In my module, most of my variables are set by a dsp on a pci board. This
variables are on a Dual Port Ram (dpram) and I access them with a
pointer on a structure (piraq).
An handler of interrupt uses 2 pointers to know where to get the data on
dpram (piraq->bufptr[], piraq->flag) and one to know the amount of data
to transfer (piraq->size).
unsigned int PII_intr_handler(unsigned int irq, struct pt_regs *regs)
{
u8 * buff;
u8 * ptr;
u32 part;
int i;
buff = (u8 *) piraq->bufptr[1-(*(piraq->flag)&1)];
*Pos= Pos_next;
for (i=0;i<2;i++) {
ptr = (u8 *)shm + sizeof(u32)+ Pos_next;
part = Pos_next + *(piraq->size);
if ( part > BUFF_SIZE ) {
part = BUFF_SIZE - Pos_next;
memcpy_fromio(ptr,buff + (OFFSET_DPRAM_U8 * i) ,part);
ptr = (u8 *)shm + sizeof(u32);
memcpy_fromio(ptr,buff + (OFFSET_DPRAM_U8 * i)
,*(piraq->size)-part);
Pos_next = *(piraq->size) - part;
}else {
memcpy_fromio(ptr,buff + (OFFSET_DPRAM_U8 * i), *(piraq->size));
Pos_next += *(piraq->size);
}
}
#ifdef DEBUG
state ^= 0x800;
writew(state,STATUS);
#endif
outl(0x01000000,INTCSR); /* reset control register */
outl(0x00000000,INTCSR); /* reset control register */
rtl_hard_enable_irq(PII_Intr);
return 0;
}
piraq->bufptr, piraq->flag, piraq->size are defined as following :
(u32 *) piraq->bufptr[0] = (u32 *)(PII_DPRAM + BUFFER0);
(u32 *) piraq->bufptr[1] = (u32 *)(PII_DPRAM + BUFFER1);
(u32 *) piraq->flag = (u32 *)(PII_DPRAM + FLAG);
(u32 *) piraq->size = (u32 *)(PII_DPRAM + SIZE);
where PII_DPRAM is the virtual address of the dpram and BUFFER0,
BUFFER1, FLAG and SIZE are the position of the variables in the DPRAM
the line "(u32 *) piraq->size = (u32 *)(PII_DPRAM + SIZE);" causes my
module to crash sometime if my interrupt handler is installed, EVEN IF
MY HANDLER IS NOT CALLED, sometimes is happened during insmod or when I
want to perform a memset_io on pci memory
I can read write to piraq->size but sometime I've got the following
message :
Unable to handle kernel paging request at virtual address d0a91000
current->tss.cr3 = 05527000, %cr3 = 05527000
*pde = 05521063
*pte = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[aic7xxx:__insmod_aic7xxx_S.bss_L256+285476/294155188]
EFLAGS: 00210006
eax: 00000000 ebx: d0a79a00 ecx: 0027a27f edx: 009ffffc
esi: d0a91000 edi: d0087604 ebp: c5529df8 esp: c5529de8
ds: 0018 es: 0018 ss: 0018
Process memtest (pid: 1078, process nr: 62, stackpage=c5529000)
Stack: 0000000a 00000000 00000000 d0a79a00 c5529e54 d00464c6 0000000a
c5529e5c
00200096 00000000 00000000 00000028 00200096 d00554c4 0000174d 00000000
00000000 c5529e94 00000001 d0050018 c5520018 ffffff0a d004c648 00000010
Call Trace: [aic7xxx:__insmod_aic7xxx_S.bss_L256+151238/294289426]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+212676/294227988]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+191000/294249664]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+176200/294264464]
[ret_from_intr+0/32]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+212676/294227988]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+191000/294249664]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+176200/294264464]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+151238/294289426]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+287573/294153091]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+291125/294149539]
[ret_from_intr+0/32]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+287573/294153091]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+291125/294149539]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+289610/294151054]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+234901/294205763]
[sys_write+219/256]
[aic7xxx:__insmod_aic7xxx_S.bss_L256+234380/294206284]
[system_call+52/56]
Code: f3 a5 f6 c2 02 74 02 66 a5 f6 c2 01 74 01 a4 8b 3d 80 8c 06
If I comment this line or if I change my code to :
int size; // as global
.
.
.
(u32 *) piraq->size = &size;
everything is fine.
Is there some restrictions concerning pointers in handler ???
Thanks
Fred
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| Frederic CAZENAVE |
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