/* 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
 */
#define init_new_context init_new_context
extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
#define destroy_context destroy_context
extern void destroy_context(struct mm_struct *mm);
#ifdef CONFIG_SPAPR_TCE_IOMMU
struct mm_iommu_table_group_mem_t;

extern bool mm_iommu_preregistered(struct mm_struct *mm);
extern long mm_iommu_new(struct mm_struct *mm,
                unsigned long ua, unsigned long entries,
                struct mm_iommu_table_group_mem_t **pmem);
extern long mm_iommu_newdev(struct mm_struct *mm, unsigned long ua,
                unsigned long entries, unsigned long dev_hpa,
                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 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_get(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 int pageshift, unsigned long *hpa);
extern bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
                unsigned int pageshift, unsigned long *size);
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);
#else
static inline bool mm_iommu_is_devmem(struct mm_struct *mm, unsigned long hpa,
                unsigned int pageshift, unsigned long *size)
{
        return false;
}
static inline void mm_iommu_init(struct mm_struct *mm) { }
#endif
extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);

#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);
void __init hash__reserve_context_id(int id);
extern void __destroy_context(int context_id);
static inline void mmu_context_init(void) { }

#ifdef CONFIG_PPC_64S_HASH_MMU
static inline int alloc_extended_context(struct mm_struct *mm,
                                         unsigned long ea)
{
        int context_id;

        int index = ea >> MAX_EA_BITS_PER_CONTEXT;

        context_id = hash__alloc_context_id();
        if (context_id < 0)
                return context_id;

        VM_WARN_ON(mm->context.extended_id[index]);
        mm->context.extended_id[index] = context_id;
        return context_id;
}

static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
{
        int context_id;

        context_id = get_user_context(&mm->context, ea);
        if (!context_id)
                return true;
        return false;
}
#endif

#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);
static inline int alloc_extended_context(struct mm_struct *mm,
                                         unsigned long ea)
{
        /* non book3s_64 should never find this called */
        WARN_ON(1);
        return -ENOMEM;
}

static inline bool need_extra_context(struct mm_struct *mm, unsigned long ea)
{
        return false;
}
#endif

#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)
{
        VM_WARN_ON_ONCE(atomic_read(&mm->context.active_cpus) <= 0);
        atomic_dec(&mm->context.active_cpus);
}

static inline void mm_context_add_copro(struct mm_struct *mm)
{
        /*
         * If any copro is in use, increment the active CPU count
         * in order to force TLB invalidations to be global as to
         * propagate to the Nest MMU.
         */
        if (atomic_inc_return(&mm->context.copros) == 1)
                inc_mm_active_cpus(mm);
}

static inline void mm_context_remove_copro(struct mm_struct *mm)
{
        int c;

        /*
         * When removing the last copro, we need to broadcast a global
         * flush of the full mm, as the next TLBI may be local and the
         * nMMU and/or PSL need to be cleaned up.
         *
         * Both the 'copros' and 'active_cpus' counts are looked at in
         * radix__flush_all_mm() to determine the scope (local/global)
         * of the TLBIs, so we need to flush first before decrementing
         * 'copros'. If this API is used by several callers for the
         * same context, it can lead to over-flushing. It's hopefully
         * not common enough to be a problem.
         *
         * 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. Note that we can't drop 'copros' either, as
         * it could make some invalidations local with no flush
         * in-between.
         */
        if (radix_enabled()) {
                radix__flush_all_mm(mm);

                c = atomic_dec_if_positive(&mm->context.copros);
                /* Detect imbalance between add and remove */
                WARN_ON(c < 0);

                if (c == 0)
                        dec_mm_active_cpus(mm);
        }
}

/*
 * vas_windows counter shows number of open windows in the mm
 * context. During context switch, use this counter to clear the
 * foreign real address mapping (CP_ABORT) for the thread / process
 * that intend to use COPY/PASTE. When a process closes all windows,
 * disable CP_ABORT which is expensive to run.
 *
 * For user context, register a copro so that TLBIs are seen by the
 * nest MMU. mm_context_add/remove_vas_window() are used only for user
 * space windows.
 */
static inline void mm_context_add_vas_window(struct mm_struct *mm)
{
        atomic_inc(&mm->context.vas_windows);
        mm_context_add_copro(mm);
}

static inline void mm_context_remove_vas_window(struct mm_struct *mm)
{
        int v;

        mm_context_remove_copro(mm);
        v = atomic_dec_if_positive(&mm->context.vas_windows);

        /* Detect imbalance between add and remove */
        WARN_ON(v < 0);
}
#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

#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
void do_h_rpt_invalidate_prt(unsigned long pid, unsigned long lpid,
                             unsigned long type, unsigned long pg_sizes,
                             unsigned long start, unsigned long end);
#else
static inline void do_h_rpt_invalidate_prt(unsigned long pid,
                                           unsigned long lpid,
                                           unsigned long type,
                                           unsigned long pg_sizes,
                                           unsigned long start,
                                           unsigned long end) { }
#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

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

/* We don't currently use enter_lazy_tlb() for anything */
#ifdef CONFIG_PPC_BOOK3E_64
#define enter_lazy_tlb enter_lazy_tlb
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 */
        get_paca()->pgd = NULL;
}
#endif

extern void arch_exit_mmap(struct mm_struct *mm);

#ifdef CONFIG_PPC_MEM_KEYS
bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
                               bool execute, bool foreign);
void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm);
#else /* CONFIG_PPC_MEM_KEYS */
static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
                bool write, bool execute, bool foreign)
{
        /* by default, allow everything */
        return true;
}

#define pkey_mm_init(mm)
#define arch_dup_pkeys(oldmm, mm)

static inline u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags)
{
        return 0x0UL;
}

#endif /* CONFIG_PPC_MEM_KEYS */

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

#include <asm-generic/mmu_context.h>

#endif /* __KERNEL__ */
#endif /* __ASM_POWERPC_MMU_CONTEXT_H */