Messages in this thread Patch in this message | | | From | Zayd Qumsieh <> | Subject | [PATCH 2/3] tso: aarch64: context-switch tso bit on thread switch | Date | Wed, 10 Apr 2024 14:16:40 -0700 |
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Add support for context-switching the tso bit when the thread switches. This allows per-thread setting of the tso bit, and prepares future work to allow userspace to set the tso bit of their thread at will.
Signed-off-by: Zayd Qumsieh <zayd_qumsieh@apple.com> --- arch/arm64/include/asm/processor.h | 4 ++++ arch/arm64/include/asm/tso.h | 1 + arch/arm64/kernel/process.c | 9 +++++++++ arch/arm64/kernel/tso.c | 9 +++++++++ 4 files changed, 23 insertions(+)
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index f77371232d8c..a247bee24c73 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -4,6 +4,7 @@ * * Copyright (C) 1995-1999 Russell King * Copyright (C) 2012 ARM Ltd. + * Copyright © 2024 Apple Inc. All rights reserved. */ #ifndef __ASM_PROCESSOR_H #define __ASM_PROCESSOR_H @@ -184,6 +185,9 @@ struct thread_struct { u64 sctlr_user; u64 svcr; u64 tpidr2_el0; +#ifdef CONFIG_ARM64_TSO + bool tso; +#endif }; static inline unsigned int thread_get_vl(struct thread_struct *thread, diff --git a/arch/arm64/include/asm/tso.h b/arch/arm64/include/asm/tso.h index d9e1a7602c44..405e9a5efdf5 100644 --- a/arch/arm64/include/asm/tso.h +++ b/arch/arm64/include/asm/tso.h @@ -12,6 +12,7 @@ #include <linux/types.h> int modify_tso_enable(bool tso_enable); +void tso_thread_switch(struct task_struct *next); #endif /* CONFIG_ARM64_TSO */ #endif /* __ASM_TSO_H */ diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 4ae31b7af6c3..3831c1a97f79 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -5,6 +5,7 @@ * Original Copyright (C) 1995 Linus Torvalds * Copyright (C) 1996-2000 Russell King - Converted to ARM. * Copyright (C) 2012 ARM Ltd. + * Copyright © 2024 Apple Inc. All rights reserved. */ #include <linux/compat.h> #include <linux/efi.h> @@ -55,6 +56,7 @@ #include <asm/stacktrace.h> #include <asm/switch_to.h> #include <asm/system_misc.h> +#include <asm/tso.h> #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) #include <linux/stackprotector.h> @@ -530,6 +532,9 @@ struct task_struct *__switch_to(struct task_struct *prev, ssbs_thread_switch(next); erratum_1418040_thread_switch(next); ptrauth_thread_switch_user(next); +#ifdef CONFIG_ARM64_TSO + tso_thread_switch(next); +#endif /* * Complete any pending TLB or cache maintenance on this CPU in case @@ -651,6 +656,10 @@ void arch_setup_new_exec(void) arch_prctl_spec_ctrl_set(current, PR_SPEC_STORE_BYPASS, PR_SPEC_ENABLE); } + +#ifdef CONFIG_ARM64_TSO + modify_tso_enable(false); +#endif } #ifdef CONFIG_ARM64_TAGGED_ADDR_ABI diff --git a/arch/arm64/kernel/tso.c b/arch/arm64/kernel/tso.c index b3964db7aa66..9a15d825943f 100644 --- a/arch/arm64/kernel/tso.c +++ b/arch/arm64/kernel/tso.c @@ -3,6 +3,7 @@ * Copyright © 2024 Apple Inc. All rights reserved. */ +#include <linux/sched.h> #include <linux/types.h> #include <asm/cputype.h> @@ -49,4 +50,12 @@ int modify_tso_enable(bool tso_enable) return 0; } +void tso_thread_switch(struct task_struct *next) +{ + if (tso_supported()) { + current->thread.tso = tso_enabled(); + modify_tso_enable(next->thread.tso); + } +} + #endif /* CONFIG_ARM64_TSO */ -- 2.39.3 (Apple Git-146)
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