[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6

The attached patches provides part 6 of an architecture implementation for the
Tensilica Xtensa CPU series.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 146 insertions, 0 deletions

diff --git a/include/asm-xtensa/thread_info.h b/include/asm-xtensa/thread_info.h
new file mode 100644
index 0000000..af208d4
--- /dev/null
+++ b/include/asm-xtensa/thread_info.h
@@ -0,0 +1,146 @@
+/*
+ * include/asm-xtensa/thread_info.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_THREAD_INFO_H
+#define _XTENSA_THREAD_INFO_H
+
+#ifdef __KERNEL__
+
+#ifndef __ASSEMBLY__
+# include <asm/processor.h>
+#endif
+
+/*
+ * 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__
+
+struct thread_info {
+	struct task_struct	*task;		/* main task structure */
+	struct exec_domain	*exec_domain;	/* execution domain */
+	unsigned long		flags;		/* low level flags */
+	unsigned long		status;		/* thread-synchronous flags */
+	__u32			cpu;		/* current CPU */
+	__s32			preempt_count;	/* 0 => preemptable,< 0 => BUG*/
+
+	mm_segment_t		addr_limit;	/* thread address space */
+	struct restart_block    restart_block;
+
+
+};
+
+#else /* !__ASSEMBLY__ */
+
+/* offsets into the thread_info struct for assembly code access */
+#define TI_TASK		 0x00000000
+#define TI_EXEC_DOMAIN	 0x00000004
+#define TI_FLAGS	 0x00000008
+#define TI_STATUS	 0x0000000C
+#define TI_CPU		 0x00000010
+#define TI_PRE_COUNT	 0x00000014
+#define TI_ADDR_LIMIT	 0x00000018
+#define TI_RESTART_BLOCK 0x000001C
+
+#endif
+
+#define PREEMPT_ACTIVE		0x10000000
+
+/*
+ * 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,	\
+	},					\
+}
+
+#define init_thread_info	(init_thread_union.thread_info)
+#define init_stack		(init_thread_union.stack)
+
+/* how to get the thread information struct from C */
+static inline struct thread_info *current_thread_info(void)
+{
+	struct thread_info *ti;
+	 __asm__("extui %0,a1,0,13\n\t"
+	         "xor %0, a1, %0" : "=&r" (ti) : );
+	return ti;
+}
+
+/* thread information allocation */
+#define alloc_thread_info(tsk) ((struct thread_info *) __get_free_pages(GFP_KERNEL,1))
+#define free_thread_info(ti) free_pages((unsigned long) (ti), 1)
+#define get_thread_info(ti) get_task_struct((ti)->task)
+#define put_thread_info(ti) put_task_struct((ti)->task)
+
+#else /* !__ASSEMBLY__ */
+
+/* how to get the thread information struct from ASM */
+#define GET_THREAD_INFO(reg,sp) \
+	extui reg, sp, 0, 13; \
+	xor   reg, sp, reg
+#endif
+
+
+/*
+ * 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_IRET		5	/* return with iret */
+#define TIF_MEMDIE		6
+#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
+
+#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_IRET		(1<<TIF_IRET)
+#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
+
+#define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
+#define _TIF_ALLWORK_MASK	0x0000FFFF	/* work to do on any return to u-space */
+
+/*
+ * Thread-synchronous status.
+ *
+ * This is different from the flags in that nobody else
+ * ever touches our thread-synchronous status, so we don't
+ * have to worry about atomic accesses.
+ */
+#define TS_USEDFPU		0x0001	/* FPU was used by this task this quantum (SMP) */
+
+#define THREAD_SIZE 8192	//(2*PAGE_SIZE)
+
+#endif	/* __KERNEL__ */
+#endif	/* _XTENSA_THREAD_INFO */