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/*
* Platform dependent support for IO probing.
*
* Copyright (C) 2000 Silicon Graphics
* Copyright (C) 2000 Jack Steiner (steiner@sgi.com)
*/
#include <asm/sn/sn_sal.h>
/*
* ia64_sn_probe_io_slot
* This function will probe a physical address to determine if
* the address can be read. If reading the address causes a BUS
* error, an error is returned. If the probe succeeds, the contents
* of the memory location is returned.
*
* Calling sequence:
* ia64_probe_io_slot(paddr, size, data_ptr)
*
* Input:
* paddr Physical address to probe
* size Number bytes to read (1,2,4,8)
* data_ptr Address to store value read by probe
* (-1 returned if probe fails)
*
* Output:
* Status
* 0 - probe successful
* 1 - probe failed (generated MCA)
* 2 - Bad arg
* <0 - PAL error
*/
u64
ia64_sn_probe_io_slot(long paddr, long size, void *data_ptr)
{
struct ia64_sal_retval isrv;
SAL_CALL(isrv, SN_SAL_PROBE, paddr, size, 0, 0, 0, 0, 0);
if (data_ptr) {
switch (size) {
case 1:
*((u8*)data_ptr) = (u8)isrv.v0;
break;
case 2:
*((u16*)data_ptr) = (u16)isrv.v0;
break;
case 4:
*((u32*)data_ptr) = (u32)isrv.v0;
break;
case 8:
*((u64*)data_ptr) = (u64)isrv.v0;
break;
default:
isrv.status = 2;
}
}
return isrv.status;
}
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