target-ppc: Disentangle pte_check()

[mirror_qemu.git] / target-ppc / mmu-hash32.c

/*
 *  PowerPC MMU, TLB and BAT emulation helpers for QEMU.
 *
 *  Copyright (c) 2003-2007 Jocelyn Mayer
 *  Copyright (c) 2013 David Gibson, IBM Corporation
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#include "cpu.h"
#include "helper.h"
#include "sysemu/kvm.h"
#include "kvm_ppc.h"
#include "mmu-hash32.h"

//#define DEBUG_MMU

#ifdef DEBUG_MMU
#  define LOG_MMU(...) qemu_log(__VA_ARGS__)
#  define LOG_MMU_STATE(env) log_cpu_state((env), 0)
#else
#  define LOG_MMU(...) do { } while (0)
#  define LOG_MMU_STATE(...) do { } while (0)
#endif

#define PTE_PTEM_MASK 0x7FFFFFBF
#define PTE_CHECK_MASK (TARGET_PAGE_MASK | 0x7B)

static inline int pte_is_valid_hash32(target_ulong pte0)
{
    return pte0 & 0x80000000 ? 1 : 0;
}

int pte_check_hash32(mmu_ctx_t *ctx, target_ulong pte0,
                     target_ulong pte1, int h, int rw, int type)
{
    target_ulong ptem, mmask;
    int access, ret, pteh, ptev, pp;

    ret = -1;
    /* Check validity and table match */
    ptev = pte_is_valid_hash32(pte0);
    pteh = (pte0 >> 6) & 1;
    if (ptev && h == pteh) {
        /* Check vsid & api */
        ptem = pte0 & PTE_PTEM_MASK;
        mmask = PTE_CHECK_MASK;
        pp = pte1 & 0x00000003;
        if (ptem == ctx->ptem) {
            if (ctx->raddr != (hwaddr)-1ULL) {
                /* all matches should have equal RPN, WIMG & PP */
                if ((ctx->raddr & mmask) != (pte1 & mmask)) {
                    qemu_log("Bad RPN/WIMG/PP\n");
                    return -3;
                }
            }
            /* Compute access rights */
            access = pp_check(ctx->key, pp, ctx->nx);
            /* Keep the matching PTE informations */
            ctx->raddr = pte1;
            ctx->prot = access;
            ret = check_prot(ctx->prot, rw, type);
            if (ret == 0) {
                /* Access granted */
                LOG_MMU("PTE access granted !\n");
            } else {
                /* Access right violation */
                LOG_MMU("PTE access rejected\n");
            }
        }
    }

    return ret;
}