[PATCH v14 3/4] arm64: Use generic TIF bits for common thread flags

[Jinjie Ruan]

Use the generic TIF bits defined in <asm-generic/thread_info_tif.h> for
standard thread flags (TIF_SIGPENDING, TIF_NEED_RESCHED, TIF_NOTIFY_RESUME,
TIF_RESTORE_SIGMASK, TIF_SINGLESTEP, etc.) instead of defining
them locally.

Arm64-specific bits (TIF_FOREIGN_FPSTATE, TIF_MTE_ASYNC_FAULT, TIF_SVE,
TIF_SSBD, etc.) are renumbered to start at bit 16 to avoid conflicts.

This enables RSEQ optimizations which require CONFIG_HAVE_GENERIC_TIF_BITS
combined with the generic entry infrastructure (already used by arm64).

By the way, remove TIF_FREEZE because this flag became unused since
commit d88e4cb67197 ("freezer: remove now unused TIF_FREEZE").

Cc: Thomas Gleixner <tglx at kernel.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky at arm.com>
Reviewed-by: Linus Walleij <linusw at kernel.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun at arm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie at huawei.com>
---
 arch/arm64/Kconfig                   |  1 +
 arch/arm64/include/asm/thread_info.h | 61 ++++++++++++----------------
 2 files changed, 27 insertions(+), 35 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 96fef01598be..33cf901fb1a0 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -224,6 +224,7 @@ config ARM64
 	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
 	select HAVE_BUILDTIME_MCOUNT_SORT
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
+	select HAVE_GENERIC_TIF_BITS
 	select HAVE_GUP_FAST
 	select HAVE_FTRACE_GRAPH_FUNC
 	select HAVE_FUNCTION_TRACER
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index f89a15dc6ad5..57c37b05b961 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -58,42 +58,33 @@ void arch_setup_new_exec(void);
 
 #endif
 
-#define TIF_SIGPENDING		0	/* signal pending */
-#define TIF_NEED_RESCHED	1	/* rescheduling necessary */
-#define TIF_NEED_RESCHED_LAZY	2	/* Lazy rescheduling needed */
-#define TIF_NOTIFY_RESUME	3	/* callback before returning to user */
-#define TIF_FOREIGN_FPSTATE	4	/* CPU's FP state is not current's */
-#define TIF_UPROBE		5	/* uprobe breakpoint or singlestep */
-#define TIF_MTE_ASYNC_FAULT	6	/* MTE Asynchronous Tag Check Fault */
-#define TIF_NOTIFY_SIGNAL	7	/* signal notifications exist */
-#define TIF_PATCH_PENDING	13	/* pending live patching update */
-#define TIF_MEMDIE		18	/* is terminating due to OOM killer */
-#define TIF_FREEZE		19
-#define TIF_RESTORE_SIGMASK	20
-#define TIF_SINGLESTEP		21
-#define TIF_32BIT		22	/* 32bit process */
-#define TIF_SVE			23	/* Scalable Vector Extension in use */
-#define TIF_SVE_VL_INHERIT	24	/* Inherit SVE vl_onexec across exec */
-#define TIF_SSBD		25	/* Wants SSB mitigation */
-#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_TSC_SIGSEGV		30	/* SIGSEGV on counter-timer access */
-#define TIF_LAZY_MMU_PENDING	31	/* Ops pending for lazy mmu mode exit */
+/*
+ * Tell the generic TIF infrastructure which bits arm64 supports
+ */
+#define HAVE_TIF_NEED_RESCHED_LAZY
+#define HAVE_TIF_RESTORE_SIGMASK
+#define HAVE_TIF_SINGLESTEP
+
+#include <asm-generic/thread_info_tif.h>
+
+#define TIF_FOREIGN_FPSTATE	16	/* CPU's FP state is not current's */
+#define TIF_MTE_ASYNC_FAULT	17	/* MTE Asynchronous Tag Check Fault */
+#define TIF_32BIT		18      /* 32bit process */
+#define TIF_SVE			19	/* Scalable Vector Extension in use */
+#define TIF_SVE_VL_INHERIT	20	/* Inherit SVE vl_onexec across exec */
+#define TIF_SSBD		21	/* Wants SSB mitigation */
+#define TIF_TAGGED_ADDR		22	/* Allow tagged user addresses */
+#define TIF_SME			23	/* SME in use */
+#define TIF_SME_VL_INHERIT	24	/* Inherit SME vl_onexec across exec */
+#define TIF_KERNEL_FPSTATE	25	/* Task is in a kernel mode FPSIMD section */
+#define TIF_TSC_SIGSEGV		26	/* SIGSEGV on counter-timer access */
+#define TIF_LAZY_MMU_PENDING	27	/* Ops pending for lazy mmu mode exit */
 
-#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
-#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
-#define _TIF_NEED_RESCHED_LAZY	(1 << TIF_NEED_RESCHED_LAZY)
-#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
-#define _TIF_FOREIGN_FPSTATE	(1 << TIF_FOREIGN_FPSTATE)
-#define _TIF_PATCH_PENDING	(1 << TIF_PATCH_PENDING)
-#define _TIF_UPROBE		(1 << TIF_UPROBE)
-#define _TIF_32BIT		(1 << TIF_32BIT)
-#define _TIF_SVE		(1 << TIF_SVE)
-#define _TIF_MTE_ASYNC_FAULT	(1 << TIF_MTE_ASYNC_FAULT)
-#define _TIF_NOTIFY_SIGNAL	(1 << TIF_NOTIFY_SIGNAL)
-#define _TIF_TSC_SIGSEGV	(1 << TIF_TSC_SIGSEGV)
+#define _TIF_FOREIGN_FPSTATE	BIT(TIF_FOREIGN_FPSTATE)
+#define _TIF_32BIT		BIT(TIF_32BIT)
+#define _TIF_SVE		BIT(TIF_SVE)
+#define _TIF_MTE_ASYNC_FAULT	BIT(TIF_MTE_ASYNC_FAULT)
+#define _TIF_TSC_SIGSEGV	BIT(TIF_TSC_SIGSEGV)
 
 #ifdef CONFIG_SHADOW_CALL_STACK
 #define INIT_SCS							\
-- 
2.34.1