source: mainline/uspace/srv/hw/irc/apic/apic.c@ 1737bfb

/*
 * Copyright (c) 2011 Martin Decky
 * 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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.
 */

/** @addtogroup apic
 * @{
 */

/**
 * @file apic.c
 * @brief APIC driver.
 */

#include <ipc/services.h>
#include <ipc/irc.h>
#include <ns.h>
#include <sysinfo.h>
#include <as.h>
#include <ddi.h>
#include <bool.h>
#include <errno.h>
#include <async.h>
#include <stdio.h>

#define NAME  "apic"

#define APIC_MAX_IRQ    15

#define IOREGSEL  (0x00U / sizeof(uint32_t))
#define IOWIN     (0x10U / sizeof(uint32_t))

#define IOREDTBL   0x10U

/** I/O Register Select Register. */
typedef union {
        uint32_t value;
        struct {
                uint8_t reg_addr;       /**< APIC Register Address. */
                unsigned int : 24;      /**< Reserved. */
        } __attribute__ ((packed));
} io_regsel_t;

/** I/O Redirection Register. */
typedef struct io_redirection_reg {
        union {
                uint32_t lo;
                struct {
                        uint8_t intvec;                 /**< Interrupt Vector. */
                        unsigned int delmod : 3;        /**< Delivery Mode. */
                        unsigned int destmod : 1;       /**< Destination mode. */
                        unsigned int delivs : 1;        /**< Delivery status (RO). */
                        unsigned int intpol : 1;        /**< Interrupt Input Pin Polarity. */
                        unsigned int irr : 1;           /**< Remote IRR (RO). */
                        unsigned int trigger_mode : 1;  /**< Trigger Mode. */
                        unsigned int masked : 1;        /**< Interrupt Mask. */
                        unsigned int : 15;              /**< Reserved. */
                } __attribute__ ((packed));
        };
        union {
                uint32_t hi;
                struct {
                        unsigned int : 24;      /**< Reserved. */
                        uint8_t dest : 8;       /**< Destination Field. */
                } __attribute__ ((packed));
        };
} __attribute__ ((packed)) io_redirection_reg_t;

// FIXME: get the address from the kernel
#define IO_APIC_BASE    0xfec00000UL
#define IO_APIC_SIZE    20

ioport32_t *io_apic = NULL;

/** Read from IO APIC register.
 *
 * @param address IO APIC register address.
 *
 * @return Content of the addressed IO APIC register.
 *
 */
static uint32_t io_apic_read(uint8_t address)
{
        io_regsel_t regsel;

        regsel.value = io_apic[IOREGSEL];
        regsel.reg_addr = address;
        io_apic[IOREGSEL] = regsel.value;
        return io_apic[IOWIN];
}

/** Write to IO APIC register.
 *
 * @param address IO APIC register address.
 * @param val     Content to be written to the addressed IO APIC register.
 *
 */
static void io_apic_write(uint8_t address, uint32_t val)
{
        io_regsel_t regsel;

        regsel.value = io_apic[IOREGSEL];
        regsel.reg_addr = address;
        io_apic[IOREGSEL] = regsel.value;
        io_apic[IOWIN] = val;
}

static int irq_to_pin(int irq)
{
        // FIXME: get the map from the kernel, even though this may work
        //        for simple cases
        if (irq == 0)
                return 2;
        return irq;
}

static int apic_enable_irq(sysarg_t irq)
{
        io_redirection_reg_t reg;

        if (irq > APIC_MAX_IRQ)
                return ELIMIT;

        int pin = irq_to_pin(irq);
        if (pin == -1)
                return ENOENT;

        reg.lo = io_apic_read((uint8_t) (IOREDTBL + pin * 2));
        reg.masked = false;
        io_apic_write((uint8_t) (IOREDTBL + pin * 2), reg.lo);

        return EOK;
}

/** Handle one connection to APIC.
 *
 * @param iid   Hash of the request that opened the connection.
 * @param icall Call data of the request that opened the connection.
 * @param arg   Local argument.
 */
static void apic_connection(ipc_callid_t iid, ipc_call_t *icall, void *arg)
{
        ipc_callid_t callid;
        ipc_call_t call;
        
        /*
         * Answer the first IPC_M_CONNECT_ME_TO call.
         */
        async_answer_0(iid, EOK);
        
        while (true) {
                callid = async_get_call(&call);
                
                if (!IPC_GET_IMETHOD(call)) {
                        /* The other side has hung up. */
                        async_answer_0(callid, EOK);
                        return;
                }
                
                switch (IPC_GET_IMETHOD(call)) {
                case IRC_ENABLE_INTERRUPT:
                        async_answer_0(callid, apic_enable_irq(IPC_GET_ARG1(call)));
                        break;
                case IRC_CLEAR_INTERRUPT:
                        /* Noop */
                        async_answer_0(callid, EOK);
                        break;
                default:
                        async_answer_0(callid, EINVAL);
                        break;
                }
        }
}

/** Initialize the APIC driver.
 *
 */
static bool apic_init(void)
{
        sysarg_t apic;
        
        if ((sysinfo_get_value("apic", &apic) != EOK) || (!apic)) {
                printf("%s: No APIC found\n", NAME);
                return false;
        }

        int rc = pio_enable((void *) IO_APIC_BASE, IO_APIC_SIZE,
                (void **) &io_apic);
        if (rc != EOK) {
                printf("%s: Failed to enable PIO for APIC: %d\n", NAME, rc);
                return false;   
        }
        
        async_set_client_connection(apic_connection);
        service_register(SERVICE_IRC);
        
        return true;
}

int main(int argc, char **argv)
{
        printf("%s: HelenOS APIC driver\n", NAME);
        
        if (!apic_init())
                return -1;
        
        printf("%s: Accepting connections\n", NAME);
        task_retval(0);
        async_manager();
        
        /* Never reached */
        return 0;
}

/**
 * @}
 */