path: root/arch/powerpc/kvm/e500_mmu.c

/*
 * Copyright (C) 2008-2013 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Author: Yu Liu, yu.liu@freescale.com
 *         Scott Wood, scottwood@freescale.com
 *         Ashish Kalra, ashish.kalra@freescale.com
 *         Varun Sethi, varun.sethi@freescale.com
 *         Alexander Graf, agraf@suse.de
 *
 * Description:
 * This file is based on arch/powerpc/kvm/44x_tlb.c,
 * by Hollis Blanchard <hollisb@us.ibm.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.
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <linux/log2.h>
#include <linux/uaccess.h>
#include <linux/sched.h>
#include <linux/rwsem.h>
#include <linux/vmalloc.h>
#include <linux/hugetlb.h>
#include <asm/kvm_ppc.h>

#include "e500.h"
#include "trace.h"
#include "timing.h"
#include "e500_mmu_host.h"

static inline unsigned int gtlb0_get_next_victim(
		struct kvmppc_vcpu_e500 *vcpu_e500)
{
	unsigned int victim;

	victim = vcpu_e500->gtlb_nv[0]++;
	if (unlikely(vcpu_e500->gtlb_nv[0] >= vcpu_e500->gtlb_params[0].ways))
		vcpu_e500->gtlb_nv[0] = 0;

	return victim;
}

static int tlb0_set_base(gva_t addr, int sets, int ways)
{
	int set_base;

	set_base = (addr >> PAGE_SHIFT) & (sets - 1);
	set_base *= ways;

	return set_base;
}

static int gtlb0_set_base(struct kvmppc_vcpu_e500 *vcpu_e500, gva_t addr)
{
	return tlb0_set_base(addr, vcpu_e500->gtlb_params[0].sets,
			     vcpu_e500->gtlb_params[0].ways);
}

static unsigned int get_tlb_esel(struct kvm_vcpu *vcpu, int tlbsel)
{
	struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
	int esel = get_tlb_esel_bit(vcpu);

	if (tlbsel == 0) {
		esel &= vcpu_e500->gtlb_params[0].ways - 1;
		esel += gtlb0_set_base(vcpu_e500, vcpu->arch.shared->mas2);
	} else {
		esel &= vcpu_e500->gtlb_params[tlbsel].entries - 1;
	}

	return esel;
}

/* Search the guest TLB for a matching entry. */
static int kvmppc_e500_tlb_index(struct kvmppc_vcpu_e500 *vcpu_e500,
		gva_t eaddr, int tlbsel, unsigned int pid, int as)
{
	int size = vcpu_e500->gtlb_params[tlbsel].entries;
	unsigned int set_base, offset;
	int i;

	if (tlbsel == 0) {
		set_base = gtlb0_set_base(vcpu_e500, eaddr);
		size = vcpu_e500->gtlb_params[0].ways;
	} else {
		if (eaddr < vcpu_e500->tlb1_min_eaddr ||
				eaddr > vcpu_e500->tlb1_max_eaddr)
			return -1;
		set_base = 0;
	}

	offset = vcpu_e500->gtlb_offset[tlbsel];

	for (i = 0; i < size; i++) {
		struct kvm_book3e_206_tlb_entry *tlbe =
			&vcpu_e500->gtlb_arch[offset + set_base + i];
		unsigned int tid;

		if (eaddr < get_tlb_eaddr(tlbe))
			continue;

		if (eaddr > get_tlb_end(tlbe))
			continue;

		tid = get_tlb_tid(tlbe);
		if (tid && (tid != pid))
			continue;

		if (!get_tlb_v(tlbe))
			continue;

		if (get_tlb_ts(tlbe) != as && as != -1)
			continue;

		return set_base + i;
	}

	return -1;
}

static inline void kvmppc_e500_deliver_tlb_miss(struct kvm_vcpu *vcpu,
		unsigned int eaddr, int as)
{
	struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
	unsigned int victim, tsized;
	int tlbsel;

	/* since we only have two TLBs, only lower bit is used. */
	tlbsel = (vcpu->arch.shared->mas4 >> 28) & 0x1;
	victim = (tlbsel == 0) ? gtlb0_get_next_victim(vcpu_e500) : 0;
	tsized = (vcpu->arch.shared->mas4 >> 7) & 0x1f;

	vcpu->arch.shared->mas0 = MAS0_TLBSEL(tlbsel) | MAS0_ESEL(victim)
		| MAS0_NV(vcpu_e500->gtlb_nv[tlbsel]);
	vcpu->arch.shared->mas1 = MAS1_VALID | (as ? MAS1_TS : 0