-static DEFINE_MUTEX(hmm_devmem_lock);
-static RADIX_TREE(hmm_devmem_radix, GFP_KERNEL);
-
-static void hmm_devmem_radix_release(struct resource *resource)
-{
- resource_size_t key;
-
- mutex_lock(&hmm_devmem_lock);
- for (key = resource->start;
- key <= resource->end;
- key += PA_SECTION_SIZE)
- radix_tree_delete(&hmm_devmem_radix, key >> PA_SECTION_SHIFT);
- mutex_unlock(&hmm_devmem_lock);
-}
-
-static void hmm_devmem_release(struct device *dev, void *data)
-{
- struct hmm_devmem *devmem = data;
- struct resource *resource = devmem->resource;
- unsigned long start_pfn, npages;
- struct zone *zone;
- struct page *page;
-
- if (percpu_ref_tryget_live(&devmem->ref)) {
- dev_WARN(dev, "%s: page mapping is still live!\n", __func__);
- percpu_ref_put(&devmem->ref);
- }
-
- /* pages are dead and unused, undo the arch mapping */
- start_pfn = (resource->start & ~(PA_SECTION_SIZE - 1)) >> PAGE_SHIFT;
- npages = ALIGN(resource_size(resource), PA_SECTION_SIZE) >> PAGE_SHIFT;
-
- page = pfn_to_page(start_pfn);
- zone = page_zone(page);
-
- mem_hotplug_begin();
- if (resource->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY)
- __remove_pages(zone, start_pfn, npages, NULL);
- else
- arch_remove_memory(start_pfn << PAGE_SHIFT,
- npages << PAGE_SHIFT, NULL);
- mem_hotplug_done();
-
- hmm_devmem_radix_release(resource);
-}
-
-static int hmm_devmem_pages_create(struct hmm_devmem *devmem)
-{
- resource_size_t key, align_start, align_size, align_end;
- struct device *device = devmem->device;
- int ret, nid, is_ram;
-
- align_start = devmem->resource->start & ~(PA_SECTION_SIZE - 1);
- align_size = ALIGN(devmem->resource->start +
- resource_size(devmem->resource),
- PA_SECTION_SIZE) - align_start;
-
- is_ram = region_intersects(align_start, align_size,
- IORESOURCE_SYSTEM_RAM,
- IORES_DESC_NONE);
- if (is_ram == REGION_MIXED) {
- WARN_ONCE(1, "%s attempted on mixed region %pr\n",
- __func__, devmem->resource);
- return -ENXIO;
- }
- if (is_ram == REGION_INTERSECTS)
- return -ENXIO;
-
- if (devmem->resource->desc == IORES_DESC_DEVICE_PUBLIC_MEMORY)
- devmem->pagemap.type = MEMORY_DEVICE_PUBLIC;
- else
- devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
-
- devmem->pagemap.res = *devmem->resource;
- devmem->pagemap.page_fault = hmm_devmem_fault;
- devmem->pagemap.page_free = hmm_devmem_free;
- devmem->pagemap.dev = devmem->device;
- devmem->pagemap.ref = &devmem->ref;
- devmem->pagemap.data = devmem;
-
- mutex_lock(&hmm_devmem_lock);
- align_end = align_start + align_size - 1;
- for (key = align_start; key <= align_end; key += PA_SECTION_SIZE) {
- struct hmm_devmem *dup;
-
- dup = radix_tree_lookup(&hmm_devmem_radix,
- key >> PA_SECTION_SHIFT);
- if (dup) {
- dev_err(device, "%s: collides with mapping for %s\n",
- __func__, dev_name(dup->device));
- mutex_unlock(&hmm_devmem_lock);
- ret = -EBUSY;
- goto error;
- }
- ret = radix_tree_insert(&hmm_devmem_radix,
- key >> PA_SECTION_SHIFT,
- devmem);
- if (ret) {
- dev_err(device, "%s: failed: %d\n", __func__, ret);
- mutex_unlock(&hmm_devmem_lock);
- goto error_radix;
- }
- }
- mutex_unlock(&hmm_devmem_lock);
-
- nid = dev_to_node(device);
- if (nid < 0)
- nid = numa_mem_id();
-
- mem_hotplug_begin();
- /*
- * For device private memory we call add_pages() as we only need to
- * allocate and initialize struct page for the device memory. More-
- * over the device memory is un-accessible thus we do not want to
- * create a linear mapping for the memory like arch_add_memory()
- * would do.
- *
- * For device public memory, which is accesible by the CPU, we do
- * want the linear mapping and thus use arch_add_memory().
- */
- if (devmem->pagemap.type == MEMORY_DEVICE_PUBLIC)
- ret = arch_add_memory(nid, align_start, align_size, NULL,
- false);
- else
- ret = add_pages(nid, align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, NULL, false);
- if (ret) {
- mem_hotplug_done();
- goto error_add_memory;
- }
- move_pfn_range_to_zone(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
- align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, NULL);
- mem_hotplug_done();
-
- /*
- * Initialization of the pages has been deferred until now in order
- * to allow us to do the work while not holding the hotplug lock.
- */
- memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
- align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, &devmem->pagemap);
-
- return 0;
-
-error_add_memory:
- untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
-error_radix:
- hmm_devmem_radix_release(devmem->resource);
-error:
- return ret;
-}
-
-static int hmm_devmem_match(struct device *dev, void *data, void *match_data)
-{
- struct hmm_devmem *devmem = data;
-
- return devmem->resource == match_data;
-}
-
-static void hmm_devmem_pages_remove(struct hmm_devmem *devmem)
-{
- devres_release(devmem->device, &hmm_devmem_release,
- &hmm_devmem_match, devmem->resource);
-}
-