91 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  *  include/asm-s390/mmu_context.h
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|  *
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|  *  S390 version
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|  *
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|  *  Derived from "include/asm-i386/mmu_context.h"
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|  */
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| 
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| #ifndef __S390_MMU_CONTEXT_H
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| #define __S390_MMU_CONTEXT_H
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| 
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| #include <asm/pgalloc.h>
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| #include <asm/uaccess.h>
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| #include <asm-generic/mm_hooks.h>
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| 
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| static inline int init_new_context(struct task_struct *tsk,
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| 				   struct mm_struct *mm)
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| {
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| 	mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
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| #ifdef CONFIG_64BIT
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| 	mm->context.asce_bits |= _ASCE_TYPE_REGION3;
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| #endif
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| 	if (current->mm->context.alloc_pgste) {
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| 		/*
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| 		 * alloc_pgste indicates, that any NEW context will be created
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| 		 * with extended page tables. The old context is unchanged. The
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| 		 * page table allocation and the page table operations will
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| 		 * look at has_pgste to distinguish normal and extended page
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| 		 * tables. The only way to create extended page tables is to
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| 		 * set alloc_pgste and then create a new context (e.g. dup_mm).
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| 		 * The page table allocation is called after init_new_context
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| 		 * and if has_pgste is set, it will create extended page
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| 		 * tables.
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| 		 */
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| 		mm->context.noexec = 0;
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| 		mm->context.has_pgste = 1;
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| 		mm->context.alloc_pgste = 1;
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| 	} else {
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| 		mm->context.noexec = s390_noexec;
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| 		mm->context.has_pgste = 0;
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| 		mm->context.alloc_pgste = 0;
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| 	}
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| 	mm->context.asce_limit = STACK_TOP_MAX;
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| 	crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
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| 	return 0;
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| }
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| 
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| #define destroy_context(mm)             do { } while (0)
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| 
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| #ifndef __s390x__
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| #define LCTL_OPCODE "lctl"
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| #else
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| #define LCTL_OPCODE "lctlg"
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| #endif
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| 
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| static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
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| {
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| 	pgd_t *pgd = mm->pgd;
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| 
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| 	S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
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| 	if (switch_amode) {
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| 		/* Load primary space page table origin. */
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| 		pgd = mm->context.noexec ? get_shadow_table(pgd) : pgd;
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| 		S390_lowcore.user_exec_asce = mm->context.asce_bits | __pa(pgd);
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| 		asm volatile(LCTL_OPCODE" 1,1,%0\n"
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| 			     : : "m" (S390_lowcore.user_exec_asce) );
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| 	} else
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| 		/* Load home space page table origin. */
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| 		asm volatile(LCTL_OPCODE" 13,13,%0"
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| 			     : : "m" (S390_lowcore.user_asce) );
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| 	set_fs(current->thread.mm_segment);
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| }
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| 
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| static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
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| 			     struct task_struct *tsk)
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| {
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| 	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
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| 	update_mm(next, tsk);
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| }
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| 
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| #define enter_lazy_tlb(mm,tsk)	do { } while (0)
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| #define deactivate_mm(tsk,mm)	do { } while (0)
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| 
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| static inline void activate_mm(struct mm_struct *prev,
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|                                struct mm_struct *next)
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| {
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|         switch_mm(prev, next, current);
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| }
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| 
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| #endif /* __S390_MMU_CONTEXT_H */
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