d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix pmap_change_attr() on arm64 to allow KV addresses

Browse Source 
Altough in the comment above the pmap_change_attr() it was mentioned
that VA could be in KV or DMAP memory space. However,
pmap_change_attr_locked() was accepting only the values inside the DMAP
memory range.

To fix that, the condition check was changed so also the va inside the
KV memory range would be accepted.

The sample use case that wasn't supported is the PCI Device that has the
BAR which should me mapped with the Write Combine attribute - for
example BAR2 of the ENA network controller on the A1 instances on AWS.

Tested on A1 AWS instance and changed ENA BAR2 mapped resource to be
write-combined memory region.

Differential Revision: https://reviews.freebsd.org/D22055
MFC after: 2 weeks
Submitted by: Michal Krawczyk <mk@semihalf.com>
Obtained from: Semihalf
Sponsored by: Amazon, Inc.
This commit is contained in:
Marcin Wojtas 2019-10-31 15:16:10 +00:00
parent abe476d083
commit a3da4fc60b
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
sys/arm64/arm64/pmap.c
View File

@ -5291,7 +5291,8 @@ pmap_change_attr_locked(vm_offset_t va, vm_size_t size, int mode)
offset = va & PAGE_MASK;
size = round_page(offset + size);
if (!VIRT_IN_DMAP(base))
if (!VIRT_IN_DMAP(base) &&
!(base >= VM_MIN_KERNEL_ADDRESS && base < VM_MAX_KERNEL_ADDRESS))
return (EINVAL);
for (tmpva = base; tmpva < base + size; ) {