OpenRISC: Scheduling/Process management

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 134 insertions, 0 deletions

diff --git a/arch/openrisc/include/asm/thread_info.h b/arch/openrisc/include/asm/thread_info.h
new file mode 100644
index 0000000..07a8bc0
--- /dev/null
+++ b/arch/openrisc/include/asm/thread_info.h
@@ -0,0 +1,134 @@
+/*
+ * OpenRISC Linux
+ *
+ * Linux architectural port borrowing liberally from similar works of
+ * others.  All original copyrights apply as per the original source
+ * declaration.
+ *
+ * OpenRISC implementation:
+ * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
+ * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
+ * et al.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef _ASM_THREAD_INFO_H
+#define _ASM_THREAD_INFO_H
+
+#ifdef __KERNEL__
+
+#ifndef __ASSEMBLY__
+#include <asm/types.h>
+#include <asm/processor.h>
+#endif
+
+
+/* THREAD_SIZE is the size of the task_struct/kernel_stack combo.
+ * normally, the stack is found by doing something like p + THREAD_SIZE
+ * in or32, a page is 8192 bytes, which seems like a sane size
+ */
+
+#define THREAD_SIZE_ORDER 0
+#define THREAD_SIZE       (PAGE_SIZE << THREAD_SIZE_ORDER)
+
+/*
+ * low level task data that entry.S needs immediate access to
+ * - this struct should fit entirely inside of one cache line
+ * - this struct shares the supervisor stack pages
+ * - if the contents of this structure are changed, the assembly constants
+ *   must also be changed
+ */
+#ifndef __ASSEMBLY__
+
+typedef unsigned long mm_segment_t;
+
+struct thread_info {
+	struct task_struct	*task;		/* main task structure */
+	struct exec_domain	*exec_domain;	/* execution domain */
+	unsigned long		flags;		/* low level flags */
+	__u32			cpu;		/* current CPU */
+	__s32			preempt_count; /* 0 => preemptable, <0 => BUG */
+
+	mm_segment_t		addr_limit; /* thread address space:
+					       0-0x7FFFFFFF for user-thead
+					       0-0xFFFFFFFF for kernel-thread
+					     */
+	struct restart_block    restart_block;
+	__u8			supervisor_stack[0];
+
+	/* saved context data */
+	unsigned long           ksp;
+};
+#endif
+
+/*
+ * macros/functions for gaining access to the thread information structure
+ *
+ * preempt_count needs to be 1 initially, until the scheduler is functional.
+ */
+#ifndef __ASSEMBLY__
+#define INIT_THREAD_INFO(tsk)				\
+{							\
+	.task		= &tsk,				\
+	.exec_domain	= &default_exec_domain,		\
+	.flags		= 0,				\
+	.cpu		= 0,				\
+	.preempt_count	= 1,				\
+	.addr_limit	= KERNEL_DS,			\
+	.restart_block  = {				\
+			  .fn = do_no_restart_syscall,	\
+	},						\
+	.ksp            = 0,                            \
+}
+
+#define init_thread_info	(init_thread_union.thread_info)
+
+/* how to get the thread information struct from C */
+register struct thread_info *current_thread_info_reg asm("r10");
+#define current_thread_info()   (current_thread_info_reg)
+
+#define get_thread_info(ti) get_task_struct((ti)->task)
+#define put_thread_info(ti) put_task_struct((ti)->task)
+
+#endif /* !__ASSEMBLY__ */
+
+/*
+ * thread information flags
+ *   these are process state flags that various assembly files may need to
+ *   access
+ *   - pending work-to-be-done flags are in LSW
+ *   - other flags in MSW
+ */
+#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
+#define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
+#define TIF_SIGPENDING		2	/* signal pending */
+#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
+#define TIF_SINGLESTEP		4	/* restore singlestep on return to user
+					 * mode
+					 */
+#define TIF_SYSCALL_TRACEPOINT  8       /* for ftrace syscall instrumentation */
+#define TIF_RESTORE_SIGMASK     9
+#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling						 * TIF_NEED_RESCHED
+					 */
+#define TIF_MEMDIE              17
+
+#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
+#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
+#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
+#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
+#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
+#define _TIF_RESTORE_SIGMASK     (1<<TIF_RESTORE_SIGMASK)
+#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
+
+
+/* Work to do when returning from interrupt/exception */
+/* For OpenRISC, this is anything in the LSW other than syscall trace */
+#define _TIF_WORK_MASK (0xff & ~(_TIF_SYSCALL_TRACE|_TIF_SINGLESTEP))
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_THREAD_INFO_H */