Archipelago » qemu

/*

 * Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *     * Redistributions of source code must retain the above copyright

 *       notice, this list of conditions and the following disclaimer.

 *     * Redistributions in binary form must reproduce the above copyright

 *       notice, this list of conditions and the following disclaimer in the

 *       documentation and/or other materials provided with the distribution.

 *     * Neither the name of the Open Source and Linux Lab nor the

 *       names of its contributors may be used to endorse or promote products

 *       derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY

 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "cpu.h"

#include "exec-all.h"

#include "gdbstub.h"

#include "host-utils.h"

#if !defined(CONFIG_USER_ONLY)

#include "hw/loader.h"

#endif

static struct XtensaConfigList *xtensa_cores;

void xtensa_register_core(XtensaConfigList *node)

{

    node->next = xtensa_cores;

    xtensa_cores = node;

}

static uint32_t check_hw_breakpoints(CPUXtensaState *env)

{

    unsigned i;

    for (i = 0; i < env->config->ndbreak; ++i) {

        if (env->cpu_watchpoint[i] &&

                env->cpu_watchpoint[i]->flags & BP_WATCHPOINT_HIT) {

            return DEBUGCAUSE_DB | (i << DEBUGCAUSE_DBNUM_SHIFT);

        }

    }

    return 0;

}

static CPUDebugExcpHandler *prev_debug_excp_handler;

static void breakpoint_handler(CPUXtensaState *env)

{

    if (env->watchpoint_hit) {

        if (env->watchpoint_hit->flags & BP_CPU) {

            uint32_t cause;

            env->watchpoint_hit = NULL;

            cause = check_hw_breakpoints(env);

            if (cause) {

                debug_exception_env(env, cause);

            }

            cpu_resume_from_signal(env, NULL);

        }

    }

    if (prev_debug_excp_handler) {

        prev_debug_excp_handler(env);

    }

}

XtensaCPU *cpu_xtensa_init(const char *cpu_model)

{

    static int tcg_inited;

    static int debug_handler_inited;

    XtensaCPU *cpu;

    CPUXtensaState *env;

    const XtensaConfig *config = NULL;

    XtensaConfigList *core = xtensa_cores;

    for (; core; core = core->next)

        if (strcmp(core->config->name, cpu_model) == 0) {

            config = core->config;

            break;

        }

    if (config == NULL) {

        return NULL;

    }

    cpu = XTENSA_CPU(object_new(TYPE_XTENSA_CPU));

    env = &cpu->env;

    env->config = config;

    if (!tcg_inited) {

        tcg_inited = 1;

        xtensa_translate_init();

    }

    if (!debug_handler_inited && tcg_enabled()) {

        debug_handler_inited = 1;

        prev_debug_excp_handler =

            cpu_set_debug_excp_handler(breakpoint_handler);

    }

    xtensa_irq_init(env);

    qemu_init_vcpu(env);

    return cpu;

}

void xtensa_cpu_list(FILE *f, fprintf_function cpu_fprintf)

{

    XtensaConfigList *core = xtensa_cores;

    cpu_fprintf(f, "Available CPUs:\n");

    for (; core; core = core->next) {

        cpu_fprintf(f, "  %s\n", core->config->name);

    }

}

target_phys_addr_t cpu_get_phys_page_debug(CPUXtensaState *env, target_ulong addr)

{

    uint32_t paddr;

    uint32_t page_size;

    unsigned access;

    if (xtensa_get_physical_addr(env, false, addr, 0, 0,

                &paddr, &page_size, &access) == 0) {

        return paddr;

    }

    if (xtensa_get_physical_addr(env, false, addr, 2, 0,

                &paddr, &page_size, &access) == 0) {

        return paddr;

    }

    return ~0;

}

static uint32_t relocated_vector(CPUXtensaState *env, uint32_t vector)

{

    if (xtensa_option_enabled(env->config,

                XTENSA_OPTION_RELOCATABLE_VECTOR)) {

        return vector - env->config->vecbase + env->sregs[VECBASE];

    } else {

        return vector;

    }

}

/*!

 * Handle penging IRQ.

 * For the high priority interrupt jump to the corresponding interrupt vector.

 * For the level-1 interrupt convert it to either user, kernel or double

 * exception with the 'level-1 interrupt' exception cause.

 */

static void handle_interrupt(CPUXtensaState *env)

{

    int level = env->pending_irq_level;

    if (level > xtensa_get_cintlevel(env) &&

            level <= env->config->nlevel &&

            (env->config->level_mask[level] &

             env->sregs[INTSET] &

             env->sregs[INTENABLE])) {

        if (level > 1) {

            env->sregs[EPC1 + level - 1] = env->pc;

            env->sregs[EPS2 + level - 2] = env->sregs[PS];

            env->sregs[PS] =

                (env->sregs[PS] & ~PS_INTLEVEL) | level | PS_EXCM;

            env->pc = relocated_vector(env,

                    env->config->interrupt_vector[level]);

        } else {

            env->sregs[EXCCAUSE] = LEVEL1_INTERRUPT_CAUSE;

            if (env->sregs[PS] & PS_EXCM) {

                if (env->config->ndepc) {

                    env->sregs[DEPC] = env->pc;

                } else {

                    env->sregs[EPC1] = env->pc;

                }

                env->exception_index = EXC_DOUBLE;

            } else {

                env->sregs[EPC1] = env->pc;

                env->exception_index =

                    (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;

            }

            env->sregs[PS] |= PS_EXCM;

        }

        env->exception_taken = 1;

    }

}

void do_interrupt(CPUXtensaState *env)

{

    if (env->exception_index == EXC_IRQ) {

        qemu_log_mask(CPU_LOG_INT,

                "%s(EXC_IRQ) level = %d, cintlevel = %d, "

                "pc = %08x, a0 = %08x, ps = %08x, "

                "intset = %08x, intenable = %08x, "

                "ccount = %08x\n",

                __func__, env->pending_irq_level, xtensa_get_cintlevel(env),

                env->pc, env->regs[0], env->sregs[PS],

                env->sregs[INTSET], env->sregs[INTENABLE],

                env->sregs[CCOUNT]);

        handle_interrupt(env);

    }

    switch (env->exception_index) {

    case EXC_WINDOW_OVERFLOW4:

    case EXC_WINDOW_UNDERFLOW4:

    case EXC_WINDOW_OVERFLOW8:

    case EXC_WINDOW_UNDERFLOW8:

    case EXC_WINDOW_OVERFLOW12:

    case EXC_WINDOW_UNDERFLOW12:

    case EXC_KERNEL:

    case EXC_USER:

    case EXC_DOUBLE:

    case EXC_DEBUG:

        qemu_log_mask(CPU_LOG_INT, "%s(%d) "

                "pc = %08x, a0 = %08x, ps = %08x, ccount = %08x\n",

                __func__, env->exception_index,

                env->pc, env->regs[0], env->sregs[PS], env->sregs[CCOUNT]);

        if (env->config->exception_vector[env->exception_index]) {

            env->pc = relocated_vector(env,

                    env->config->exception_vector[env->exception_index]);

            env->exception_taken = 1;

        } else {

            qemu_log("%s(pc = %08x) bad exception_index: %d\n",

                    __func__, env->pc, env->exception_index);

        }

        break;

    case EXC_IRQ:

        break;

    default:

        qemu_log("%s(pc = %08x) unknown exception_index: %d\n",

                __func__, env->pc, env->exception_index);

        break;

    }

    check_interrupts(env);

}

static void reset_tlb_mmu_all_ways(CPUXtensaState *env,

        const xtensa_tlb *tlb, xtensa_tlb_entry entry[][MAX_TLB_WAY_SIZE])

{

    unsigned wi, ei;

    for (wi = 0; wi < tlb->nways; ++wi) {

        for (ei = 0; ei < tlb->way_size[wi]; ++ei) {

            entry[wi][ei].asid = 0;

            entry[wi][ei].variable = true;

        }

    }

}

static void reset_tlb_mmu_ways56(CPUXtensaState *env,

        const xtensa_tlb *tlb, xtensa_tlb_entry entry[][MAX_TLB_WAY_SIZE])

{

    if (!tlb->varway56) {

        static const xtensa_tlb_entry way5[] = {

            {

                .vaddr = 0xd0000000,

                .paddr = 0,

                .asid = 1,

                .attr = 7,

                .variable = false,

            }, {

                .vaddr = 0xd8000000,

                .paddr = 0,

                .asid = 1,

                .attr = 3,

                .variable = false,

            }

        };

        static const xtensa_tlb_entry way6[] = {

            {

                .vaddr = 0xe0000000,

                .paddr = 0xf0000000,

                .asid = 1,

                .attr = 7,

                .variable = false,

            }, {

                .vaddr = 0xf0000000,

                .paddr = 0xf0000000,

                .asid = 1,

                .attr = 3,

                .variable = false,

            }

        };

        memcpy(entry[5], way5, sizeof(way5));

        memcpy(entry[6], way6, sizeof(way6));

    } else {

        uint32_t ei;

        for (ei = 0; ei < 8; ++ei) {

            entry[6][ei].vaddr = ei << 29;

            entry[6][ei].paddr = ei << 29;

            entry[6][ei].asid = 1;

            entry[6][ei].attr = 3;

        }

    }

}

static void reset_tlb_region_way0(CPUXtensaState *env,

        xtensa_tlb_entry entry[][MAX_TLB_WAY_SIZE])

{

    unsigned ei;

    for (ei = 0; ei < 8; ++ei) {

        entry[0][ei].vaddr = ei << 29;

        entry[0][ei].paddr = ei << 29;

        entry[0][ei].asid = 1;

        entry[0][ei].attr = 2;

        entry[0][ei].variable = true;

    }

}

void reset_mmu(CPUXtensaState *env)

{

    if (xtensa_option_enabled(env->config, XTENSA_OPTION_MMU)) {

        env->sregs[RASID] = 0x04030201;

        env->sregs[ITLBCFG] = 0;

        env->sregs[DTLBCFG] = 0;

        env->autorefill_idx = 0;

        reset_tlb_mmu_all_ways(env, &env->config->itlb, env->itlb);

        reset_tlb_mmu_all_ways(env, &env->config->dtlb, env->dtlb);

        reset_tlb_mmu_ways56(env, &env->config->itlb, env->itlb);

        reset_tlb_mmu_ways56(env, &env->config->dtlb, env->dtlb);

    } else {

        reset_tlb_region_way0(env, env->itlb);

        reset_tlb_region_way0(env, env->dtlb);

    }

}

static unsigned get_ring(const CPUXtensaState *env, uint8_t asid)

{

    unsigned i;

    for (i = 0; i < 4; ++i) {

        if (((env->sregs[RASID] >> i * 8) & 0xff) == asid) {

            return i;

        }

    }

    return 0xff;

}

/*!

 * Lookup xtensa TLB for the given virtual address.

 * See ISA, 4.6.2.2

 *

 * \param pwi: [out] way index

 * \param pei: [out] entry index

 * \param pring: [out] access ring

 * \return 0 if ok, exception cause code otherwise

 */

int xtensa_tlb_lookup(const CPUXtensaState *env, uint32_t addr, bool dtlb,

        uint32_t *pwi, uint32_t *pei, uint8_t *pring)

{

    const xtensa_tlb *tlb = dtlb ?

        &env->config->dtlb : &env->config->itlb;

    const xtensa_tlb_entry (*entry)[MAX_TLB_WAY_SIZE] = dtlb ?

        env->dtlb : env->itlb;

    int nhits = 0;

    unsigned wi;

    for (wi = 0; wi < tlb->nways; ++wi) {

        uint32_t vpn;

        uint32_t ei;

        split_tlb_entry_spec_way(env, addr, dtlb, &vpn, wi, &ei);

        if (entry[wi][ei].vaddr == vpn && entry[wi][ei].asid) {

            unsigned ring = get_ring(env, entry[wi][ei].asid);

            if (ring < 4) {

                if (++nhits > 1) {

                    return dtlb ?

                        LOAD_STORE_TLB_MULTI_HIT_CAUSE :

                        INST_TLB_MULTI_HIT_CAUSE;

                }

                *pwi = wi;

                *pei = ei;

                *pring = ring;

            }

        }

    }

    return nhits ? 0 :

        (dtlb ? LOAD_STORE_TLB_MISS_CAUSE : INST_TLB_MISS_CAUSE);

}

/*!

 * Convert MMU ATTR to PAGE_{READ,WRITE,EXEC} mask.

 * See ISA, 4.6.5.10

 */

static unsigned mmu_attr_to_access(uint32_t attr)

{

    unsigned access = 0;

    if (attr < 12) {

        access |= PAGE_READ;

        if (attr & 0x1) {

            access |= PAGE_EXEC;

        }

        if (attr & 0x2) {

            access |= PAGE_WRITE;

        }

    } else if (attr == 13) {

        access |= PAGE_READ | PAGE_WRITE;

    }

    return access;

}

/*!

 * Convert region protection ATTR to PAGE_{READ,WRITE,EXEC} mask.

 * See ISA, 4.6.3.3

 */

static unsigned region_attr_to_access(uint32_t attr)

{

    unsigned access = 0;

    if ((attr < 6 && attr != 3) || attr == 14) {

        access |= PAGE_READ | PAGE_WRITE;

    }

    if (attr > 0 && attr < 6) {

        access |= PAGE_EXEC;

    }

    return access;

}

static bool is_access_granted(unsigned access, int is_write)

{

    switch (is_write) {

    case 0:

        return access & PAGE_READ;

    case 1:

        return access & PAGE_WRITE;

    case 2:

        return access & PAGE_EXEC;

    default:

        return 0;

    }

}

static int get_pte(CPUXtensaState *env, uint32_t vaddr, uint32_t *pte);

static int get_physical_addr_mmu(CPUXtensaState *env, bool update_tlb,

        uint32_t vaddr, int is_write, int mmu_idx,

        uint32_t *paddr, uint32_t *page_size, unsigned *access,

        bool may_lookup_pt)

{

    bool dtlb = is_write != 2;

    uint32_t wi;

    uint32_t ei;

    uint8_t ring;

    uint32_t vpn;

    uint32_t pte;

    const xtensa_tlb_entry *entry = NULL;

    xtensa_tlb_entry tmp_entry;

    int ret = xtensa_tlb_lookup(env, vaddr, dtlb, &wi, &ei, &ring);

    if ((ret == INST_TLB_MISS_CAUSE || ret == LOAD_STORE_TLB_MISS_CAUSE) &&

            may_lookup_pt && get_pte(env, vaddr, &pte) == 0) {

        ring = (pte >> 4) & 0x3;

        wi = 0;

        split_tlb_entry_spec_way(env, vaddr, dtlb, &vpn, wi, &ei);

        if (update_tlb) {

            wi = ++env->autorefill_idx & 0x3;

            xtensa_tlb_set_entry(env, dtlb, wi, ei, vpn, pte);

            env->sregs[EXCVADDR] = vaddr;

            qemu_log("%s: autorefill(%08x): %08x -> %08x\n",

                    __func__, vaddr, vpn, pte);

        } else {

            xtensa_tlb_set_entry_mmu(env, &tmp_entry, dtlb, wi, ei, vpn, pte);

            entry = &tmp_entry;

        }

        ret = 0;

    }

    if (ret != 0) {

        return ret;

    }

    if (entry == NULL) {

        entry = xtensa_tlb_get_entry(env, dtlb, wi, ei);

    }

    if (ring < mmu_idx) {

        return dtlb ?

            LOAD_STORE_PRIVILEGE_CAUSE :

            INST_FETCH_PRIVILEGE_CAUSE;

    }

    *access = mmu_attr_to_access(entry->attr);

    if (!is_access_granted(*access, is_write)) {

        return dtlb ?

            (is_write ?

             STORE_PROHIBITED_CAUSE :

             LOAD_PROHIBITED_CAUSE) :

            INST_FETCH_PROHIBITED_CAUSE;

    }

    *paddr = entry->paddr | (vaddr & ~xtensa_tlb_get_addr_mask(env, dtlb, wi));

    *page_size = ~xtensa_tlb_get_addr_mask(env, dtlb, wi) + 1;

    return 0;

}

static int get_pte(CPUXtensaState *env, uint32_t vaddr, uint32_t *pte)

{

    uint32_t paddr;

    uint32_t page_size;

    unsigned access;

    uint32_t pt_vaddr =

        (env->sregs[PTEVADDR] | (vaddr >> 10)) & 0xfffffffc;

    int ret = get_physical_addr_mmu(env, false, pt_vaddr, 0, 0,

            &paddr, &page_size, &access, false);

    qemu_log("%s: trying autorefill(%08x) -> %08x\n", __func__,

            vaddr, ret ? ~0 : paddr);

    if (ret == 0) {

        *pte = ldl_phys(paddr);

    }

    return ret;

}

static int get_physical_addr_region(CPUXtensaState *env,

        uint32_t vaddr, int is_write, int mmu_idx,

        uint32_t *paddr, uint32_t *page_size, unsigned *access)

{

    bool dtlb = is_write != 2;

    uint32_t wi = 0;

    uint32_t ei = (vaddr >> 29) & 0x7;

    const xtensa_tlb_entry *entry =

        xtensa_tlb_get_entry(env, dtlb, wi, ei);

    *access = region_attr_to_access(entry->attr);

    if (!is_access_granted(*access, is_write)) {

        return dtlb ?

            (is_write ?

             STORE_PROHIBITED_CAUSE :

             LOAD_PROHIBITED_CAUSE) :

            INST_FETCH_PROHIBITED_CAUSE;

    }

    *paddr = entry->paddr | (vaddr & ~REGION_PAGE_MASK);

    *page_size = ~REGION_PAGE_MASK + 1;

    return 0;

}

/*!

 * Convert virtual address to physical addr.

 * MMU may issue pagewalk and change xtensa autorefill TLB way entry.

 *

 * \return 0 if ok, exception cause code otherwise

 */

int xtensa_get_physical_addr(CPUXtensaState *env, bool update_tlb,

        uint32_t vaddr, int is_write, int mmu_idx,

        uint32_t *paddr, uint32_t *page_size, unsigned *access)

{

    if (xtensa_option_enabled(env->config, XTENSA_OPTION_MMU)) {

        return get_physical_addr_mmu(env, update_tlb,

                vaddr, is_write, mmu_idx, paddr, page_size, access, true);

    } else if (xtensa_option_bits_enabled(env->config,

                XTENSA_OPTION_BIT(XTENSA_OPTION_REGION_PROTECTION) |

                XTENSA_OPTION_BIT(XTENSA_OPTION_REGION_TRANSLATION))) {

        return get_physical_addr_region(env, vaddr, is_write, mmu_idx,

                paddr, page_size, access);

    } else {

        *paddr = vaddr;

        *page_size = TARGET_PAGE_SIZE;

        *access = PAGE_READ | PAGE_WRITE | PAGE_EXEC;

        return 0;

    }

}

static void dump_tlb(FILE *f, fprintf_function cpu_fprintf,

        CPUXtensaState *env, bool dtlb)

{

    unsigned wi, ei;

    const xtensa_tlb *conf =

        dtlb ? &env->config->dtlb : &env->config->itlb;

    unsigned (*attr_to_access)(uint32_t) =

        xtensa_option_enabled(env->config, XTENSA_OPTION_MMU) ?

        mmu_attr_to_access : region_attr_to_access;

    for (wi = 0; wi < conf->nways; ++wi) {

        uint32_t sz = ~xtensa_tlb_get_addr_mask(env, dtlb, wi) + 1;

        const char *sz_text;

        bool print_header = true;

        if (sz >= 0x100000) {

            sz >>= 20;

            sz_text = "MB";

        } else {

            sz >>= 10;

            sz_text = "KB";

        }

        for (ei = 0; ei < conf->way_size[wi]; ++ei) {

            const xtensa_tlb_entry *entry =

                xtensa_tlb_get_entry(env, dtlb, wi, ei);

            if (entry->asid) {

                unsigned access = attr_to_access(entry->attr);

                if (print_header) {

                    print_header = false;

                    cpu_fprintf(f, "Way %u (%d %s)\n", wi, sz, sz_text);

                    cpu_fprintf(f,

                            "\tVaddr       Paddr       ASID  Attr RWX\n"

                            "\t----------  ----------  ----  ---- ---\n");

                }

                cpu_fprintf(f,

                        "\t0x%08x  0x%08x  0x%02x  0x%02x %c%c%c\n",

                        entry->vaddr,

                        entry->paddr,

                        entry->asid,

                        entry->attr,

                        (access & PAGE_READ) ? 'R' : '-',

                        (access & PAGE_WRITE) ? 'W' : '-',

                        (access & PAGE_EXEC) ? 'X' : '-');

            }

        }

    }

}

void dump_mmu(FILE *f, fprintf_function cpu_fprintf, CPUXtensaState *env)

{

    if (xtensa_option_bits_enabled(env->config,

                XTENSA_OPTION_BIT(XTENSA_OPTION_REGION_PROTECTION) |

                XTENSA_OPTION_BIT(XTENSA_OPTION_REGION_TRANSLATION) |

                XTENSA_OPTION_BIT(XTENSA_OPTION_MMU))) {

        cpu_fprintf(f, "ITLB:\n");

        dump_tlb(f, cpu_fprintf, env, false);

        cpu_fprintf(f, "\nDTLB:\n");

        dump_tlb(f, cpu_fprintf, env, true);

    } else {

        cpu_fprintf(f, "No TLB for this CPU core\n");

    }

}