Commit 7f2e8e1d authored Dec 18, 2025 by Leon Romanovsky Committed by Marek Szyprowski Dec 19, 2025

parisc: Set valid bit in high byte of 64‑bit physical address



On 32‑bit systems, phys_addr_t is defined as u32. However, parisc
expects physical addresses to be 64‑bit values so it can store a
validity bit in the upper byte.

Resolve this mismatch by casting the physical address to unsigned
long, ensuring it is treated as a 64‑bit value where required. This
fixes the failure to start block device drivers on the C3700
platform, as reported by Guenter.

QEMU command line to reproduce the issue (with Debian SID as rootfs):
  qemu-system-hppa -machine C3700 \
	-kernel arch/parisc/boot/bzImage \
	-append "console=ttyS0 \
	root=/dev/sda rw rootwait panic=-1" \
	-nographic \
	-device lsi53c895a \
	-drive file=rootfs-hppa.img,if=none,format=raw,id=hd0 \
	-device scsi-hd,drive=hd0

Fixes: 96ddf2ef ("parisc: Convert DMA map_page to map_phys interface")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/all/b184f1bf-96dc-4546-8512-9cba5ecb58f7@roeck-us.net/


Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
[mszyprow: dropped the lpa() macro removal]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20251218-fix-parisc-conversion-v1-1-4a04d26b0168@nvidia.com

parent 8f0b4cce

drivers/parisc/sba_iommu.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -578,8 +578,8 @@ sba_io_pdir_entry(__le64 *pdir_ptr, space_t sid, phys_addr_t pba,
		pba &= IOVP_MASK;
		pba \|= (ci >> PAGE_SHIFT) & 0xff; /* move CI (8 bits) into lowest byte */

		pba \|= SBA_PDIR_VALID_BIT; /* set "valid" bit */
		pdir_ptr = cpu_to_le64(pba); / swap and store into I/O Pdir */
		/* set "valid" bit, swap and store into I/O Pdir */
		*pdir_ptr = cpu_to_le64((unsigned long)pba \| SBA_PDIR_VALID_BIT);

		/*
		* If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit set