diff options
| author |   Dave Martin <Dave.Martin@arm.com> | 2018-06-01 11:10:13 +0100 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2018-06-01 15:53:07 +0100 |
| commit | 87c021a8143b6133e0085a8162f2a127462b54a3 (patch) | |
| tree | 63cf1f0255bc65b88b28614be8465c81e6598090 /arch/arm64 | |
| parent | Merge branch 'for-next/perf' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux (diff) | |
| download | linux-dev-87c021a8143b6133e0085a8162f2a127462b54a3.tar.xz linux-dev-87c021a8143b6133e0085a8162f2a127462b54a3.zip | |
arm64/sve: Thin out initialisation sanity-checks for sve_max_vl
Now that the kernel SVE support is reasonably mature, it is
excessive to default sve_max_vl to the invalid value -1 and then
sprinkle WARN_ON()s around the place to make sure it has been
initialised before use. The cpufeatures code already runs pretty
early, and will ensure sve_max_vl gets initialised.
This patch initialises sve_max_vl to something sane that will be
supported by every SVE implementation, and removes most of the
sanity checks.
The checks in find_supported_vector_length() are retained for now.
If anything goes horribly wrong, we are likely to trip a check here
sooner or later.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/fpsimd.c | 17 | ||||
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 3 |
2 files changed, 4 insertions, 16 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 3db8ed530e56..d15f38ad70cb 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -128,7 +128,7 @@ static int sve_default_vl = -1; #ifdef CONFIG_ARM64_SVE /* Maximum supported vector length across all CPUs (initially poisoned) */ -int __ro_after_init sve_max_vl = -1; +int __ro_after_init sve_max_vl = SVE_VL_MIN; /* Set of available vector lengths, as vq_to_bit(vq): */ static __ro_after_init DECLARE_BITMAP(sve_vq_map, SVE_VQ_MAX); static void __percpu *efi_sve_state; @@ -359,22 +359,13 @@ static int sve_proc_do_default_vl(struct ctl_table *table, int write, return ret; /* Writing -1 has the special meaning "set to max": */ - if (vl == -1) { - /* Fail safe if sve_max_vl wasn't initialised */ - if (WARN_ON(!sve_vl_valid(sve_max_vl))) - vl = SVE_VL_MIN; - else - vl = sve_max_vl; - - goto chosen; - } + if (vl == -1) + vl = sve_max_vl; if (!sve_vl_valid(vl)) return -EINVAL; - vl = find_supported_vector_length(vl); -chosen: - sve_default_vl = vl; + sve_default_vl = find_supported_vector_length(vl); return 0; } diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index f847285d96f3..bd732644c2f6 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -766,9 +766,6 @@ static void sve_init_header_from_task(struct user_sve_header *header, vq = sve_vq_from_vl(header->vl); header->max_vl = sve_max_vl; - if (WARN_ON(!sve_vl_valid(sve_max_vl))) - header->max_vl = header->vl; - header->size = SVE_PT_SIZE(vq, header->flags); header->max_size = SVE_PT_SIZE(sve_vq_from_vl(header->max_vl), SVE_PT_REGS_SVE); |