Disintegrate asm/system.h for Tile

Disintegrate asm/system.h for Tile.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>

1 files changed, 148 insertions, 0 deletions

diff --git a/arch/tile/include/asm/barrier.h b/arch/tile/include/asm/barrier.h
new file mode 100644
index 000000000000..990a217a0b72
--- /dev/null
+++ b/arch/tile/include/asm/barrier.h
@@ -0,0 +1,148 @@
+/*
+ * 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>
+
+/*
+ * read_barrier_depends - Flush all pending reads that subsequents reads
+ * depend on.
+ *
+ * No data-dependent reads from memory-like regions are ever reordered
+ * over this barrier.  All reads preceding this primitive are guaranteed
+ * to access memory (but not necessarily other CPUs' caches) before any
+ * reads following this primitive that depend on the data return by
+ * any of the preceding reads.  This primitive is much lighter weight than
+ * rmb() on most CPUs, and is never heavier weight than is
+ * rmb().
+ *
+ * These ordering constraints are respected by both the local CPU
+ * and the compiler.
+ *
+ * Ordering is not guaranteed by anything other than these primitives,
+ * not even by data dependencies.  See the documentation for
+ * memory_barrier() for examples and URLs to more information.
+ *
+ * For example, the following code would force ordering (the initial
+ * value of "a" is zero, "b" is one, and "p" is "&a"):
+ *
+ * <programlisting>
+ *	CPU 0				CPU 1
+ *
+ *	b = 2;
+ *	memory_barrier();
+ *	p = &b;				q = p;
+ *					read_barrier_depends();
+ *					d = *q;
+ * </programlisting>
+ *
+ * because the read of "*q" depends on the read of "p" and these
+ * two reads are separated by a read_barrier_depends().  However,
+ * the following code, with the same initial values for "a" and "b":
+ *
+ * <programlisting>
+ *	CPU 0				CPU 1
+ *
+ *	a = 2;
+ *	memory_barrier();
+ *	b = 3;				y = b;
+ *					read_barrier_depends();
+ *					x = a;
+ * </programlisting>
+ *
+ * does not enforce ordering, since there is no data dependency between
+ * the read of "a" and the read of "b".  Therefore, on some CPUs, such
+ * as Alpha, "y" could be set to 3 and "x" to 0.  Use rmb()
+ * in cases like this where there are no data dependencies.
+ */
+#define read_barrier_depends()	do { } while (0)
+
+#define __sync()	__insn_mf()
+
+#if !CHIP_HAS_MF_WAITS_FOR_VICTIMS()
+#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");
+}
+#endif
+
+/* Fence to guarantee visibility of stores to incoherent memory. */
+static inline void
+mb_incoherent(void)
+{
+	__insn_mf();
+
+#if !CHIP_HAS_MF_WAITS_FOR_VICTIMS()
+	{
+#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();
+	}
+#endif /* CHIP_HAS_MF_WAITS_FOR_VICTIMS() */
+}
+
+#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()
+
+#ifdef CONFIG_SMP
+#define smp_mb()	mb()
+#define smp_rmb()	rmb()
+#define smp_wmb()	wmb()
+#define smp_read_barrier_depends()	read_barrier_depends()
+#else
+#define smp_mb()	barrier()
+#define smp_rmb()	barrier()
+#define smp_wmb()	barrier()
+#define smp_read_barrier_depends()	do { } while (0)
+#endif
+
+#define set_mb(var, value) \
+	do { var = value; mb(); } while (0)
+
+#endif /* !__ASSEMBLY__ */
+#endif /* _ASM_TILE_BARRIER_H */