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, 99 insertions, 0 deletions

diff --git a/arch/hexagon/include/asm/cacheflush.h b/arch/hexagon/include/asm/cacheflush.h
new file mode 100644
index 000000000000..6865c1be927a
--- /dev/null
+++ b/arch/hexagon/include/asm/cacheflush.h
@@ -0,0 +1,99 @@
+/*
+ * Cache flush operations 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_CACHEFLUSH_H
+#define _ASM_CACHEFLUSH_H
+
+#include <linux/cache.h>
+#include <linux/mm.h>
+#include <asm/string.h>
+#include <asm-generic/cacheflush.h>
+
+/* Cache flushing:
+ *
+ *  - flush_cache_all() flushes entire cache
+ *  - flush_cache_mm(mm) flushes the specified mm context's cache lines
+ *  - flush_cache_page(mm, vmaddr, pfn) flushes a single page
+ *  - flush_cache_range(vma, start, end) flushes a range of pages
+ *  - flush_icache_range(start, end) flush a range of instructions
+ *  - flush_dcache_page(pg) flushes(wback&invalidates) a page for dcache
+ *  - flush_icache_page(vma, pg) flushes(invalidates) a page for icache
+ *
+ *  Need to doublecheck which one is really needed for ptrace stuff to work.
+ */
+#define LINESIZE	32
+#define LINEBITS	5
+
+/*
+ * Flush Dcache range through current map.
+ */
+extern void flush_dcache_range(unsigned long start, unsigned long end);
+
+/*
+ * Flush Icache range through current map.
+ */
+#undef flush_icache_range
+extern void flush_icache_range(unsigned long start, unsigned long end);
+
+/*
+ * Memory-management related flushes are there to ensure in non-physically
+ * indexed cache schemes that stale lines belonging to a given ASID aren't
+ * in the cache to confuse things.  The prototype Hexagon Virtual Machine
+ * only uses a single ASID for all user-mode maps, which should
+ * mean that they aren't necessary.  A brute-force, flush-everything
+ * implementation, with the name xxxxx_hexagon() is present in
+ * arch/hexagon/mm/cache.c, but let's not wire it up until we know
+ * it is needed.
+ */
+extern void flush_cache_all_hexagon(void);
+
+/*
+ * This may or may not ever have to be non-null, depending on the
+ * virtual machine MMU.  For a native kernel, it's definitiely  a no-op
+ *
+ * This is also the place where deferred cache coherency stuff seems
+ * to happen, classically...  but instead we do it like ia64 and
+ * clean the cache when the PTE is set.
+ *
+ */
+static inline void update_mmu_cache(struct vm_area_struct *vma,
+					unsigned long address, pte_t *ptep)
+{
+	/*  generic_ptrace_pokedata doesn't wind up here, does it?  */
+}
+
+#undef copy_to_user_page
+static inline void copy_to_user_page(struct vm_area_struct *vma,
+					     struct page *page,
+					     unsigned long vaddr,
+					     void *dst, void *src, int len)
+{
+	memcpy(dst, src, len);
+	if (vma->vm_flags & VM_EXEC) {
+		flush_icache_range((unsigned long) dst,
+		(unsigned long) dst + len);
+	}
+}
+
+
+extern void hexagon_inv_dcache_range(unsigned long start, unsigned long end);
+extern void hexagon_clean_dcache_range(unsigned long start, unsigned long end);
+
+#endif