1 files changed, 134 insertions, 0 deletions

diff --git a/drivers/char/drm/drm_memory.c b/drivers/char/drm/drm_memory.c
index dddf8de66143..7e3318e1d1c6 100644
--- a/drivers/char/drm/drm_memory.c
+++ b/drivers/char/drm/drm_memory.c
@@ -80,6 +80,71 @@ void *drm_realloc(void *oldpt, size_t oldsize, size_t size, int area)
 }
 
 #if __OS_HAS_AGP
+/*
+ * Find the drm_map that covers the range [offset, offset+size).
+ */
+static drm_map_t *drm_lookup_map(unsigned long offset,
+                                 unsigned long size, drm_device_t * dev)
+{
+        struct list_head *list;
+        drm_map_list_t *r_list;
+        drm_map_t *map;
+
+        list_for_each(list, &dev->maplist->head) {
+                r_list = (drm_map_list_t *) list;
+                map = r_list->map;
+                if (!map)
+                        continue;
+                if (map->offset <= offset
+                    && (offset + size) <= (map->offset + map->size))
+                        return map;
+        }
+        return NULL;
+}
+
+static void *agp_remap(unsigned long offset, unsigned long size,
+                       drm_device_t * dev)
+{
+        unsigned long *phys_addr_map, i, num_pages =
+            PAGE_ALIGN(size) / PAGE_SIZE;
+        struct drm_agp_mem *agpmem;
+        struct page **page_map;
+        void *addr;
+
+        size = PAGE_ALIGN(size);
+
+#ifdef __alpha__
+        offset -= dev->hose->mem_space->start;
+#endif
+
+        for (agpmem = dev->agp->memory; agpmem; agpmem = agpmem->next)
+                if (agpmem->bound <= offset
+                    && (agpmem->bound + (agpmem->pages << PAGE_SHIFT)) >=
+                    (offset + size))
+                        break;
+        if (!agpmem)
+                return NULL;
+
+        /*
+         * OK, we're mapping AGP space on a chipset/platform on which memory accesses by
+         * the CPU do not get remapped by the GART.  We fix this by using the kernel's
+         * page-table instead (that's probably faster anyhow...).
+         */
+        /* note: use vmalloc() because num_pages could be large... */
+        page_map = vmalloc(num_pages * sizeof(struct page *));
+        if (!page_map)
+                return NULL;
+
+        phys_addr_map =
+            agpmem->memory->memory + (offset - agpmem->bound) / PAGE_SIZE;
+        for (i = 0; i < num_pages; ++i)
+                page_map[i] = pfn_to_page(phys_addr_map[i] >> PAGE_SHIFT);
+        addr = vmap(page_map, num_pages, VM_IOREMAP, PAGE_AGP);
+        vfree(page_map);
+
+        return addr;
+}
+
 /** Wrapper around agp_allocate_memory() */
 DRM_AGP_MEM *drm_alloc_agp(drm_device_t * dev, int pages, u32 type)
 {
@@ -103,5 +168,74 @@ int drm_unbind_agp(DRM_AGP_MEM * handle)
 {
         return drm_agp_unbind_memory(handle);
 }
+
+#else  /*  __OS_HAS_AGP  */
+
+static inline drm_map_t *drm_lookup_map(unsigned long offset,
+                                        unsigned long size, drm_device_t * dev)
+{
+        return NULL;
+}
+
+static inline void *agp_remap(unsigned long offset, unsigned long size,
+                              drm_device_t * dev)
+{
+        return NULL;
+}
+
 #endif                          /* agp */
+
+void *drm_ioremap(unsigned long offset, unsigned long size,
+                                drm_device_t * dev)
+{
+        if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture) {
+                drm_map_t *map = drm_lookup_map(offset, size, dev);
+
+                if (map && map->type == _DRM_AGP)
+                        return agp_remap(offset, size, dev);
+        }
+        return ioremap(offset, size);
+}
+EXPORT_SYMBOL(drm_ioremap);
+
+#if 0
+void *drm_ioremap_nocache(unsigned long offset,
+                                        unsigned long size, drm_device_t * dev)
+{
+        if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture) {
+                drm_map_t *map = drm_lookup_map(offset, size, dev);
+
+                if (map && map->type == _DRM_AGP)
+                        return agp_remap(offset, size, dev);
+        }
+        return ioremap_nocache(offset, size);
+}
+#endif  /*  0  */
+
+void drm_ioremapfree(void *pt, unsigned long size,
+                                   drm_device_t * dev)
+{
+        /*
+         * This is a bit ugly.  It would be much cleaner if the DRM API would use separate
+         * routines for handling mappings in the AGP space.  Hopefully this can be done in
+         * a future revision of the interface...
+         */
+        if (drm_core_has_AGP(dev) && dev->agp && dev->agp->cant_use_aperture
+            && ((unsigned long)pt >= VMALLOC_START
+                && (unsigned long)pt < VMALLOC_END)) {
+                unsigned long offset;
+                drm_map_t *map;
+
+                offset = drm_follow_page(pt) | ((unsigned long)pt & ~PAGE_MASK);
+                map = drm_lookup_map(offset, size, dev);
+                if (map && map->type == _DRM_AGP) {
+                        vunmap(pt);
+                        return;
+                }
+        }
+
+        iounmap(pt);
+}
+EXPORT_SYMBOL(drm_ioremapfree);
+
 #endif                          /* debug_memory */