[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v5 11/22] target/arm: default SVE length to 64 bytes for linux-us
From: |
Alex Bennée |
Subject: |
[PATCH v5 11/22] target/arm: default SVE length to 64 bytes for linux-user |
Date: |
Tue, 14 Jan 2020 15:09:42 +0000 |
The Linux kernel chooses the default of 64 bytes for SVE registers on
the basis that it is the largest size on known hardware that won't
grow the signal frame. We still honour the sve-max-vq property and
userspace can expand the number of lanes by calling PR_SVE_SET_VL.
This should not make any difference to SVE enabled software as the SVE
is of course vector length agnostic.
Signed-off-by: Alex Bennée <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
---
v2
- tweak zcr_el[1] instead
---
target/arm/cpu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index d62fd5fdc6..1c1f34ee5d 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -199,9 +199,9 @@ static void arm_cpu_reset(CPUState *s)
/* and to the SVE instructions */
env->cp15.cpacr_el1 = deposit64(env->cp15.cpacr_el1, 16, 2, 3);
env->cp15.cptr_el[3] |= CPTR_EZ;
- /* with maximum vector length */
+ /* with reasonable vector length */
env->vfp.zcr_el[1] = cpu_isar_feature(aa64_sve, cpu) ?
- cpu->sve_max_vq - 1 : 0;
+ MIN(cpu->sve_max_vq - 1, 3) : 0;
env->vfp.zcr_el[2] = env->vfp.zcr_el[1];
env->vfp.zcr_el[3] = env->vfp.zcr_el[1];
/*
--
2.20.1
- [PATCH v5 03/22] gdbstub: move str_buf to GDBState and use GString, (continued)
- [PATCH v5 03/22] gdbstub: move str_buf to GDBState and use GString, Alex Bennée, 2020/01/14
- [PATCH v5 07/22] target/m68k: use gdb_get_reg helpers, Alex Bennée, 2020/01/14
- [PATCH v5 09/22] target/arm: prepare for multiple dynamic XMLs, Alex Bennée, 2020/01/14
- [PATCH v5 05/22] gdbstub: add helper for 128 bit registers, Alex Bennée, 2020/01/14
- [PATCH v5 04/22] gdbstub: move mem_buf to GDBState and use GByteArray, Alex Bennée, 2020/01/14
- [PATCH v5 14/22] target/arm: don't bother with id_aa64pfr0_read for USER_ONLY, Alex Bennée, 2020/01/14
- [PATCH v5 02/22] gdbstub: stop passing GDBState * around and use global, Alex Bennée, 2020/01/14
- [PATCH v5 11/22] target/arm: default SVE length to 64 bytes for linux-user,
Alex Bennée <=
- [PATCH v5 12/22] target/arm: generate xml description of our SVE registers, Alex Bennée, 2020/01/14
- [PATCH v5 10/22] target/arm: explicitly encode regnum in our XML, Alex Bennée, 2020/01/14
- [PATCH v5 13/22] tests/tcg: add a configure compiler check for ARMv8.1 and SVE, Alex Bennée, 2020/01/14
- [PATCH v5 21/22] gdbstub: change GDBState.last_packet to GByteArray, Alex Bennée, 2020/01/14
- [PATCH v5 22/22] gdbstub: do not split gdb_monitor_write payload, Alex Bennée, 2020/01/14
- [PATCH v5 08/22] gdbstub: extend GByteArray to read register helpers, Alex Bennée, 2020/01/14