mailbox.c

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/*
Copyright (c) 2012, Broadcom Europe Ltd.
Copyright (c) 2016, Jeremy Garff
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 copyright holder 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 COPYRIGHT HOLDER OR CONTRIBUTORS 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 <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>
#include <stdint.h>
#include <errno.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/sysmacros.h>
#include <sys/stat.h>

#include "mailbox.h"


void *mapmem(uint32_t base, uint32_t size, const char *mem_dev) {
    uint32_t pagemask = ~0UL ^ (getpagesize() - 1);
    uint32_t offsetmask = getpagesize() - 1;
    int mem_fd;
    void *mem;

    mem_fd = open(mem_dev, O_RDWR | O_SYNC);
    if (mem_fd < 0) {
       perror("Can't open /dev/mem");
       return NULL;
    }

    mem = mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, mem_fd, base & pagemask);
    if (mem == MAP_FAILED) {
        perror("mmap error\n");
        return NULL;
    }

    close(mem_fd);

    return (char *)mem + (base & offsetmask);
}

void *unmapmem(void *addr, uint32_t size) {
    uint32_t pagemask = ~0UL ^ (getpagesize() - 1);
    uintptr_t baseaddr = (uintptr_t)addr & pagemask;
    int s;
    
    s = munmap((void *)baseaddr, size);
    if (s != 0) {
        perror("munmap error\n");
    }

    return NULL;
}

/*
 * use ioctl to send mbox property message
 */

static int mbox_property(int file_desc, void *buf) {
    int fd = file_desc;
    int ret_val = -1;

    if (fd < 0) {
        fd = mbox_open();
    }

    if (fd >= 0) {
        ret_val = ioctl(fd, IOCTL_MBOX_PROPERTY, buf);

        if (ret_val < 0) {
            perror("ioctl_set_msg failed\n");
        }
    }

    if (file_desc < 0) {
        mbox_close(fd);
    }

    return ret_val;
}

uint32_t mem_alloc(int file_desc, uint32_t size, uint32_t align, uint32_t flags) {
    int i=0;
    uint32_t p[32];

    p[i++] = 0; // size
    p[i++] = 0x00000000; // process request

    p[i++] = 0x3000c; // (the tag id)
    p[i++] = 12; // (size of the buffer)
    p[i++] = 12; // (size of the data)
    p[i++] = size; // (num bytes? or pages?)
    p[i++] = align; // (alignment)
    p[i++] = flags; // (MEM_FLAG_L1_NONALLOCATING)

    p[i++] = 0x00000000; // end tag
    p[0] = i*sizeof *p; // actual size

    if (mbox_property(file_desc, p) < 0)
        return 0;
    else
        return p[5];
}

uint32_t mem_free(int file_desc, uint32_t handle) {
    int i=0;
    uint32_t p[32];

    p[i++] = 0; // size
    p[i++] = 0x00000000; // process request

    p[i++] = 0x3000f; // (the tag id)
    p[i++] = 4; // (size of the buffer)
    p[i++] = 4; // (size of the data)
    p[i++] = handle;

    p[i++] = 0x00000000; // end tag
    p[0] = i*sizeof *p; // actual size

    mbox_property(file_desc, p);

    return p[5];
}

uint32_t mem_lock(int file_desc, uint32_t handle) {
    int i=0;
    uint32_t p[32];

    p[i++] = 0; // size
    p[i++] = 0x00000000; // process request

    p[i++] = 0x3000d; // (the tag id)
    p[i++] = 4; // (size of the buffer)
    p[i++] = 4; // (size of the data)
    p[i++] = handle;

    p[i++] = 0x00000000; // end tag
    p[0] = i*sizeof *p; // actual size

    if (mbox_property(file_desc, p) < 0)
        return ~0;
    else
        return p[5];
}

uint32_t mem_unlock(int file_desc, uint32_t handle) {
   int i=0;
   uint32_t p[32];

   p[i++] = 0; // size
   p[i++] = 0x00000000; // process request

   p[i++] = 0x3000e; // (the tag id)
   p[i++] = 4; // (size of the buffer)
   p[i++] = 4; // (size of the data)
   p[i++] = handle;

   p[i++] = 0x00000000; // end tag
   p[0] = i * sizeof(*p); // actual size

   mbox_property(file_desc, p);

   return p[5];
}

uint32_t execute_code(int file_desc, uint32_t code, uint32_t r0, uint32_t r1, 
                      uint32_t r2, uint32_t r3, uint32_t r4, uint32_t r5) {
    int i=0;
    uint32_t p[32];

    p[i++] = 0; // size
    p[i++] = 0x00000000; // process request

    p[i++] = 0x30010; // (the tag id)
    p[i++] = 28; // (size of the buffer)
    p[i++] = 28; // (size of the data)
    p[i++] = code;
    p[i++] = r0;
    p[i++] = r1;
    p[i++] = r2;
    p[i++] = r3;
    p[i++] = r4;
    p[i++] = r5;

    p[i++] = 0x00000000; // end tag
    p[0] = i * sizeof(*p); // actual size

    mbox_property(file_desc, p);

    return p[5];
}

uint32_t qpu_enable(int file_desc, uint32_t enable) {
    int i=0;
    uint32_t p[32];

    p[i++] = 0; // size
    p[i++] = 0x00000000; // process request

    p[i++] = 0x30012; // (the tag id)
    p[i++] = 4; // (size of the buffer)
    p[i++] = 4; // (size of the data)
    p[i++] = enable;

    p[i++] = 0x00000000; // end tag
    p[0] = i * sizeof(*p); // actual size

    mbox_property(file_desc, p);

    return p[5];
}

uint32_t execute_qpu(int file_desc, uint32_t num_qpus, uint32_t control,
                     uint32_t noflush, uint32_t timeout) {
    int i = 0;
    uint32_t p[32];

    p[i++] = 0; // size
    p[i++] = 0x00000000; // process request
    p[i++] = 0x30011; // (the tag id)
    p[i++] = 16; // (size of the buffer)
    p[i++] = 16; // (size of the data)
    p[i++] = num_qpus;
    p[i++] = control;
    p[i++] = noflush;
    p[i++] = timeout; // ms

    p[i++] = 0x00000000; // end tag
    p[0] = i * sizeof(*p); // actual size

    mbox_property(file_desc, p);

    return p[5];
}

int mbox_open(void) {
    int file_desc;
    char filename[64];

    file_desc = open("/dev/vcio", 0);
    if (file_desc >= 0) {
        return file_desc;
    }

    // open a char device file used for communicating with kernel mbox driver
    sprintf(filename, "/tmp/mailbox-%d", getpid());
    unlink(filename);
    if (mknod(filename, S_IFCHR|0600, makedev(100, 0)) < 0) {
        perror("Failed to create mailbox device\n");
        return -1;
    }
    file_desc = open(filename, 0);
    if (file_desc < 0) {
        perror("Can't open device file\n");
        unlink(filename);
        return -1;
    }
    unlink(filename);

    return file_desc;
}

void mbox_close(int file_desc) {
    close(file_desc);
}