On 01/02/18 05:03, Suravee Suthikulpanit wrote:
Hi Robin,
On 2/1/18 1:02 AM, Robin Murphy wrote:
Hi Suravee,
On 31/01/18 01:48, Suravee Suthikulpanit wrote:
Currently, iommu_unmap and iommu_unmap_fast return unmapped
pages with size_t. However, the actual value returned could
be error codes (< 0), which can be misinterpreted as large
number of unmapped pages. Therefore, change the return type to ssize_t.
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
drivers/iommu/amd_iommu.c | 6 +++---
drivers/iommu/intel-iommu.c | 4 ++--
Er, there are a few more drivers than that implementing iommu_ops ;)
Ahh right.
It seems like it might be more sensible to fix the single instance of
a driver returning -EINVAL (which appears to be a "should never happen
if used correctly" kinda thing anyway) and leave the API-internal
callback prototype as-is. I do agree the inconsistency of
iommu_unmap() itself wants sorting, though (particularly the
!IOMMU_API stubs which are wrong either way).
Robin.
Make sense. I'll leave the API alone, and change the code to not
returning error then.
Actually, on a second look I think that check in amd_iommu is 99%
redundant anyway, since PAGE_MODE_NONE is only normally set for
IOMMU_DOMAIN_IDENTITY domains, thus iommu_unmap() would have bailed out
from the __IOMMU_DOMAIN_PAGING check before ops->unmap could be called.
AFAICS the only way to hit it at all is if a caller somehow managed to
get hold of the dev_state->domain set up in amd_iommu_init_device(),
then tried to unmap something from that, which seems such a very wrong
thing to do it should probably just crash and burn with extreme
prejudice anyway.
Cheers,
Robin.
