On 22-07-2026 04:02, Matthew Brost wrote:
HPAGE_PMD_SHIFT expands to BUILD_BUG() when CONFIG_PGTABLE_HAS_HUGE_LEAVES
is not set, causing a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
and CONFIG_HUGETLB_PAGE are disabled:
drivers/gpu/drm/drm_pagemap.c:480:12: error: call to
'__compiletime_assert_458'
declared with 'error' attribute: BUILD_BUG failed
480 | order = HPAGE_PMD_ORDER;
| ^
include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
| ^
include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
Define DRM_PAGEMAP_PMD_ORDER, which maps to HPAGE_PMD_ORDER when
CONFIG_ARCH_ENABLE_THP_MIGRATION is enabled and to -1 otherwise.
This is safe because all code paths that use DRM_PAGEMAP_PMD_ORDER are
reachable only when CONFIG_ARCH_ENABLE_THP_MIGRATION is enabled.
Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for
migrate_vma_setup")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]/
Cc: Jan Stancek <[email protected]>
Signed-off-by: Matthew Brost <[email protected]>
Reviewed-by: Himal Prasad Ghimiray <[email protected]>
---
drivers/gpu/drm/drm_pagemap.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
index 15c78eca180b..951cd92c930c 100644
--- a/drivers/gpu/drm/drm_pagemap.c
+++ b/drivers/gpu/drm/drm_pagemap.c
@@ -12,6 +12,12 @@
#include <drm/drm_pagemap_util.h>
#include <drm/drm_print.h>
+#if IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)
+#define DRM_PAGEMAP_PMD_ORDER HPAGE_PMD_ORDER
+#else
+#define DRM_PAGEMAP_PMD_ORDER (-1)
+#endif
+
/**
* DOC: Overview
*
@@ -579,7 +585,7 @@ static int drm_pagemap_cpages(unsigned long *migrate_pfn,
unsigned long npages)
order = folio_order(folio);
cpages += NR_PAGES(order);
} else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
- order = HPAGE_PMD_ORDER;
+ order = DRM_PAGEMAP_PMD_ORDER;
cpages += NR_PAGES(order);
}
@@ -765,10 +771,11 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
if (migrate.src[i] & MIGRATE_PFN_COMPOUND) {
drm_WARN_ONCE(dpagemap->drm, src_page &&
- folio_order(page_folio(src_page)) !=
HPAGE_PMD_ORDER,
+ folio_order(page_folio(src_page)) !=
+ DRM_PAGEMAP_PMD_ORDER,
"Unexpected folio order\n");
- order = HPAGE_PMD_ORDER;
+ order = DRM_PAGEMAP_PMD_ORDER;
migrate.dst[i] |= MIGRATE_PFN_COMPOUND;
for (j = 1; j < NR_PAGES(order) && i + j < npages; j++)
