[PATCH 13/13] PCI/P2PDMA: enable compound page support for p2pdma memory

From: Hou Tao

Date: Fri Dec 19 2025 - 23:16:19 EST


From: Hou Tao <houtao1@xxxxxxxxxx>

Compound page support for P2PDMA memory in both kernel and user space is
now in place. Enable it by allowing PUD_SIZE and PMD_SIZE alignment.

Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
drivers/pci/p2pdma.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 4a133219ac43..969bdacdcf8b 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -452,9 +452,19 @@ static inline int pci_p2pdma_check_pagemap_align(struct pci_dev *pdev, int bar,
u64 size, size_t align,
u64 offset)
{
+ if (has_transparent_pud_hugepage() && align == PUD_SIZE)
+ goto more_check;
+ if (has_transparent_hugepage() && align == PMD_SIZE)
+ goto more_check;
if (align == PAGE_SIZE)
return 0;
return -EINVAL;
+
+more_check:
+ if (IS_ALIGNED(pci_resource_start(pdev, bar), align) &&
+ IS_ALIGNED(size, align) && IS_ALIGNED(offset, align))
+ return 0;
+ return -EINVAL;
}

/**
--
2.29.2