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, 254 insertions, 0 deletions

diff --git a/arch/hexagon/kernel/kgdb.c b/arch/hexagon/kernel/kgdb.c
new file mode 100644
index 0000000..fe4aa1b
--- /dev/null
+++ b/arch/hexagon/kernel/kgdb.c
@@ -0,0 +1,254 @@
+/*
+ * arch/hexagon/kernel/kgdb.c - Hexagon KGDB Support
+ *
+ * Copyright (c) 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 <linux/kdebug.h>
+#include <linux/kgdb.h>
+
+/* All registers are 4 bytes, for now */
+#define GDB_SIZEOF_REG 4
+
+/* The register names are used during printing of the regs;
+ * Keep these at three letters to pretty-print. */
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
+	{ " r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, r00)},
+	{ " r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, r01)},
+	{ " r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r02)},
+	{ " r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r03)},
+	{ " r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r04)},
+	{ " r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r05)},
+	{ " r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r06)},
+	{ " r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r07)},
+	{ " r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r08)},
+	{ " r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r09)},
+	{ "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, r10)},
+	{ "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, r11)},
+	{ "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, r12)},
+	{ "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, r13)},
+	{ "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, r14)},
+	{ "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, r15)},
+	{ "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, r16)},
+	{ "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, r17)},
+	{ "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, r18)},
+	{ "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, r19)},
+	{ "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, r20)},
+	{ "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, r21)},
+	{ "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, r22)},
+	{ "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, r23)},
+	{ "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, r24)},
+	{ "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, r25)},
+	{ "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, r26)},
+	{ "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, r27)},
+	{ "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, r28)},
+	{ "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, r29)},
+	{ "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, r30)},
+	{ "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, r31)},
+
+	{ "usr", GDB_SIZEOF_REG, offsetof(struct pt_regs, usr)},
+	{ "preds", GDB_SIZEOF_REG, offsetof(struct pt_regs, preds)},
+	{ " m0", GDB_SIZEOF_REG, offsetof(struct pt_regs, m0)},
+	{ " m1", GDB_SIZEOF_REG, offsetof(struct pt_regs, m1)},
+	{ "sa0", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa0)},
+	{ "sa1", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa1)},
+	{ "lc0", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc0)},
+	{ "lc1", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc1)},
+	{ " gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp)},
+	{ "ugp", GDB_SIZEOF_REG, offsetof(struct pt_regs, ugp)},
+	{ "psp", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmpsp)},
+	{ "elr", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmel)},
+	{ "est", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmest)},
+	{ "badva", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmbadva)},
+	{ "restart_r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, restart_r0)},
+	{ "syscall_nr", GDB_SIZEOF_REG, offsetof(struct pt_regs, syscall_nr)},
+};
+
+struct kgdb_arch arch_kgdb_ops = {
+	/* trap0(#0xDB) 0x0cdb0054 */
+	.gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c},
+};
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return NULL;
+
+	*((unsigned long *) mem) = *((unsigned long *) ((void *)regs +
+		dbg_reg_def[regno].offset));
+
+	return dbg_reg_def[regno].name;
+}
+
+int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return -EINVAL;
+
+	*((unsigned long *) ((void *)regs + dbg_reg_def[regno].offset)) =
+		*((unsigned long *) mem);
+
+	return 0;
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+	instruction_pointer(regs) = pc;
+}
+
+#ifdef CONFIG_SMP
+
+/**
+ * kgdb_roundup_cpus - Get other CPUs into a holding pattern
+ * @flags: Current IRQ state
+ *
+ * On SMP systems, we need to get the attention of the other CPUs
+ * and get them be in a known state.  This should do what is needed
+ * to get the other CPUs to call kgdb_wait(). Note that on some arches,
+ * the NMI approach is not used for rounding up all the CPUs. For example,
+ * in case of MIPS, smp_call_function() is used to roundup CPUs. In
+ * this case, we have to make sure that interrupts are enabled before
+ * calling smp_call_function(). The argument to this function is
+ * the flags that will be used when restoring the interrupts. There is
+ * local_irq_save() call before kgdb_roundup_cpus().
+ *
+ * On non-SMP systems, this is not called.
+ */
+
+static void hexagon_kgdb_nmi_hook(void *ignored)
+{
+	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
+}
+
+void kgdb_roundup_cpus(unsigned long flags)
+{
+	local_irq_enable();
+	smp_call_function(hexagon_kgdb_nmi_hook, NULL, 0);
+	local_irq_disable();
+}
+#endif
+
+
+/*  Not yet working  */
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
+				 struct task_struct *task)
+{
+	struct pt_regs *thread_regs;
+
+	if (task == NULL)
+		return;
+
+	/* Initialize to zero */
+	memset(gdb_regs, 0, NUMREGBYTES);
+
+	/* Otherwise, we have only some registers from switch_to() */
+	thread_regs = task_pt_regs(task);
+	gdb_regs[0] = thread_regs->r00;
+}
+
+/**
+ * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
+ * @vector: The error vector of the exception that happened.
+ * @signo: The signal number of the exception that happened.
+ * @err_code: The error code of the exception that happened.
+ * @remcom_in_buffer: The buffer of the packet we have read.
+ * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
+ * @regs: The &struct pt_regs of the current process.
+ *
+ * This function MUST handle the 'c' and 's' command packets,
+ * as well packets to set / remove a hardware breakpoint, if used.
+ * If there are additional packets which the hardware needs to handle,
+ * they are handled here.  The code should return -1 if it wants to
+ * process more packets, and a %0 or %1 if it wants to exit from the
+ * kgdb callback.
+ *
+ * Not yet working.
+ */
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+			       char *remcom_in_buffer, char *remcom_out_buffer,
+			       struct pt_regs *linux_regs)
+{
+	switch (remcom_in_buffer[0]) {
+	case 's':
+	case 'c':
+		return 0;
+	}
+	/* Stay in the debugger. */
+	return -1;
+}
+
+static int __kgdb_notify(struct die_args *args, unsigned long cmd)
+{
+	/* cpu roundup */
+	if (atomic_read(&kgdb_active) != -1) {
+		kgdb_nmicallback(smp_processor_id(), args->regs);
+		return NOTIFY_STOP;
+	}
+
+	if (user_mode(args->regs))
+		return NOTIFY_DONE;
+
+	if (kgdb_handle_exception(args->trapnr & 0xff, args->signr, args->err,
+				    args->regs))
+		return NOTIFY_DONE;
+
+	return NOTIFY_STOP;
+}
+
+static int
+kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
+{
+	unsigned long flags;
+	int ret;
+
+	local_irq_save(flags);
+	ret = __kgdb_notify(ptr, cmd);
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+static struct notifier_block kgdb_notifier = {
+	.notifier_call = kgdb_notify,
+
+	/*
+	 * Lowest-prio notifier priority, we want to be notified last:
+	 */
+	.priority = -INT_MAX,
+};
+
+/**
+ * kgdb_arch_init - Perform any architecture specific initalization.
+ *
+ * This function will handle the initalization of any architecture
+ * specific callbacks.
+ */
+int kgdb_arch_init(void)
+{
+	return register_die_notifier(&kgdb_notifier);
+}
+
+/**
+ * kgdb_arch_exit - Perform any architecture specific uninitalization.
+ *
+ * This function will handle the uninitalization of any architecture
+ * specific callbacks, for dynamic registration and unregistration.
+ */
+void kgdb_arch_exit(void)
+{
+	unregister_die_notifier(&kgdb_notifier);
+}