Commit 954fc7ac authored by Hou Wenlong's avatar Hou Wenlong Committed by Borislav Petkov (AMD)
Browse files

x86/mm: Hide mm_free_global_asid() definition under CONFIG_BROADCAST_TLB_FLUSH 



When CONFIG_BROADCAST_TLB_FLUSH is not enabled, mm_free_global_asid() remains
a globally visible symbol and generates a useless function call to it in
destroy_context(). Therefore, hide the mm_free_global_asid() definition under
CONFIG_BROADCAST_TLB_FLUSH and provide a static inline empty version when it
is not enabled to remove the function call.

Signed-off-by: default avatarHou Wenlong <houwenlong.hwl@antgroup.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarRik van Riel <riel@surriel.com>
Link: https://patch.msgid.link/b262a8ec8076fb26bb692aaf113848b1e6f40e40.1768448079.git.houwenlong.hwl@antgroup.com
parent 8a4e92b3

arch/x86/include/asm/mmu_context.h

+0 −2
Original line number Diff line number Diff line
@@ -139,9 +139,7 @@ static inline void mm_reset_untag_mask(struct mm_struct *mm) 
#define enter_lazy_tlb enter_lazy_tlb

extern void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk);



#define mm_init_global_asid mm_init_global_asid

extern void mm_init_global_asid(struct mm_struct *mm);



extern void mm_free_global_asid(struct mm_struct *mm);



/*

arch/x86/include/asm/tlbflush.h

+3 −0
Original line number Diff line number Diff line
@@ -292,9 +292,12 @@ static inline bool mm_in_asid_transition(struct mm_struct *mm) 


	return mm && READ_ONCE(mm->context.asid_transition);

}



extern void mm_free_global_asid(struct mm_struct *mm);

#else

static inline u16 mm_global_asid(struct mm_struct *mm) { return 0; }

static inline void mm_init_global_asid(struct mm_struct *mm) { }

static inline void mm_free_global_asid(struct mm_struct *mm) { }

static inline void mm_assign_global_asid(struct mm_struct *mm, u16 asid) { }

static inline void mm_clear_asid_transition(struct mm_struct *mm) { }

static inline bool mm_in_asid_transition(struct mm_struct *mm) { return false; }

arch/x86/mm/tlb.c

+2 −2
Original line number Diff line number Diff line
@@ -401,6 +401,7 @@ static void use_global_asid(struct mm_struct *mm) 
	mm_assign_global_asid(mm, asid);

}



#ifdef CONFIG_BROADCAST_TLB_FLUSH

void mm_free_global_asid(struct mm_struct *mm)

{

	if (!cpu_feature_enabled(X86_FEATURE_INVLPGB))
@@ -412,13 +413,12 @@ void mm_free_global_asid(struct mm_struct *mm) 
	guard(raw_spinlock_irqsave)(&global_asid_lock);



	/* The global ASID can be re-used only after flush at wrap-around. */

#ifdef CONFIG_BROADCAST_TLB_FLUSH

	__set_bit(mm->context.global_asid, global_asid_freed);



	mm->context.global_asid = 0;

	global_asid_available++;

#endif

}

#endif



/*

 * Is the mm transitioning from a CPU-local ASID to a global ASID?