[PATCH] drm: another mga bug

[linux-2.6/pdupreez.git] / drivers / char / drm / drm_vm.c

/**
 * \file drm_vm.h
 * Memory mapping for DRM
 * 
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.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
 * 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 "drmP.h"
#if defined(__ia64__)
#include <linux/efi.h>
#endif

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

/**
 * \c nopage method for AGP virtual memory.
 *
 * \param vma virtual memory area.
 * \param address access address.
 * \return pointer to the page structure.
 * 
 * Find the right map and if it's AGP memory find the real physical page to
 * map, get the page, increment the use count and return it.
 */
#if __OS_HAS_AGP
static __inline__ struct page *drm_do_vm_nopage(struct vm_area_struct *vma,
                                                 unsigned long address)
{
        drm_file_t *priv  = vma->vm_file->private_data;
        drm_device_t *dev = priv->head->dev;
        drm_map_t *map    = NULL;
        drm_map_list_t  *r_list;
        struct list_head *list;

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

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

        list_for_each(list, &dev->maplist->head) {
                r_list = list_entry(list, drm_map_list_t, head);
                map = r_list->map;
                if (!map) continue;
                if (r_list->user_token == VM_OFFSET(vma))
                        break;
        }

        if (map && map->type == _DRM_AGP) {
                unsigned long offset = address - vma->vm_start;
                unsigned long 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
                 */
                for(agpmem = dev->agp->memory; agpmem; agpmem = agpmem->next) {
                        if (agpmem->bound <= baddr &&
                            agpmem->bound + agpmem->pages * PAGE_SIZE > baddr) 
                                break;
                }

                if (!agpmem) goto vm_nopage_error;

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

                DRM_DEBUG("baddr = 0x%lx page = 0x%p, offset = 0x%lx, count=%d\n",
                          baddr, __va(agpmem->memory->memory[offset]), offset,
                          page_count(page));

                return page;
        }
vm_nopage_error:
        return NOPAGE_SIGBUS;           /* Disallow mremap */
}
#else /* __OS_HAS_AGP */
static __inline__ struct page *drm_do_vm_nopage(struct vm_area_struct *vma,
                                                 unsigned long address)
{
        return NOPAGE_SIGBUS;
}
#endif /* __OS_HAS_AGP */

/**
 * \c nopage method for shared virtual memory.
 *
 * \param vma virtual memory area.
 * \param address access address.
 * \return pointer to the page structure.
 * 
 * Get the the mapping, find the real physical page to map, get the page, and
 * return it.
 */
static __inline__ struct page *drm_do_vm_shm_nopage(struct vm_area_struct *vma,
                                                     unsigned long address)
{
        drm_map_t        *map    = (drm_map_t *)vma->vm_private_data;
        unsigned long    offset;
        unsigned long    i;
        struct page      *page;

        if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
        if (!map)                  return NOPAGE_OOM;  /* Nothing allocated */

        offset   = address - vma->vm_start;
        i = (unsigned long)map->handle + offset;
        page = (map->type == _DRM_CONSISTENT) ?
                virt_to_page((void *)i) : vmalloc_to_page((void *)i);
        if (!page)
                return NOPAGE_OOM;
        get_page(page);

        DRM_DEBUG("shm_nopage 0x%lx\n", address);
        return page;
}


/**
 * \c close method for shared virtual memory.
 * 
 * \param vma virtual memory area.
 * 
 * Deletes map information if we are the last
 * person to close a mapping and it's not in the global maplist.
 */
static void drm_vm_shm_close(struct vm_area_struct *vma)
{
        drm_file_t      *priv   = vma->vm_file->private_data;
        drm_device_t    *dev    = priv->head->dev;
        drm_vma_entry_t *pt, *prev, *next;
        drm_map_t *map;
        drm_map_list_t *r_list;
        struct list_head *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;

        down(&dev->struct_sem);
        for (pt = dev->vmalist, prev = NULL; pt; pt = next) {
                next = pt->next;
                if (pt->vma->vm_private_data == map) found_maps++;
                if (pt->vma == vma) {
                        if (prev) {
                                prev->next = pt->next;
                        } else {
                                dev->vmalist = pt->next;
                        }
                        drm_free(pt, sizeof(*pt), DRM_MEM_VMAS);
                } else {
                        prev = 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 = &dev->maplist->head;
                list_for_each(list, &dev->maplist->head) {
                        r_list = list_entry(list, drm_map_list_t, 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);
                                }
                                drm_ioremapfree(map->handle, map->size, dev);
                                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;
                        }
                        drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                }
        }
        up(&dev->struct_sem);
}

/**
 * \c nopage method for DMA virtual memory.
 *
 * \param vma virtual memory area.
 * \param address access address.
 * \return pointer to the page structure.
 * 
 * Determine the page number from the page offset and get it from drm_device_dma::pagelist.
 */
static __inline__ struct page *drm_do_vm_dma_nopage(struct vm_area_struct *vma,
                                                     unsigned long address)
{
        drm_file_t       *priv   = vma->vm_file->private_data;
        drm_device_t     *dev    = priv->head->dev;
        drm_device_dma_t *dma    = dev->dma;
        unsigned long    offset;
        unsigned long    page_nr;
        struct page      *page;

        if (!dma)                  return NOPAGE_SIGBUS; /* Error */
        if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
        if (!dma->pagelist)        return NOPAGE_OOM ; /* Nothing allocated */

        offset   = address - vma->vm_start; /* vm_[pg]off[set] should be 0 */
        page_nr  = offset >> PAGE_SHIFT;
        page = virt_to_page((dma->pagelist[page_nr] + 
                             (offset & (~PAGE_MASK))));

        get_page(page);

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

/**
 * \c nopage method for scatter-gather virtual memory.
 *
 * \param vma virtual memory area.
 * \param address access address.
 * \return pointer to the page structure.
 * 
 * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist.
 */
static __inline__ struct page *drm_do_vm_sg_nopage(struct vm_area_struct *vma,
                                                    unsigned long address)
{
        drm_map_t        *map    = (drm_map_t *)vma->vm_private_data;
        drm_file_t *priv = vma->vm_file->private_data;
        drm_device_t *dev = priv->head->dev;
        drm_sg_mem_t *entry = dev->sg;
        unsigned long offset;
        unsigned long map_offset;
        unsigned long page_offset;
        struct page *page;

        if (!entry)                return NOPAGE_SIGBUS; /* Error */
        if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
        if (!entry->pagelist)      return NOPAGE_OOM ;  /* Nothing allocated */


        offset = 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);

        return page;
}


static struct page *drm_vm_nopage(struct vm_area_struct *vma,
                                   unsigned long address,
                                   int *type) {
        if (type) *type = VM_FAULT_MINOR;
        return drm_do_vm_nopage(vma, address);
}

static struct page *drm_vm_shm_nopage(struct vm_area_struct *vma,
                                       unsigned long address,
                                       int *type) {
        if (type) *type = VM_FAULT_MINOR;
        return drm_do_vm_shm_nopage(vma, address);
}

static struct page *drm_vm_dma_nopage(struct vm_area_struct *vma,
                                       unsigned long address,
                                       int *type) {
        if (type) *type = VM_FAULT_MINOR;
        return drm_do_vm_dma_nopage(vma, address);
}

static struct page *drm_vm_sg_nopage(struct vm_area_struct *vma,
                                      unsigned long address,
                                      int *type) {
        if (type) *type = VM_FAULT_MINOR;
        return drm_do_vm_sg_nopage(vma, address);
}

/** AGP virtual memory operations */
static struct vm_operations_struct   drm_vm_ops = {
        .nopage = drm_vm_nopage,
        .open   = drm_vm_open,
        .close  = drm_vm_close,
};

/** Shared virtual memory operations */
static struct vm_operations_struct   drm_vm_shm_ops = {
        .nopage = drm_vm_shm_nopage,
        .open   = drm_vm_open,
        .close  = drm_vm_shm_close,
};

/** DMA virtual memory operations */
static struct vm_operations_struct   drm_vm_dma_ops = {
        .nopage = drm_vm_dma_nopage,
        .open   = drm_vm_open,
        .close  = drm_vm_close,
};

/** Scatter-gather virtual memory operations */
static struct vm_operations_struct   drm_vm_sg_ops = {
        .nopage = drm_vm_sg_nopage,
        .open   = drm_vm_open,
        .close  = drm_vm_close,
};


/**
 * \c open method for shared virtual memory.
 * 
 * \param vma virtual memory area.
 * 
 * Create a new drm_vma_entry structure as the \p vma private data entry and
 * add it to drm_device::vmalist.
 */
static void drm_vm_open(struct vm_area_struct *vma)
{
        drm_file_t      *priv   = vma->vm_file->private_data;
        drm_device_t    *dev    = priv->head->dev;
        drm_vma_entry_t *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 = drm_alloc(sizeof(*vma_entry), DRM_MEM_VMAS);
        if (vma_entry) {
                down(&dev->struct_sem);
                vma_entry->vma  = vma;
                vma_entry->next = dev->vmalist;
                vma_entry->pid  = current->pid;
                dev->vmalist    = vma_entry;
                up(&dev->struct_sem);
        }
}

/**
 * \c close method for all virtual memory types.
 * 
 * \param vma virtual memory area.
 * 
 * Search the \p vma private data entry in drm_device::vmalist, unlink it, and
 * free it.
 */
static void drm_vm_close(struct vm_area_struct *vma)
{
        drm_file_t      *priv   = vma->vm_file->private_data;
        drm_device_t    *dev    = priv->head->dev;
        drm_vma_entry_t *pt, *prev;

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

        down(&dev->struct_sem);
        for (pt = dev->vmalist, prev = NULL; pt; prev = pt, pt = pt->next) {
                if (pt->vma == vma) {
                        if (prev) {
                                prev->next = pt->next;
                        } else {
                                dev->vmalist = pt->next;
                        }
                        drm_free(pt, sizeof(*pt), DRM_MEM_VMAS);
                        break;
                }
        }
        up(&dev->struct_sem);
}

/**
 * mmap DMA memory.
 *
 * \param filp file pointer.
 * \param vma virtual memory area.
 * \return zero on success or a negative number on failure.
 * 
 * Sets the virtual memory area operations structure to vm_dma_ops, the file
 * pointer, and calls vm_open().
 */
static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
{
        drm_file_t       *priv   = filp->private_data;
        drm_device_t     *dev;
        drm_device_dma_t *dma;
        unsigned long    length  = vma->vm_end - vma->vm_start;

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

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

        vma->vm_ops   = &drm_vm_dma_ops;

        vma->vm_flags |= VM_RESERVED; /* Don't swap */

        vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
        drm_vm_open(vma);
        return 0;
}

unsigned long drm_core_get_map_ofs(drm_map_t *map)
{
        return map->offset;
}
EXPORT_SYMBOL(drm_core_get_map_ofs);

unsigned long drm_core_get_reg_ofs(struct drm_device *dev)
{
#ifdef __alpha__
        return dev->hose->dense_mem_base - dev->hose->mem_space->start;
#else
        return 0;
#endif
}
EXPORT_SYMBOL(drm_core_get_reg_ofs);

/**
 * mmap DMA memory.
 *
 * \param filp file pointer.
 * \param vma virtual memory area.
 * \return zero on success or a negative number on failure.
 * 
 * If the virtual memory area has no offset associated with it then it's a DMA
 * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist,
 * checks that the restricted flag is not set, sets the virtual memory operations
 * according to the mapping type and remaps the pages. Finally sets the file
 * pointer and calls vm_open().
 */
int drm_mmap(struct file *filp, struct vm_area_struct *vma)
{
        drm_file_t      *priv   = filp->private_data;
        drm_device_t    *dev    = priv->head->dev;
        drm_map_t       *map    = NULL;
        drm_map_list_t  *r_list;
        unsigned long   offset  = 0;
        struct list_head *list;

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

        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 (!VM_OFFSET(vma)
#if __OS_HAS_AGP
            && (!dev->agp || dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
#endif
            )
                return drm_mmap_dma(filp, vma);

                                /* A sequential search of a linked list is
                                   fine here because: 1) there will only be
                                   about 5-10 entries in the list and, 2) a
                                   DRI client only has to do this mapping
                                   once, so it doesn't have to be optimized
                                   for performance, even if the list was a
                                   bit longer. */
        list_for_each(list, &dev->maplist->head) {

                r_list = list_entry(list, drm_map_list_t, head);
                map = r_list->map;
                if (!map) continue;
                if (r_list->user_token == VM_OFFSET(vma))
                        break;
        }

        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) {
        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 nopage()
                 */
#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... */        
        case _DRM_FRAME_BUFFER:
        case _DRM_REGISTERS:
#if defined(__i386__) || defined(__x86_64__)
                if (boot_cpu_data.x86 > 3 && map->type != _DRM_AGP) {
                        pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
                        pgprot_val(vma->vm_page_prot) &= ~_PAGE_PWT;
                }
#elif defined(__powerpc__)
                pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
                if (map->type == _DRM_REGISTERS)
                        pgprot_val(vma->vm_page_prot) |= _PAGE_GUARDED;
#endif
                vma->vm_flags |= VM_IO; /* not in core dump */
#if defined(__ia64__)
                if (efi_range_is_wc(vma->vm_start, vma->vm_end -
                                    vma->vm_start))
                        vma->vm_page_prot =
                                pgprot_writecombine(vma->vm_page_prot);
                else
                        vma->vm_page_prot =
                                pgprot_noncached(vma->vm_page_prot);
#endif
                offset = dev->driver->get_reg_ofs(dev);
#ifdef __sparc__
                if (io_remap_pfn_range(DRM_RPR_ARG(vma) vma->vm_start,
                                        (map->offset + offset) >> PAGE_SHIFT,
                                        vma->vm_end - vma->vm_start,
                                        vma->vm_page_prot))
#else
                if (io_remap_pfn_range(vma, vma->vm_start,
                                     (map->offset + offset) >> PAGE_SHIFT,
                                     vma->vm_end - vma->vm_start,
                                     vma->vm_page_prot))
#endif
                                return -EAGAIN;
                DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
                          " offset = 0x%lx\n",
                          map->type,
                          vma->vm_start, vma->vm_end, map->offset + offset);
                vma->vm_ops = &drm_vm_ops;
                break;
        case _DRM_SHM:
        case _DRM_CONSISTENT:
                /* Consistent memory is really like shared memory. It's only
                 * allocate in a different way */
                vma->vm_ops = &drm_vm_shm_ops;
                vma->vm_private_data = (void *)map;
                                /* Don't let this area swap.  Change when
                                   DRM_KERNEL advisory is supported. */
                vma->vm_flags |= VM_RESERVED;
                break;
        case _DRM_SCATTER_GATHER:
                vma->vm_ops = &drm_vm_sg_ops;
                vma->vm_private_data = (void *)map;
                vma->vm_flags |= VM_RESERVED;
                break;
        default:
                return -EINVAL; /* This should never happen. */
        }
        vma->vm_flags |= VM_RESERVED; /* Don't swap */

        vma->vm_file  =  filp;  /* Needed for drm_vm_open() */
        drm_vm_open(vma);
        return 0;
}
EXPORT_SYMBOL(drm_mmap);