[ubicom32]: move new files out from platform support patch

[openwrt/svn-archive/archive.git] / target / linux / ubicom32 / files / arch / ubicom32 / include / asm / system.h

diff --git a/target/linux/ubicom32/files/arch/ubicom32/include/asm/system.h b/target/linux/ubicom32/files/arch/ubicom32/include/asm/system.h
new file mode 100644 (file)
index 0000000..c3ec608
--- /dev/null
+++ b/target/linux/ubicom32/files/arch/ubicom32/include/asm/system.h
@@ -0,0 +1,101 @@
+/*
+ * arch/ubicom32/include/asm/system.h
+ *   Low level switching definitions.
+ *
+ * (C) Copyright 2009, Ubicom, Inc.
+ *
+ * This file is part of the Ubicom32 Linux Kernel Port.
+ *
+ * The Ubicom32 Linux Kernel Port 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, either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * The Ubicom32 Linux Kernel Port 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.  See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the Ubicom32 Linux Kernel Port.  If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Ubicom32 implementation derived from (with many thanks):
+ *   arch/m68knommu
+ *   arch/blackfin
+ *   arch/parisc
+ */
+#ifndef _ASM_UBICOM32_SYSTEM_H
+#define _ASM_UBICOM32_SYSTEM_H
+
+#include <linux/irqflags.h>
+#include <linux/linkage.h>
+#include <asm/segment.h>
+#include <asm/entry.h>
+#include <asm/ldsr.h>
+#include <asm/irq.h>
+#include <asm/percpu.h>
+#include <asm/ubicom32-common.h>
+#include <asm/processor.h>
+
+/*
+ * switch_to(n) should switch tasks to task ptr, first checking that
+ * ptr isn't the current task, in which case it does nothing.
+ */
+asmlinkage void resume(void);
+extern void *__switch_to(struct task_struct *prev,
+               struct thread_struct *prev_switch,
+               struct thread_struct *next_switch);
+
+/*
+ * We will need a per linux thread sw_ksp for the switch_to macro to
+ * track the kernel stack pointer for the current thread on that linux thread.
+ */
+#define switch_to(prev,next,last)                                      \
+({                                                                     \
+       void *_last;                                                    \
+       _last = (void *)                                                \
+               __switch_to(prev, &prev->thread, &next->thread);        \
+       (last) = _last;                                                 \
+})
+
+/*
+ * Force strict CPU ordering.
+ * Not really required on ubicom32...
+ */
+#define nop()  asm volatile ("nop"::)
+#define mb()   asm volatile (""   : : :"memory")
+#define rmb()  asm volatile (""   : : :"memory")
+#define wmb()  asm volatile (""   : : :"memory")
+#define set_mb(var, value)     ({ (var) = (value); wmb(); })
+
+#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()       mb()
+#define smp_rmb()      rmb()
+#define smp_wmb()      wmb()
+#define smp_read_barrier_depends()     do { } while(0)
+#endif
+
+#define read_barrier_depends()  ((void)0)
+
+/*
+ * The following defines change how the scheduler calls the switch_to()
+ * macro.
+ *
+ * 1) The first causes the runqueue to be unlocked on entry to
+ * switch_to().  Since our ctx code does not play with the runqueue
+ * we do not need it unlocked.
+ *
+ * 2) The later turns interrupts on during a ctxsw to reduce the latency of
+ * interrupts during ctx.  At this point in the port, we believe that this
+ * latency is not a problem since we have very little code to perform a ctxsw.
+ */
+// #define __ARCH_WANT_UNLOCKED_CTXSW
+// #define __ARCH_WANT_INTERRUPTS_ON_CTXSW
+
+#endif /* _ASM_UBICOM32_SYSTEM_H */