2022-09-29 15:37:03

by Niklas Schnelle

[permalink] [raw]
Subject: [PATCH v3 5/5] iommu/s390: Fix incorrect pgsize_bitmap

The .pgsize_bitmap property of struct iommu_ops is not a page mask but
rather has a bit set for each size of pages the IOMMU supports. As the
comment correctly pointed out at this moment the code only support 4K
pages so simply use SZ_4K here.

Signed-off-by: Niklas Schnelle <[email protected]>
---
drivers/iommu/s390-iommu.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index 6d4a9c7db32c..2bad24d6cfef 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -12,13 +12,6 @@
#include <linux/sizes.h>
#include <asm/pci_dma.h>

-/*
- * Physically contiguous memory regions can be mapped with 4 KiB alignment,
- * we allow all page sizes that are an order of 4KiB (no special large page
- * support so far).
- */
-#define S390_IOMMU_PGSIZES (~0xFFFUL)
-
static const struct iommu_ops s390_iommu_ops;

struct s390_domain {
@@ -360,7 +353,7 @@ static const struct iommu_ops s390_iommu_ops = {
.probe_device = s390_iommu_probe_device,
.release_device = s390_iommu_release_device,
.device_group = generic_device_group,
- .pgsize_bitmap = S390_IOMMU_PGSIZES,
+ .pgsize_bitmap = SZ_4K,
.get_resv_regions = s390_iommu_get_resv_regions,
.default_domain_ops = &(const struct iommu_domain_ops) {
.attach_dev = s390_iommu_attach_device,
--
2.34.1


2022-09-29 17:15:00

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH v3 5/5] iommu/s390: Fix incorrect pgsize_bitmap

On Thu, Sep 29, 2022 at 05:33:02PM +0200, Niklas Schnelle wrote:
> The .pgsize_bitmap property of struct iommu_ops is not a page mask but
> rather has a bit set for each size of pages the IOMMU supports. As the
> comment correctly pointed out at this moment the code only support 4K
> pages so simply use SZ_4K here.
>
> Signed-off-by: Niklas Schnelle <[email protected]>
> ---
> drivers/iommu/s390-iommu.c | 9 +--------
> 1 file changed, 1 insertion(+), 8 deletions(-)

Yep!

Reviewed-by: Jason Gunthorpe <[email protected]>

Jason