doc: RISC-V: Document that misaligned accesses are supported

The RISC-V ISA manual used to mandate that misaligned accesses were
supported in user mode, but that requirement was removed in 2018 via
riscv-isa-manual commit 61cadb9 ("Provide new description of misaligned
load/store behavior compatible with privileged architecture.").  Since
the Linux uABI was already frozen at that point it's just been demoted
to part of the uABI, but that was never written down.

Link: https://lore.kernel.org/r/20220728210715.17214-1-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Palmer Dabbelt 2022-07-28 14:07:15 -07:00
parent 10f6913c54
commit 06267eb2de
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
2 changed files with 7 additions and 0 deletions

View File

@ -8,6 +8,7 @@ RISC-V architecture
boot-image-header boot-image-header
vm-layout vm-layout
patch-acceptance patch-acceptance
uabi
features features

View File

@ -0,0 +1,6 @@
.. SPDX-License-Identifier: GPL-2.0
RISC-V Linux User ABI
=====================
Misaligned accesses are supported in userspace, but they may perform poorly.