Commit c9826613 authored by Rik van Riel's avatar Rik van Riel Committed by Ingo Molnar
Browse files

x86/mm: Add global ASID process exit helpers 



A global ASID is allocated for the lifetime of a process. Free the global ASID
at process exit time.

  [ bp: Massage, create helpers, hide details inside them. ]

Signed-off-by: default avatarRik van Riel <riel@surriel.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250226030129.530345-10-riel@surriel.com
parent be88a1dd

arch/x86/include/asm/mmu_context.h

+7 −1
Original line number Diff line number Diff line
@@ -2,7 +2,6 @@ 
#ifndef _ASM_X86_MMU_CONTEXT_H

#define _ASM_X86_MMU_CONTEXT_H



#include <asm/desc.h>

#include <linux/atomic.h>

#include <linux/mm_types.h>

#include <linux/pkeys.h>
@@ -13,6 +12,7 @@ 
#include <asm/paravirt.h>

#include <asm/debugreg.h>

#include <asm/gsseg.h>

#include <asm/desc.h>



extern atomic64_t last_mm_ctx_id;
@@ -139,6 +139,9 @@ 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);



/*
@@ -163,6 +166,8 @@ static inline int init_new_context(struct task_struct *tsk, 
		mm->context.execute_only_pkey = -1;

	}

#endif



	mm_init_global_asid(mm);

	mm_reset_untag_mask(mm);

	init_new_context_ldt(mm);

	return 0;
@@ -172,6 +177,7 @@ static inline int init_new_context(struct task_struct *tsk, 
static inline void destroy_context(struct mm_struct *mm)

{

	destroy_context_ldt(mm);

	mm_free_global_asid(mm);

}



extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,

arch/x86/include/asm/tlbflush.h

+9 −0
Original line number Diff line number Diff line
@@ -261,6 +261,14 @@ static inline u16 mm_global_asid(struct mm_struct *mm) 
	return asid;

}



static inline void mm_init_global_asid(struct mm_struct *mm)

{

	if (cpu_feature_enabled(X86_FEATURE_INVLPGB)) {

		mm->context.global_asid = 0;

		mm->context.asid_transition = false;

	}

}



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

{

	/*
@@ -281,6 +289,7 @@ static inline bool mm_in_asid_transition(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_assign_global_asid(struct mm_struct *mm, u16 asid) { }

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

#endif /* CONFIG_BROADCAST_TLB_FLUSH */