On Thu, Feb 19, 2026 at 12:10:56PM -0800, Matthew Brost wrote: > Split drm_pagemap_migrate_map_pages into device / system helpers clearly > seperating these operations. Will help with upcoming changes to split > IOVA allocation steps.
Side effect is that it makes the code a lot more readable. A couple of nits below. Reviewed-by: Francois Dugast <[email protected]> > > Signed-off-by: Matthew Brost <[email protected]> > > --- > v5: > - s/map_device_pages/map_device_private_pages (Thomas) > - Fix map_system_pages kernel doc (Thomas) > --- > drivers/gpu/drm/drm_pagemap.c | 150 ++++++++++++++++++++++------------ > 1 file changed, 100 insertions(+), 50 deletions(-) > > diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c > index 32535ab01c0f..ef8b9c69d1d4 100644 > --- a/drivers/gpu/drm/drm_pagemap.c > +++ b/drivers/gpu/drm/drm_pagemap.c > @@ -205,7 +205,8 @@ static void drm_pagemap_get_devmem_page(struct page *page, > } > > /** > - * drm_pagemap_migrate_map_pages() - Map migration pages for GPU SVM > migration > + * drm_pagemap_migrate_map_device_private_pages() - Map device privaet > migration s/privaet/private/ > + * pages for GPU SVM migration > * @dev: The device performing the migration. > * @local_dpagemap: The drm_pagemap local to the migrating device. > * @pagemap_addr: Array to store DMA information corresponding to mapped > pages. > @@ -221,19 +222,22 @@ static void drm_pagemap_get_devmem_page(struct page > *page, > * > * Returns: 0 on success, -EFAULT if an error occurs during mapping. > */ > -static int drm_pagemap_migrate_map_pages(struct device *dev, > - struct drm_pagemap *local_dpagemap, > - struct drm_pagemap_addr *pagemap_addr, > - unsigned long *migrate_pfn, > - unsigned long npages, > - enum dma_data_direction dir, > - const struct > drm_pagemap_migrate_details *mdetails) > +static int > +drm_pagemap_migrate_map_device_private_pages(struct device *dev, > + struct drm_pagemap *local_dpagemap, > + struct drm_pagemap_addr > *pagemap_addr, > + unsigned long *migrate_pfn, > + unsigned long npages, > + enum dma_data_direction dir, > + const struct > drm_pagemap_migrate_details *mdetails) > { > unsigned long num_peer_pages = 0, num_local_pages = 0, i; > > for (i = 0; i < npages;) { > struct page *page = migrate_pfn_to_page(migrate_pfn[i]); > - dma_addr_t dma_addr; > + struct drm_pagemap_zdd *zdd; > + struct drm_pagemap *dpagemap; > + struct drm_pagemap_addr addr; > struct folio *folio; > unsigned int order = 0; > > @@ -243,36 +247,26 @@ static int drm_pagemap_migrate_map_pages(struct device > *dev, > folio = page_folio(page); > order = folio_order(folio); > > - if (is_device_private_page(page)) { > - struct drm_pagemap_zdd *zdd = > drm_pagemap_page_zone_device_data(page); > - struct drm_pagemap *dpagemap = zdd->dpagemap; > - struct drm_pagemap_addr addr; > - > - if (dpagemap == local_dpagemap) { > - if (!mdetails->can_migrate_same_pagemap) > - goto next; > + WARN_ON_ONCE(!is_device_private_page(page)); Another nit: could we move this line ^ above that one: folio = page_folio(page); so that the check is the first thing we do with that page, and also to have a bit more symmetry with +drm_pagemap_migrate_map_system_pages(). Francois > > - num_local_pages += NR_PAGES(order); > - } else { > - num_peer_pages += NR_PAGES(order); > - } > + zdd = drm_pagemap_page_zone_device_data(page); > + dpagemap = zdd->dpagemap; > > - addr = dpagemap->ops->device_map(dpagemap, dev, page, > order, dir); > - if (dma_mapping_error(dev, addr.addr)) > - return -EFAULT; > + if (dpagemap == local_dpagemap) { > + if (!mdetails->can_migrate_same_pagemap) > + goto next; > > - pagemap_addr[i] = addr; > + num_local_pages += NR_PAGES(order); > } else { > - dma_addr = dma_map_page(dev, page, 0, page_size(page), > dir); > - if (dma_mapping_error(dev, dma_addr)) > - return -EFAULT; > - > - pagemap_addr[i] = > - drm_pagemap_addr_encode(dma_addr, > - DRM_INTERCONNECT_SYSTEM, > - order, dir); > + num_peer_pages += NR_PAGES(order); > } > > + addr = dpagemap->ops->device_map(dpagemap, dev, page, order, > dir); > + if (dma_mapping_error(dev, addr.addr)) > + return -EFAULT; > + > + pagemap_addr[i] = addr; > + > next: > i += NR_PAGES(order); > } > @@ -287,6 +281,60 @@ static int drm_pagemap_migrate_map_pages(struct device > *dev, > return 0; > } > > +/** > + * drm_pagemap_migrate_map_system_pages() - Map system or device coherent > + * migration pages for GPU SVM migration > + * @dev: The device performing the migration. > + * @pagemap_addr: Array to store DMA information corresponding to mapped > pages. > + * @migrate_pfn: Array of page frame numbers of system pages or peer pages > to map. > + * @npages: Number of system or device coherent pages to map. > + * @dir: Direction of data transfer (e.g., DMA_BIDIRECTIONAL) > + * > + * This function maps pages of memory for migration usage in GPU SVM. It > + * iterates over each page frame number provided in @migrate_pfn, maps the > + * corresponding page, and stores the DMA address in the provided @dma_addr > + * array. > + * > + * Returns: 0 on success, -EFAULT if an error occurs during mapping. > + */ > +static int > +drm_pagemap_migrate_map_system_pages(struct device *dev, > + struct drm_pagemap_addr *pagemap_addr, > + unsigned long *migrate_pfn, > + unsigned long npages, > + enum dma_data_direction dir) > +{ > + unsigned long i; > + > + for (i = 0; i < npages;) { > + struct page *page = migrate_pfn_to_page(migrate_pfn[i]); > + dma_addr_t dma_addr; > + struct folio *folio; > + unsigned int order = 0; > + > + if (!page) > + goto next; > + > + WARN_ON_ONCE(is_device_private_page(page)); > + folio = page_folio(page); > + order = folio_order(folio); > + > + dma_addr = dma_map_page(dev, page, 0, page_size(page), dir); > + if (dma_mapping_error(dev, dma_addr)) > + return -EFAULT; > + > + pagemap_addr[i] = > + drm_pagemap_addr_encode(dma_addr, > + DRM_INTERCONNECT_SYSTEM, > + order, dir); > + > +next: > + i += NR_PAGES(order); > + } > + > + return 0; > +} > + > /** > * drm_pagemap_migrate_unmap_pages() - Unmap pages previously mapped for GPU > SVM migration > * @dev: The device for which the pages were mapped > @@ -347,9 +395,13 @@ drm_pagemap_migrate_remote_to_local(struct > drm_pagemap_devmem *devmem, > const struct drm_pagemap_migrate_details > *mdetails) > > { > - int err = drm_pagemap_migrate_map_pages(remote_device, remote_dpagemap, > - pagemap_addr, local_pfns, > - npages, DMA_FROM_DEVICE, > mdetails); > + int err = drm_pagemap_migrate_map_device_private_pages(remote_device, > + remote_dpagemap, > + pagemap_addr, > + local_pfns, > + npages, > + DMA_FROM_DEVICE, > + mdetails); > > if (err) > goto out; > @@ -368,12 +420,11 @@ drm_pagemap_migrate_sys_to_dev(struct > drm_pagemap_devmem *devmem, > struct page *local_pages[], > struct drm_pagemap_addr pagemap_addr[], > unsigned long npages, > - const struct drm_pagemap_devmem_ops *ops, > - const struct drm_pagemap_migrate_details > *mdetails) > + const struct drm_pagemap_devmem_ops *ops) > { > - int err = drm_pagemap_migrate_map_pages(devmem->dev, devmem->dpagemap, > - pagemap_addr, sys_pfns, npages, > - DMA_TO_DEVICE, mdetails); > + int err = drm_pagemap_migrate_map_system_pages(devmem->dev, > + pagemap_addr, sys_pfns, > + npages, DMA_TO_DEVICE); > > if (err) > goto out; > @@ -437,7 +488,7 @@ static int drm_pagemap_migrate_range(struct > drm_pagemap_devmem *devmem, > &pages[last->start], > &pagemap_addr[last->start], > cur->start - last->start, > - last->ops, mdetails); > + last->ops); > > out: > *last = *cur; > @@ -942,7 +993,6 @@ EXPORT_SYMBOL(drm_pagemap_put); > int drm_pagemap_evict_to_ram(struct drm_pagemap_devmem *devmem_allocation) > { > const struct drm_pagemap_devmem_ops *ops = devmem_allocation->ops; > - struct drm_pagemap_migrate_details mdetails = {}; > unsigned long npages, mpages = 0; > struct page **pages; > unsigned long *src, *dst; > @@ -981,10 +1031,10 @@ int drm_pagemap_evict_to_ram(struct drm_pagemap_devmem > *devmem_allocation) > if (err || !mpages) > goto err_finalize; > > - err = drm_pagemap_migrate_map_pages(devmem_allocation->dev, > - devmem_allocation->dpagemap, > pagemap_addr, > - dst, npages, DMA_FROM_DEVICE, > - &mdetails); > + err = drm_pagemap_migrate_map_system_pages(devmem_allocation->dev, > + pagemap_addr, > + dst, npages, > + DMA_FROM_DEVICE); > if (err) > goto err_finalize; > > @@ -1045,7 +1095,6 @@ static int __drm_pagemap_migrate_to_ram(struct > vm_area_struct *vas, > MIGRATE_VMA_SELECT_DEVICE_COHERENT, > .fault_page = page, > }; > - struct drm_pagemap_migrate_details mdetails = {}; > struct drm_pagemap_zdd *zdd; > const struct drm_pagemap_devmem_ops *ops; > struct device *dev = NULL; > @@ -1103,8 +1152,9 @@ static int __drm_pagemap_migrate_to_ram(struct > vm_area_struct *vas, > if (err) > goto err_finalize; > > - err = drm_pagemap_migrate_map_pages(dev, zdd->dpagemap, pagemap_addr, > migrate.dst, npages, > - DMA_FROM_DEVICE, &mdetails); > + err = drm_pagemap_migrate_map_system_pages(dev, pagemap_addr, > + migrate.dst, npages, > + DMA_FROM_DEVICE); > if (err) > goto err_finalize; > > -- > 2.34.1 >
