[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 000000000000..af208d41fd82
--- /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 */