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, 123 insertions, 0 deletions

diff --git a/arch/hexagon/include/asm/processor.h b/arch/hexagon/include/asm/processor.h
new file mode 100644
index 0000000..20c5dda
--- /dev/null
+++ b/arch/hexagon/include/asm/processor.h
@@ -0,0 +1,123 @@
+/*
+ * Process/processor 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_PROCESSOR_H
+#define _ASM_PROCESSOR_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/mem-layout.h>
+#include <asm/registers.h>
+#include <asm/hexagon_vm.h>
+
+/*  must be a macro  */
+#define current_text_addr() ({ __label__ _l; _l: &&_l; })
+
+/*  task_struct, defined elsewhere, is the "process descriptor" */
+struct task_struct;
+
+/*  this is defined in arch/process.c  */
+extern pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
+extern unsigned long thread_saved_pc(struct task_struct *tsk);
+
+extern void start_thread(struct pt_regs *, unsigned long, unsigned long);
+
+/*
+ * thread_struct is supposed to be for context switch data.
+ * Specifically, to hold the state necessary to perform switch_to...
+ */
+struct thread_struct {
+	void *switch_sp;
+};
+
+/*
+ * initializes thread_struct
+ * The only thing we have in there is switch_sp
+ * which doesn't really need to be initialized.
+ */
+
+#define INIT_THREAD { \
+}
+
+#define cpu_relax() __vmyield()
+
+/*
+ * "Unlazying all lazy status" occurs here.
+ */
+static inline void prepare_to_copy(struct task_struct *tsk)
+{
+}
+
+/*
+ * Decides where the kernel will search for a free chunk of vm space during
+ * mmaps.
+ * See also arch_get_unmapped_area.
+ * Doesn't affect if you have MAX_FIXED in the page flags set though...
+ *
+ * Apparently the convention is that ld.so will ask for "unmapped" private
+ * memory to be allocated SOMEWHERE, but it also asks for memory explicitly
+ * via MAP_FIXED at the lower * addresses starting at VA=0x0.
+ *
+ * If the two requests collide, you get authentic segfaulting action, so
+ * you have to kick the "unmapped" base requests higher up.
+ */
+#define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE/3))
+
+
+#define task_pt_regs(task) \
+	((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE) - 1)
+
+#define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk)))
+#define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk)))
+
+/*  Free all resources held by a thread; defined in process.c  */
+extern void release_thread(struct task_struct *dead_task);
+
+/* Get wait channel for task P.  */
+extern unsigned long get_wchan(struct task_struct *p);
+
+/*  The following stuff is pretty HEXAGON specific.  */
+
+/*  This is really just here for __switch_to.
+    Offsets are pulled via asm-offsets.c  */
+
+/*
+ * No real reason why VM and native switch stacks should be different.
+ * Ultimately this should merge.  Note that Rev C. ABI called out only
+ * R24-27 as callee saved GPRs needing explicit attention (R29-31 being
+ * dealt with automagically by allocframe), but the current ABI has
+ * more, R16-R27.  By saving more, the worst case is that we waste some
+ * cycles if building with the old compilers.
+ */
+
+struct hexagon_switch_stack {
+	unsigned long long	r1716;
+	unsigned long long	r1918;
+	unsigned long long	r2120;
+	unsigned long long	r2322;
+	unsigned long long	r2524;
+	unsigned long long	r2726;
+	unsigned long		fp;
+	unsigned long		lr;
+};
+
+#endif /* !__ASSEMBLY__ */
+
+#endif