1 files changed, 76 insertions, 0 deletions
diff --git a/arch/tile/include/asm/switch_to.h b/arch/tile/include/asm/switch_to.h
new file mode 100644
index 00000000..1d48c5fe
--- /dev/null
+++ b/arch/tile/include/asm/switch_to.h
@@ -0,0 +1,76 @@
+/*
+ * 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_SWITCH_TO_H
+#define _ASM_TILE_SWITCH_TO_H
+
+#include <arch/sim_def.h>
+
+/*
+ * switch_to(n) should switch tasks to task nr n, first
+ * checking that n isn't the current task, in which case it does nothing.
+ * The number of callee-saved registers saved on the kernel stack
+ * is defined here for use in copy_thread() and must agree with __switch_to().
+ */
+#define CALLEE_SAVED_FIRST_REG 30
+#define CALLEE_SAVED_REGS_COUNT 24   /* r30 to r52, plus an empty to align */
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+/*
+ * Pause the DMA engine and static network before task switching.
+ */
+#define prepare_arch_switch(next) _prepare_arch_switch(next)
+void _prepare_arch_switch(struct task_struct *next);
+
+struct task_struct;
+#define switch_to(prev, next, last) ((last) = _switch_to((prev), (next)))
+extern struct task_struct *_switch_to(struct task_struct *prev,
+				      struct task_struct *next);
+
+/* Helper function for _switch_to(). */
+extern struct task_struct *__switch_to(struct task_struct *prev,
+				       struct task_struct *next,
+				       unsigned long new_system_save_k_0);
+
+/* Address that switched-away from tasks are at. */
+extern unsigned long get_switch_to_pc(void);
+
+/*
+ * Kernel threads can check to see if they need to migrate their
+ * stack whenever they return from a context switch; for user
+ * threads, we defer until they are returning to user-space.
+ */
+#define finish_arch_switch(prev) do {                                     \
+	if (unlikely((prev)->state == TASK_DEAD))                         \
+		__insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_EXIT |       \
+			((prev)->pid << _SIM_CONTROL_OPERATOR_BITS));     \
+	__insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_SWITCH |             \
+		(current->pid << _SIM_CONTROL_OPERATOR_BITS));            \
+	if (current->mm == NULL && !kstack_hash &&                        \
+	    current_thread_info()->homecache_cpu != smp_processor_id())   \
+		homecache_migrate_kthread();                              \
+} while (0)
+
+/* Support function for forking a new task. */
+void ret_from_fork(void);
+
+/* Called from ret_from_fork() when a new process starts up. */
+struct task_struct *sim_notify_fork(struct task_struct *prev);
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_TILE_SWITCH_TO_H */