/* SPDX-License-Identifier: GPL-2.0 */
/**
 * Copyright(c) 2016-20 Intel Corporation.
 *
 * Contains the software defined data structures for enclaves.
 */
#ifndef _X86_ENCL_H
#define _X86_ENCL_H

#include <linux/cpumask.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/mm_types.h>
#include <linux/mmu_notifier.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/srcu.h>
#include <linux/workqueue.h>
#include <linux/xarray.h>
#include "sgx.h"

/* 'desc' bits holding the offset in the VA (version array) page. */
#define SGX_ENCL_PAGE_VA_OFFSET_MASK    GENMASK_ULL(11, 3)

/* 'desc' bit marking that the page is being reclaimed. */
#define SGX_ENCL_PAGE_BEING_RECLAIMED   BIT(3)

struct sgx_encl_page {
        unsigned long desc;
        unsigned long vm_max_prot_bits:8;
        enum sgx_page_type type:16;
        struct sgx_epc_page *epc_page;
        struct sgx_encl *encl;
        struct sgx_va_page *va_page;
};

enum sgx_encl_flags {
        SGX_ENCL_IOCTL          = BIT(0),
        SGX_ENCL_DEBUG          = BIT(1),
        SGX_ENCL_CREATED        = BIT(2),
        SGX_ENCL_INITIALIZED    = BIT(3),
};

struct sgx_encl_mm {
        struct sgx_encl *encl;
        struct mm_struct *mm;
        struct list_head list;
        struct mmu_notifier mmu_notifier;
};

struct sgx_encl {
        unsigned long base;
        unsigned long size;
        unsigned long flags;
        unsigned int page_cnt;
        unsigned int secs_child_cnt;
        struct mutex lock;
        struct xarray page_array;
        struct sgx_encl_page secs;
        unsigned long attributes;
        unsigned long attributes_mask;

        cpumask_t cpumask;
        struct file *backing;
        struct kref refcount;
        struct list_head va_pages;
        unsigned long mm_list_version;
        struct list_head mm_list;
        spinlock_t mm_lock;
        struct srcu_struct srcu;
};

#define SGX_VA_SLOT_COUNT 512

struct sgx_va_page {
        struct sgx_epc_page *epc_page;
        DECLARE_BITMAP(slots, SGX_VA_SLOT_COUNT);
        struct list_head list;
};

struct sgx_backing {
        struct page *contents;
        struct page *pcmd;
        unsigned long pcmd_offset;
};

extern const struct vm_operations_struct sgx_vm_ops;

static inline int sgx_encl_find(struct mm_struct *mm, unsigned long addr,
                                struct vm_area_struct **vma)
{
        struct vm_area_struct *result;

        result = vma_lookup(mm, addr);
        if (!result || result->vm_ops != &sgx_vm_ops)
                return -EINVAL;

        *vma = result;

        return 0;
}

int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
                     unsigned long end, vm_flags_t vm_flags);

bool current_is_ksgxd(void);
void sgx_encl_release(struct kref *ref);
int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm);
const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl);
int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index,
                           struct sgx_backing *backing);
void sgx_encl_put_backing(struct sgx_backing *backing);
int sgx_encl_test_and_clear_young(struct mm_struct *mm,
                                  struct sgx_encl_page *page);
struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
                                          unsigned long offset,
                                          u64 secinfo_flags);
void sgx_zap_enclave_ptes(struct sgx_encl *encl, unsigned long addr);
struct sgx_epc_page *sgx_alloc_va_page(bool reclaim);
unsigned int sgx_alloc_va_slot(struct sgx_va_page *va_page);
void sgx_free_va_slot(struct sgx_va_page *va_page, unsigned int offset);
bool sgx_va_page_full(struct sgx_va_page *va_page);
void sgx_encl_free_epc_page(struct sgx_epc_page *page);
struct sgx_encl_page *sgx_encl_load_page(struct sgx_encl *encl,
                                         unsigned long addr);
struct sgx_va_page *sgx_encl_grow(struct sgx_encl *encl, bool reclaim);
void sgx_encl_shrink(struct sgx_encl *encl, struct sgx_va_page *va_page);

#endif /* _X86_ENCL_H */