[PATCH 1/3] drm/gpusvm, drm/pagemap: Move migration functionality to drm_pagemap
kernel test robot
lkp at intel.com
Wed May 7 13:08:16 UTC 2025
Hi Thomas,
kernel test robot noticed the following build warnings:
[auto build test WARNING on next-20250417]
[cannot apply to drm-xe/drm-xe-next drm-exynos/exynos-drm-next linus/master drm/drm-next drm-intel/for-linux-next drm-intel/for-linux-next-fixes v6.15-rc2 v6.15-rc1 v6.14 v6.15-rc5]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Thomas-Hellstr-m/drm-gpusvm-drm-pagemap-Move-migration-functionality-to-drm_pagemap/20250417-193413
base: next-20250417
patch link: https://lore.kernel.org/r/20250417105113.48831-2-thomas.hellstrom%40linux.intel.com
patch subject: [PATCH 1/3] drm/gpusvm, drm/pagemap: Move migration functionality to drm_pagemap
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20250507/202505072016.4HmSIZT8-lkp@intel.com/config)
compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250507/202505072016.4HmSIZT8-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202505072016.4HmSIZT8-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/gpu/drm/drm_pagemap.c:653:7: warning: variable 'dev' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
653 | if (!page)
| ^~~~~
drivers/gpu/drm/drm_pagemap.c:683:34: note: uninitialized use occurs here
683 | drm_pagemap_migrate_unmap_pages(dev, dma_addr, npages,
| ^~~
drivers/gpu/drm/drm_pagemap.c:653:3: note: remove the 'if' if its condition is always false
653 | if (!page)
| ^~~~~~~~~~
654 | goto err_finalize;
| ~~~~~~~~~~~~~~~~~
drivers/gpu/drm/drm_pagemap.c:602:20: note: initialize the variable 'dev' to silence this warning
602 | struct device *dev;
| ^
| = NULL
1 warning generated.
vim +653 drivers/gpu/drm/drm_pagemap.c
571
572 /**
573 * __drm_pagemap_migrate_to_ram() - Migrate a virtual range to RAM (internal)
574 * @vas: Pointer to the VM area structure
575 * @device_private_page_owner: Device private pages owner
576 * @page: Pointer to the page for fault handling (can be NULL)
577 * @fault_addr: Fault address
578 * @size: Size of migration
579 *
580 * This internal function performs the migration of the specified GPU SVM range
581 * to RAM. It sets up the migration, populates + dma maps RAM PFNs, and
582 * invokes the driver-specific operations for migration to RAM.
583 *
584 * Returns:
585 * 0 on success, negative error code on failure.
586 */
587 static int __drm_pagemap_migrate_to_ram(struct vm_area_struct *vas,
588 void *device_private_page_owner,
589 struct page *page,
590 unsigned long fault_addr,
591 unsigned long size)
592 {
593 struct migrate_vma migrate = {
594 .vma = vas,
595 .pgmap_owner = device_private_page_owner,
596 .flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE |
597 MIGRATE_VMA_SELECT_DEVICE_COHERENT,
598 .fault_page = page,
599 };
600 struct drm_pagemap_zdd *zdd;
601 const struct drm_pagemap_devmem_ops *ops;
602 struct device *dev;
603 unsigned long npages, mpages = 0;
604 struct page **pages;
605 dma_addr_t *dma_addr;
606 unsigned long start, end;
607 void *buf;
608 int i, err = 0;
609
610 start = ALIGN_DOWN(fault_addr, size);
611 end = ALIGN(fault_addr + 1, size);
612
613 /* Corner where VMA area struct has been partially unmapped */
614 if (start < vas->vm_start)
615 start = vas->vm_start;
616 if (end > vas->vm_end)
617 end = vas->vm_end;
618
619 migrate.start = start;
620 migrate.end = end;
621 npages = npages_in_range(start, end);
622
623 buf = kvcalloc(npages, 2 * sizeof(*migrate.src) + sizeof(*dma_addr) +
624 sizeof(*pages), GFP_KERNEL);
625 if (!buf) {
626 err = -ENOMEM;
627 goto err_out;
628 }
629 dma_addr = buf + (2 * sizeof(*migrate.src) * npages);
630 pages = buf + (2 * sizeof(*migrate.src) + sizeof(*dma_addr)) * npages;
631
632 migrate.vma = vas;
633 migrate.src = buf;
634 migrate.dst = migrate.src + npages;
635
636 err = migrate_vma_setup(&migrate);
637 if (err)
638 goto err_free;
639
640 /* Raced with another CPU fault, nothing to do */
641 if (!migrate.cpages)
642 goto err_free;
643
644 if (!page) {
645 for (i = 0; i < npages; ++i) {
646 if (!(migrate.src[i] & MIGRATE_PFN_MIGRATE))
647 continue;
648
649 page = migrate_pfn_to_page(migrate.src[i]);
650 break;
651 }
652
> 653 if (!page)
654 goto err_finalize;
655 }
656 zdd = page->zone_device_data;
657 ops = zdd->devmem_allocation->ops;
658 dev = zdd->devmem_allocation->dev;
659
660 err = drm_pagemap_migrate_populate_ram_pfn(vas, page, npages, &mpages,
661 migrate.src, migrate.dst,
662 start);
663 if (err)
664 goto err_finalize;
665
666 err = drm_pagemap_migrate_map_pages(dev, dma_addr, migrate.dst, npages,
667 DMA_FROM_DEVICE);
668 if (err)
669 goto err_finalize;
670
671 for (i = 0; i < npages; ++i)
672 pages[i] = migrate_pfn_to_page(migrate.src[i]);
673
674 err = ops->copy_to_ram(pages, dma_addr, npages);
675 if (err)
676 goto err_finalize;
677
678 err_finalize:
679 if (err)
680 drm_pagemap_migration_unlock_put_pages(npages, migrate.dst);
681 migrate_vma_pages(&migrate);
682 migrate_vma_finalize(&migrate);
683 drm_pagemap_migrate_unmap_pages(dev, dma_addr, npages,
684 DMA_FROM_DEVICE);
685 err_free:
686 kvfree(buf);
687 err_out:
688
689 return err;
690 }
691
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