Merge Qualcom Hexagon architecture

This is the fifth version of the patchset (with one tiny whitespace fix)
to the Linux kernel to support the Qualcomm Hexagon architecture.

Between now and the next pull requests, Richard Kuo should have his key
signed, etc., and should be back on kernel.org.  In the meantime, this
got merged as a emailed patch-series.

* Hexagon: (36 commits)
  Add extra arch overrides to asm-generic/checksum.h
  Hexagon: Add self to MAINTAINERS
  Hexagon: Add basic stacktrace functionality for Hexagon architecture.
  Hexagon: Add configuration and makefiles for the Hexagon architecture.
  Hexagon: Comet platform support
  Hexagon: kgdb support files
  Hexagon: Add page-fault support.
  Hexagon: Add page table header files & etc.
  Hexagon: Add ioremap support
  Hexagon: Provide DMA implementation
  Hexagon: Implement basic TLB management routines for Hexagon.
  Hexagon: Implement basic cache-flush support
  Hexagon: Provide basic implementation and/or stubs for I/O routines.
  Hexagon: Add user access functions
  Hexagon: Add locking types and functions
  Hexagon: Add SMP support
  Hexagon: Provide basic debugging and system trap support.
  Hexagon: Add ptrace support
  Hexagon: Add time and timer functions
  Hexagon: Add interrupts
  ...

1 files changed, 154 insertions, 0 deletions

diff --git a/arch/hexagon/include/asm/thread_info.h b/arch/hexagon/include/asm/thread_info.h
new file mode 100644
index 0000000..9c2934f
--- /dev/null
+++ b/arch/hexagon/include/asm/thread_info.h
@@ -0,0 +1,154 @@
+/*
+ * Thread support for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, Code Aurora Forum. 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 version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_THREAD_INFO_H
+#define _ASM_THREAD_INFO_H
+
+#ifdef __KERNEL__
+
+#ifndef __ASSEMBLY__
+#include <asm/processor.h>
+#include <asm/registers.h>
+#include <asm/page.h>
+#endif
+
+#define THREAD_SHIFT		12
+#define THREAD_SIZE		(1<<THREAD_SHIFT)
+
+#if THREAD_SHIFT >= PAGE_SHIFT
+#define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
+#else  /*  don't use standard allocator  */
+#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
+extern struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node);
+extern void free_thread_info(struct thread_info *ti);
+#endif
+
+
+#ifndef __ASSEMBLY__
+
+typedef struct {
+	unsigned long seg;
+} mm_segment_t;
+
+/*
+ * This is union'd with the "bottom" of the kernel stack.
+ * It keeps track of thread info which is handy for routines
+ * to access quickly.
+ */
+
+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 */
+	int                     preempt_count;  /* 0=>preemptible,<0=>BUG */
+	mm_segment_t            addr_limit;     /* segmentation sux */
+	/*
+	 * used for syscalls somehow;
+	 * seems to have a function pointer and four arguments
+	 */
+	struct restart_block    restart_block;
+	/* Points to the current pt_regs frame  */
+	struct pt_regs		*regs;
+	/*
+	 * saved kernel sp at switch_to time;
+	 * not sure if this is used (it's not in the VM model it seems;
+	 * see thread_struct)
+	 */
+	unsigned long		sp;
+};
+
+#else /* !__ASSEMBLY__ */
+
+#include <asm/asm-offsets.h>
+
+#endif  /* __ASSEMBLY__  */
+
+/*  looks like "linux/hardirq.h" uses this.  */
+
+#define PREEMPT_ACTIVE		0x10000000
+
+#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,    \
+	},                                      \
+	.sp = 0,				\
+	.regs = NULL,			\
+}
+
+#define init_thread_info        (init_thread_union.thread_info)
+#define init_stack              (init_thread_union.stack)
+
+/* Tacky preprocessor trickery */
+#define	qqstr(s) qstr(s)
+#define qstr(s) #s
+#define QUOTED_THREADINFO_REG qqstr(THREADINFO_REG)
+
+register struct thread_info *__current_thread_info asm(QUOTED_THREADINFO_REG);
+#define current_thread_info()  __current_thread_info
+
+#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 ss @ return to usr mode */
+#define TIF_IRET                5       /* return with iret */
+#define TIF_RESTORE_SIGMASK     6       /* restore sig mask in do_signal() */
+/* true if poll_idle() is polling TIF_NEED_RESCHED */
+#define TIF_POLLING_NRFLAG      16
+#define TIF_MEMDIE              17      /* OOM killer killed process */
+
+#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_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
+#define _TIF_POLLING_NRFLAG     (1 << TIF_POLLING_NRFLAG)
+
+/* work to do on interrupt/exception return - All but TIF_SYSCALL_TRACE */
+#define _TIF_WORK_MASK          (0x0000FFFF & ~_TIF_SYSCALL_TRACE)
+
+/* work to do on any return to u-space */
+#define _TIF_ALLWORK_MASK       0x0000FFFF
+
+#endif /* __KERNEL__ */
+
+#endif