[PATCH v4 21/24] alpha/PCI: Compute legacy size in pci_mmap_legacy_page_range()

Krzysztof Wilczyński
2026-04-11T08:03:08Z

Currently, pci_mmap_legacy_page_range() reads the legacy resource
size from bus->legacy_mem->size or bus->legacy_io->size. This
couples the mmap bounds check to the struct pci_bus fields that
will be removed when legacy attributes are converted to static
definitions.

Compute the size directly using PCI_LEGACY_MEM_SIZE (0x100000) and
PCI_LEGACY_IO_SIZE (0xffff) macros, and shift by 5 bits for sparse
systems.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
---
arch/alpha/kernel/pci-sysfs.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/alpha/kernel/pci-sysfs.c b/arch/alpha/kernel/pci-sysfs.c
index 2e9693e5abe1..a9dea147528d 100644
--- a/arch/alpha/kernel/pci-sysfs.c
+++ b/arch/alpha/kernel/pci-sysfs.c
@@ -180,8 +180,11 @@ int pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,
int sparse = has_sparse(hose, mmap_type);
unsigned long res_size;

- res_size = (mmap_type == pci_mmap_mem) ? bus->legacy_mem->size :
- bus->legacy_io->size;
+ res_size = (mmap_type == pci_mmap_mem) ? PCI_LEGACY_MEM_SIZE : \
+ PCI_LEGACY_IO_SIZE;
+ if (sparse)
+ res_size <<= 5;
+
if (!__legacy_mmap_fits(hose, vma, res_size, sparse))
return -EINVAL;

--
2.53.0