Merge tag 'nios2-v3.20-rc1' of git://git.rocketboards.org/linux-socfpga-next

Pull arch/nios2 update from Ley Foon Tan:
 "Here is the nios2 update for 3.20:

   - add early printk support
   - add kgdb support
   - add compressed kernel support
   - bugfixes"

* tag 'nios2-v3.20-rc1' of git://git.rocketboards.org/linux-socfpga-next:
  nios2: add kgdb support
  MAINTAINERS: update arch/nios2 git tree
  nios2: default CONFIG_NIOS2_BOOT_LINK_OFFSET to 8MB
  nios2: Add support for compressed kernel
  nios2: add early printk support
  nios2: Port OOM changes to do_page_fault()
  nios2: Remove unused prepare_to_copy()

6 files changed, 357 insertions, 2 deletions

diff --git a/arch/nios2/kernel/Makefile b/arch/nios2/kernel/Makefile
index 8ae76823ff93..1aae25703657 100644
--- a/arch/nios2/kernel/Makefile
+++ b/arch/nios2/kernel/Makefile
@@ -20,5 +20,7 @@ obj-y	+= syscall_table.o
 obj-y	+= time.o
 obj-y	+= traps.o
 
+obj-$(CONFIG_EARLY_PRINTK)		+= early_printk.o
+obj-$(CONFIG_KGDB)			+= kgdb.o
 obj-$(CONFIG_MODULES)			+= module.o
 obj-$(CONFIG_NIOS2_ALIGNMENT_TRAP)	+= misaligned.o
diff --git a/arch/nios2/kernel/early_printk.c b/arch/nios2/kernel/early_printk.c
new file mode 100644
index 000000000000..c08e4c1486fc
--- /dev/null
+++ b/arch/nios2/kernel/early_printk.c
@@ -0,0 +1,118 @@
+/*
+ * Early printk for Nios2.
+ *
+ * Copyright (C) 2015, Altera Corporation
+ * Copyright (C) 2010, Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2009, Wind River Systems Inc
+ *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+
+#include <asm/prom.h>
+
+static unsigned long base_addr;
+
+#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
+
+#define ALTERA_JTAGUART_DATA_REG		0
+#define ALTERA_JTAGUART_CONTROL_REG		4
+#define ALTERA_JTAGUART_CONTROL_WSPACE_MSK	0xFFFF0000
+#define ALTERA_JTAGUART_CONTROL_AC_MSK		0x00000400
+
+#define JUART_GET_CR() \
+	__builtin_ldwio((void *)(base_addr + ALTERA_JTAGUART_CONTROL_REG))
+#define JUART_SET_CR(v) \
+	__builtin_stwio((void *)(base_addr + ALTERA_JTAGUART_CONTROL_REG), v)
+#define JUART_SET_TX(v) \
+	__builtin_stwio((void *)(base_addr + ALTERA_JTAGUART_DATA_REG), v)
+
+static void early_console_write(struct console *con, const char *s, unsigned n)
+{
+	unsigned long status;
+
+	while (n-- && *s) {
+		while (((status = JUART_GET_CR())
+				& ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
+#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
+			if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0)
+				return;	/* no connection activity */
+#endif
+		}
+		JUART_SET_TX(*s);
+		s++;
+	}
+}
+
+#elif defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
+
+#define ALTERA_UART_TXDATA_REG		4
+#define ALTERA_UART_STATUS_REG		8
+#define ALTERA_UART_STATUS_TRDY		0x0040
+
+#define UART_GET_SR() \
+	__builtin_ldwio((void *)(base_addr + ALTERA_UART_STATUS_REG))
+#define UART_SET_TX(v) \
+	__builtin_stwio((void *)(base_addr + ALTERA_UART_TXDATA_REG), v)
+
+static void early_console_putc(char c)
+{
+	while (!(UART_GET_SR() & ALTERA_UART_STATUS_TRDY))
+		;
+
+	UART_SET_TX(c);
+}
+
+static void early_console_write(struct console *con, const char *s, unsigned n)
+{
+	while (n-- && *s) {
+		early_console_putc(*s);
+		if (*s == '\n')
+			early_console_putc('\r');
+		s++;
+	}
+}
+
+#else
+# error Neither SERIAL_ALTERA_JTAGUART_CONSOLE nor SERIAL_ALTERA_UART_CONSOLE \
+selected
+#endif
+
+static struct console early_console_prom = {
+	.name	= "early",
+	.write	= early_console_write,
+	.flags	= CON_PRINTBUFFER | CON_BOOT,
+	.index	= -1
+};
+
+void __init setup_early_printk(void)
+{
+#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE) ||	\
+	defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
+	base_addr = of_early_console();
+#else
+	base_addr = 0;
+#endif
+
+	if (!base_addr)
+		return;
+
+#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
+	/* Clear activity bit so BYPASS doesn't stall if we've used JTAG for
+	 * downloading the kernel. This might cause early data to be lost even
+	 * if the JTAG terminal is running.
+	 */
+	JUART_SET_CR(JUART_GET_CR() | ALTERA_JTAGUART_CONTROL_AC_MSK);
+#endif
+
+	early_console = &early_console_prom;
+	register_console(early_console);
+	pr_info("early_console initialized at 0x%08lx\n", base_addr);
+}
diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S
index 0bdfd13ff98b..7729bd3f2e79 100644
--- a/arch/nios2/kernel/entry.S
+++ b/arch/nios2/kernel/entry.S
@@ -121,7 +121,11 @@ trap_table:
 	.word	instruction_trap	/* 27 */
 	.word	instruction_trap	/* 28 */
 	.word	instruction_trap	/* 29 */
-	.word	instruction_trap	/* 30 */
+#ifdef CONFIG_KGDB
+	.word	handle_kgdb_breakpoint	/* 30 KGDB breakpoint */
+#else
+	.word	instruction_trap		/* 30 */
+#endif
 	.word	handle_breakpoint	/* 31 */
 
 .text
@@ -445,6 +449,12 @@ handle_diverror:
 	call	handle_diverror_c
 	br	ret_from_exception
 
+#ifdef CONFIG_KGDB
+handle_kgdb_breakpoint:
+	call	kgdb_breakpoint_c
+	br	ret_from_exception
+#endif
+
 /*
  * Beware - when entering resume, prev (the current task) is
  * in r4, next (the new task) is in r5, don't change these
diff --git a/arch/nios2/kernel/kgdb.c b/arch/nios2/kernel/kgdb.c
new file mode 100644
index 000000000000..117859122d1c
--- /dev/null
+++ b/arch/nios2/kernel/kgdb.c
@@ -0,0 +1,171 @@
+/*
+ * Nios2 KGDB support
+ *
+ * Copyright (C) 2015 Altera Corporation
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ *
+ * Based on the code posted by Kazuyasu on the Altera Forum at:
+ * http://www.alteraforum.com/forum/showpost.php?p=77003&postcount=20
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#include <linux/ptrace.h>
+#include <linux/kgdb.h>
+#include <linux/kdebug.h>
+#include <linux/io.h>
+
+static int wait_for_remote_debugger;
+
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
+{
+	{ "zero", GDB_SIZEOF_REG, -1 },
+	{ "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, r1) },
+	{ "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r2) },
+	{ "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r3) },
+	{ "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r4) },
+	{ "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r5) },
+	{ "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r6) },
+	{ "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r7) },
+	{ "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r8) },
+	{ "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r9) },
+	{ "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, -1 },
+	{ "r17", GDB_SIZEOF_REG, -1 },
+	{ "r18", GDB_SIZEOF_REG, -1 },
+	{ "r19", GDB_SIZEOF_REG, -1 },
+	{ "r20", GDB_SIZEOF_REG, -1 },
+	{ "r21", GDB_SIZEOF_REG, -1 },
+	{ "r22", GDB_SIZEOF_REG, -1 },
+	{ "r23", GDB_SIZEOF_REG, -1 },
+	{ "et", GDB_SIZEOF_REG, -1 },
+	{ "bt", GDB_SIZEOF_REG, -1 },
+	{ "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp) },
+	{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, sp) },
+	{ "fp", GDB_SIZEOF_REG, offsetof(struct pt_regs, fp) },
+	{ "ea", GDB_SIZEOF_REG, -1 },
+	{ "ba", GDB_SIZEOF_REG, -1 },
+	{ "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, ra) },
+	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, ea) },
+	{ "status", GDB_SIZEOF_REG, -1 },
+	{ "estatus", GDB_SIZEOF_REG, offsetof(struct pt_regs, estatus) },
+	{ "bstatus", GDB_SIZEOF_REG, -1 },
+	{ "ienable", GDB_SIZEOF_REG, -1 },
+	{ "ipending", GDB_SIZEOF_REG, -1},
+	{ "cpuid", GDB_SIZEOF_REG, -1 },
+	{ "ctl6", GDB_SIZEOF_REG, -1 },
+	{ "exception", GDB_SIZEOF_REG, -1 },
+	{ "pteaddr", GDB_SIZEOF_REG, -1 },
+	{ "tlbacc", GDB_SIZEOF_REG, -1 },
+	{ "tlbmisc", GDB_SIZEOF_REG, -1 },
+	{ "eccinj", GDB_SIZEOF_REG, -1 },
+	{ "badaddr", GDB_SIZEOF_REG, -1 },
+	{ "config", GDB_SIZEOF_REG, -1 },
+	{ "mpubase", GDB_SIZEOF_REG, -1 },
+	{ "mpuacc", GDB_SIZEOF_REG, -1 },
+};
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+	if (regno >= DBG_MAX_REG_NUM || regno < 0)
+		return NULL;
+
+	if (dbg_reg_def[regno].offset != -1)
+		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+		       dbg_reg_def[regno].size);
+	else
+		memset(mem, 0, dbg_reg_def[regno].size);
+
+	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;
+
+	if (dbg_reg_def[regno].offset != -1)
+		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+		       dbg_reg_def[regno].size);
+
+	return 0;
+}
+
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+	memset((char *)gdb_regs, 0, NUMREGBYTES);
+	gdb_regs[GDB_SP] = p->thread.kregs->sp;
+	gdb_regs[GDB_PC] = p->thread.kregs->ea;
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+	regs->ea = pc;
+}
+
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+				char *remcom_in_buffer, char *remcom_out_buffer,
+				struct pt_regs *regs)
+{
+	char *ptr;
+	unsigned long addr;
+
+	switch (remcom_in_buffer[0]) {
+	case 's':
+	case 'c':
+		/* handle the optional parameters */
+		ptr = &remcom_in_buffer[1];
+		if (kgdb_hex2long(&ptr, &addr))
+			regs->ea = addr;
+
+		return 0;
+	}
+
+	return -1; /* this means that we do not want to exit from the handler */
+}
+
+asmlinkage void kgdb_breakpoint_c(struct pt_regs *regs)
+{
+	/*
+	 * The breakpoint entry code has moved the PC on by 4 bytes, so we must
+	 * move it back.  This could be done on the host but we do it here
+	 */
+	if (!wait_for_remote_debugger)
+		regs->ea -= 4;
+	else	/* pass the first trap 30 code */
+		wait_for_remote_debugger = 0;
+
+	kgdb_handle_exception(30, SIGTRAP, 0, regs);
+}
+
+int kgdb_arch_init(void)
+{
+	wait_for_remote_debugger = 1;
+	return 0;
+}
+
+void kgdb_arch_exit(void)
+{
+	/* Nothing to do */
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+	/* Breakpoint instruction: trap 30 */
+	.gdb_bpt_instr = { 0xba, 0x6f, 0x3b, 0x00 },
+};
diff --git a/arch/nios2/kernel/prom.c b/arch/nios2/kernel/prom.c
index 0522d3378e3f..718dd197909f 100644
--- a/arch/nios2/kernel/prom.c
+++ b/arch/nios2/kernel/prom.c
@@ -1,7 +1,7 @@
 /*
  * Device tree support
  *
- * Copyright (C) 2013 Altera Corporation
+ * Copyright (C) 2013, 2015 Altera Corporation
  * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
  *
  * Based on MIPS support for CONFIG_OF device tree support
@@ -30,6 +30,7 @@
 #include <linux/of_fdt.h>
 #include <linux/io.h>
 
+#include <asm/prom.h>
 #include <asm/sections.h>
 
 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
@@ -63,3 +64,52 @@ void __init early_init_devtree(void *params)
 
 	early_init_dt_scan(params);
 }
+
+#ifdef CONFIG_EARLY_PRINTK
+static int __init early_init_dt_scan_serial(unsigned long node,
+			const char *uname, int depth, void *data)
+{
+	u64 *addr64 = (u64 *) data;
+	const char *p;
+
+	/* only consider serial nodes */
+	if (strncmp(uname, "serial", 6) != 0)
+		return 0;
+
+	p = of_get_flat_dt_prop(node, "compatible", NULL);
+	if (!p)
+		return 0;
+
+	/*
+	 * We found an altera_jtaguart but it wasn't configured for console, so
+	 * skip it.
+	 */
+#ifndef CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE
+	if (strncmp(p, "altr,juart", 10) == 0)
+		return 0;
+#endif
+
+	/*
+	 * Same for altera_uart.
+	 */
+#ifndef CONFIG_SERIAL_ALTERA_UART_CONSOLE
+	if (strncmp(p, "altr,uart", 9) == 0)
+		return 0;
+#endif
+
+	*addr64 = fdt_translate_address((const void *)initial_boot_params,
+		node);
+
+	return *addr64 == OF_BAD_ADDR ? 0 : 1;
+}
+
+unsigned long __init of_early_console(void)
+{
+	u64 base = 0;
+
+	if (of_scan_flat_dt(early_init_dt_scan_serial, &base))
+		return (u32)ioremap(base, 32);
+	else
+		return 0;
+}
+#endif /* CONFIG_EARLY_PRINTK */
diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c
index cb3121f975d4..b101a43d3c5a 100644
--- a/arch/nios2/kernel/setup.c
+++ b/arch/nios2/kernel/setup.c
@@ -139,6 +139,10 @@ void __init setup_arch(char **cmdline_p)
 
 	console_verbose();
 
+#ifdef CONFIG_EARLY_PRINTK
+	setup_early_printk();
+#endif
+
 	memory_start = PAGE_ALIGN((unsigned long)__pa(_end));
 	memory_end = (unsigned long) CONFIG_NIOS2_MEM_BASE + memory_size;