Archipelago » qemu

/*

 * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator

 *

 * PAPR Virtualized Interrupt System, aka ICS/ICP aka xics

 *

 * Copyright (c) 2010,2011 David Gibson, IBM Corporation.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 *

 */

#include "hw.h"

#include "hw/spapr.h"

#include "hw/xics.h"

#include <pthread.h>

/*

 * ICP: Presentation layer

 */

struct icp_server_state {

    uint32_t xirr;

    uint8_t pending_priority;

    uint8_t mfrr;

    qemu_irq output;

};

#define XISR_MASK  0x00ffffff

#define CPPR_MASK  0xff000000

#define XISR(ss)   (((ss)->xirr) & XISR_MASK)

#define CPPR(ss)   (((ss)->xirr) >> 24)

struct ics_state;

struct icp_state {

    long nr_servers;

    struct icp_server_state *ss;

    struct ics_state *ics;

};

static void ics_reject(struct ics_state *ics, int nr);

static void ics_resend(struct ics_state *ics);

static void ics_eoi(struct ics_state *ics, int nr);

static void icp_check_ipi(struct icp_state *icp, int server)

{

    struct icp_server_state *ss = icp->ss + server;

    if (XISR(ss) && (ss->pending_priority <= ss->mfrr)) {

        return;

    }

    if (XISR(ss)) {

        ics_reject(icp->ics, XISR(ss));

    }

    ss->xirr = (ss->xirr & ~XISR_MASK) | XICS_IPI;

    ss->pending_priority = ss->mfrr;

    qemu_irq_raise(ss->output);

}

static void icp_resend(struct icp_state *icp, int server)

{

    struct icp_server_state *ss = icp->ss + server;

    if (ss->mfrr < CPPR(ss)) {

        icp_check_ipi(icp, server);

    }

    ics_resend(icp->ics);

}

static void icp_set_cppr(struct icp_state *icp, int server, uint8_t cppr)

{

    struct icp_server_state *ss = icp->ss + server;

    uint8_t old_cppr;

    uint32_t old_xisr;

    old_cppr = CPPR(ss);

    ss->xirr = (ss->xirr & ~CPPR_MASK) | (cppr << 24);

    if (cppr < old_cppr) {

        if (XISR(ss) && (cppr <= ss->pending_priority)) {

            old_xisr = XISR(ss);

            ss->xirr &= ~XISR_MASK; /* Clear XISR */

            qemu_irq_lower(ss->output);

            ics_reject(icp->ics, old_xisr);

        }

    } else {

        if (!XISR(ss)) {

            icp_resend(icp, server);

        }

    }

}

static void icp_set_mfrr(struct icp_state *icp, int nr, uint8_t mfrr)

{

    struct icp_server_state *ss = icp->ss + nr;

    ss->mfrr = mfrr;

    if (mfrr < CPPR(ss)) {

        icp_check_ipi(icp, nr);

    }

}

static uint32_t icp_accept(struct icp_server_state *ss)

{

    uint32_t xirr;

    qemu_irq_lower(ss->output);

    xirr = ss->xirr;

    ss->xirr = ss->pending_priority << 24;

    return xirr;

}

static void icp_eoi(struct icp_state *icp, int server, uint32_t xirr)

{

    struct icp_server_state *ss = icp->ss + server;

    ics_eoi(icp->ics, xirr & XISR_MASK);

    /* Send EOI -> ICS */

    ss->xirr = (ss->xirr & ~CPPR_MASK) | (xirr & CPPR_MASK);

    if (!XISR(ss)) {

        icp_resend(icp, server);

    }

}

static void icp_irq(struct icp_state *icp, int server, int nr, uint8_t priority)

{

    struct icp_server_state *ss = icp->ss + server;

    if ((priority >= CPPR(ss))

        || (XISR(ss) && (ss->pending_priority <= priority))) {

        ics_reject(icp->ics, nr);

    } else {

        if (XISR(ss)) {

            ics_reject(icp->ics, XISR(ss));

        }

        ss->xirr = (ss->xirr & ~XISR_MASK) | (nr & XISR_MASK);

        ss->pending_priority = priority;

        qemu_irq_raise(ss->output);

    }

}

/*

 * ICS: Source layer

 */

struct ics_irq_state {

    int server;

    uint8_t priority;

    uint8_t saved_priority;

    /* int pending:1; */

    /* int presented:1; */

    int rejected:1;

    int masked_pending:1;

};

struct ics_state {

    int nr_irqs;

    int offset;

    qemu_irq *qirqs;

    struct ics_irq_state *irqs;

    struct icp_state *icp;

};

static int ics_valid_irq(struct ics_state *ics, uint32_t nr)

{

    return (nr >= ics->offset)

        && (nr < (ics->offset + ics->nr_irqs));

}

static void ics_set_irq_msi(void *opaque, int nr, int val)

{

    struct ics_state *ics = (struct ics_state *)opaque;

    struct ics_irq_state *irq = ics->irqs + nr;

    if (val) {

        if (irq->priority == 0xff) {

            irq->masked_pending = 1;

            /* masked pending */ ;

        } else  {

            icp_irq(ics->icp, irq->server, nr + ics->offset, irq->priority);

        }

    }

}

static void ics_reject_msi(struct ics_state *ics, int nr)

{

    struct ics_irq_state *irq = ics->irqs + nr - ics->offset;

    irq->rejected = 1;

}

static void ics_resend_msi(struct ics_state *ics)

{

    int i;

    for (i = 0; i < ics->nr_irqs; i++) {

        struct ics_irq_state *irq = ics->irqs + i;

        /* FIXME: filter by server#? */

        if (irq->rejected) {

            irq->rejected = 0;

            if (irq->priority != 0xff) {

                icp_irq(ics->icp, irq->server, i + ics->offset, irq->priority);

            }

        }

    }

}

static void ics_write_xive_msi(struct ics_state *ics, int nr, int server,

                               uint8_t priority)

{

    struct ics_irq_state *irq = ics->irqs + nr;

    irq->server = server;

    irq->priority = priority;

    if (!irq->masked_pending || (priority == 0xff)) {

        return;

    }

    irq->masked_pending = 0;

    icp_irq(ics->icp, server, nr + ics->offset, priority);

}

static void ics_reject(struct ics_state *ics, int nr)

{

    ics_reject_msi(ics, nr);

}

static void ics_resend(struct ics_state *ics)

{

    ics_resend_msi(ics);

}

static void ics_eoi(struct ics_state *ics, int nr)

{

}

/*

 * Exported functions

 */

qemu_irq xics_find_qirq(struct icp_state *icp, int irq)

{

    if ((irq < icp->ics->offset)

        || (irq >= (icp->ics->offset + icp->ics->nr_irqs))) {

        return NULL;

    }

    return icp->ics->qirqs[irq - icp->ics->offset];

}

static target_ulong h_cppr(CPUState *env, sPAPREnvironment *spapr,

                           target_ulong opcode, target_ulong *args)

{

    target_ulong cppr = args[0];

    icp_set_cppr(spapr->icp, env->cpu_index, cppr);

    return H_SUCCESS;

}

static target_ulong h_ipi(CPUState *env, sPAPREnvironment *spapr,

                          target_ulong opcode, target_ulong *args)

{

    target_ulong server = args[0];

    target_ulong mfrr = args[1];

    if (server >= spapr->icp->nr_servers) {

        return H_PARAMETER;

    }

    icp_set_mfrr(spapr->icp, server, mfrr);

    return H_SUCCESS;

}

static target_ulong h_xirr(CPUState *env, sPAPREnvironment *spapr,

                           target_ulong opcode, target_ulong *args)

{

    uint32_t xirr = icp_accept(spapr->icp->ss + env->cpu_index);

    args[0] = xirr;

    return H_SUCCESS;

}

static target_ulong h_eoi(CPUState *env, sPAPREnvironment *spapr,

                          target_ulong opcode, target_ulong *args)

{

    target_ulong xirr = args[0];

    icp_eoi(spapr->icp, env->cpu_index, xirr);

    return H_SUCCESS;

}

static void rtas_set_xive(sPAPREnvironment *spapr, uint32_t token,

                          uint32_t nargs, target_ulong args,

                          uint32_t nret, target_ulong rets)

{

    struct ics_state *ics = spapr->icp->ics;

    uint32_t nr, server, priority;

    if ((nargs != 3) || (nret != 1)) {

        rtas_st(rets, 0, -3);

        return;

    }

    nr = rtas_ld(args, 0);

    server = rtas_ld(args, 1);

    priority = rtas_ld(args, 2);

    if (!ics_valid_irq(ics, nr) || (server >= ics->icp->nr_servers)

        || (priority > 0xff)) {

        rtas_st(rets, 0, -3);

        return;

    }

    ics_write_xive_msi(ics, nr - ics->offset, server, priority);

    rtas_st(rets, 0, 0); /* Success */

}

static void rtas_get_xive(sPAPREnvironment *spapr, uint32_t token,

                          uint32_t nargs, target_ulong args,

                          uint32_t nret, target_ulong rets)

{

    struct ics_state *ics = spapr->icp->ics;

    uint32_t nr;

    if ((nargs != 1) || (nret != 3)) {

        rtas_st(rets, 0, -3);

        return;

    }

    nr = rtas_ld(args, 0);

    if (!ics_valid_irq(ics, nr)) {

        rtas_st(rets, 0, -3);

        return;

    }

    rtas_st(rets, 0, 0); /* Success */

    rtas_st(rets, 1, ics->irqs[nr - ics->offset].server);

    rtas_st(rets, 2, ics->irqs[nr - ics->offset].priority);

}

static void rtas_int_off(sPAPREnvironment *spapr, uint32_t token,

                         uint32_t nargs, target_ulong args,

                         uint32_t nret, target_ulong rets)

{

    struct ics_state *ics = spapr->icp->ics;

    uint32_t nr;

    if ((nargs != 1) || (nret != 1)) {

        rtas_st(rets, 0, -3);

        return;

    }

    nr = rtas_ld(args, 0);

    if (!ics_valid_irq(ics, nr)) {

        rtas_st(rets, 0, -3);

        return;

    }

    /* This is a NOP for now, since the described PAPR semantics don't

     * seem to gel with what Linux does */

#if 0

    struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);

    irq->saved_priority = irq->priority;

    ics_write_xive_msi(xics, nr - xics->offset, irq->server, 0xff);

#endif

    rtas_st(rets, 0, 0); /* Success */

}

static void rtas_int_on(sPAPREnvironment *spapr, uint32_t token,

                        uint32_t nargs, target_ulong args,

                        uint32_t nret, target_ulong rets)

{

    struct ics_state *ics = spapr->icp->ics;

    uint32_t nr;

    if ((nargs != 1) || (nret != 1)) {

        rtas_st(rets, 0, -3);

        return;

    }

    nr = rtas_ld(args, 0);

    if (!ics_valid_irq(ics, nr)) {

        rtas_st(rets, 0, -3);

        return;

    }

    /* This is a NOP for now, since the described PAPR semantics don't

     * seem to gel with what Linux does */

#if 0

    struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);

    ics_write_xive_msi(xics, nr - xics->offset,

                       irq->server, irq->saved_priority);

#endif

    rtas_st(rets, 0, 0); /* Success */

}

struct icp_state *xics_system_init(int nr_irqs)

{

    CPUState *env;

    int max_server_num;

    int i;

    struct icp_state *icp;

    struct ics_state *ics;

    max_server_num = -1;

    for (env = first_cpu; env != NULL; env = env->next_cpu) {

        if (env->cpu_index > max_server_num) {

            max_server_num = env->cpu_index;

        }

    }

    icp = qemu_mallocz(sizeof(*icp));

    icp->nr_servers = max_server_num + 1;

    icp->ss = qemu_mallocz(icp->nr_servers*sizeof(struct icp_server_state));

    for (i = 0; i < icp->nr_servers; i++) {

        icp->ss[i].mfrr = 0xff;

    }

    for (env = first_cpu; env != NULL; env = env->next_cpu) {

        struct icp_server_state *ss = &icp->ss[env->cpu_index];

        switch (PPC_INPUT(env)) {

        case PPC_FLAGS_INPUT_POWER7:

            ss->output = env->irq_inputs[POWER7_INPUT_INT];

            break;

        case PPC_FLAGS_INPUT_970:

            ss->output = env->irq_inputs[PPC970_INPUT_INT];

            break;

        default:

            hw_error("XICS interrupt model does not support this CPU bus "

                     "model\n");

            exit(1);

        }

    }

    ics = qemu_mallocz(sizeof(*ics));

    ics->nr_irqs = nr_irqs;

    ics->offset = 16;

    ics->irqs = qemu_mallocz(nr_irqs * sizeof(struct ics_irq_state));

    icp->ics = ics;

    ics->icp = icp;

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

        ics->irqs[i].priority = 0xff;

        ics->irqs[i].saved_priority = 0xff;

    }

    ics->qirqs = qemu_allocate_irqs(ics_set_irq_msi, ics, nr_irqs);

    spapr_register_hypercall(H_CPPR, h_cppr);

    spapr_register_hypercall(H_IPI, h_ipi);

    spapr_register_hypercall(H_XIRR, h_xirr);

    spapr_register_hypercall(H_EOI, h_eoi);

    spapr_rtas_register("ibm,set-xive", rtas_set_xive);

    spapr_rtas_register("ibm,get-xive", rtas_get_xive);

    spapr_rtas_register("ibm,int-off", rtas_int_off);

    spapr_rtas_register("ibm,int-on", rtas_int_on);

    return icp;

}