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Date:      Sat, 10 Jul 2004 02:15:12 +0200
From:      thefly <thefly@acaro.org>
To:        freebsd-hackers@freebsd.org
Subject:   mmap() implementation
Message-ID:  <20040710001512.GA13356@tyler>
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Hello everybody, i'm implementing the mmap part of my nodegraph. At the
moment i'm actually stuck at a point where the process can't actually
access the memory allocation: this is the mmap() function:

static int
ng_counter_mmap(dev_t dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
{
        if (nprot !=3D VM_PROT_READ)
                return (-1);
       =20
        *paddr =3D (vm_paddr_t) (ng_counters.B_array + offset / sizeof(u_in=
t32_t));
       =20
	return (0);
}


ng_couters.B_array is u_int32_t *, and the memory is allocated via :


 counters->B_array =3D (u_int32_t*) contigmalloc((65536*2*sizeof(u_int32_t)=
)+(65536*2*sizeof(u_int16_t)), M_NG_COUNTER, M_WAITOK | M_ZERO, 0, ~0, PAGE=
_SIZE, 0);

I actually need 2 u_int32_t arrays and two u_int16_t arrays, and need to ex=
port
all of them at the same time. I don't know if i need anything like
vtophys() inside of that. The app in userspace does this:


        array =3D (unsigned int *) mmap(0, (65536*2*sizeof(u_int32_t))+(655=
36*2*sizeof(u_int16_t)), PROT_READ, 0, fd, 0);
        if(array =3D=3D (void *) -1){
                printf("mmap failed\n");
                return -1;
        }

        for(i=3D0; i<65536; i++){
                printf("array[%d]=3D%u\n", i, *(array+i));
        }


i'm trying to print the values of the first array, but what i get is a
lot of:

array[484]=3D4294967295
array[485]=3D4294967295
array[486]=3D4294967295
array[487]=3D4294967295
array[488]=3D4294967295
array[489]=3D4294967295

Thanks in advance
--=20
    Claudio "thefly" Martella
    thefly@acaro.org
    GNU/PG keyid: 0x8EA95625

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