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, 137 insertions, 0 deletions

diff --git a/arch/hexagon/include/asm/futex.h b/arch/hexagon/include/asm/futex.h
new file mode 100644
index 0000000..7e597f8
--- /dev/null
+++ b/arch/hexagon/include/asm/futex.h
@@ -0,0 +1,137 @@
+#ifndef _ASM_HEXAGON_FUTEX_H
+#define _ASM_HEXAGON_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+
+/* XXX TODO-- need to add sync barriers! */
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+	__asm__ __volatile( \
+	"1: %0 = memw_locked(%3);\n" \
+	    /* For example: %1 = %4 */ \
+	    insn \
+	"2: memw_locked(%3,p2) = %1;\n" \
+	"   if !p2 jump 1b;\n" \
+	"   %1 = #0;\n" \
+	"3:\n" \
+	".section .fixup,\"ax\"\n" \
+	"4: %1 = #%5;\n" \
+	"   jump 3b\n" \
+	".previous\n" \
+	".section __ex_table,\"a\"\n" \
+	".long 1b,4b,2b,4b\n" \
+	".previous\n" \
+	: "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \
+	: "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
+	: "p2", "memory")
+
+
+static inline int
+futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
+{
+	int op = (encoded_op >> 28) & 7;
+	int cmp = (encoded_op >> 24) & 15;
+	int oparg = (encoded_op << 8) >> 20;
+	int cmparg = (encoded_op << 20) >> 20;
+	int oldval = 0, ret;
+	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+		oparg = 1 << oparg;
+
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
+		return -EFAULT;
+
+	pagefault_disable();
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		__futex_atomic_op("%1 = %4\n", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ADD:
+		__futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr,
+				  oparg);
+		break;
+	case FUTEX_OP_OR:
+		__futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr,
+				  oparg);
+		break;
+	case FUTEX_OP_ANDN:
+		__futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret,
+				  oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_XOR:
+		__futex_atomic_op("%1 = xor(%0,%4)\n", ret, oldval, uaddr,
+				  oparg);
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+
+	pagefault_enable();
+
+	if (!ret) {
+		switch (cmp) {
+		case FUTEX_OP_CMP_EQ:
+			ret = (oldval == cmparg);
+			break;
+		case FUTEX_OP_CMP_NE:
+			ret = (oldval != cmparg);
+			break;
+		case FUTEX_OP_CMP_LT:
+			ret = (oldval < cmparg);
+			break;
+		case FUTEX_OP_CMP_GE:
+			ret = (oldval >= cmparg);
+			break;
+		case FUTEX_OP_CMP_LE:
+			ret = (oldval <= cmparg);
+			break;
+		case FUTEX_OP_CMP_GT:
+			ret = (oldval > cmparg);
+			break;
+		default:
+			ret = -ENOSYS;
+		}
+	}
+	return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval,
+			      u32 newval)
+{
+	int prev;
+	int ret;
+
+	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
+		return -EFAULT;
+
+	__asm__ __volatile__ (
+	"1: %1 = memw_locked(%3)\n"
+	"   {\n"
+	"      p2 = cmp.eq(%1,%4)\n"
+	"      if !p2.new jump:NT 3f\n"
+	"   }\n"
+	"2: memw_locked(%3,p2) = %5\n"
+	"   if !p2 jump 1b\n"
+	"3:\n"
+	".section .fixup,\"ax\"\n"
+	"4: %0 = #%6\n"
+	"   jump 3b\n"
+	".previous\n"
+	".section __ex_table,\"a\"\n"
+	".long 1b,4b,2b,4b\n"
+	".previous\n"
+	: "+r" (ret), "=&r" (prev), "+m" (*uaddr)
+	: "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT)
+	: "p2", "memory");
+
+	*uval = prev;
+	return ret;
+}
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_HEXAGON_FUTEX_H */