On Mon, Nov 04, 2024 at 01:30:41PM -0800, Matthew Brost wrote: > On Mon, Nov 04, 2024 at 08:47:01PM +0100, Christian König wrote: > > Am 01.11.24 um 00:43 schrieb Matthew Brost: > > > On Thu, Oct 31, 2024 at 11:10:42AM -0700, Matthew Brost wrote: > > > > Non-contiguous VRAM cannot easily be mapped in TTM nor can non-visible > > > > VRAM easily be accessed. Add ttm_bo_access, which is similar to > > > > ttm_bo_vm_access, to access such memory. > > > > > > > > v4: > > > > - Fix checkpatch warnings (CI) > > > > v5: > > > > - Fix checkpatch warnings (CI) > > > > v6: > > > > - Fix kernel doc (Auld) > > > > > > > Christian - Do you mind if I merge patch along with the rest of the > > > series to drm-xe-next? > > > > I don't see the original patch anywhere in my inbox, please make sure to CC > > me while sending things out. > > > > I think I had you on an earlier revision but used the wrong alias to send out > this latest one. I will be sure to include you on future patches. > > Would you like to continue the discussion here, or should I send out a fresh > revision with you included and an updated commit message?
please send over a refreshed version with updated commit message and also cc'ing dri-devel > > > Apart from that I absolutely don't see any justification for this patch. You > > move stuff into ttm_bo_util.c which not even remotely belongs in there. > > > > The justification is that EuDebugger requires essentially the same > functionality > as ptrace -> vm_access. This patch simply adds a helper to achieve this. There > is no functional change to the existing code. > > Regarding the statement about ttm_bo_util.c, that seems quite aggressive. It > is > a TTM BO helper function, so it could logically belong in either ttm_bo.c or > ttm_bo_util.c. A BO helper definitely shouldn't call into ttm_bo_vm.c, nor > should it reside there. Perhaps I chose the wrong ttm_bo* file? I apologize > for > that. It would be helpful to know why you think this is the wrong place so I > can > better understand your expectations for TTM. I also believe that the ttm_bo_util seems a good place for that, but perhaps someone else has some other better ideas or suggestions there > > Matt > > > Regards, > > Christian. > > > > > > > > Matt > > > > > > > Reported-by: Christoph Manszewski <[email protected]> > > > > Suggested-by: Thomas Hellström <[email protected]> > > > > Signed-off-by: Matthew Brost <[email protected]> > > > > Tested-by: Mika Kuoppala <[email protected]> > > > > Reviewed-by: Matthew Auld <[email protected]> > > > > --- > > > > drivers/gpu/drm/ttm/ttm_bo_util.c | 86 +++++++++++++++++++++++++++++++ > > > > drivers/gpu/drm/ttm/ttm_bo_vm.c | 65 +---------------------- > > > > include/drm/ttm/ttm_bo.h | 2 + > > > > 3 files changed, 89 insertions(+), 64 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c > > > > b/drivers/gpu/drm/ttm/ttm_bo_util.c > > > > index d939925efa81..77e760ea7193 100644 > > > > --- a/drivers/gpu/drm/ttm/ttm_bo_util.c > > > > +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c > > > > @@ -919,3 +919,89 @@ s64 ttm_lru_walk_for_evict(struct ttm_lru_walk > > > > *walk, struct ttm_device *bdev, > > > > return progress; > > > > } > > > > + > > > > +static int ttm_bo_access_kmap(struct ttm_buffer_object *bo, > > > > + unsigned long offset, > > > > + void *buf, int len, int write) > > > > +{ > > > > + unsigned long page = offset >> PAGE_SHIFT; > > > > + unsigned long bytes_left = len; > > > > + int ret; > > > > + > > > > + /* Copy a page at a time, that way no extra virtual address > > > > + * mapping is needed > > > > + */ > > > > + offset -= page << PAGE_SHIFT; > > > > + do { > > > > + unsigned long bytes = min(bytes_left, PAGE_SIZE - > > > > offset); > > > > + struct ttm_bo_kmap_obj map; > > > > + void *ptr; > > > > + bool is_iomem; > > > > + > > > > + ret = ttm_bo_kmap(bo, page, 1, &map); > > > > + if (ret) > > > > + return ret; > > > > + > > > > + ptr = (void *)ttm_kmap_obj_virtual(&map, &is_iomem) + > > > > offset; > > > > + WARN_ON_ONCE(is_iomem); > > > > + if (write) > > > > + memcpy(ptr, buf, bytes); > > > > + else > > > > + memcpy(buf, ptr, bytes); > > > > + ttm_bo_kunmap(&map); > > > > + > > > > + page++; > > > > + buf += bytes; > > > > + bytes_left -= bytes; > > > > + offset = 0; > > > > + } while (bytes_left); > > > > + > > > > + return len; > > > > +} > > > > + > > > > +/** > > > > + * ttm_bo_access - Helper to access a buffer object > > > > + * > > > > + * @bo: ttm buffer object > > > > + * @offset: access offset into buffer object > > > > + * @buf: pointer to caller memory to read into or write from > > > > + * @len: length of access > > > > + * @write: write access > > > > + * > > > > + * Utility function to access a buffer object. Useful when buffer > > > > object cannot > > > > + * be easily mapped (non-contiguous, non-visible, etc...). > > > > + * > > > > + * Returns: > > > > + * @len if successful, negative error code on failure. > > > > + */ > > > > +int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset, > > > > + void *buf, int len, int write) > > > > +{ > > > > + int ret; > > > > + > > > > + if (len < 1 || (offset + len) > bo->base.size) > > > > + return -EIO; > > > > + > > > > + ret = ttm_bo_reserve(bo, true, false, NULL); > > > > + if (ret) > > > > + return ret; > > > > + > > > > + switch (bo->resource->mem_type) { > > > > + case TTM_PL_SYSTEM: > > > > + fallthrough; > > > > + case TTM_PL_TT: > > > > + ret = ttm_bo_access_kmap(bo, offset, buf, len, write); > > > > + break; > > > > + default: > > > > + if (bo->bdev->funcs->access_memory) > > > > + ret = bo->bdev->funcs->access_memory > > > > + (bo, offset, buf, len, write); > > > > + else > > > > + ret = -EIO; > > > > + } > > > > + > > > > + ttm_bo_unreserve(bo); > > > > + > > > > + return ret; > > > > +} > > > > +EXPORT_SYMBOL(ttm_bo_access); > > > > diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > b/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > index 2c699ed1963a..20b1e5f78684 100644 > > > > --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c > > > > @@ -366,45 +366,6 @@ void ttm_bo_vm_close(struct vm_area_struct *vma) > > > > } > > > > EXPORT_SYMBOL(ttm_bo_vm_close); > > > > -static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo, > > > > - unsigned long offset, > > > > - uint8_t *buf, int len, int write) > > > > -{ > > > > - unsigned long page = offset >> PAGE_SHIFT; > > > > - unsigned long bytes_left = len; > > > > - int ret; > > > > - > > > > - /* Copy a page at a time, that way no extra virtual address > > > > - * mapping is needed > > > > - */ > > > > - offset -= page << PAGE_SHIFT; > > > > - do { > > > > - unsigned long bytes = min(bytes_left, PAGE_SIZE - > > > > offset); > > > > - struct ttm_bo_kmap_obj map; > > > > - void *ptr; > > > > - bool is_iomem; > > > > - > > > > - ret = ttm_bo_kmap(bo, page, 1, &map); > > > > - if (ret) > > > > - return ret; > > > > - > > > > - ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) > > > > + offset; > > > > - WARN_ON_ONCE(is_iomem); > > > > - if (write) > > > > - memcpy(ptr, buf, bytes); > > > > - else > > > > - memcpy(buf, ptr, bytes); > > > > - ttm_bo_kunmap(&map); > > > > - > > > > - page++; > > > > - buf += bytes; > > > > - bytes_left -= bytes; > > > > - offset = 0; > > > > - } while (bytes_left); > > > > - > > > > - return len; > > > > -} > > > > - > > > > int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, > > > > void *buf, int len, int write) > > > > { > > > > @@ -412,32 +373,8 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, > > > > unsigned long addr, > > > > unsigned long offset = (addr) - vma->vm_start + > > > > ((vma->vm_pgoff - > > > > drm_vma_node_start(&bo->base.vma_node)) > > > > << PAGE_SHIFT); > > > > - int ret; > > > > - > > > > - if (len < 1 || (offset + len) > bo->base.size) > > > > - return -EIO; > > > > - ret = ttm_bo_reserve(bo, true, false, NULL); > > > > - if (ret) > > > > - return ret; > > > > - > > > > - switch (bo->resource->mem_type) { > > > > - case TTM_PL_SYSTEM: > > > > - fallthrough; > > > > - case TTM_PL_TT: > > > > - ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, > > > > write); > > > > - break; > > > > - default: > > > > - if (bo->bdev->funcs->access_memory) > > > > - ret = bo->bdev->funcs->access_memory( > > > > - bo, offset, buf, len, write); > > > > - else > > > > - ret = -EIO; > > > > - } > > > > - > > > > - ttm_bo_unreserve(bo); > > > > - > > > > - return ret; > > > > + return ttm_bo_access(bo, offset, buf, len, write); > > > > } > > > > EXPORT_SYMBOL(ttm_bo_vm_access); > > > > diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h > > > > index 5804408815be..8ea11cd8df39 100644 > > > > --- a/include/drm/ttm/ttm_bo.h > > > > +++ b/include/drm/ttm/ttm_bo.h > > > > @@ -421,6 +421,8 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo); > > > > int ttm_bo_evict_first(struct ttm_device *bdev, > > > > struct ttm_resource_manager *man, > > > > struct ttm_operation_ctx *ctx); > > > > +int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset, > > > > + void *buf, int len, int write); > > > > vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, > > > > struct vm_fault *vmf); > > > > vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, > > > > -- > > > > 2.34.1 > > > > > >
