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authorWill Deacon <will@kernel.org>2024-01-04 15:27:29 +0300
committerWill Deacon <will@kernel.org>2024-01-04 15:27:29 +0300
commit79eb42b269d425ec9c9e1d0613f62b273026de78 (patch)
tree0fdd7d88b1637a5b94464f9ecd9c6f05e4bebb32 /arch/arm64/include
parente90a8a210fd0fc633ed9c6c7d76ad35ae65d37dc (diff)
parent2632e25217696712681dd1f3ecc0d71624ea3b23 (diff)
downloadlinux-79eb42b269d425ec9c9e1d0613f62b273026de78.tar.xz
Merge branch 'for-next/fpsimd' into for-next/core
* for-next/fpsimd: arm64: fpsimd: Implement lazy restore for kernel mode FPSIMD arm64: fpsimd: Preserve/restore kernel mode NEON at context switch arm64: fpsimd: Drop unneeded 'busy' flag
Diffstat (limited to 'arch/arm64/include')
-rw-r--r--arch/arm64/include/asm/processor.h3
-rw-r--r--arch/arm64/include/asm/simd.h11
-rw-r--r--arch/arm64/include/asm/thread_info.h1
3 files changed, 5 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index e5bc54522e71..5b0a04810b23 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -167,6 +167,9 @@ struct thread_struct {
unsigned long fault_address; /* fault info */
unsigned long fault_code; /* ESR_EL1 value */
struct debug_info debug; /* debugging */
+
+ struct user_fpsimd_state kernel_fpsimd_state;
+ unsigned int kernel_fpsimd_cpu;
#ifdef CONFIG_ARM64_PTR_AUTH
struct ptrauth_keys_user keys_user;
#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL
diff --git a/arch/arm64/include/asm/simd.h b/arch/arm64/include/asm/simd.h
index 6a75d7ecdcaa..8e86c9e70e48 100644
--- a/arch/arm64/include/asm/simd.h
+++ b/arch/arm64/include/asm/simd.h
@@ -12,8 +12,6 @@
#include <linux/preempt.h>
#include <linux/types.h>
-DECLARE_PER_CPU(bool, fpsimd_context_busy);
-
#ifdef CONFIG_KERNEL_MODE_NEON
/*
@@ -28,17 +26,10 @@ static __must_check inline bool may_use_simd(void)
/*
* We must make sure that the SVE has been initialized properly
* before using the SIMD in kernel.
- * fpsimd_context_busy is only set while preemption is disabled,
- * and is clear whenever preemption is enabled. Since
- * this_cpu_read() is atomic w.r.t. preemption, fpsimd_context_busy
- * cannot change under our feet -- if it's set we cannot be
- * migrated, and if it's clear we cannot be migrated to a CPU
- * where it is set.
*/
return !WARN_ON(!system_capabilities_finalized()) &&
system_supports_fpsimd() &&
- !in_hardirq() && !irqs_disabled() && !in_nmi() &&
- !this_cpu_read(fpsimd_context_busy);
+ !in_hardirq() && !irqs_disabled() && !in_nmi();
}
#else /* ! CONFIG_KERNEL_MODE_NEON */
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 553d1bc559c6..e72a3bf9e563 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -80,6 +80,7 @@ void arch_setup_new_exec(void);
#define TIF_TAGGED_ADDR 26 /* Allow tagged user addresses */
#define TIF_SME 27 /* SME in use */
#define TIF_SME_VL_INHERIT 28 /* Inherit SME vl_onexec across exec */
+#define TIF_KERNEL_FPSTATE 29 /* Task is in a kernel mode FPSIMD section */
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)