/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2008 Silicon Graphics, Inc. All Rights Reserved.
*/
/*
* Cross Partition (XP) sn2-based functions.
*
* Architecture specific implementation of common functions.
*/
#include <linux/device.h>
#include <asm/sn/bte.h>
#include <asm/sn/sn_sal.h>
#include "xp.h"
/*
* The export of xp_nofault_PIOR needs to happen here since it is defined
* in drivers/misc/sgi-xp/xp_nofault.S. The target of the nofault read is
* defined here.
*/
EXPORT_SYMBOL_GPL(xp_nofault_PIOR);
u64 xp_nofault_PIOR_target;
EXPORT_SYMBOL_GPL(xp_nofault_PIOR_target);
/*
* Register a nofault code region which performs a cross-partition PIO read.
* If the PIO read times out, the MCA handler will consume the error and
* return to a kernel-provided instruction to indicate an error. This PIO read
* exists because it is guaranteed to timeout if the destination is down
* (AMO operations do not timeout on at least some CPUs on Shubs <= v1.2,
* which unfortunately we have to work around).
*/
static enum xp_retval
xp_register_nofault_code_sn2(void)
{
int ret;
u64 func_addr;
u64 err_func_addr;
func_addr = *(u64 *)xp_nofault_PIOR;
err_func_addr = *(u64 *)xp_error_PIOR;
ret = sn_register_nofault_code(func_addr, err_func_addr, err_func_addr,
1, 1);
if (ret != 0) {
dev_err(xp, "can't register nofault code, error=%d\n", ret);
return xpSalError;
}
/*
* Setup the nofault PIO read target. (There is no special reason why
* SH_IPI_ACCESS was selected.)
*/
if (is_shub1())
xp_nofault_PIOR_target = SH1_IPI_ACCESS;
else if (is_shub2())
xp_nofault_PIOR_target = SH2_IPI_ACCESS0;
return xpSuccess;
}
void
xp_unregister_nofault_code_sn2(void)
{
u64 func_addr = *(u64 *)xp_nofault_PIOR;
u64 err_func_addr = *(u64 *)xp_error_PIOR;
/* unregister the PIO read nofault code region */
(void)sn_register_nofault_code(func_addr, err_func_addr,
err_func_addr, 1, 0);
}
/*
* Wrapper for bte_copy().
*
* vdst - virtual address of the destination of the transfer.
* psrc - physical address of the source of the transfer.
* len - number of bytes to transfer from source to destination.
*
* Note: xp_remote_memcpy_sn2() should never be called while holding a spinlock.
*/
static enum xp_retval
xp_remote_memcpy_sn2(void *vdst, const void *psrc, size_t len)
{
bte_result_t ret;
u64 pdst = ia64_tpa(vdst);
/* >>> What are the rules governing the src and dst addresses passed in?
* >>> Currently we're assuming that dst is a virtual address and src
* >>> is a physical address, is this appropriate? Can we allow them to
* >>> be whatever and we make the change here without damaging the
* >>> addresses?
*/
/*
* Ensure that the physically mapped memory is contiguous.
*
* We do this by ensuring that the memory is from region 7 only.
* If the need should arise to use memory from one of the other
* regions, then modify the BUG_ON() statement to ensure that the
* memory from that region is always physically contiguous.
*/
BUG_ON(REGION_NUMBER(vdst) != RGN_KERNEL);
ret = bte_copy((u64)psrc, pdst, len, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
if (ret == BTE_SUCCESS)
return xpSuccess;
if (is_shub2())
dev_err(xp, "bte_copy() on shub2 failed, error=0x%x\n", ret);
else
dev_err(xp, "bte_copy() failed, error=%d\n", ret);
return xpBteCopyError;
}
enum xp_retval
xp_init_sn2(void)
{
BUG_ON(!is_shub());
xp_max_npartitions = XP_MAX_NPARTITIONS_SN2;
xp_remote_memcpy = xp_remote_memcpy_sn2;
return xp_register_nofault_code_sn2();
}
void
xp_exit_sn2(void)
{
BUG_ON(!is_shub());
xp_unregister_nofault_code_sn2();
}
