On Thu, Oct 15, 2020 at 04:08:13PM +0200, Christian König wrote: > Am 15.10.20 um 14:38 schrieb Thomas Zimmermann: > > The new functions ttm_bo_{vmap,vunmap}() map and unmap a TTM BO in kernel > > address space. The mapping's address is returned as struct dma_buf_map. > > Each function is a simplified version of TTM's existing kmap code. Both > > functions respect the memory's location ani/or writecombine flags. > > > > On top TTM's functions, GEM TTM helpers got drm_gem_ttm_{vmap,vunmap}(), > > two helpers that convert a GEM object into the TTM BO and forward the call > > to TTM's vmap/vunmap. These helpers can be dropped into the rsp GEM object > > callbacks. > > > > v4: > > * drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel, > > Christian) > > Bunch of minor comments below, but over all look very solid to me.
Yeah I think just duplicating the ttm bo map stuff for vmap is indeed the cleanest. And then we can maybe push the combinatorial monster into vmwgfx, which I think is the only user after this series. Or perhaps a dedicated set of helpers to map an invidual page (again using the dma_buf_map stuff). I'll let Christian with the details, but at a high level this is definitely Acked-by: Daniel Vetter <daniel.vet...@ffwll.ch> Thanks a lot for doing all this. -Daniel > > > > > Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de> > > --- > > drivers/gpu/drm/drm_gem_ttm_helper.c | 38 +++++++++++++++ > > drivers/gpu/drm/ttm/ttm_bo_util.c | 72 ++++++++++++++++++++++++++++ > > include/drm/drm_gem_ttm_helper.h | 6 +++ > > include/drm/ttm/ttm_bo_api.h | 28 +++++++++++ > > include/linux/dma-buf-map.h | 20 ++++++++ > > 5 files changed, 164 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c > > b/drivers/gpu/drm/drm_gem_ttm_helper.c > > index 0e4fb9ba43ad..db4c14d78a30 100644 > > --- a/drivers/gpu/drm/drm_gem_ttm_helper.c > > +++ b/drivers/gpu/drm/drm_gem_ttm_helper.c > > @@ -49,6 +49,44 @@ void drm_gem_ttm_print_info(struct drm_printer *p, > > unsigned int indent, > > } > > EXPORT_SYMBOL(drm_gem_ttm_print_info); > > +/** > > + * drm_gem_ttm_vmap() - vmap &ttm_buffer_object > > + * @gem: GEM object. > > + * @map: [out] returns the dma-buf mapping. > > + * > > + * Maps a GEM object with ttm_bo_vmap(). This function can be used as > > + * &drm_gem_object_funcs.vmap callback. > > + * > > + * Returns: > > + * 0 on success, or a negative errno code otherwise. > > + */ > > +int drm_gem_ttm_vmap(struct drm_gem_object *gem, > > + struct dma_buf_map *map) > > +{ > > + struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem); > > + > > + return ttm_bo_vmap(bo, map); > > + > > +} > > +EXPORT_SYMBOL(drm_gem_ttm_vmap); > > + > > +/** > > + * drm_gem_ttm_vunmap() - vunmap &ttm_buffer_object > > + * @gem: GEM object. > > + * @map: dma-buf mapping. > > + * > > + * Unmaps a GEM object with ttm_bo_vunmap(). This function can be used as > > + * &drm_gem_object_funcs.vmap callback. > > + */ > > +void drm_gem_ttm_vunmap(struct drm_gem_object *gem, > > + struct dma_buf_map *map) > > +{ > > + struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem); > > + > > + ttm_bo_vunmap(bo, map); > > +} > > +EXPORT_SYMBOL(drm_gem_ttm_vunmap); > > + > > /** > > * drm_gem_ttm_mmap() - mmap &ttm_buffer_object > > * @gem: GEM object. > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c > > b/drivers/gpu/drm/ttm/ttm_bo_util.c > > index bdee4df1f3f2..80c42c774c7d 100644 > > --- a/drivers/gpu/drm/ttm/ttm_bo_util.c > > +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c > > @@ -32,6 +32,7 @@ > > #include <drm/ttm/ttm_bo_driver.h> > > #include <drm/ttm/ttm_placement.h> > > #include <drm/drm_vma_manager.h> > > +#include <linux/dma-buf-map.h> > > #include <linux/io.h> > > #include <linux/highmem.h> > > #include <linux/wait.h> > > @@ -526,6 +527,77 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map) > > } > > EXPORT_SYMBOL(ttm_bo_kunmap); > > +int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map) > > +{ > > + struct ttm_resource *mem = &bo->mem; > > + int ret; > > + > > + ret = ttm_mem_io_reserve(bo->bdev, mem); > > + if (ret) > > + return ret; > > + > > + if (mem->bus.is_iomem) { > > + void __iomem *vaddr_iomem; > > + unsigned long size = bo->num_pages << PAGE_SHIFT; > > Please use uint64_t here and make sure to cast bo->num_pages before > shifting. > > We have an unit tests of allocating a 8GB BO and that should work on a 32bit > machine as well :) > > > + > > + if (mem->bus.addr) > > + vaddr_iomem = (void *)(((u8 *)mem->bus.addr)); > > + else if (mem->placement & TTM_PL_FLAG_WC) > > I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new > mem->bus.caching enum as replacement. > > > + vaddr_iomem = ioremap_wc(mem->bus.offset, size); > > + else > > + vaddr_iomem = ioremap(mem->bus.offset, size); > > + > > + if (!vaddr_iomem) > > + return -ENOMEM; > > + > > + dma_buf_map_set_vaddr_iomem(map, vaddr_iomem); > > + > > + } else { > > + struct ttm_operation_ctx ctx = { > > + .interruptible = false, > > + .no_wait_gpu = false > > + }; > > + struct ttm_tt *ttm = bo->ttm; > > + pgprot_t prot; > > + void *vaddr; > > + > > + BUG_ON(!ttm); > > I think we can drop this, populate will just crash badly anyway. > > > + > > + ret = ttm_tt_populate(bo->bdev, ttm, &ctx); > > + if (ret) > > + return ret; > > + > > + /* > > + * We need to use vmap to get the desired page protection > > + * or to make the buffer object look contiguous. > > + */ > > + prot = ttm_io_prot(mem->placement, PAGE_KERNEL); > > The calling convention has changed on drm-misc-next as well, but should be > trivial to adapt. > > Regards, > Christian. > > > + vaddr = vmap(ttm->pages, bo->num_pages, 0, prot); > > + if (!vaddr) > > + return -ENOMEM; > > + > > + dma_buf_map_set_vaddr(map, vaddr); > > + } > > + > > + return 0; > > +} > > +EXPORT_SYMBOL(ttm_bo_vmap); > > + > > +void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map) > > +{ > > + if (dma_buf_map_is_null(map)) > > + return; > > + > > + if (map->is_iomem) > > + iounmap(map->vaddr_iomem); > > + else > > + vunmap(map->vaddr); > > + dma_buf_map_clear(map); > > + > > + ttm_mem_io_free(bo->bdev, &bo->mem); > > +} > > +EXPORT_SYMBOL(ttm_bo_vunmap); > > + > > static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo, > > bool dst_use_tt) > > { > > diff --git a/include/drm/drm_gem_ttm_helper.h > > b/include/drm/drm_gem_ttm_helper.h > > index 118cef76f84f..7c6d874910b8 100644 > > --- a/include/drm/drm_gem_ttm_helper.h > > +++ b/include/drm/drm_gem_ttm_helper.h > > @@ -10,11 +10,17 @@ > > #include <drm/ttm/ttm_bo_api.h> > > #include <drm/ttm/ttm_bo_driver.h> > > +struct dma_buf_map; > > + > > #define drm_gem_ttm_of_gem(gem_obj) \ > > container_of(gem_obj, struct ttm_buffer_object, base) > > void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent, > > const struct drm_gem_object *gem); > > +int drm_gem_ttm_vmap(struct drm_gem_object *gem, > > + struct dma_buf_map *map); > > +void drm_gem_ttm_vunmap(struct drm_gem_object *gem, > > + struct dma_buf_map *map); > > int drm_gem_ttm_mmap(struct drm_gem_object *gem, > > struct vm_area_struct *vma); > > diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h > > index 37102e45e496..2c59a785374c 100644 > > --- a/include/drm/ttm/ttm_bo_api.h > > +++ b/include/drm/ttm/ttm_bo_api.h > > @@ -48,6 +48,8 @@ struct ttm_bo_global; > > struct ttm_bo_device; > > +struct dma_buf_map; > > + > > struct drm_mm_node; > > struct ttm_placement; > > @@ -494,6 +496,32 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned > > long start_page, > > */ > > void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map); > > +/** > > + * ttm_bo_vmap > > + * > > + * @bo: The buffer object. > > + * @map: pointer to a struct dma_buf_map representing the map. > > + * > > + * Sets up a kernel virtual mapping, using ioremap or vmap to the > > + * data in the buffer object. The parameter @map returns the virtual > > + * address as struct dma_buf_map. Unmap the buffer with ttm_bo_vunmap(). > > + * > > + * Returns > > + * -ENOMEM: Out of memory. > > + * -EINVAL: Invalid range. > > + */ > > +int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map); > > + > > +/** > > + * ttm_bo_vunmap > > + * > > + * @bo: The buffer object. > > + * @map: Object describing the map to unmap. > > + * > > + * Unmaps a kernel map set up by ttm_bo_vmap(). > > + */ > > +void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map); > > + > > /** > > * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object. > > * > > diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h > > index fd1aba545fdf..2e8bbecb5091 100644 > > --- a/include/linux/dma-buf-map.h > > +++ b/include/linux/dma-buf-map.h > > @@ -45,6 +45,12 @@ > > * > > * dma_buf_map_set_vaddr(&map. 0xdeadbeaf); > > * > > + * To set an address in I/O memory, use dma_buf_map_set_vaddr_iomem(). > > + * > > + * .. code-block:: c > > + * > > + * dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf); > > + * > > * Test if a mapping is valid with either dma_buf_map_is_set() or > > * dma_buf_map_is_null(). > > * > > @@ -118,6 +124,20 @@ static inline void dma_buf_map_set_vaddr(struct > > dma_buf_map *map, void *vaddr) > > map->is_iomem = false; > > } > > +/** > > + * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an > > address in I/O memory > > + * @map: The dma-buf mapping structure > > + * @vaddr_iomem: An I/O-memory address > > + * > > + * Sets the address and the I/O-memory flag. > > + */ > > +static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map, > > + void __iomem *vaddr_iomem) > > +{ > > + map->vaddr_iomem = vaddr_iomem; > > + map->is_iomem = true; > > +} > > + > > /** > > * dma_buf_map_is_equal - Compares two dma-buf mapping structures for > > equality > > * @lhs: The dma-buf mapping structure > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch