Merge tag 'nds32-for-linus-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/greentime/linux

Pull nds32 architecture support from Greentime Hu:
 "This contains the core nds32 Linux port (including interrupt
  controller driver and timer driver), which has been through seven
  rounds of review on mailing list.

  It is able to boot to shell and passes most LTP-2017 testsuites in
  nds32 AE3XX platform:

    Total Tests: 1901
    Total Skipped Tests: 618
    Total Failures: 78"

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

* tag 'nds32-for-linus-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/greentime/linux: (44 commits)
  nds32: To use the generic dump_stack()
  nds32: fix building failed if using elf toolchain.
  nios2: add ioremap_nocache declaration before include asm-generic/io.h.
  nds32: fix building failed if using older version gcc.
  dt-bindings: timer: Add andestech atcpit100 timer binding doc
  clocksource/drivers/atcpit100: VDSO support
  clocksource/drivers/atcpit100: Add andestech atcpit100 timer
  net: faraday add nds32 support.
  irqchip: Andestech Internal Vector Interrupt Controller driver
  dt-bindings: interrupt-controller: Andestech Internal Vector Interrupt Controller
  dt-bindings: nds32 SoC Bindings
  dt-bindings: nds32 L2 cache controller Bindings
  dt-bindings: nds32 CPU Bindings
  MAINTAINERS: Add nds32
  nds32: Build infrastructure
  nds32: defconfig
  nds32: Miscellaneous header files
  nds32: Device tree support
  nds32: Generic timers support
  nds32: Loadable modules
  ...

1 files changed, 430 insertions, 0 deletions

diff --git a/arch/nds32/kernel/traps.c b/arch/nds32/kernel/traps.c
new file mode 100644
index 000000000000..6e34eb9824a4
--- /dev/null
+++ b/arch/nds32/kernel/traps.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/module.h>
+#include <linux/personality.h>
+#include <linux/kallsyms.h>
+#include <linux/hardirq.h>
+#include <linux/kdebug.h>
+#include <linux/sched/task_stack.h>
+#include <linux/uaccess.h>
+
+#include <asm/proc-fns.h>
+#include <asm/unistd.h>
+
+#include <linux/ptrace.h>
+#include <nds32_intrinsic.h>
+
+extern void show_pte(struct mm_struct *mm, unsigned long addr);
+
+/*
+ * Dump out the contents of some memory nicely...
+ */
+void dump_mem(const char *lvl, unsigned long bottom, unsigned long top)
+{
+	unsigned long first;
+	mm_segment_t fs;
+	int i;
+
+	/*
+	 * We need to switch to kernel mode so that we can use __get_user
+	 * to safely read from kernel space.  Note that we now dump the
+	 * code first, just in case the backtrace kills us.
+	 */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	pr_emerg("%s(0x%08lx to 0x%08lx)\n", lvl, bottom, top);
+
+	for (first = bottom & ~31; first < top; first += 32) {
+		unsigned long p;
+		char str[sizeof(" 12345678") * 8 + 1];
+
+		memset(str, ' ', sizeof(str));
+		str[sizeof(str) - 1] = '\0';
+
+		for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
+			if (p >= bottom && p < top) {
+				unsigned long val;
+				if (__get_user(val, (unsigned long *)p) == 0)
+					sprintf(str + i * 9, " %08lx", val);
+				else
+					sprintf(str + i * 9, " ????????");
+			}
+		}
+		pr_emerg("%s%04lx:%s\n", lvl, first & 0xffff, str);
+	}
+
+	set_fs(fs);
+}
+
+EXPORT_SYMBOL(dump_mem);
+
+static void dump_instr(struct pt_regs *regs)
+{
+	unsigned long addr = instruction_pointer(regs);
+	mm_segment_t fs;
+	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
+	int i;
+
+	return;
+	/*
+	 * We need to switch to kernel mode so that we can use __get_user
+	 * to safely read from kernel space.  Note that we now dump the
+	 * code first, just in case the backtrace kills us.
+	 */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	pr_emerg("Code: ");
+	for (i = -4; i < 1; i++) {
+		unsigned int val, bad;
+
+		bad = __get_user(val, &((u32 *) addr)[i]);
+
+		if (!bad) {
+			p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
+		} else {
+			p += sprintf(p, "bad PC value");
+			break;
+		}
+	}
+	pr_emerg("Code: %s\n", str);
+
+	set_fs(fs);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#include <linux/ftrace.h>
+static void
+get_real_ret_addr(unsigned long *addr, struct task_struct *tsk, int *graph)
+{
+	if (*addr == (unsigned long)return_to_handler) {
+		int index = tsk->curr_ret_stack;
+
+		if (tsk->ret_stack && index >= *graph) {
+			index -= *graph;
+			*addr = tsk->ret_stack[index].ret;
+			(*graph)++;
+		}
+	}
+}
+#else
+static inline void
+get_real_ret_addr(unsigned long *addr, struct task_struct *tsk, int *graph)
+{
+}
+#endif
+
+#define LOOP_TIMES (100)
+static void __dump(struct task_struct *tsk, unsigned long *base_reg)
+{
+	unsigned long ret_addr;
+	int cnt = LOOP_TIMES, graph = 0;
+	pr_emerg("Call Trace:\n");
+	if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
+		while (!kstack_end(base_reg)) {
+			ret_addr = *base_reg++;
+			if (__kernel_text_address(ret_addr)) {
+				get_real_ret_addr(&ret_addr, tsk, &graph);
+				print_ip_sym(ret_addr);
+			}
+			if (--cnt < 0)
+				break;
+		}
+	} else {
+		while (!kstack_end((void *)base_reg) &&
+		       !((unsigned long)base_reg & 0x3) &&
+		       ((unsigned long)base_reg >= TASK_SIZE)) {
+			unsigned long next_fp;
+#if !defined(NDS32_ABI_2)
+			ret_addr = base_reg[0];
+			next_fp = base_reg[1];
+#else
+			ret_addr = base_reg[-1];
+			next_fp = base_reg[FP_OFFSET];
+#endif
+			if (__kernel_text_address(ret_addr)) {
+				get_real_ret_addr(&ret_addr, tsk, &graph);
+				print_ip_sym(ret_addr);
+			}
+			if (--cnt < 0)
+				break;
+			base_reg = (unsigned long *)next_fp;
+		}
+	}
+	pr_emerg("\n");
+}
+
+void show_stack(struct task_struct *tsk, unsigned long *sp)
+{
+	unsigned long *base_reg;
+
+	if (!tsk)
+		tsk = current;
+	if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
+		if (tsk != current)
+			base_reg = (unsigned long *)(tsk->thread.cpu_context.sp);
+		else
+			__asm__ __volatile__("\tori\t%0, $sp, #0\n":"=r"(base_reg));
+	} else {
+		if (tsk != current)
+			base_reg = (unsigned long *)(tsk->thread.cpu_context.fp);
+		else
+			__asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(base_reg));
+	}
+	__dump(tsk, base_reg);
+	barrier();
+}
+
+DEFINE_SPINLOCK(die_lock);
+
+/*
+ * This function is protected against re-entrancy.
+ */
+void die(const char *str, struct pt_regs *regs, int err)
+{
+	struct task_struct *tsk = current;
+	static int die_counter;
+
+	console_verbose();
+	spin_lock_irq(&die_lock);
+	bust_spinlocks(1);
+
+	pr_emerg("Internal error: %s: %x [#%d]\n", str, err, ++die_counter);
+	print_modules();
+	pr_emerg("CPU: %i\n", smp_processor_id());
+	show_regs(regs);
+	pr_emerg("Process %s (pid: %d, stack limit = 0x%p)\n",
+		 tsk->comm, tsk->pid, task_thread_info(tsk) + 1);
+
+	if (!user_mode(regs) || in_interrupt()) {
+		dump_mem("Stack: ", regs->sp,
+			 THREAD_SIZE + (unsigned long)task_thread_info(tsk));
+		dump_instr(regs);
+		dump_stack();
+	}
+
+	bust_spinlocks(0);
+	spin_unlock_irq(&die_lock);
+	do_exit(SIGSEGV);
+}
+
+EXPORT_SYMBOL(die);
+
+void die_if_kernel(const char *str, struct pt_regs *regs, int err)
+{
+	if (user_mode(regs))
+		return;
+
+	die(str, regs, err);
+}
+
+int bad_syscall(int n, struct pt_regs *regs)
+{
+	siginfo_t info;
+
+	if (current->personality != PER_LINUX) {
+		send_sig(SIGSEGV, current, 1);
+		return regs->uregs[0];
+	}
+
+	info.si_signo = SIGILL;
+	info.si_errno = 0;
+	info.si_code = ILL_ILLTRP;
+	info.si_addr = (void __user *)instruction_pointer(regs) - 4;
+
+	force_sig_info(SIGILL, &info, current);
+	die_if_kernel("Oops - bad syscall", regs, n);
+	return regs->uregs[0];
+}
+
+void __pte_error(const char *file, int line, unsigned long val)
+{
+	pr_emerg("%s:%d: bad pte %08lx.\n", file, line, val);
+}
+
+void __pmd_error(const char *file, int line, unsigned long val)
+{
+	pr_emerg("%s:%d: bad pmd %08lx.\n", file, line, val);
+}
+
+void __pgd_error(const char *file, int line, unsigned long val)
+{
+	pr_emerg("%s:%d: bad pgd %08lx.\n", file, line, val);
+}
+
+extern char *exception_vector, *exception_vector_end;
+void __init trap_init(void)
+{
+	return;
+}
+
+void __init early_trap_init(void)
+{
+	unsigned long ivb = 0;
+	unsigned long base = PAGE_OFFSET;
+
+	memcpy((unsigned long *)base, (unsigned long *)&exception_vector,
+	       ((unsigned long)&exception_vector_end -
+		(unsigned long)&exception_vector));
+	ivb = __nds32__mfsr(NDS32_SR_IVB);
+	/* Check platform support. */
+	if (((ivb & IVB_mskNIVIC) >> IVB_offNIVIC) < 2)
+		panic
+		    ("IVIC mode is not allowed on the platform with interrupt controller\n");
+	__nds32__mtsr((ivb & ~IVB_mskESZ) | (IVB_valESZ16 << IVB_offESZ) |
+		      IVB_BASE, NDS32_SR_IVB);
+	__nds32__mtsr(INT_MASK_INITAIAL_VAL, NDS32_SR_INT_MASK);
+
+	/*
+	 * 0x800 = 128 vectors * 16byte.
+	 * It should be enough to flush a page.
+	 */
+	cpu_cache_wbinval_page(base, true);
+}
+
+void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
+		  int error_code, int si_code)
+{
+	struct siginfo info;
+
+	tsk->thread.trap_no = ENTRY_DEBUG_RELATED;
+	tsk->thread.error_code = error_code;
+
+	memset(&info, 0, sizeof(info));
+	info.si_signo = SIGTRAP;
+	info.si_code = si_code;
+	info.si_addr = (void __user *)instruction_pointer(regs);
+	force_sig_info(SIGTRAP, &info, tsk);
+}
+
+void do_debug_trap(unsigned long entry, unsigned long addr,
+		   unsigned long type, struct pt_regs *regs)
+{
+	if (notify_die(DIE_OOPS, "Oops", regs, addr, type, SIGTRAP)
+	    == NOTIFY_STOP)
+		return;
+
+	if (user_mode(regs)) {
+		/* trap_signal */
+		send_sigtrap(current, regs, 0, TRAP_BRKPT);
+	} else {
+		/* kernel_trap */
+		if (!fixup_exception(regs))
+			die("unexpected kernel_trap", regs, 0);
+	}
+}
+
+void unhandled_interruption(struct pt_regs *regs)
+{
+	siginfo_t si;
+	pr_emerg("unhandled_interruption\n");
+	show_regs(regs);
+	if (!user_mode(regs))
+		do_exit(SIGKILL);
+	si.si_signo = SIGKILL;
+	si.si_errno = 0;
+	force_sig_info(SIGKILL, &si, current);
+}
+
+void unhandled_exceptions(unsigned long entry, unsigned long addr,
+			  unsigned long type, struct pt_regs *regs)
+{
+	siginfo_t si;
+	pr_emerg("Unhandled Exception: entry: %lx addr:%lx itype:%lx\n", entry,
+		 addr, type);
+	show_regs(regs);
+	if (!user_mode(regs))
+		do_exit(SIGKILL);
+	si.si_signo = SIGKILL;
+	si.si_errno = 0;
+	si.si_addr = (void *)addr;
+	force_sig_info(SIGKILL, &si, current);
+}
+
+extern int do_page_fault(unsigned long entry, unsigned long addr,
+			 unsigned int error_code, struct pt_regs *regs);
+
+/*
+ * 2:DEF dispatch for TLB MISC exception handler
+*/
+
+void do_dispatch_tlb_misc(unsigned long entry, unsigned long addr,
+			  unsigned long type, struct pt_regs *regs)
+{
+	type = type & (ITYPE_mskINST | ITYPE_mskETYPE);
+	if ((type & ITYPE_mskETYPE) < 5) {
+		/* Permission exceptions */
+		do_page_fault(entry, addr, type, regs);
+	} else
+		unhandled_exceptions(entry, addr, type, regs);
+}
+
+void do_revinsn(struct pt_regs *regs)
+{
+	siginfo_t si;
+	pr_emerg("Reserved Instruction\n");
+	show_regs(regs);
+	if (!user_mode(regs))
+		do_exit(SIGILL);
+	si.si_signo = SIGILL;
+	si.si_errno = 0;
+	force_sig_info(SIGILL, &si, current);
+}
+
+#ifdef CONFIG_ALIGNMENT_TRAP
+extern int unalign_access_mode;
+extern int do_unaligned_access(unsigned long addr, struct pt_regs *regs);
+#endif
+void do_dispatch_general(unsigned long entry, unsigned long addr,
+			 unsigned long itype, struct pt_regs *regs,
+			 unsigned long oipc)
+{
+	unsigned int swid = itype >> ITYPE_offSWID;
+	unsigned long type = itype & (ITYPE_mskINST | ITYPE_mskETYPE);
+	if (type == ETYPE_ALIGNMENT_CHECK) {
+#ifdef CONFIG_ALIGNMENT_TRAP
+		/* Alignment check */
+		if (user_mode(regs) && unalign_access_mode) {
+			int ret;
+			ret = do_unaligned_access(addr, regs);
+
+			if (ret == 0)
+				return;
+
+			if (ret == -EFAULT)
+				pr_emerg
+				    ("Unhandled unaligned access exception\n");
+		}
+#endif
+		do_page_fault(entry, addr, type, regs);
+	} else if (type == ETYPE_RESERVED_INSTRUCTION) {
+		/* Reserved instruction */
+		do_revinsn(regs);
+	} else if (type == ETYPE_TRAP && swid == SWID_RAISE_INTERRUPT_LEVEL) {
+		/* trap, used on v3 EDM target debugging workaround */
+		/*
+		 * DIPC(OIPC) is passed as parameter before
+		 * interrupt is enabled, so the DIPC will not be corrupted
+		 * even though interrupts are coming in
+		 */
+		/*
+		 * 1. update ipc
+		 * 2. update pt_regs ipc with oipc
+		 * 3. update pt_regs ipsw (clear DEX)
+		 */
+		__asm__ volatile ("mtsr %0, $IPC\n\t"::"r" (oipc));
+		regs->ipc = oipc;
+		if (regs->pipsw & PSW_mskDEX) {
+			pr_emerg
+			    ("Nested Debug exception is possibly happened\n");
+			pr_emerg("ipc:%08x pipc:%08x\n",
+				 (unsigned int)regs->ipc,
+				 (unsigned int)regs->pipc);
+		}
+		do_debug_trap(entry, addr, itype, regs);
+		regs->ipsw &= ~PSW_mskDEX;
+	} else
+		unhandled_exceptions(entry, addr, type, regs);
+}