Thread (57 messages) 57 messages, 5 authors, 2023-10-24

Re: [PATCH v2 02/19] riscv: add ISA extension parsing for scalar crypto

From: Clément Léger <hidden>
Date: 2023-10-24 07:18:38
Also in: linux-doc, linux-riscv, lkml


On 23/10/2023 18:21, Evan Green wrote:
On Tue, Oct 17, 2023 at 6:15 AM Clément Léger [off-list ref] wrote:
quoted
From: Evan Green <redacted>

The Scalar Crypto specification defines Zk as a shorthand for the
Zkn, Zkr and Zkt extensions. The same follows for both Zkn, Zks and Zbk,
which are all shorthands for various other extensions. The detailed
breakdown can be found in their dt-binding entries.

Since Zkn also implies the Zbkb, Zbkc and Zbkx extensions, simply passing
"zk" through a DT should enable all of Zbkb, Zbkc, Zbkx, Zkn, Zkr and Zkt.
For example, setting the "riscv,isa" DT property to "rv64imafdc_zk"
should generate the following cpuinfo output:
"rv64imafdc_zicntr_zicsr_zifencei_zihpm_zbkb_zbkc_zbkx_zknd_zkne_zknh_zkr_zkt"

riscv_isa_ext_data grows a pair of new members, to permit setting the
relevant bits for "bundled" extensions, both while parsing the ISA string
and the new dedicated extension properties

Co-developed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Evan Green <redacted>
Signed-off-by: Clément Léger <redacted>
My tree might be out of sync, but in my search for riscv_isa_ext, I
also found a use in print_isa() (cpu.c) where we're reaching into
riscv_isa_ext[].id and assuming it's always valid. If that's still in
there we'll want to fix up that spot too, since now with bundles .id
may or may not be valid.
Oh indeed, the array is visible outside of this compilation unit :/.
I'll check that before sending V3.

Clément
-Evan
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help