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, 180 insertions, 0 deletions

diff --git a/arch/hexagon/kernel/ptrace.c b/arch/hexagon/kernel/ptrace.c
new file mode 100644
index 000000000000..bea3f08470fd
--- /dev/null
+++ b/arch/hexagon/kernel/ptrace.c
@@ -0,0 +1,180 @@
+/*
+ * Ptrace support for Hexagon
+ *
+ * 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.
+ */
+
+#include <generated/compile.h>
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/regset.h>
+#include <linux/user.h>
+
+#include <asm/system.h>
+#include <asm/user.h>
+
+static int genregs_get(struct task_struct *target,
+		   const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   void *kbuf, void __user *ubuf)
+{
+	int ret;
+	unsigned int dummy;
+	struct pt_regs *regs = task_pt_regs(target);
+
+
+	if (!regs)
+		return -EIO;
+
+	/* The general idea here is that the copyout must happen in
+	 * exactly the same order in which the userspace expects these
+	 * regs. Now, the sequence in userspace does not match the
+	 * sequence in the kernel, so everything past the 32 gprs
+	 * happens one at a time.
+	 */
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  &regs->r00, 0, 32*sizeof(unsigned long));
+
+#define ONEXT(KPT_REG, USR_REG) \
+	if (!ret) \
+		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, \
+			KPT_REG, offsetof(struct user_regs_struct, USR_REG), \
+			offsetof(struct user_regs_struct, USR_REG) + \
+				 sizeof(unsigned long));
+
+	/* Must be exactly same sequence as struct user_regs_struct */
+	ONEXT(&regs->sa0, sa0);
+	ONEXT(&regs->lc0, lc0);
+	ONEXT(&regs->sa1, sa1);
+	ONEXT(&regs->lc1, lc1);
+	ONEXT(&regs->m0, m0);
+	ONEXT(&regs->m1, m1);
+	ONEXT(&regs->usr, usr);
+	ONEXT(&regs->preds, p3_0);
+	ONEXT(&regs->gp, gp);
+	ONEXT(&regs->ugp, ugp);
+	ONEXT(&pt_elr(regs), pc);
+	dummy = pt_cause(regs);
+	ONEXT(&dummy, cause);
+	ONEXT(&pt_badva(regs), badva);
+
+	/* Pad the rest with zeros, if needed */
+	if (!ret)
+		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+					offsetof(struct user_regs_struct, pad1), -1);
+	return ret;
+}
+
+static int genregs_set(struct task_struct *target,
+		   const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+	unsigned long bucket;
+	struct pt_regs *regs = task_pt_regs(target);
+
+	if (!regs)
+		return -EIO;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &regs->r00, 0, 32*sizeof(unsigned long));
+
+#define INEXT(KPT_REG, USR_REG) \
+	if (!ret) \
+		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
+			KPT_REG, offsetof(struct user_regs_struct, USR_REG), \
+			offsetof(struct user_regs_struct, USR_REG) + \
+				sizeof(unsigned long));
+
+	/* Must be exactly same sequence as struct user_regs_struct */
+	INEXT(&regs->sa0, sa0);
+	INEXT(&regs->lc0, lc0);
+	INEXT(&regs->sa1, sa1);
+	INEXT(&regs->lc1, lc1);
+	INEXT(&regs->m0, m0);
+	INEXT(&regs->m1, m1);
+	INEXT(&regs->usr, usr);
+	INEXT(&regs->preds, p3_0);
+	INEXT(&regs->gp, gp);
+	INEXT(&regs->ugp, ugp);
+	INEXT(&pt_elr(regs), pc);
+
+	/* CAUSE and BADVA aren't writeable. */
+	INEXT(&bucket, cause);
+	INEXT(&bucket, badva);
+
+	/* Ignore the rest, if needed */
+	if (!ret)
+		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+					offsetof(struct user_regs_struct, pad1), -1);
+
+	if (ret)
+		return ret;
+
+	/*
+	 * This is special; SP is actually restored by the VM via the
+	 * special event record which is set by the special trap.
+	 */
+	regs->hvmer.vmpsp = regs->r29;
+	return 0;
+}
+
+enum hexagon_regset {
+	REGSET_GENERAL,
+};
+
+static const struct user_regset hexagon_regsets[] = {
+	[REGSET_GENERAL] = {
+		.core_note_type = NT_PRSTATUS,
+		.n = ELF_NGREG,
+		.size = sizeof(unsigned long),
+		.align = sizeof(unsigned long),
+		.get = genregs_get,
+		.set = genregs_set,
+	},
+};
+
+static const struct user_regset_view hexagon_user_view = {
+	.name = UTS_MACHINE,
+	.e_machine = ELF_ARCH,
+	.ei_osabi = ELF_OSABI,
+	.regsets = hexagon_regsets,
+	.n = ARRAY_SIZE(hexagon_regsets)
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &hexagon_user_view;
+}
+
+void ptrace_disable(struct task_struct *child)
+{
+	/* Boilerplate - resolves to null inline if no HW single-step */
+	user_disable_single_step(child);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+		 unsigned long addr, unsigned long data)
+{
+	return ptrace_request(child, request, addr, data);
+}