drm/ttm: Fix up io_mem_reserve / io_mem_free calling
This patch attempts to fix up shortcomings with the current calling
sequences.
1) There's a fastpath where no locking occurs and only io_mem_reserved is
called to obtain needed info for mapping. The fastpath is set per
memory type manager.
2) If the fastpath is disabled, io_mem_reserve and io_mem_free will be exactly
balanced and not called recursively for the same struct ttm_mem_reg.
3) Optionally the driver can choose to enable a per memory type manager LRU
eviction mechanism that, when io_mem_reserve returns -EAGAIN will attempt
to kill user-space mappings of memory in that manager to free up needed
resources
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 25e4c2a..cf2ec56 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -378,8 +378,13 @@
int ret = 0;
if (old_is_pci || new_is_pci ||
- ((mem->placement & bo->mem.placement & TTM_PL_MASK_CACHING) == 0))
- ttm_bo_unmap_virtual(bo);
+ ((mem->placement & bo->mem.placement & TTM_PL_MASK_CACHING) == 0)) {
+ ret = ttm_mem_io_lock(old_man, true);
+ if (unlikely(ret != 0))
+ goto out_err;
+ ttm_bo_unmap_virtual_locked(bo);
+ ttm_mem_io_unlock(old_man);
+ }
/*
* Create and bind a ttm if required.
@@ -466,7 +471,6 @@
ttm_tt_destroy(bo->ttm);
bo->ttm = NULL;
}
-
ttm_bo_mem_put(bo, &bo->mem);
atomic_set(&bo->reserved, 0);
@@ -665,6 +669,7 @@
struct ttm_buffer_object *bo =
container_of(kref, struct ttm_buffer_object, kref);
struct ttm_bo_device *bdev = bo->bdev;
+ struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
if (likely(bo->vm_node != NULL)) {
rb_erase(&bo->vm_rb, &bdev->addr_space_rb);
@@ -672,6 +677,9 @@
bo->vm_node = NULL;
}
write_unlock(&bdev->vm_lock);
+ ttm_mem_io_lock(man, false);
+ ttm_mem_io_free_vm(bo);
+ ttm_mem_io_unlock(man);
ttm_bo_cleanup_refs_or_queue(bo);
kref_put(&bo->list_kref, ttm_bo_release_list);
write_lock(&bdev->vm_lock);
@@ -728,7 +736,8 @@
evict_mem = bo->mem;
evict_mem.mm_node = NULL;
- evict_mem.bus.io_reserved = false;
+ evict_mem.bus.io_reserved_vm = false;
+ evict_mem.bus.io_reserved_count = 0;
placement.fpfn = 0;
placement.lpfn = 0;
@@ -1065,7 +1074,8 @@
mem.num_pages = bo->num_pages;
mem.size = mem.num_pages << PAGE_SHIFT;
mem.page_alignment = bo->mem.page_alignment;
- mem.bus.io_reserved = false;
+ mem.bus.io_reserved_vm = false;
+ mem.bus.io_reserved_count = 0;
/*
* Determine where to move the buffer.
*/
@@ -1184,6 +1194,7 @@
INIT_LIST_HEAD(&bo->lru);
INIT_LIST_HEAD(&bo->ddestroy);
INIT_LIST_HEAD(&bo->swap);
+ INIT_LIST_HEAD(&bo->io_reserve_lru);
bo->bdev = bdev;
bo->glob = bdev->glob;
bo->type = type;
@@ -1193,7 +1204,8 @@
bo->mem.num_pages = bo->num_pages;
bo->mem.mm_node = NULL;
bo->mem.page_alignment = page_alignment;
- bo->mem.bus.io_reserved = false;
+ bo->mem.bus.io_reserved_vm = false;
+ bo->mem.bus.io_reserved_count = 0;
bo->buffer_start = buffer_start & PAGE_MASK;
bo->priv_flags = 0;
bo->mem.placement = (TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED);
@@ -1367,6 +1379,10 @@
BUG_ON(type >= TTM_NUM_MEM_TYPES);
man = &bdev->man[type];
BUG_ON(man->has_type);
+ man->io_reserve_fastpath = true;
+ man->use_io_reserve_lru = false;
+ mutex_init(&man->io_reserve_mutex);
+ INIT_LIST_HEAD(&man->io_reserve_lru);
ret = bdev->driver->init_mem_type(bdev, type, man);
if (ret)
@@ -1574,7 +1590,7 @@
return true;
}
-void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
+void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo)
{
struct ttm_bo_device *bdev = bo->bdev;
loff_t offset = (loff_t) bo->addr_space_offset;
@@ -1583,8 +1599,20 @@
if (!bdev->dev_mapping)
return;
unmap_mapping_range(bdev->dev_mapping, offset, holelen, 1);
- ttm_mem_io_free(bdev, &bo->mem);
+ ttm_mem_io_free_vm(bo);
}
+
+void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo)
+{
+ struct ttm_bo_device *bdev = bo->bdev;
+ struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
+
+ ttm_mem_io_lock(man, false);
+ ttm_bo_unmap_virtual_locked(bo);
+ ttm_mem_io_unlock(man);
+}
+
+
EXPORT_SYMBOL(ttm_bo_unmap_virtual);
static void ttm_bo_vm_insert_rb(struct ttm_buffer_object *bo)