);
    else
        tmp = pgprot_noncached(tmp);
#elif defined(__sparc__) || defined(__arm__) || defined(__mips__)
    tmp = pgprot_noncached(tmp);
#endif
    return tmp;
}

static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
{
    pgprot_t tmp = vm_get_page_prot(vma->vm_flags);

#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
    tmp |= _PAGE_NO_CACHE;
#endif
    return tmp;
}

#if __OS_HAS_AGP
static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    struct drm_file *priv = vma->vm_file->private_data;
    struct drm_device *dev = priv->minor->dev;
    struct drm_local_map *map = NULL;
    struct drm_map_list *r_list;
    struct drm_hash_item *hash;

    /*
     * Find the right map
     */
    if (!drm_core_has_AGP(dev))
        goto vm_fault_error;

    if (!dev->agp || !dev->agp->cant_use_aperture)
        goto vm_fault_error;

    if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash))
        goto vm_fault_error;

    r_list = drm_hash_entry(hash, struct drm_map_list, hash);
    map = r_list->map;

    if (map && map->type == _DRM_AGP) {
        /*
         * Using vm_pgoff as a selector forces us to use this unusual
         * addressing scheme.
         */
        resource_size_t offset = (unsigned long)vmf->virtual_address -
            vma->vm_start;
        resource_size_t baddr = map->offset + offset;
        struct drm_agp_mem *agpmem;
        struct page *page;

#ifdef __alpha__
        /*
         * Adjust to a bus-relative address
         */
        baddr -= dev->hose->mem_space->start;
#endif

        /*
         * It's AGP memory - find the real physical page to map
         */
        list_for_each_entry(agpmem, &dev->agp->memory, head) {
            if (agpmem->bound <= baddr &&
                agpmem->bound + agpmem->pages * PAGE_SIZE > baddr)
                break;
        }

        if (&agpmem->head == &dev->agp->memory)
            goto vm_fault_error;

        /*
         * Get the page, inc the use count, and return it
         */
        offset = (baddr - agpmem->bound) >> PAGE_SHIFT;
        page = agpmem->memory->pages[offset];
        get_page(page);
        vmf->page = page;

        DRM_DEBUG
            ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n",
             (unsigned long long)baddr,
             agpmem->memory->pages[offset],
             (unsigned long long)offset,
             page_count(page));
        return 0;
    }
vm_fault_error:
    return VM_FAULT_SIGBUS; /* Disallow mremap */
}
#else               /* __OS_HAS_AGP */
static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    return VM_FAULT_SIGBUS;
}
#endif              /* __OS_HAS_AGP */

static int drm_do_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    struct drm_local_map *map = vma->vm_private_data;
    unsigned long offset;
    unsigned long i;
    struct page *page;

    if (!map)
        return VM_FAULT_SIGBUS; /* Nothing allocated */

    offset = (unsigned long)vmf->virtual_address - vma->vm_start;
    i = (unsigned long)map->handle + offset;
    page = vmalloc_to_page((void *)i);
    if (!page)
        return VM_FAULT_SIGBUS;
    get_page(page);
    vmf->page = page;

    DRM_DEBUG("shm_fault 0x%lx\n", offset);
    return 0;
}

static void drm_vm_shm_close(struct vm_area_struct *vma)
{
    struct drm_file *priv = vma->vm_file->private_data;
    struct drm_device *dev = priv->minor->dev;
    struct drm_vma_entry *pt, *temp;
    struct drm_local_map *map;
    struct drm_map_list *r_list;
    int found_maps = 0;

    DRM_DEBUG("0x%08lx,0x%08lx\n",
          vma->vm_start, vma->vm_end - vma->vm_start);
    atomic_dec(&dev->vma_count);

    map = vma->vm_private_data;

    mutex_lock(&dev->struct_mutex);
    list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
        if (pt->vma->vm_private_data == map)
            found_maps++;
        if (pt->vma == vma) {
            list_del(&pt->head);
            kfree(pt);
        }
    }

    /* We were the only map that was found */
    if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
        /* Check to see if we are in the maplist, if we are not, then
         * we delete this mappings information.
         */
        found_maps = 0;
        list_for_each_entry(r_list, &dev->maplist, head) {
            if (r_list->map == map)
                found_maps++;
        }

        if (!found_maps) {
            drm_dma_handle_t dmah;

            switch (map->type) {
            case _DRM_REGISTERS:
            case _DRM_FRAME_BUFFER:
                if (drm_core_has_MTRR(dev) && map->mtrr >= 0) {
                    int retcode;
                    retcode = mtrr_del(map->mtrr,
                               map->offset,
                               map->size);
                    DRM_DEBUG("mtrr_del = %d\n", retcode);
                }
                iounmap(map->handle);
                break;
            case _DRM_SHM:
                vfree(map->handle);
                break;
            case _DRM_AGP:
            case _DRM_SCATTER_GATHER:
                break;
            case _DRM_CONSISTENT:
                dmah.vaddr = map->handle;
                dmah.busaddr = map->offset;
                dmah.size = map->size;
                __drm_pci_free(dev, &dmah);
                break;
            case _DRM_GEM:
                DRM_ERROR("tried to rmmap GEM object\n");
                break;
            }
            kfree(map);
        }
    }
    mutex_unlock(&dev->struct_mutex);
}

static int drm_do_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    struct drm_file *priv = vma->vm_file->private_data;
    struct drm_device *dev = priv->minor->dev;
    struct drm_device_dma *dma = dev->dma;
    unsigned long offset;
    unsigned long page_nr;
    struct page *page;

    if (!dma)
        return VM_FAULT_SIGBUS; /* Error */
    if (!dma->pagelist)
        return VM_FAULT_SIGBUS; /* Nothing allocated */

    offset = (unsigned long)vmf->virtual_address - vma->vm_start;   /* vm_[pg]off[set] should be 0 */
    page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
    page = virt_to_page((dma->pagelist[page_nr] + (offset & (~PAGE_MASK))));

    get_page(page);
    vmf->page = page;

    DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr);
    return 0;
}

static int drm_do_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    struct drm_local_map *map = vma->vm_private_data;
    struct drm_file *priv = vma->vm_file->private_data;
    struct drm_device *dev = priv->minor->dev;
    struct drm_sg_mem *entry = dev->sg;
    unsigned long offset;
    unsigned long map_offset;
    unsigned long page_offset;
    struct page *page;

    if (!entry)
        return VM_FAULT_SIGBUS; /* Error */
    if (!entry->pagelist)
        return VM_FAULT_SIGBUS; /* Nothing allocated */

    offset = (unsigned long)vmf->virtual_address - vma->vm_start;
    map_offset = map->offset - (unsigned long)dev->sg->virtual;
    page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
    page = entry->pagelist[page_offset];
    get_page(page);
    vmf->page = page;

    return 0;
}

static int drm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    return drm_do_vm_fault(vma, vmf);
}

static int drm_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    return drm_do_vm_shm_fault(vma, vmf);
}

static int drm_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    return drm_do_vm_dma_fault(vma, vmf);
}

static int drm_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
    return drm_do_vm_sg_fault(vma, vmf);
}

static const struct vm_operations_struct drm_vm_ops = {
    .fault = drm_vm_fault,
    .open = drm_vm_open,
    .close = drm_vm_close,
};

static const struct vm_operations_struct drm_vm_shm_ops = {
    .fault = drm_vm_shm_fault,
    .open = drm_vm_open,
    .close = drm_vm_shm_close,
};

static const struct vm_operations_struct drm_vm_dma_ops = {
    .fault = drm_vm_dma_fault,
    .open = drm_vm_open,
    .close = drm_vm_close,
};

static const struct vm_operations_struct drm_vm_sg_ops = {
    .fault = drm_vm_sg_fault,
    .open = drm_vm_open,
    .close = drm_vm_close,
};

void drm_vm_open_locked(struct drm_device *dev,
        struct vm_area_struct *vma)
{
    struct drm_vma_entry *vma_entry;

    DRM_DEBUG("0x%08lx,0x%08lx\n",
          vma->vm_start, vma->vm_end - vma->vm_start);
    atomic_inc(&dev->vma_count);

    vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
    if (vma_entry) {
        vma_entry->vma = vma;
        vma_entry->pid = current->pid;
        list_add(&vma_entry->head, &dev->vmalist);
    }
}

static void drm_vm_open(struct vm_area_struct *vma)
{
    struct drm_file *priv = vma->vm_file->private_data;
    struct drm_device *dev = priv->minor->dev;

    mutex_lock(&dev->struct_mutex);
    drm_vm_open_locked(dev, vma);
    mutex_unlock(&dev->struct_mutex);
}

void drm_vm_close_locked(struct drm_device *dev,
        struct vm_area_struct *vma)
{
    struct drm_vma_entry *pt, *temp;

    DRM_DEBUG("0x%08lx,0x%08lx\n",
          vma->vm_start, vma->vm_end - vma->vm_start);
    atomic_dec(&dev->vma_count);

    list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
        if (pt->vma == vma) {
            list_del(&pt->head);
            kfree(pt);
            break;
        }
    }
}

static void drm_vm_close(struct vm_area_struct *vma)
{
    struct drm_file *priv = vma->vm_file->private_data;
    struct drm_device *dev = priv->minor->dev;

    mutex_lock(&dev->struct_mutex);
    drm_vm_close_locked(dev, vma);
    mutex_unlock(&dev->struct_mutex);
}

static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
{
    struct drm_file *priv = filp->private_data;
    struct drm_device *dev;
    struct drm_device_dma *dma;
    unsigned long length = vma->vm_end - vma->vm_start;

    dev = priv->minor->dev;
    dma = dev->dma;
    DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
          vma->vm_start, vma->vm_end, vma->vm_pgoff);

    /* Length must match exact page count */
    if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
        return -EINVAL;
    }

    if (!capable(CAP_SYS_ADMIN) &&
        (dma->flags & _DRM_DMA_USE_PCI_RO)) {
        vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
#if defined(__i386__) || defined(__x86_64__)
        pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
#else
        /* Ye gads this is ugly.  With more thought
           we could move this up higher and use
           `protection_map' instead.  */
        vma->vm_page_prot =
            __pgprot(pte_val
                 (pte_wrprotect
                  (__pte(pgprot_val(vma->vm_page_prot)))));
#endif
    }

    vma->vm_ops = &drm_vm_dma_ops;

    vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;

    drm_vm_open_locked(dev, vma);
    return 0;
}

static resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
{
#ifdef __alpha__
    return dev->hose->dense_mem_base;
#else
    return 0;
#endif
}

int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
{
    struct drm_file *priv = filp->private_data;
    struct drm_device *dev = priv->minor->dev;
    struct drm_local_map *map = NULL;
    resource_size_t offset = 0;
    struct drm_hash_item *hash;

    DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
          vma->vm_start, vma->vm_end, vma->vm_pgoff);

    if (!priv->authenticated)
        return -EACCES;

    /* We check for "dma". On Apple's UniNorth, it's valid to have
     * the AGP mapped at physical address 0
     * --BenH.
     */
    if (!vma->vm_pgoff
#if __OS_HAS_AGP
        && (!dev->agp
        || dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
#endif
        )
        return drm_mmap_dma(filp, vma);

    if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) {
        DRM_ERROR("Could not find map\n");
        return -EINVAL;
    }

    map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
    if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
        return -EPERM;

    /* Check for valid size. */
    if (map->size < vma->vm_end - vma->vm_start)
        return -EINVAL;

    if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
        vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
#if defined(__i386__) || defined(__x86_64__)
        pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
#else
        /* Ye gads this is ugly.  With more thought
           we could move this up higher and use
           `protection_map' instead.  */
        vma->vm_page_prot =
            __pgprot(pte_val
                 (pte_wrprotect
                  (__pte(pgprot_val(vma->vm_page_prot)))));
#endif
    }

    switch (map->type) {
#if !defined(__arm__)
    case _DRM_AGP:
        if (drm_core_has_AGP(dev) && dev->agp->cant_use_aperture) {
            /*
             * On some platforms we can't talk to bus dma address from the CPU, so for
             * memory of type DRM_AGP, we'll deal with sorting out the real physical
             * pages and mappings in fault()
             */
#if defined(__powerpc__)
            pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
#endif
            vma->vm_ops = &drm_vm_ops;
            break;
        }
        /* fall through to _DRM_FRAME_BUFFER... */
#endif
    case _DRM_FRAME_BUFFER:
    case _DRM_REGISTERS:
        offset = drm_core_get_reg_ofs(dev);
        vma->vm_flags |= VM_IO; /* not in core dump */
        vma->vm_page_prot = drm_io_prot(map->type, vma);
        if (io_remap_pfn_range(vma, vma->vm_start,
                       (map->offset + offset) >> PAGE_SHIFT,
                       vma->vm_end - vma->vm_start,
                       vma->vm_page_prot))
            return -EAGAIN;
        DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
              " offset = 0x%llx\n",
              map->type,
              vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset));

        vma->vm_ops = &drm_vm_ops;
        break;
    case _DRM_CONSISTENT:
        /* Consistent memory is really like shared memory. But
         * it's allocated in a different way, so avoid fault */
        if (remap_pfn_range(vma, vma->vm_start,
            page_to_pfn(virt_to_page(map->handle)),
            vma->vm_end - vma->vm_start, vma->vm_page_prot))
            return -EAGAIN;
        vma->vm_page_prot = drm_dma_prot(map->type, vma);
    /* fall through to _DRM_SHM */
    case _DRM_SHM:
        vma->vm_ops = &drm_vm_shm_ops;
        vma->vm_private_data = (void *)map;
        break;
    case _DRM_SCATTER_GATHER:
        vma->vm_ops = &drm_vm_sg_ops;
        vma->vm_private_data = (void *)map;
        vma->vm_page_prot = drm_dma_prot(map->type, vma);
        break;
    default:
        return -EINVAL; /* This should never happen. */
    }
    vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;

    drm_vm_open_locked(dev, vma);
    return 0;
}

int drm_mmap(struct file *filp, struct vm_area_struct *vma)
{
    struct drm_file *priv = filp->private_data;
    struct drm_device *dev = priv->minor->dev;
    int ret;

    if (drm_device_is_unplugged(dev))
        return -ENODEV;

    mutex_lock(&dev->struct_mutex);
    ret = drm_mmap_locked(filp, vma);
    mutex_unlock(&dev->struct_mutex);

    return ret;
}
EXPORT_SYMBOL(drm_mmap);