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R. Silva" , Erick Archer , Joel Granados , , , Subject: Re: [PATCH v2 1/6] RISC-V: Add Zicclsm to cpufeature and hwprobe Message-ID: <20240614-oyster-ditch-80e8f00fd91b@wendy> References: <20240613191616.2101821-1-jesse@rivosinc.com> <20240613191616.2101821-2-jesse@rivosinc.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="OQKmvcs8HRT7+PY2" Content-Disposition: inline In-Reply-To: <20240613191616.2101821-2-jesse@rivosinc.com> --OQKmvcs8HRT7+PY2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jun 13, 2024 at 03:16:10PM -0400, Jesse Taube wrote: > > Zicclsm Misaligned loads and stores to main memory regions with both > > the cacheability and coherence PMAs must be supported. > > Note: > > This introduces a new extension name for this feature. > > This requires misaligned support for all regular load and store > > instructions (including scalar and vector) but not AMOs or other > > specialized forms of memory access. Even though mandated, misaligned > > loads and stores might execute extremely slowly. Standard software > > distributions should assume their existence only for correctness, > > not for performance. >=20 > Detecing zicclsm allows the kernel to report if the > hardware supports misaligned accesses even if support wasn't probed. >=20 > This is useful for usermode to know if vector misaligned accesses are > supported. >=20 > Signed-off-by: Jesse Taube Reviewed-by: Conor Dooley --OQKmvcs8HRT7+PY2 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZmv6qwAKCRB4tDGHoIJi 0mzaAP9YBq9BuQ1DEPPsxpTTaIEq91WxQdesurCAlXQCERPNnQEA5hS94j7obJ9J hv52wvk6In81vYzmCTh9UFDBJVVc9gw= =TSBq -----END PGP SIGNATURE----- --OQKmvcs8HRT7+PY2--