diff options
author | Mark Brown <broonie@kernel.org> | 2021-10-19 18:22:14 +0100 |
---|---|---|
committer | Will Deacon <will@kernel.org> | 2021-10-21 10:18:17 +0100 |
commit | 5838a155798479e3fe7e1482a31f0db657d5bbdd (patch) | |
tree | c18be9ebffb090c46147fb23c1e1e6781da9d595 /arch/arm64/kernel/fpsimd.c | |
parent | ddc806b5c4752d35bdaa4dfa2aaa72785711a3da (diff) |
arm64/sve: Track vector lengths for tasks in an array
As for SVE we will track a per task SME vector length for tasks. Convert
the existing storage for the vector length into an array and update
fpsimd_flush_task() to initialise this in a function.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211019172247.3045838-10-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/fpsimd.c')
-rw-r--r-- | arch/arm64/kernel/fpsimd.c | 97 |
1 files changed, 57 insertions, 40 deletions
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index e75dd20a40cf..3474122f9207 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -133,6 +133,17 @@ __ro_after_init struct vl_info vl_info[ARM64_VEC_MAX] = { #endif }; +static unsigned int vec_vl_inherit_flag(enum vec_type type) +{ + switch (type) { + case ARM64_VEC_SVE: + return TIF_SVE_VL_INHERIT; + default: + WARN_ON_ONCE(1); + return 0; + } +} + struct vl_config { int __default_vl; /* Default VL for tasks */ }; @@ -239,24 +250,27 @@ static void sve_free(struct task_struct *task) __sve_free(task); } -unsigned int task_get_sve_vl(const struct task_struct *task) +unsigned int task_get_vl(const struct task_struct *task, enum vec_type type) { - return task->thread.sve_vl; + return task->thread.vl[type]; } -void task_set_sve_vl(struct task_struct *task, unsigned long vl) +void task_set_vl(struct task_struct *task, enum vec_type type, + unsigned long vl) { - task->thread.sve_vl = vl; + task->thread.vl[type] = vl; } -unsigned int task_get_sve_vl_onexec(const struct task_struct *task) +unsigned int task_get_vl_onexec(const struct task_struct *task, + enum vec_type type) { - return task->thread.sve_vl_onexec; + return task->thread.vl_onexec[type]; } -void task_set_sve_vl_onexec(struct task_struct *task, unsigned long vl) +void task_set_vl_onexec(struct task_struct *task, enum vec_type type, + unsigned long vl) { - task->thread.sve_vl_onexec = vl; + task->thread.vl_onexec[type] = vl; } /* @@ -1074,10 +1088,43 @@ void fpsimd_thread_switch(struct task_struct *next) __put_cpu_fpsimd_context(); } -void fpsimd_flush_thread(void) +static void fpsimd_flush_thread_vl(enum vec_type type) { int vl, supported_vl; + /* + * Reset the task vector length as required. This is where we + * ensure that all user tasks have a valid vector length + * configured: no kernel task can become a user task without + * an exec and hence a call to this function. By the time the + * first call to this function is made, all early hardware + * probing is complete, so __sve_default_vl should be valid. + * If a bug causes this to go wrong, we make some noise and + * try to fudge thread.sve_vl to a safe value here. + */ + vl = task_get_vl_onexec(current, type); + if (!vl) + vl = get_default_vl(type); + + if (WARN_ON(!sve_vl_valid(vl))) + vl = SVE_VL_MIN; + + supported_vl = find_supported_vector_length(type, vl); + if (WARN_ON(supported_vl != vl)) + vl = supported_vl; + + task_set_vl(current, type, vl); + + /* + * If the task is not set to inherit, ensure that the vector + * length will be reset by a subsequent exec: + */ + if (!test_thread_flag(vec_vl_inherit_flag(type))) + task_set_vl_onexec(current, type, 0); +} + +void fpsimd_flush_thread(void) +{ if (!system_supports_fpsimd()) return; @@ -1090,37 +1137,7 @@ void fpsimd_flush_thread(void) if (system_supports_sve()) { clear_thread_flag(TIF_SVE); sve_free(current); - - /* - * Reset the task vector length as required. - * This is where we ensure that all user tasks have a valid - * vector length configured: no kernel task can become a user - * task without an exec and hence a call to this function. - * By the time the first call to this function is made, all - * early hardware probing is complete, so __sve_default_vl - * should be valid. - * If a bug causes this to go wrong, we make some noise and - * try to fudge thread.sve_vl to a safe value here. - */ - vl = task_get_sve_vl_onexec(current); - if (!vl) - vl = get_sve_default_vl(); - - if (WARN_ON(!sve_vl_valid(vl))) - vl = SVE_VL_MIN; - - supported_vl = find_supported_vector_length(ARM64_VEC_SVE, vl); - if (WARN_ON(supported_vl != vl)) - vl = supported_vl; - - task_set_sve_vl(current, vl); - - /* - * If the task is not set to inherit, ensure that the vector - * length will be reset by a subsequent exec: - */ - if (!test_thread_flag(TIF_SVE_VL_INHERIT)) - task_set_sve_vl_onexec(current, 0); + fpsimd_flush_thread_vl(ARM64_VEC_SVE); } put_cpu_fpsimd_context(); |