// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
 *
 * Authors:
 *     Alexander Graf <agraf@suse.de>
 */

#include <linux/kvm_host.h>
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/rculist.h>

#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/machdep.h>
#include <asm/mmu_context.h>
#include <asm/hw_irq.h>

#include "trace_pr.h"

#define PTE_SIZE        12

static struct kmem_cache *hpte_cache;

static inline u64 kvmppc_mmu_hash_pte(u64 eaddr)
{
        return hash_64(eaddr >> PTE_SIZE, HPTEG_HASH_BITS_PTE);
}

static inline u64 kvmppc_mmu_hash_pte_long(u64 eaddr)
{
        return hash_64((eaddr & 0x0ffff000) >> PTE_SIZE,
                       HPTEG_HASH_BITS_PTE_LONG);
}

static inline u64 kvmppc_mmu_hash_vpte(u64 vpage)
{
        return hash_64(vpage & 0xfffffffffULL, HPTEG_HASH_BITS_VPTE);
}

static inline u64 kvmppc_mmu_hash_vpte_long(u64 vpage)
{
        return hash_64((vpage & 0xffffff000ULL) >> 12,
                       HPTEG_HASH_BITS_VPTE_LONG);
}

#ifdef CONFIG_PPC_BOOK3S_64
static inline u64 kvmppc_mmu_hash_vpte_64k(u64 vpage)
{
        return hash_64((vpage & 0xffffffff0ULL) >> 4,
                       HPTEG_HASH_BITS_VPTE_64K);
}
#endif

void kvmppc_mmu_hpte_cache_map(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
{
        u64 index;
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);

        trace_kvm_book3s_mmu_map(pte);

        spin_lock(&vcpu3s->mmu_lock);

        /* Add to ePTE list */
        index = kvmppc_mmu_hash_pte(pte->pte.eaddr);
        hlist_add_head_rcu(&pte->list_pte, &vcpu3s->hpte_hash_pte[index]);

        /* Add to ePTE_long list */
        index = kvmppc_mmu_hash_pte_long(pte->pte.eaddr);
        hlist_add_head_rcu(&pte->list_pte_long,
                           &vcpu3s->hpte_hash_pte_long[index]);

        /* Add to vPTE list */
        index = kvmppc_mmu_hash_vpte(pte->pte.vpage);
        hlist_add_head_rcu(&pte->list_vpte, &vcpu3s->hpte_hash_vpte[index]);

        /* Add to vPTE_long list */
        index = kvmppc_mmu_hash_vpte_long(pte->pte.vpage);
        hlist_add_head_rcu(&pte->list_vpte_long,
                           &vcpu3s->hpte_hash_vpte_long[index]);

#ifdef CONFIG_PPC_BOOK3S_64
        /* Add to vPTE_64k list */
        index = kvmppc_mmu_hash_vpte_64k(pte->pte.vpage);
        hlist_add_head_rcu(&pte->list_vpte_64k,
                           &vcpu3s->hpte_hash_vpte_64k[index]);
#endif

        vcpu3s->hpte_cache_count++;

        spin_unlock(&vcpu3s->mmu_lock);
}

static void invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);

        trace_kvm_book3s_mmu_invalidate(pte);

        /* Different for 32 and 64 bit */
        kvmppc_mmu_invalidate_pte(vcpu, pte);

        spin_lock(&vcpu3s->mmu_lock);

        /* pte already invalidated in between? */
        if (hlist_unhashed(&pte->list_pte)) {
                spin_unlock(&vcpu3s->mmu_lock);
                return;
        }

        hlist_del_init_rcu(&pte->list_pte);
        hlist_del_init_rcu(&pte->list_pte_long);
        hlist_del_init_rcu(&pte->list_vpte);
        hlist_del_init_rcu(&pte->list_vpte_long);
#ifdef CONFIG_PPC_BOOK3S_64
        hlist_del_init_rcu(&pte->list_vpte_64k);
#endif
        vcpu3s->hpte_cache_count--;

        spin_unlock(&vcpu3s->mmu_lock);

        kfree_rcu(pte, rcu_head);
}

static void kvmppc_mmu_pte_flush_all(struct kvm_vcpu *vcpu)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
        struct hpte_cache *pte;
        int i;

        rcu_read_lock();

        for (i = 0; i < HPTEG_HASH_NUM_VPTE_LONG; i++) {
                struct hlist_head *list = &vcpu3s->hpte_hash_vpte_long[i];

                hlist_for_each_entry_rcu(pte, list, list_vpte_long)
                        invalidate_pte(vcpu, pte);
        }

        rcu_read_unlock();
}

static void kvmppc_mmu_pte_flush_page(struct kvm_vcpu *vcpu, ulong guest_ea)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
        struct hlist_head *list;
        struct hpte_cache *pte;

        /* Find the list of entries in the map */
        list = &vcpu3s->hpte_hash_pte[kvmppc_mmu_hash_pte(guest_ea)];

        rcu_read_lock();

        /* Check the list for matching entries and invalidate */
        hlist_for_each_entry_rcu(pte, list, list_pte)
                if ((pte->pte.eaddr & ~0xfffUL) == guest_ea)
                        invalidate_pte(vcpu, pte);

        rcu_read_unlock();
}

static void kvmppc_mmu_pte_flush_long(struct kvm_vcpu *vcpu, ulong guest_ea)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
        struct hlist_head *list;
        struct hpte_cache *pte;

        /* Find the list of entries in the map */
        list = &vcpu3s->hpte_hash_pte_long[
                        kvmppc_mmu_hash_pte_long(guest_ea)];

        rcu_read_lock();

        /* Check the list for matching entries and invalidate */
        hlist_for_each_entry_rcu(pte, list, list_pte_long)
                if ((pte->pte.eaddr & 0x0ffff000UL) == guest_ea)
                        invalidate_pte(vcpu, pte);

        rcu_read_unlock();
}

void kvmppc_mmu_pte_flush(struct kvm_vcpu *vcpu, ulong guest_ea, ulong ea_mask)
{
        trace_kvm_book3s_mmu_flush("", vcpu, guest_ea, ea_mask);
        guest_ea &= ea_mask;

        switch (ea_mask) {
        case ~0xfffUL:
                kvmppc_mmu_pte_flush_page(vcpu, guest_ea);
                break;
        case 0x0ffff000:
                kvmppc_mmu_pte_flush_long(vcpu, guest_ea);
                break;
        case 0:
                /* Doing a complete flush -> start from scratch */
                kvmppc_mmu_pte_flush_all(vcpu);
                break;
        default:
                WARN_ON(1);
                break;
        }
}

/* Flush with mask 0xfffffffff */
static void kvmppc_mmu_pte_vflush_short(struct kvm_vcpu *vcpu, u64 guest_vp)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
        struct hlist_head *list;
        struct hpte_cache *pte;
        u64 vp_mask = 0xfffffffffULL;

        list = &vcpu3s->hpte_hash_vpte[kvmppc_mmu_hash_vpte(guest_vp)];

        rcu_read_lock();

        /* Check the list for matching entries and invalidate */
        hlist_for_each_entry_rcu(pte, list, list_vpte)
                if ((pte->pte.vpage & vp_mask) == guest_vp)
                        invalidate_pte(vcpu, pte);

        rcu_read_unlock();
}

#ifdef CONFIG_PPC_BOOK3S_64
/* Flush with mask 0xffffffff0 */
static void kvmppc_mmu_pte_vflush_64k(struct kvm_vcpu *vcpu, u64 guest_vp)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
        struct hlist_head *list;
        struct hpte_cache *pte;
        u64 vp_mask = 0xffffffff0ULL;

        list = &vcpu3s->hpte_hash_vpte_64k[
                kvmppc_mmu_hash_vpte_64k(guest_vp)];

        rcu_read_lock();

        /* Check the list for matching entries and invalidate */
        hlist_for_each_entry_rcu(pte, list, list_vpte_64k)
                if ((pte->pte.vpage & vp_mask) == guest_vp)
                        invalidate_pte(vcpu, pte);

        rcu_read_unlock();
}
#endif

/* Flush with mask 0xffffff000 */
static void kvmppc_mmu_pte_vflush_long(struct kvm_vcpu *vcpu, u64 guest_vp)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
        struct hlist_head *list;
        struct hpte_cache *pte;
        u64 vp_mask = 0xffffff000ULL;

        list = &vcpu3s->hpte_hash_vpte_long[
                kvmppc_mmu_hash_vpte_long(guest_vp)];

        rcu_read_lock();

        /* Check the list for matching entries and invalidate */
        hlist_for_each_entry_rcu(pte, list, list_vpte_long)
                if ((pte->pte.vpage & vp_mask) == guest_vp)
                        invalidate_pte(vcpu, pte);

        rcu_read_unlock();
}

void kvmppc_mmu_pte_vflush(struct kvm_vcpu *vcpu, u64 guest_vp, u64 vp_mask)
{
        trace_kvm_book3s_mmu_flush("v", vcpu, guest_vp, vp_mask);
        guest_vp &= vp_mask;

        switch(vp_mask) {
        case 0xfffffffffULL:
                kvmppc_mmu_pte_vflush_short(vcpu, guest_vp);
                break;
#ifdef CONFIG_PPC_BOOK3S_64
        case 0xffffffff0ULL:
                kvmppc_mmu_pte_vflush_64k(vcpu, guest_vp);
                break;
#endif
        case 0xffffff000ULL:
                kvmppc_mmu_pte_vflush_long(vcpu, guest_vp);
                break;
        default:
                WARN_ON(1);
                return;
        }
}

void kvmppc_mmu_pte_pflush(struct kvm_vcpu *vcpu, ulong pa_start, ulong pa_end)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
        struct hpte_cache *pte;
        int i;

        trace_kvm_book3s_mmu_flush("p", vcpu, pa_start, pa_end);

        rcu_read_lock();

        for (i = 0; i < HPTEG_HASH_NUM_VPTE_LONG; i++) {
                struct hlist_head *list = &vcpu3s->hpte_hash_vpte_long[i];

                hlist_for_each_entry_rcu(pte, list, list_vpte_long)
                        if ((pte->pte.raddr >= pa_start) &&
                            (pte->pte.raddr < pa_end))
                                invalidate_pte(vcpu, pte);
        }

        rcu_read_unlock();
}

struct hpte_cache *kvmppc_mmu_hpte_cache_next(struct kvm_vcpu *vcpu)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
        struct hpte_cache *pte;

        if (vcpu3s->hpte_cache_count == HPTEG_CACHE_NUM)
                kvmppc_mmu_pte_flush_all(vcpu);

        pte = kmem_cache_zalloc(hpte_cache, GFP_KERNEL);

        return pte;
}

void kvmppc_mmu_hpte_cache_free(struct hpte_cache *pte)
{
        kmem_cache_free(hpte_cache, pte);
}

void kvmppc_mmu_hpte_destroy(struct kvm_vcpu *vcpu)
{
        kvmppc_mmu_pte_flush(vcpu, 0, 0);
}

static void kvmppc_mmu_hpte_init_hash(struct hlist_head *hash_list, int len)
{
        int i;

        for (i = 0; i < len; i++)
                INIT_HLIST_HEAD(&hash_list[i]);
}

int kvmppc_mmu_hpte_init(struct kvm_vcpu *vcpu)
{
        struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);

        /* init hpte lookup hashes */
        kvmppc_mmu_hpte_init_hash(vcpu3s->hpte_hash_pte,
                                  ARRAY_SIZE(vcpu3s->hpte_hash_pte));
        kvmppc_mmu_hpte_init_hash(vcpu3s->hpte_hash_pte_long,
                                  ARRAY_SIZE(vcpu3s->hpte_hash_pte_long));
        kvmppc_mmu_hpte_init_hash(vcpu3s->hpte_hash_vpte,
                                  ARRAY_SIZE(vcpu3s->hpte_hash_vpte));
        kvmppc_mmu_hpte_init_hash(vcpu3s->hpte_hash_vpte_long,
                                  ARRAY_SIZE(vcpu3s->hpte_hash_vpte_long));
#ifdef CONFIG_PPC_BOOK3S_64
        kvmppc_mmu_hpte_init_hash(vcpu3s->hpte_hash_vpte_64k,
                                  ARRAY_SIZE(vcpu3s->hpte_hash_vpte_64k));
#endif

        spin_lock_init(&vcpu3s->mmu_lock);

        return 0;
}

int kvmppc_mmu_hpte_sysinit(void)
{
        /* init hpte slab cache */
        hpte_cache = kmem_cache_create("kvm-spt", sizeof(struct hpte_cache),
                                       sizeof(struct hpte_cache), 0, NULL);

        return 0;
}

void kvmppc_mmu_hpte_sysexit(void)
{
        kmem_cache_destroy(hpte_cache);
}