/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#ifndef _ASM_TILE_BARRIER_H
#define _ASM_TILE_BARRIER_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <arch/chip.h>
#include <arch/spr_def.h>
#include <asm/timex.h>
#define __sync() __insn_mf()
#include <hv/syscall_public.h>
/*
* Issue an uncacheable load to each memory controller, then
* wait until those loads have completed.
*/
static inline void __mb_incoherent(void)
{
long clobber_r10;
asm volatile("swint2"
: "=R10" (clobber_r10)
: "R10" (HV_SYS_fence_incoherent)
: "r0", "r1", "r2", "r3", "r4",
"r5", "r6", "r7", "r8", "r9",
"r11", "r12", "r13", "r14",
"r15", "r16", "r17", "r18", "r19",
"r20", "r21", "r22", "r23", "r24",
"r25", "r26", "r27", "r28", "r29");
}
/* Fence to guarantee visibility of stores to incoherent memory. */
static inline void
mb_incoherent(void)
{
__insn_mf();
{
#if CHIP_HAS_TILE_WRITE_PENDING()
const unsigned long WRITE_TIMEOUT_CYCLES = 400;
unsigned long start = get_cycles_low();
do {
if (__insn_mfspr(SPR_TILE_WRITE_PENDING) == 0)
return;
} while ((get_cycles_low() - start) < WRITE_TIMEOUT_CYCLES);
#endif /* CHIP_HAS_TILE_WRITE_PENDING() */
(void) __mb_incoherent();
}
}
#define fast_wmb() __sync()
#define fast_rmb() __sync()
#define fast_mb() __sync()
#define fast_iob() mb_incoherent()
#define wmb() fast_wmb()
#define rmb() fast_rmb()
#define mb() fast_mb()
#define iob() fast_iob()
#ifndef __tilegx__ /* 32 bit */
/*
* We need to barrier before modifying the word, since the _atomic_xxx()
* routines just tns the lock and then read/modify/write of the word.
* But after the word is updated, the routine issues an "mf" before returning,
* and since it's a function call, we don't even need a compiler barrier.
*/
#define smp_mb__before_atomic() smp_mb()
#define smp_mb__after_atomic() do { } while (0)
#else /* 64 bit */
#define smp_mb__before_atomic() smp_mb()
#define smp_mb__after_atomic() smp_mb()
#endif
#include <asm-generic/barrier.h>
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_TILE_BARRIER_H */
