/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef __ARM64_KVM_MMU_H__
#define __ARM64_KVM_MMU_H__

#include <asm/page.h>
#include <asm/memory.h>

/*
 * As we only have the TTBR0_EL2 register, we cannot express
 * "negative" addresses. This makes it impossible to directly share
 * mappings with the kernel.
 *
 * Instead, give the HYP mode its own VA region at a fixed offset from
 * the kernel by just masking the top bits (which are all ones for a
 * kernel address).
 */
#define HYP_PAGE_OFFSET_SHIFT	VA_BITS
#define HYP_PAGE_OFFSET_MASK	((UL(1) << HYP_PAGE_OFFSET_SHIFT) - 1)
#define HYP_PAGE_OFFSET		(PAGE_OFFSET & HYP_PAGE_OFFSET_MASK)

/*
 * Our virtual mapping for the idmap-ed MMU-enable code. Must be
 * shared across all the page-tables. Conveniently, we use the last
 * possible page, where no kernel mapping will ever exist.
 */
#define TRAMPOLINE_VA		(HYP_PAGE_OFFSET_MASK & PAGE_MASK)

#ifdef __ASSEMBLY__

/*
 * Convert a kernel VA into a HYP VA.
 * reg: VA to be converted.
 */
.macro kern_hyp_va	reg
	and	\reg, \reg, #HYP_PAGE_OFFSET_MASK
.endm

#else

#include <asm/cachetype.h>
#include <asm/cacheflush.h>

#define KERN_TO_HYP(kva)	((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)

/*
 * We currently only support a 40bit IPA.
 */
#define KVM_PHYS_SHIFT	(40)
#define KVM_PHYS_SIZE	(1UL << KVM_PHYS_SHIFT)
#define KVM_PHYS_MASK	(KVM_PHYS_SIZE - 1UL)

/* Make sure we get the right size, and thus the right alignment */
#define PTRS_PER_S2_PGD (1 << (KVM_PHYS_SHIFT - PGDIR_SHIFT))
#define S2_PGD_ORDER	get_order(PTRS_PER_S2_PGD * sizeof(pgd_t))

int create_hyp_mappings(void *from, void *to);
int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
void free_boot_hyp_pgd(void);
void free_hyp_pgds(void);

void stage2_unmap_vm(struct kvm *kvm);
int kvm_alloc_stage2_pgd(struct kvm *kvm);
void kvm_free_stage2_pgd(struct kvm *kvm);
int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
			  phys_addr_t pa, unsigned long size);

int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);

void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);

phys_addr_t kvm_mmu_get_httbr(void);
phys_addr_t kvm_mmu_get_boot_httbr(void);
phys_addr_t kvm_get_idmap_vector(void);
int kvm_mmu_init(void);
void kvm_clear_hyp_idmap(void);

#define	kvm_set_pte(ptep, pte)		set_pte(ptep, pte)

static inline void kvm_clean_pgd(pgd_t *pgd) {}
static inline void kvm_clean_pmd_entry(pmd_t *pmd) {}
static inline void kvm_clean_pte(pte_t *pte) {}
static inline void kvm_clean_pte_entry(pte_t *pte) {}

static inline void kvm_set_s2pte_writable(pte_t *pte)
{
	pte_val(*pte) |= PTE_S2_RDWR;
}

#define kvm_pgd_addr_end(addr, end)    pgd_addr_end(addr, end)
#define kvm_pud_addr_end(addr, end)    pud_addr_end(addr, end)
#define kvm_pmd_addr_end(addr, end)    pmd_addr_end(addr, end)

#define kvm_pgd_index(addr)    (((addr) >> PGDIR_SHIFT) & (PTRS_PER_S2_PGD - 1))

static inline bool kvm_page_empty(void *ptr)
{
	struct page *ptr_page = virt_to_page(ptr);
	return page_count(ptr_page) == 1;
}

#define kvm_pte_table_empty(ptep) kvm_page_empty(ptep)
#ifndef CONFIG_ARM64_64K_PAGES
#define kvm_pmd_table_empty(pmdp) kvm_page_empty(pmdp)
#else
#define kvm_pmd_table_empty(pmdp) (0)
#endif
#define kvm_pud_table_empty(pudp) (0)

struct kvm;

#define kvm_flush_dcache_to_poc(a,l)   __flush_dcache_area((a), (l))

static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
{
	return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101;
}

static inline void coherent_cache_guest_page(struct kvm_vcpu *vcpu, hva_t hva,
					    unsigned long size)
{
	if (!vcpu_has_cache_enabled(vcpu))
		kvm_flush_dcache_to_poc((void *)hva, size);

	if (!icache_is_aliasing()) {		/* PIPT */
		flush_icache_range(hva, hva + size);
	} else if (!icache_is_aivivt()) {	/* non ASID-tagged VIVT */
		/* any kind of VIPT cache */
		__flush_icache_all();
	}
}

void stage2_flush_vm(struct kvm *kvm);

#endif /* __ASSEMBLY__ */
#endif /* __ARM64_KVM_MMU_H__ */