Thomas Zimmermann
2020-Oct-07 12:57 UTC
[Nouveau] [PATCH v3 2/7] drm/ttm: Add ttm_kmap_obj_to_dma_buf_map() for type conversion
Hi Am 02.10.20 um 11:58 schrieb Daniel Vetter:> On Wed, Sep 30, 2020 at 02:51:46PM +0200, Daniel Vetter wrote: >> On Wed, Sep 30, 2020 at 2:34 PM Christian K?nig >> <christian.koenig at amd.com> wrote: >>> >>> Am 30.09.20 um 11:47 schrieb Daniel Vetter: >>>> On Wed, Sep 30, 2020 at 10:34:31AM +0200, Christian K?nig wrote: >>>>> Am 30.09.20 um 10:19 schrieb Thomas Zimmermann: >>>>>> Hi >>>>>> >>>>>> Am 30.09.20 um 10:05 schrieb Christian K?nig: >>>>>>> Am 29.09.20 um 19:49 schrieb Thomas Zimmermann: >>>>>>>> Hi Christian >>>>>>>> >>>>>>>> Am 29.09.20 um 17:35 schrieb Christian K?nig: >>>>>>>>> Am 29.09.20 um 17:14 schrieb Thomas Zimmermann: >>>>>>>>>> The new helper ttm_kmap_obj_to_dma_buf() extracts address and location >>>>>>>>>> from and instance of TTM's kmap_obj and initializes struct dma_buf_map >>>>>>>>>> with these values. Helpful for TTM-based drivers. >>>>>>>>> We could completely drop that if we use the same structure inside TTM as >>>>>>>>> well. >>>>>>>>> >>>>>>>>> Additional to that which driver is going to use this? >>>>>>>> As Daniel mentioned, it's in patch 3. The TTM-based drivers will >>>>>>>> retrieve the pointer via this function. >>>>>>>> >>>>>>>> I do want to see all that being more tightly integrated into TTM, but >>>>>>>> not in this series. This one is about fixing the bochs-on-sparc64 >>>>>>>> problem for good. Patch 7 adds an update to TTM to the DRM TODO list. >>>>>>> I should have asked which driver you try to fix here :) >>>>>>> >>>>>>> In this case just keep the function inside bochs and only fix it there. >>>>>>> >>>>>>> All other drivers can be fixed when we generally pump this through TTM. >>>>>> Did you take a look at patch 3? This function will be used by VRAM >>>>>> helpers, nouveau, radeon, amdgpu and qxl. If we don't put it here, we >>>>>> have to duplicate the functionality in each if these drivers. Bochs >>>>>> itself uses VRAM helpers and doesn't touch the function directly. >>>>> Ah, ok can we have that then only in the VRAM helpers? >>>>> >>>>> Alternative you could go ahead and use dma_buf_map in ttm_bo_kmap_obj >>>>> directly and drop the hack with the TTM_BO_MAP_IOMEM_MASK. >>>>> >>>>> What I want to avoid is to have another conversion function in TTM because >>>>> what happens here is that we already convert from ttm_bus_placement to >>>>> ttm_bo_kmap_obj and then to dma_buf_map. >>>> Hm I'm not really seeing how that helps with a gradual conversion of >>>> everything over to dma_buf_map and assorted helpers for access? There's >>>> too many places in ttm drivers where is_iomem and related stuff is used to >>>> be able to convert it all in one go. An intermediate state with a bunch of >>>> conversions seems fairly unavoidable to me. >>> >>> Fair enough. I would just have started bottom up and not top down. >>> >>> Anyway feel free to go ahead with this approach as long as we can remove >>> the new function again when we clean that stuff up for good. >> >> Yeah I guess bottom up would make more sense as a refactoring. But the >> main motivation to land this here is to fix the __mmio vs normal >> memory confusion in the fbdev emulation helpers for sparc (and >> anything else that needs this). Hence the top down approach for >> rolling this out. > > Ok I started reviewing this a bit more in-depth, and I think this is a bit > too much of a de-tour. > > Looking through all the callers of ttm_bo_kmap almost everyone maps the > entire object. Only vmwgfx uses to map less than that. Also, everyone just > immediately follows up with converting that full object map into a > pointer. > > So I think what we really want here is: > - new function > > int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map); > > _vmap name since that's consistent with both dma_buf functions and > what's usually used to implement this. Outside of the ttm world kmap > usually just means single-page mappings using kmap() or it's iomem > sibling io_mapping_map* so rather confusing name for a function which > usually is just used to set up a vmap of the entire buffer. > > - a helper which can be used for the drm_gem_object_funcs vmap/vunmap > functions for all ttm drivers. We should be able to make this fully > generic because a) we now have dma_buf_map and b) drm_gem_object is > embedded in the ttm_bo, so we can upcast for everyone who's both a ttm > and gem driver. > > This is maybe a good follow-up, since it should allow us to ditch quite > a bit of the vram helper code for this more generic stuff. I also might > have missed some special-cases here, but from a quick look everything > just pins the buffer to the current location and that's it. > > Also this obviously requires Christian's generic ttm_bo_pin rework > first. > > - roll the above out to drivers. > > Christian/Thomas, thoughts on this?I agree on the goals, but what is the immediate objective here? Adding ttm_bo_vmap() does not work out easily, as struct ttm_bo_kmap_obj is a central part of the internals of TTM. struct ttm_bo_kmap_obj has more internal state that struct dma_buf_map, so they are not easily convertible either. What you propose seems to require a reimplementation of the existing ttm_bo_kmap() code. That is it's own patch series. I'd rather go with some variant of the existing patch and add ttm_bo_vmap() in a follow-up. Best regards Thomas> > I think for the immediate need of rolling this out for vram helpers and > fbdev code we should be able to do this, but just postpone the driver wide > roll-out for now. > > Cheers, Daniel > >> -Daniel >> >>> >>> Christian. >>> >>>> -Daniel >>>> >>>>> Thanks, >>>>> Christian. >>>>> >>>>>> Best regards >>>>>> Thomas >>>>>> >>>>>>> Regards, >>>>>>> Christian. >>>>>>> >>>>>>>> Best regards >>>>>>>> Thomas >>>>>>>> >>>>>>>>> Regards, >>>>>>>>> Christian. >>>>>>>>> >>>>>>>>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de> >>>>>>>>>> --- >>>>>>>>>> include/drm/ttm/ttm_bo_api.h | 24 ++++++++++++++++++++++++ >>>>>>>>>> include/linux/dma-buf-map.h | 20 ++++++++++++++++++++ >>>>>>>>>> 2 files changed, 44 insertions(+) >>>>>>>>>> >>>>>>>>>> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h >>>>>>>>>> index c96a25d571c8..62d89f05a801 100644 >>>>>>>>>> --- a/include/drm/ttm/ttm_bo_api.h >>>>>>>>>> +++ b/include/drm/ttm/ttm_bo_api.h >>>>>>>>>> @@ -34,6 +34,7 @@ >>>>>>>>>> #include <drm/drm_gem.h> >>>>>>>>>> #include <drm/drm_hashtab.h> >>>>>>>>>> #include <drm/drm_vma_manager.h> >>>>>>>>>> +#include <linux/dma-buf-map.h> >>>>>>>>>> #include <linux/kref.h> >>>>>>>>>> #include <linux/list.h> >>>>>>>>>> #include <linux/wait.h> >>>>>>>>>> @@ -486,6 +487,29 @@ static inline void *ttm_kmap_obj_virtual(struct >>>>>>>>>> ttm_bo_kmap_obj *map, >>>>>>>>>> return map->virtual; >>>>>>>>>> } >>>>>>>>>> +/** >>>>>>>>>> + * ttm_kmap_obj_to_dma_buf_map >>>>>>>>>> + * >>>>>>>>>> + * @kmap: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap. >>>>>>>>>> + * @map: Returns the mapping as struct dma_buf_map >>>>>>>>>> + * >>>>>>>>>> + * Converts struct ttm_bo_kmap_obj to struct dma_buf_map. If the memory >>>>>>>>>> + * is not mapped, the returned mapping is initialized to NULL. >>>>>>>>>> + */ >>>>>>>>>> +static inline void ttm_kmap_obj_to_dma_buf_map(struct ttm_bo_kmap_obj >>>>>>>>>> *kmap, >>>>>>>>>> + struct dma_buf_map *map) >>>>>>>>>> +{ >>>>>>>>>> + bool is_iomem; >>>>>>>>>> + void *vaddr = ttm_kmap_obj_virtual(kmap, &is_iomem); >>>>>>>>>> + >>>>>>>>>> + if (!vaddr) >>>>>>>>>> + dma_buf_map_clear(map); >>>>>>>>>> + else if (is_iomem) >>>>>>>>>> + dma_buf_map_set_vaddr_iomem(map, (void __force __iomem *)vaddr); >>>>>>>>>> + else >>>>>>>>>> + dma_buf_map_set_vaddr(map, vaddr); >>>>>>>>>> +} >>>>>>>>>> + >>>>>>>>>> /** >>>>>>>>>> * ttm_bo_kmap >>>>>>>>>> * >>>>>>>>>> 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 >>>>>>>>> _______________________________________________ >>>>>>>>> dri-devel mailing list >>>>>>>>> dri-devel at lists.freedesktop.org >>>>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=HdHOA%2F1VcIX%2F7YtfYTiAqYEvw7Ag%2FS%2BxS5VwJKOv5y0%3D&reserved=0 >>>>>>>> _______________________________________________ >>>>>>>> amd-gfx mailing list >>>>>>>> amd-gfx at lists.freedesktop.org >>>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfx&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=H%2B5HKCsTrksRV2EyEiFGSTyS79jsWCmJimSMoJYusx8%3D&reserved=0 >>>>>>> _______________________________________________ >>>>>>> dri-devel mailing list >>>>>>> dri-devel at lists.freedesktop.org >>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=HdHOA%2F1VcIX%2F7YtfYTiAqYEvw7Ag%2FS%2BxS5VwJKOv5y0%3D&reserved=0 >>>>>>> >>>>>> _______________________________________________ >>>>>> amd-gfx mailing list >>>>>> amd-gfx at lists.freedesktop.org >>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfx&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=H%2B5HKCsTrksRV2EyEiFGSTyS79jsWCmJimSMoJYusx8%3D&reserved=0 >>> >> >> >> -- >> Daniel Vetter >> Software Engineer, Intel Corporation >> http://blog.ffwll.ch >-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 N?rnberg, Germany (HRB 36809, AG N?rnberg) Gesch?ftsf?hrer: Felix Imend?rffer -------------- next part -------------- A non-text attachment was scrubbed... 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Daniel Vetter
2020-Oct-07 13:10 UTC
[Nouveau] [PATCH v3 2/7] drm/ttm: Add ttm_kmap_obj_to_dma_buf_map() for type conversion
On Wed, Oct 7, 2020 at 2:57 PM Thomas Zimmermann <tzimmermann at suse.de> wrote:> > Hi > > Am 02.10.20 um 11:58 schrieb Daniel Vetter: > > On Wed, Sep 30, 2020 at 02:51:46PM +0200, Daniel Vetter wrote: > >> On Wed, Sep 30, 2020 at 2:34 PM Christian K?nig > >> <christian.koenig at amd.com> wrote: > >>> > >>> Am 30.09.20 um 11:47 schrieb Daniel Vetter: > >>>> On Wed, Sep 30, 2020 at 10:34:31AM +0200, Christian K?nig wrote: > >>>>> Am 30.09.20 um 10:19 schrieb Thomas Zimmermann: > >>>>>> Hi > >>>>>> > >>>>>> Am 30.09.20 um 10:05 schrieb Christian K?nig: > >>>>>>> Am 29.09.20 um 19:49 schrieb Thomas Zimmermann: > >>>>>>>> Hi Christian > >>>>>>>> > >>>>>>>> Am 29.09.20 um 17:35 schrieb Christian K?nig: > >>>>>>>>> Am 29.09.20 um 17:14 schrieb Thomas Zimmermann: > >>>>>>>>>> The new helper ttm_kmap_obj_to_dma_buf() extracts address and location > >>>>>>>>>> from and instance of TTM's kmap_obj and initializes struct dma_buf_map > >>>>>>>>>> with these values. Helpful for TTM-based drivers. > >>>>>>>>> We could completely drop that if we use the same structure inside TTM as > >>>>>>>>> well. > >>>>>>>>> > >>>>>>>>> Additional to that which driver is going to use this? > >>>>>>>> As Daniel mentioned, it's in patch 3. The TTM-based drivers will > >>>>>>>> retrieve the pointer via this function. > >>>>>>>> > >>>>>>>> I do want to see all that being more tightly integrated into TTM, but > >>>>>>>> not in this series. This one is about fixing the bochs-on-sparc64 > >>>>>>>> problem for good. Patch 7 adds an update to TTM to the DRM TODO list. > >>>>>>> I should have asked which driver you try to fix here :) > >>>>>>> > >>>>>>> In this case just keep the function inside bochs and only fix it there. > >>>>>>> > >>>>>>> All other drivers can be fixed when we generally pump this through TTM. > >>>>>> Did you take a look at patch 3? This function will be used by VRAM > >>>>>> helpers, nouveau, radeon, amdgpu and qxl. If we don't put it here, we > >>>>>> have to duplicate the functionality in each if these drivers. Bochs > >>>>>> itself uses VRAM helpers and doesn't touch the function directly. > >>>>> Ah, ok can we have that then only in the VRAM helpers? > >>>>> > >>>>> Alternative you could go ahead and use dma_buf_map in ttm_bo_kmap_obj > >>>>> directly and drop the hack with the TTM_BO_MAP_IOMEM_MASK. > >>>>> > >>>>> What I want to avoid is to have another conversion function in TTM because > >>>>> what happens here is that we already convert from ttm_bus_placement to > >>>>> ttm_bo_kmap_obj and then to dma_buf_map. > >>>> Hm I'm not really seeing how that helps with a gradual conversion of > >>>> everything over to dma_buf_map and assorted helpers for access? There's > >>>> too many places in ttm drivers where is_iomem and related stuff is used to > >>>> be able to convert it all in one go. An intermediate state with a bunch of > >>>> conversions seems fairly unavoidable to me. > >>> > >>> Fair enough. I would just have started bottom up and not top down. > >>> > >>> Anyway feel free to go ahead with this approach as long as we can remove > >>> the new function again when we clean that stuff up for good. > >> > >> Yeah I guess bottom up would make more sense as a refactoring. But the > >> main motivation to land this here is to fix the __mmio vs normal > >> memory confusion in the fbdev emulation helpers for sparc (and > >> anything else that needs this). Hence the top down approach for > >> rolling this out. > > > > Ok I started reviewing this a bit more in-depth, and I think this is a bit > > too much of a de-tour. > > > > Looking through all the callers of ttm_bo_kmap almost everyone maps the > > entire object. Only vmwgfx uses to map less than that. Also, everyone just > > immediately follows up with converting that full object map into a > > pointer. > > > > So I think what we really want here is: > > - new function > > > > int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map); > > > > _vmap name since that's consistent with both dma_buf functions and > > what's usually used to implement this. Outside of the ttm world kmap > > usually just means single-page mappings using kmap() or it's iomem > > sibling io_mapping_map* so rather confusing name for a function which > > usually is just used to set up a vmap of the entire buffer. > > > > - a helper which can be used for the drm_gem_object_funcs vmap/vunmap > > functions for all ttm drivers. We should be able to make this fully > > generic because a) we now have dma_buf_map and b) drm_gem_object is > > embedded in the ttm_bo, so we can upcast for everyone who's both a ttm > > and gem driver. > > > > This is maybe a good follow-up, since it should allow us to ditch quite > > a bit of the vram helper code for this more generic stuff. I also might > > have missed some special-cases here, but from a quick look everything > > just pins the buffer to the current location and that's it. > > > > Also this obviously requires Christian's generic ttm_bo_pin rework > > first. > > > > - roll the above out to drivers. > > > > Christian/Thomas, thoughts on this? > > I agree on the goals, but what is the immediate objective here? > > Adding ttm_bo_vmap() does not work out easily, as struct ttm_bo_kmap_obj > is a central part of the internals of TTM. struct ttm_bo_kmap_obj has > more internal state that struct dma_buf_map, so they are not easily > convertible either. What you propose seems to require a reimplementation > of the existing ttm_bo_kmap() code. That is it's own patch series. > > I'd rather go with some variant of the existing patch and add > ttm_bo_vmap() in a follow-up.ttm_bo_vmap would simply wrap what you currently open-code as ttm_bo_kmap + ttm_kmap_obj_to_dma_buf_map. Removing ttm_kmap_obj would be a much later step. Why do you think adding ttm_bo_vmap is not possible? -Daniel> Best regards > Thomas > > > > > I think for the immediate need of rolling this out for vram helpers and > > fbdev code we should be able to do this, but just postpone the driver wide > > roll-out for now. > > > > Cheers, Daniel > > > >> -Daniel > >> > >>> > >>> Christian. > >>> > >>>> -Daniel > >>>> > >>>>> Thanks, > >>>>> Christian. > >>>>> > >>>>>> Best regards > >>>>>> Thomas > >>>>>> > >>>>>>> Regards, > >>>>>>> Christian. > >>>>>>> > >>>>>>>> Best regards > >>>>>>>> Thomas > >>>>>>>> > >>>>>>>>> Regards, > >>>>>>>>> Christian. > >>>>>>>>> > >>>>>>>>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de> > >>>>>>>>>> --- > >>>>>>>>>> include/drm/ttm/ttm_bo_api.h | 24 ++++++++++++++++++++++++ > >>>>>>>>>> include/linux/dma-buf-map.h | 20 ++++++++++++++++++++ > >>>>>>>>>> 2 files changed, 44 insertions(+) > >>>>>>>>>> > >>>>>>>>>> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h > >>>>>>>>>> index c96a25d571c8..62d89f05a801 100644 > >>>>>>>>>> --- a/include/drm/ttm/ttm_bo_api.h > >>>>>>>>>> +++ b/include/drm/ttm/ttm_bo_api.h > >>>>>>>>>> @@ -34,6 +34,7 @@ > >>>>>>>>>> #include <drm/drm_gem.h> > >>>>>>>>>> #include <drm/drm_hashtab.h> > >>>>>>>>>> #include <drm/drm_vma_manager.h> > >>>>>>>>>> +#include <linux/dma-buf-map.h> > >>>>>>>>>> #include <linux/kref.h> > >>>>>>>>>> #include <linux/list.h> > >>>>>>>>>> #include <linux/wait.h> > >>>>>>>>>> @@ -486,6 +487,29 @@ static inline void *ttm_kmap_obj_virtual(struct > >>>>>>>>>> ttm_bo_kmap_obj *map, > >>>>>>>>>> return map->virtual; > >>>>>>>>>> } > >>>>>>>>>> +/** > >>>>>>>>>> + * ttm_kmap_obj_to_dma_buf_map > >>>>>>>>>> + * > >>>>>>>>>> + * @kmap: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap. > >>>>>>>>>> + * @map: Returns the mapping as struct dma_buf_map > >>>>>>>>>> + * > >>>>>>>>>> + * Converts struct ttm_bo_kmap_obj to struct dma_buf_map. If the memory > >>>>>>>>>> + * is not mapped, the returned mapping is initialized to NULL. > >>>>>>>>>> + */ > >>>>>>>>>> +static inline void ttm_kmap_obj_to_dma_buf_map(struct ttm_bo_kmap_obj > >>>>>>>>>> *kmap, > >>>>>>>>>> + struct dma_buf_map *map) > >>>>>>>>>> +{ > >>>>>>>>>> + bool is_iomem; > >>>>>>>>>> + void *vaddr = ttm_kmap_obj_virtual(kmap, &is_iomem); > >>>>>>>>>> + > >>>>>>>>>> + if (!vaddr) > >>>>>>>>>> + dma_buf_map_clear(map); > >>>>>>>>>> + else if (is_iomem) > >>>>>>>>>> + dma_buf_map_set_vaddr_iomem(map, (void __force __iomem *)vaddr); > >>>>>>>>>> + else > >>>>>>>>>> + dma_buf_map_set_vaddr(map, vaddr); > >>>>>>>>>> +} > >>>>>>>>>> + > >>>>>>>>>> /** > >>>>>>>>>> * ttm_bo_kmap > >>>>>>>>>> * > >>>>>>>>>> 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 > >>>>>>>>> _______________________________________________ > >>>>>>>>> dri-devel mailing list > >>>>>>>>> dri-devel at lists.freedesktop.org > >>>>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=HdHOA%2F1VcIX%2F7YtfYTiAqYEvw7Ag%2FS%2BxS5VwJKOv5y0%3D&reserved=0 > >>>>>>>> _______________________________________________ > >>>>>>>> amd-gfx mailing list > >>>>>>>> amd-gfx at lists.freedesktop.org > >>>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfx&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=H%2B5HKCsTrksRV2EyEiFGSTyS79jsWCmJimSMoJYusx8%3D&reserved=0 > >>>>>>> _______________________________________________ > >>>>>>> dri-devel mailing list > >>>>>>> dri-devel at lists.freedesktop.org > >>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=HdHOA%2F1VcIX%2F7YtfYTiAqYEvw7Ag%2FS%2BxS5VwJKOv5y0%3D&reserved=0 > >>>>>>> > >>>>>> _______________________________________________ > >>>>>> amd-gfx mailing list > >>>>>> amd-gfx at lists.freedesktop.org > >>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfx&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=H%2B5HKCsTrksRV2EyEiFGSTyS79jsWCmJimSMoJYusx8%3D&reserved=0 > >>> > >> > >> > >> -- > >> Daniel Vetter > >> Software Engineer, Intel Corporation > >> http://blog.ffwll.ch > > > > -- > Thomas Zimmermann > Graphics Driver Developer > SUSE Software Solutions Germany GmbH > Maxfeldstr. 5, 90409 N?rnberg, Germany > (HRB 36809, AG N?rnberg) > Gesch?ftsf?hrer: Felix Imend?rffer >-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
Thomas Zimmermann
2020-Oct-07 13:20 UTC
[Nouveau] [PATCH v3 2/7] drm/ttm: Add ttm_kmap_obj_to_dma_buf_map() for type conversion
Hi Am 07.10.20 um 15:10 schrieb Daniel Vetter:> On Wed, Oct 7, 2020 at 2:57 PM Thomas Zimmermann <tzimmermann at suse.de> wrote: >> >> Hi >> >> Am 02.10.20 um 11:58 schrieb Daniel Vetter: >>> On Wed, Sep 30, 2020 at 02:51:46PM +0200, Daniel Vetter wrote: >>>> On Wed, Sep 30, 2020 at 2:34 PM Christian K?nig >>>> <christian.koenig at amd.com> wrote: >>>>> >>>>> Am 30.09.20 um 11:47 schrieb Daniel Vetter: >>>>>> On Wed, Sep 30, 2020 at 10:34:31AM +0200, Christian K?nig wrote: >>>>>>> Am 30.09.20 um 10:19 schrieb Thomas Zimmermann: >>>>>>>> Hi >>>>>>>> >>>>>>>> Am 30.09.20 um 10:05 schrieb Christian K?nig: >>>>>>>>> Am 29.09.20 um 19:49 schrieb Thomas Zimmermann: >>>>>>>>>> Hi Christian >>>>>>>>>> >>>>>>>>>> Am 29.09.20 um 17:35 schrieb Christian K?nig: >>>>>>>>>>> Am 29.09.20 um 17:14 schrieb Thomas Zimmermann: >>>>>>>>>>>> The new helper ttm_kmap_obj_to_dma_buf() extracts address and location >>>>>>>>>>>> from and instance of TTM's kmap_obj and initializes struct dma_buf_map >>>>>>>>>>>> with these values. Helpful for TTM-based drivers. >>>>>>>>>>> We could completely drop that if we use the same structure inside TTM as >>>>>>>>>>> well. >>>>>>>>>>> >>>>>>>>>>> Additional to that which driver is going to use this? >>>>>>>>>> As Daniel mentioned, it's in patch 3. The TTM-based drivers will >>>>>>>>>> retrieve the pointer via this function. >>>>>>>>>> >>>>>>>>>> I do want to see all that being more tightly integrated into TTM, but >>>>>>>>>> not in this series. This one is about fixing the bochs-on-sparc64 >>>>>>>>>> problem for good. Patch 7 adds an update to TTM to the DRM TODO list. >>>>>>>>> I should have asked which driver you try to fix here :) >>>>>>>>> >>>>>>>>> In this case just keep the function inside bochs and only fix it there. >>>>>>>>> >>>>>>>>> All other drivers can be fixed when we generally pump this through TTM. >>>>>>>> Did you take a look at patch 3? This function will be used by VRAM >>>>>>>> helpers, nouveau, radeon, amdgpu and qxl. If we don't put it here, we >>>>>>>> have to duplicate the functionality in each if these drivers. Bochs >>>>>>>> itself uses VRAM helpers and doesn't touch the function directly. >>>>>>> Ah, ok can we have that then only in the VRAM helpers? >>>>>>> >>>>>>> Alternative you could go ahead and use dma_buf_map in ttm_bo_kmap_obj >>>>>>> directly and drop the hack with the TTM_BO_MAP_IOMEM_MASK. >>>>>>> >>>>>>> What I want to avoid is to have another conversion function in TTM because >>>>>>> what happens here is that we already convert from ttm_bus_placement to >>>>>>> ttm_bo_kmap_obj and then to dma_buf_map. >>>>>> Hm I'm not really seeing how that helps with a gradual conversion of >>>>>> everything over to dma_buf_map and assorted helpers for access? There's >>>>>> too many places in ttm drivers where is_iomem and related stuff is used to >>>>>> be able to convert it all in one go. An intermediate state with a bunch of >>>>>> conversions seems fairly unavoidable to me. >>>>> >>>>> Fair enough. I would just have started bottom up and not top down. >>>>> >>>>> Anyway feel free to go ahead with this approach as long as we can remove >>>>> the new function again when we clean that stuff up for good. >>>> >>>> Yeah I guess bottom up would make more sense as a refactoring. But the >>>> main motivation to land this here is to fix the __mmio vs normal >>>> memory confusion in the fbdev emulation helpers for sparc (and >>>> anything else that needs this). Hence the top down approach for >>>> rolling this out. >>> >>> Ok I started reviewing this a bit more in-depth, and I think this is a bit >>> too much of a de-tour. >>> >>> Looking through all the callers of ttm_bo_kmap almost everyone maps the >>> entire object. Only vmwgfx uses to map less than that. Also, everyone just >>> immediately follows up with converting that full object map into a >>> pointer. >>> >>> So I think what we really want here is: >>> - new function >>> >>> int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map); >>> >>> _vmap name since that's consistent with both dma_buf functions and >>> what's usually used to implement this. Outside of the ttm world kmap >>> usually just means single-page mappings using kmap() or it's iomem >>> sibling io_mapping_map* so rather confusing name for a function which >>> usually is just used to set up a vmap of the entire buffer. >>> >>> - a helper which can be used for the drm_gem_object_funcs vmap/vunmap >>> functions for all ttm drivers. We should be able to make this fully >>> generic because a) we now have dma_buf_map and b) drm_gem_object is >>> embedded in the ttm_bo, so we can upcast for everyone who's both a ttm >>> and gem driver. >>> >>> This is maybe a good follow-up, since it should allow us to ditch quite >>> a bit of the vram helper code for this more generic stuff. I also might >>> have missed some special-cases here, but from a quick look everything >>> just pins the buffer to the current location and that's it. >>> >>> Also this obviously requires Christian's generic ttm_bo_pin rework >>> first. >>> >>> - roll the above out to drivers. >>> >>> Christian/Thomas, thoughts on this? >> >> I agree on the goals, but what is the immediate objective here? >> >> Adding ttm_bo_vmap() does not work out easily, as struct ttm_bo_kmap_obj >> is a central part of the internals of TTM. struct ttm_bo_kmap_obj has >> more internal state that struct dma_buf_map, so they are not easily >> convertible either. What you propose seems to require a reimplementation >> of the existing ttm_bo_kmap() code. That is it's own patch series. >> >> I'd rather go with some variant of the existing patch and add >> ttm_bo_vmap() in a follow-up. > > ttm_bo_vmap would simply wrap what you currently open-code as > ttm_bo_kmap + ttm_kmap_obj_to_dma_buf_map. Removing ttm_kmap_obj would > be a much later step. Why do you think adding ttm_bo_vmap is not > possible?The calls to ttm_bo_kmap/_kunmap() require an instance of struct ttm_bo_kmap_obj that is stored in each driver's private bo structure (e.g., struct drm_gem_vram_object, struct radeon_bo, etc). When I made patch 3, I flirted with the idea of unifying the driver's _vmap code in a shared helper, but I couldn't find a simple way of doing it. That's why it's open-coded in the first place. Best regards Thomas> -Daniel > > >> Best regards >> Thomas >> >>> >>> I think for the immediate need of rolling this out for vram helpers and >>> fbdev code we should be able to do this, but just postpone the driver wide >>> roll-out for now. >>> >>> Cheers, Daniel >>> >>>> -Daniel >>>> >>>>> >>>>> Christian. >>>>> >>>>>> -Daniel >>>>>> >>>>>>> Thanks, >>>>>>> Christian. >>>>>>> >>>>>>>> Best regards >>>>>>>> Thomas >>>>>>>> >>>>>>>>> Regards, >>>>>>>>> Christian. >>>>>>>>> >>>>>>>>>> Best regards >>>>>>>>>> Thomas >>>>>>>>>> >>>>>>>>>>> Regards, >>>>>>>>>>> Christian. >>>>>>>>>>> >>>>>>>>>>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de> >>>>>>>>>>>> --- >>>>>>>>>>>> include/drm/ttm/ttm_bo_api.h | 24 ++++++++++++++++++++++++ >>>>>>>>>>>> include/linux/dma-buf-map.h | 20 ++++++++++++++++++++ >>>>>>>>>>>> 2 files changed, 44 insertions(+) >>>>>>>>>>>> >>>>>>>>>>>> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h >>>>>>>>>>>> index c96a25d571c8..62d89f05a801 100644 >>>>>>>>>>>> --- a/include/drm/ttm/ttm_bo_api.h >>>>>>>>>>>> +++ b/include/drm/ttm/ttm_bo_api.h >>>>>>>>>>>> @@ -34,6 +34,7 @@ >>>>>>>>>>>> #include <drm/drm_gem.h> >>>>>>>>>>>> #include <drm/drm_hashtab.h> >>>>>>>>>>>> #include <drm/drm_vma_manager.h> >>>>>>>>>>>> +#include <linux/dma-buf-map.h> >>>>>>>>>>>> #include <linux/kref.h> >>>>>>>>>>>> #include <linux/list.h> >>>>>>>>>>>> #include <linux/wait.h> >>>>>>>>>>>> @@ -486,6 +487,29 @@ static inline void *ttm_kmap_obj_virtual(struct >>>>>>>>>>>> ttm_bo_kmap_obj *map, >>>>>>>>>>>> return map->virtual; >>>>>>>>>>>> } >>>>>>>>>>>> +/** >>>>>>>>>>>> + * ttm_kmap_obj_to_dma_buf_map >>>>>>>>>>>> + * >>>>>>>>>>>> + * @kmap: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap. >>>>>>>>>>>> + * @map: Returns the mapping as struct dma_buf_map >>>>>>>>>>>> + * >>>>>>>>>>>> + * Converts struct ttm_bo_kmap_obj to struct dma_buf_map. If the memory >>>>>>>>>>>> + * is not mapped, the returned mapping is initialized to NULL. >>>>>>>>>>>> + */ >>>>>>>>>>>> +static inline void ttm_kmap_obj_to_dma_buf_map(struct ttm_bo_kmap_obj >>>>>>>>>>>> *kmap, >>>>>>>>>>>> + struct dma_buf_map *map) >>>>>>>>>>>> +{ >>>>>>>>>>>> + bool is_iomem; >>>>>>>>>>>> + void *vaddr = ttm_kmap_obj_virtual(kmap, &is_iomem); >>>>>>>>>>>> + >>>>>>>>>>>> + if (!vaddr) >>>>>>>>>>>> + dma_buf_map_clear(map); >>>>>>>>>>>> + else if (is_iomem) >>>>>>>>>>>> + dma_buf_map_set_vaddr_iomem(map, (void __force __iomem *)vaddr); >>>>>>>>>>>> + else >>>>>>>>>>>> + dma_buf_map_set_vaddr(map, vaddr); >>>>>>>>>>>> +} >>>>>>>>>>>> + >>>>>>>>>>>> /** >>>>>>>>>>>> * ttm_bo_kmap >>>>>>>>>>>> * >>>>>>>>>>>> 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 >>>>>>>>>>> _______________________________________________ >>>>>>>>>>> dri-devel mailing list >>>>>>>>>>> dri-devel at lists.freedesktop.org >>>>>>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=HdHOA%2F1VcIX%2F7YtfYTiAqYEvw7Ag%2FS%2BxS5VwJKOv5y0%3D&reserved=0 >>>>>>>>>> _______________________________________________ >>>>>>>>>> amd-gfx mailing list >>>>>>>>>> amd-gfx at lists.freedesktop.org >>>>>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfx&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=H%2B5HKCsTrksRV2EyEiFGSTyS79jsWCmJimSMoJYusx8%3D&reserved=0 >>>>>>>>> _______________________________________________ >>>>>>>>> dri-devel mailing list >>>>>>>>> dri-devel at lists.freedesktop.org >>>>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=HdHOA%2F1VcIX%2F7YtfYTiAqYEvw7Ag%2FS%2BxS5VwJKOv5y0%3D&reserved=0 >>>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> amd-gfx mailing list >>>>>>>> amd-gfx at lists.freedesktop.org >>>>>>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Famd-gfx&data=02%7C01%7Cchristian.koenig%40amd.com%7C472c3d655a61411deb6708d86525d1b8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370560438965013&sdata=H%2B5HKCsTrksRV2EyEiFGSTyS79jsWCmJimSMoJYusx8%3D&reserved=0 >>>>> >>>> >>>> >>>> -- >>>> Daniel Vetter >>>> Software Engineer, Intel Corporation >>>> http://blog.ffwll.ch >>> >> >> -- >> Thomas Zimmermann >> Graphics Driver Developer >> SUSE Software Solutions Germany GmbH >> Maxfeldstr. 5, 90409 N?rnberg, Germany >> (HRB 36809, AG N?rnberg) >> Gesch?ftsf?hrer: Felix Imend?rffer >> > >-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 N?rnberg, Germany (HRB 36809, AG N?rnberg) Gesch?ftsf?hrer: Felix Imend?rffer -------------- next part -------------- A non-text attachment was scrubbed... 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