linux_kernel/arch/powerpc/include/asm/mmu_context.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_POWERPC_MMU_CONTEXT_H
#define __ASM_POWERPC_MMU_CONTEXT_H
#ifdef __KERNEL__

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <asm/mmu.h>	
#include <asm/cputable.h>
#include <asm/cputhreads.h>

/*
 * Most if the context management is out of line
 */
extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
extern void destroy_context(struct mm_struct *mm);
#ifdef CONFIG_SPAPR_TCE_IOMMU
struct mm_iommu_table_group_mem_t;

extern int isolate_lru_page(struct page *page);	/* from internal.h */
extern bool mm_iommu_preregistered(struct mm_struct *mm);
extern long mm_iommu_get(struct mm_struct *mm,
		unsigned long ua, unsigned long entries,
		struct mm_iommu_table_group_mem_t **pmem);
extern long mm_iommu_put(struct mm_struct *mm,
		struct mm_iommu_table_group_mem_t *mem);
extern void mm_iommu_init(struct mm_struct *mm);
extern void mm_iommu_cleanup(struct mm_struct *mm);
extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm,
		unsigned long ua, unsigned long size);
extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup_rm(
		struct mm_struct *mm, unsigned long ua, unsigned long size);
extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm,
		unsigned long ua, unsigned long entries);
extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
		unsigned long ua, unsigned long *hpa);
extern long mm_iommu_ua_to_hpa_rm(struct mm_iommu_table_group_mem_t *mem,
		unsigned long ua, unsigned long *hpa);
extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
#endif
extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
extern void set_context(unsigned long id, pgd_t *pgd);

#ifdef CONFIG_PPC_BOOK3S_64
extern void radix__switch_mmu_context(struct mm_struct *prev,
				      struct mm_struct *next);
static inline void switch_mmu_context(struct mm_struct *prev,
				      struct mm_struct *next,
				      struct task_struct *tsk)
{
	if (radix_enabled())
		return radix__switch_mmu_context(prev, next);
	return switch_slb(tsk, next);
}

extern int hash__alloc_context_id(void);
extern void hash__reserve_context_id(int id);
extern void __destroy_context(int context_id);
static inline void mmu_context_init(void) { }
#else
extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
			       struct task_struct *tsk);
extern unsigned long __init_new_context(void);
extern void __destroy_context(unsigned long context_id);
extern void mmu_context_init(void);
#endif

#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
#else
static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
#endif

extern void switch_cop(struct mm_struct *next);
extern int use_cop(unsigned long acop, struct mm_struct *mm);
extern void drop_cop(unsigned long acop, struct mm_struct *mm);

#ifdef CONFIG_PPC_BOOK3S_64
static inline void inc_mm_active_cpus(struct mm_struct *mm)
{
	atomic_inc(&mm->context.active_cpus);
}

static inline void dec_mm_active_cpus(struct mm_struct *mm)
{
	atomic_dec(&mm->context.active_cpus);
}

static inline void mm_context_add_copro(struct mm_struct *mm)
{
	/*
	 * On hash, should only be called once over the lifetime of
	 * the context, as we can't decrement the active cpus count
	 * and flush properly for the time being.
	 */
	inc_mm_active_cpus(mm);
}

static inline void mm_context_remove_copro(struct mm_struct *mm)
{
	/*
	 * Need to broadcast a global flush of the full mm before
	 * decrementing active_cpus count, as the next TLBI may be
	 * local and the nMMU and/or PSL need to be cleaned up.
	 * Should be rare enough so that it's acceptable.
	 *
	 * Skip on hash, as we don't know how to do the proper flush
	 * for the time being. Invalidations will remain global if
	 * used on hash.
	 */
	if (radix_enabled()) {
		flush_all_mm(mm);
		dec_mm_active_cpus(mm);
	}
}
#else
static inline void inc_mm_active_cpus(struct mm_struct *mm) { }
static inline void dec_mm_active_cpus(struct mm_struct *mm) { }
static inline void mm_context_add_copro(struct mm_struct *mm) { }
static inline void mm_context_remove_copro(struct mm_struct *mm) { }
#endif


extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
			       struct task_struct *tsk);

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
			     struct task_struct *tsk)
{
	unsigned long flags;

	local_irq_save(flags);
	switch_mm_irqs_off(prev, next, tsk);
	local_irq_restore(flags);
}
#define switch_mm_irqs_off switch_mm_irqs_off


#define deactivate_mm(tsk,mm)	do { } while (0)

/*
 * After we have set current->mm to a new value, this activates
 * the context for the new mm so we see the new mappings.
 */
static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
{
	switch_mm(prev, next, current);
}

/* We don't currently use enter_lazy_tlb() for anything */
static inline void enter_lazy_tlb(struct mm_struct *mm,
				  struct task_struct *tsk)
{
	/* 64-bit Book3E keeps track of current PGD in the PACA */
#ifdef CONFIG_PPC_BOOK3E_64
	get_paca()->pgd = NULL;
#endif
}

static inline int arch_dup_mmap(struct mm_struct *oldmm,
				struct mm_struct *mm)
{
	return 0;
}

#ifndef CONFIG_PPC_BOOK3S_64
static inline void arch_exit_mmap(struct mm_struct *mm)
{
}
#else
extern void arch_exit_mmap(struct mm_struct *mm);
#endif

static inline void arch_unmap(struct mm_struct *mm,
			      struct vm_area_struct *vma,
			      unsigned long start, unsigned long end)
{
	if (start <= mm->context.vdso_base && mm->context.vdso_base < end)
		mm->context.vdso_base = 0;
}

static inline void arch_bprm_mm_init(struct mm_struct *mm,
				     struct vm_area_struct *vma)
{
}

static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
		bool write, bool execute, bool foreign)
{
	/* by default, allow everything */
	return true;
}
#endif /* __KERNEL__ */
#endif /* __ASM_POWERPC_MMU_CONTEXT_H */