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-...@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-...@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 <l...@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202505072016.4hmsizt8-...@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 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
