Re: [PATCH v4 5/5] iommu/s390: Fix incorrect pgsize_bitmap

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2022-10-04 13:07, 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.

Unless it's already been done somewhere else, you'll want to switch over to the {map,unmap}_pages() interfaces as well to avoid taking a hit on efficiency here. The "page mask" thing was an old hack to trick the core API into making fewer map/unmap calls where the driver could map arbitrary numbers of pages at once anyway. The multi-page interfaces now do that more honestly and generally better (since they work for non-power-of-two sizes as well).

Robin.

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
---
  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 94c444b909bd..6bf23e7830a2 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 {
@@ -350,7 +343,7 @@ 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,



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Kernel Development]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite Info]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Linux Media]     [Device Mapper]

  Powered by Linux