/*
 * Copyright (C) 2011. Freescale Inc. All rights reserved.
 *
 * Authors:
 *    Alexander Graf <agraf@suse.de>
 *    Paul Mackerras <paulus@samba.org>
 *
 * Description:
 *
 * Hypercall handling for running PAPR guests in PR KVM on Book 3S
 * processors.
 *
 * 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/anon_inodes.h>

#include <linux/uaccess.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>

#define HPTE_SIZE	16		/* bytes per HPT entry */

static unsigned long get_pteg_addr(struct kvm_vcpu *vcpu, long pte_index)
{
	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
	unsigned long pteg_addr;

	pte_index <<= 4;
	pte_index &= ((1 << ((vcpu_book3s->sdr1 & 0x1f) + 11)) - 1) << 7 | 0x70;
	pteg_addr = vcpu_book3s->sdr1 & 0xfffffffffffc0000ULL;
	pteg_addr |= pte_index;

	return pteg_addr;
}

static int kvmppc_h_pr_enter(struct kvm_vcpu *vcpu)
{
	long flags = kvmppc_get_gpr(vcpu, 4);
	long pte_index = kvmppc_get_gpr(vcpu, 5);
	__be64 pteg[2 * 8];
	__be64 *hpte;
	unsigned long pteg_addr, i;
	long int ret;

	i = pte_index & 7;
	pte_index &= ~7UL;
	pteg_addr = get_pteg_addr(vcpu, pte_index);

	mutex_lock(&vcpu->kvm->arch.hpt_mutex);
	copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg));
	hpte = pteg;

	ret = H_PTEG_FULL;
	if (likely((flags & H_EXACT) == 0)) {
		for (i = 0; ; ++i) {
			if (i == 8)
				goto done;
			if ((be64_to_cpu(*hpte) & HPTE_V_VALID) == 0)
				break;
			hpte += 2;
		}
	} else {
		hpte += i * 2;
		if (*hpte & HPTE_V_VALID)
			goto done;
	}

	hpte[0] = cpu_to_be64(kvmppc_get_gpr(vcpu, 6));
	hpte[1] = cpu_to_be64(kvmppc_get_gpr(vcpu, 7));
	pteg_addr += i * HPTE_SIZE;
	copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE);
	kvmppc_set_gpr(vcpu, 4, pte_index | i);
	ret = H_SUCCESS;

 done:
	mutex_unlock(&vcpu->kvm->arch.hpt_mutex);
	kvmppc_set_gpr(vcpu, 3, ret);

	return EMULATE_DONE;
}

static int kvmppc_h_pr_remove(struct kvm_vcpu *vcpu)
{
	unsigned long flags= kvmppc_get_gpr(vcpu, 4);
	unsigned long pte_index = kvmppc_get_gpr(vcpu, 5);
	unsigned long avpn = kvmppc_get_gpr(vcpu, 6);
	unsigned long v = 0, pteg, rb;
	unsigned long pte[2];
	long int ret;

	pteg = get_pteg_addr(vcpu, pte_index);
	mutex_lock(&vcpu->kvm->arch.hpt_mutex);
	copy_from_user(pte, (void __user *)pteg, sizeof(pte));
	pte[0] = be64_to_cpu((__force __be64)pte[0]);
	pte[1] = be64_to_cpu((__force __be64)pte[1]);

	ret = H_NOT_FOUND;
	if ((pte[0] & HPTE_V_VALID) == 0 ||
	    ((flags & H_AVPN) && (pte[0] & ~0x7fUL) != avpn) ||
	    ((flags & H_ANDCOND) && (pte[0] & avpn) != 0))
		goto done;

	copy_to_user((void __user *)pteg, &v, sizeof(v));

	rb = compute_tlbie_rb(pte[0], pte[1], pte_index);
	vcpu->arch.mmu.tlbie(vcpu, rb, rb & 1 ? true : false);

	ret = H_SUCCESS;
	kvmppc_set_gpr(vcpu, 4, pte[0]);
	kvmppc_set_gpr(vcpu, 5, pte[1]);

 done:
	mutex_unlock(&vcpu->kvm->arch.hpt_mutex);
	kvmppc_set_gpr(vcpu, 3, ret);

	return EMULATE_DONE;
}

/* Request defs for kvmppc_h_pr_bulk_remove() */
#define H_BULK_REMOVE_TYPE             0xc000000000000000ULL
#define   H_BULK_REMOVE_REQUEST        0x4000000000000000ULL
#define   H_BULK_REMOVE_RESPONSE       0x8000000000000000ULL
#define   H_BULK_REMOVE_END            0xc000000000000000ULL
#define H_BULK_REMOVE_CODE             0x3000000000000000ULL
#define   H_BULK_REMOVE_SUCCESS        0x0000000000000000ULL
#define   H_BULK_REMOVE_NOT_FOUND      0x1000000000000000ULL
#define   H_BULK_REMOVE_PARM           0x2000000000000000ULL
#define   H_BULK_REMOVE_HW             0x3000000000000000ULL
#define H_BULK_REMOVE_RC               0x0c00000000000000ULL
#define H_BULK_REMOVE_FLAGS            0x0300000000000000ULL
#define   H_BULK_REMOVE_ABSOLUTE       0x0000000000000000ULL
#define   H_BULK_REMOVE_ANDCOND        0x0100000000000000ULL
#define   H_BULK_REMOVE_AVPN           0x0200000000000000ULL
#define H_BULK_REMOVE_PTEX             0x00ffffffffffffffULL
#define H_BULK_REMOVE_MAX_BATCH        4

static int kvmppc_h_pr_bulk_remove(struct kvm_vcpu *vcpu)
{
	int i;
	int paramnr = 4;
	int ret = H_SUCCESS;

	mutex_lock(&vcpu->kvm->arch.hpt_mutex);
	for (i = 0; i < H_BULK_REMOVE_MAX_BATCH; i++) {
		unsigned long tsh = kvmppc_get_gpr(vcpu, paramnr+(2*i));
		unsigned long tsl = kvmppc_get_gpr(vcpu, paramnr+(2*i)+1);
		unsigned long pteg, rb, flags;
		unsigned long pte[2];
		unsigned long v = 0;

		if ((tsh & H_BULK_REMOVE_TYPE) == H_BULK_REMOVE_END) {
			break; /* Exit success */
		} else if ((tsh & H_BULK_REMOVE_TYPE) !=
			   H_BULK_REMOVE_REQUEST) {
			ret = H_PARAMETER;
			break; /* Exit fail */
		}

		tsh &= H_BULK_REMOVE_PTEX | H_BULK_REMOVE_FLAGS;
		tsh |= H_BULK_REMOVE_RESPONSE;

		if ((tsh & H_BULK_REMOVE_ANDCOND) &&
		    (tsh & H_BULK_REMOVE_AVPN)) {
			tsh |= H_BULK_REMOVE_PARM;
			kvmppc_set_gpr(vcpu, paramnr+(2*i), tsh);
			ret = H_PARAMETER;
			break; /* Exit fail */
		}

		pteg = get_pteg_addr(vcpu, tsh & H_BULK_REMOVE_PTEX);
		copy_from_user(pte, (void __user *)pteg, sizeof(pte));
		pte[0] = be64_to_cpu((__force __be64)pte[0]);
		pte[1] = be64_to_cpu((__force __be64)pte[1]);

		/* tsl = AVPN */
		flags = (tsh & H_BULK_REMOVE_FLAGS) >> 26;

		if ((pte[0] & HPTE_V_VALID) == 0 ||
		    ((flags & H_AVPN) && (pte[0] & ~0x7fUL) != tsl) ||
		    ((flags & H_ANDCOND) && (pte[0] & tsl) != 0)) {
			tsh |= H_BULK_REMOVE_NOT_FOUND;
		} else {
			/* Splat the pteg in (userland) hpt */
			copy_to_user((void __user *)pteg, &v, sizeof(v));

			rb = compute_tlbie_rb(pte[0], pte[1],
					      tsh & H_BULK_REMOVE_PTEX);
			vcpu->arch.mmu.tlbie(vcpu, rb, rb & 1 ? true : false);
			tsh |= H_BULK_REMOVE_SUCCESS;
			tsh |= (pte[1] & (HPTE_R_C | HPTE_R_R)) << 43;
		}
		kvmppc_set_gpr(vcpu, paramnr+(2*i), tsh);
	}
	mutex_unlock(&vcpu->kvm->arch.hpt_mutex);
	kvmppc_set_gpr(vcpu, 3, ret);

	return EMULATE_DONE;
}

static int kvmppc_h_pr_protect(struct kvm_vcpu *vcpu)
{
	unsigned long flags = kvmppc_get_gpr(vcpu, 4);
	unsigned long pte_index = kvmppc_get_gpr(vcpu, 5);
	unsigned long avpn = kvmppc_get_gpr(vcpu, 6);
	unsigned long rb, pteg, r, v;
	unsigned long pte[2];
	long int ret;

	pteg = get_pteg_addr(vcpu, pte_index);
	mutex_lock(&vcpu->kvm->arch.hpt_mutex);
	copy_from_user(pte, (void __user *)pteg, sizeof(pte));
	pte[0] = be64_to_cpu((__force __be64)pte[0]);
	pte[1] = be64_to_cpu((__force __be64)pte[1]);

	ret = H_NOT_FOUND;
	if ((pte[0] & HPTE_V_VALID) == 0 ||
	    ((flags & H_AVPN) && (pte[0] & ~0x7fUL) != avpn))
		goto done;

	v = pte[0];
	r = pte[1];
	r &= ~(HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_HI |
	       HPTE_R_KEY_LO);
	r |= (flags << 55) & HPTE_R_PP0;
	r |= (flags << 48) & HPTE_R_KEY_HI;
	r |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);

	pte[1] = r;

	rb = compute_tlbie_rb(v, r, pte_index);
	vcpu->arch.mmu.tlbie(vcpu, rb, rb & 1 ? true : false);
	pte[0] = (__force u64)cpu_to_be64(pte[0]);
	pte[1] = (__force u64)cpu_to_be64(pte[1]);
	copy_to_user((void __user *)pteg, pte, sizeof(pte));
	ret = H_SUCCESS;

 done:
	mutex_unlock(&vcpu->kvm->arch.hpt_mutex);
	kvmppc_set_gpr(vcpu, 3, ret);

	return EMULATE_DONE;
}

static int kvmppc_h_pr_put_tce(struct kvm_vcpu *vcpu)
{
	unsigned long liobn = kvmppc_get_gpr(vcpu, 4);
	unsigned long ioba = kvmppc_get_gpr(vcpu, 5);
	unsigned long tce = kvmppc_get_gpr(vcpu, 6);
	long rc;

	rc = kvmppc_h_put_tce(vcpu, liobn, ioba, tce);
	if (rc == H_TOO_HARD)
		return EMULATE_FAIL;
	kvmppc_set_gpr(vcpu, 3, rc);
	return EMULATE_DONE;
}

static int kvmppc_h_pr_logical_ci_load(struct kvm_vcpu *vcpu)
{
	long rc;

	rc = kvmppc_h_logical_ci_load(vcpu);
	if (rc == H_TOO_HARD)
		return EMULATE_FAIL;
	kvmppc_set_gpr(vcpu, 3, rc);
	return EMULATE_DONE;
}

static int kvmppc_h_pr_logical_ci_store(struct kvm_vcpu *vcpu)
{
	long rc;

	rc = kvmppc_h_logical_ci_store(vcpu);
	if (rc == H_TOO_HARD)
		return EMULATE_FAIL;
	kvmppc_set_gpr(vcpu, 3, rc);
	return EMULATE_DONE;
}

static int kvmppc_h_pr_put_tce_indirect(struct kvm_vcpu *vcpu)
{
	unsigned long liobn = kvmppc_get_gpr(vcpu, 4);
	unsigned long ioba = kvmppc_get_gpr(vcpu, 5);
	unsigned long tce = kvmppc_get_gpr(vcpu, 6);
	unsigned long npages = kvmppc_get_gpr(vcpu, 7);
	long rc;

	rc = kvmppc_h_put_tce_indirect(vcpu, liobn, ioba,
			tce, npages);
	if (rc == H_TOO_HARD)
		return EMULATE_FAIL;
	kvmppc_set_gpr(vcpu, 3, rc);
	return EMULATE_DONE;
}

static int kvmppc_h_pr_stuff_tce(struct kvm_vcpu *vcpu)
{
	unsigned long liobn = kvmppc_get_gpr(vcpu, 4);
	unsigned long ioba = kvmppc_get_gpr(vcpu, 5);
	unsigned long tce_value = kvmppc_get_gpr(vcpu, 6);
	unsigned long npages = kvmppc_get_gpr(vcpu, 7);
	long rc;

	rc = kvmppc_h_stuff_tce(vcpu, liobn, ioba, tce_value, npages);
	if (rc == H_TOO_HARD)
		return EMULATE_FAIL;
	kvmppc_set_gpr(vcpu, 3, rc);
	return EMULATE_DONE;
}

static int kvmppc_h_pr_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
{
	long rc = kvmppc_xics_hcall(vcpu, cmd);
	kvmppc_set_gpr(vcpu, 3, rc);
	return EMULATE_DONE;
}

int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
{
	int rc, idx;

	if (cmd <= MAX_HCALL_OPCODE &&
	    !test_bit(cmd/4, vcpu->kvm->arch.enabled_hcalls))
		return EMULATE_FAIL;

	switch (cmd) {
	case H_ENTER:
		return kvmppc_h_pr_enter(vcpu);
	case H_REMOVE:
		return kvmppc_h_pr_remove(vcpu);
	case H_PROTECT:
		return kvmppc_h_pr_protect(vcpu);
	case H_BULK_REMOVE:
		return kvmppc_h_pr_bulk_remove(vcpu);
	case H_PUT_TCE:
		return kvmppc_h_pr_put_tce(vcpu);
	case H_PUT_TCE_INDIRECT:
		return kvmppc_h_pr_put_tce_indirect(vcpu);
	case H_STUFF_TCE:
		return kvmppc_h_pr_stuff_tce(vcpu);
	case H_CEDE:
		kvmppc_set_msr_fast(vcpu, kvmppc_get_msr(vcpu) | MSR_EE);
		kvm_vcpu_block(vcpu);
		kvm_clear_request(KVM_REQ_UNHALT, vcpu);
		vcpu->stat.halt_wakeup++;
		return EMULATE_DONE;
	case H_LOGICAL_CI_LOAD:
		return kvmppc_h_pr_logical_ci_load(vcpu);
	case H_LOGICAL_CI_STORE:
		return kvmppc_h_pr_logical_ci_store(vcpu);
	case H_XIRR:
	case H_CPPR:
	case H_EOI:
	case H_IPI:
	case H_IPOLL:
	case H_XIRR_X:
		if (kvmppc_xics_enabled(vcpu))
			return kvmppc_h_pr_xics_hcall(vcpu, cmd);
		break;
	case H_RTAS:
		if (list_empty(&vcpu->kvm->arch.rtas_tokens))
			break;
		idx = srcu_read_lock(&vcpu->kvm->srcu);
		rc = kvmppc_rtas_hcall(vcpu);
		srcu_read_unlock(&vcpu->kvm->srcu, idx);
		if (rc)
			break;
		kvmppc_set_gpr(vcpu, 3, 0);
		return EMULATE_DONE;
	}

	return EMULATE_FAIL;
}

int kvmppc_hcall_impl_pr(unsigned long cmd)
{
	switch (cmd) {
	case H_ENTER:
	case H_REMOVE:
	case H_PROTECT:
	case H_BULK_REMOVE:
	case H_PUT_TCE:
	case H_CEDE:
	case H_LOGICAL_CI_LOAD:
	case H_LOGICAL_CI_STORE:
#ifdef CONFIG_KVM_XICS
	case H_XIRR:
	case H_CPPR:
	case H_EOI:
	case H_IPI:
	case H_IPOLL:
	case H_XIRR_X:
#endif
		return 1;
	}
	return 0;
}

/*
 * List of hcall numbers to enable by default.
 * For compatibility with old userspace, we enable by default
 * all hcalls that were implemented before the hcall-enabling
 * facility was added.  Note this list should not include H_RTAS.
 */
static unsigned int default_hcall_list[] = {
	H_ENTER,
	H_REMOVE,
	H_PROTECT,
	H_BULK_REMOVE,
	H_PUT_TCE,
	H_CEDE,
#ifdef CONFIG_KVM_XICS
	H_XIRR,
	H_CPPR,
	H_EOI,
	H_IPI,
	H_IPOLL,
	H_XIRR_X,
#endif
	0
};

void kvmppc_pr_init_default_hcalls(struct kvm *kvm)
{
	int i;
	unsigned int hcall;

	for (i = 0; default_hcall_list[i]; ++i) {
		hcall = default_hcall_list[i];
		WARN_ON(!kvmppc_hcall_impl_pr(hcall));
		__set_bit(hcall / 4, kvm->arch.enabled_hcalls);
	}
}