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authorLinus Torvalds <torvalds@linux-foundation.org>2017-11-13 12:12:00 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-13 12:12:00 -0800
commitf3573b8f902c507c721999cc669fbb7e045081b8 (patch)
tree703d1d7e58d50dfbf7a9c4810710acf393166a57 /arch/openrisc/kernel/stacktrace.c
parent9e09d05cfe7df9efa7bbca7d679af534a616026e (diff)
parent610f01b9a88a9ef8b506709a825c17395c56a62a (diff)
Merge tag 'for-linus' of git://github.com/openrisc/linux
Pull OpenRISC updates from Stafford Horne: "The OpenRISC work is a bit more interesting this time, adding SMP support and a few general cleanups. Small Things: - Move OpenRISC docs into Documentation and clean them up - Document previously undocumented devicetree bindings - Update the or1ksim dts to use stdout-path OpenRISC SMP support details: - First the "use shadow registers" and "define CPU_BIG_ENDIAN as true" get the architecture ready for SMP. - The "add 1 and 2 byte cmpxchg support" and "use qspinlocks and qrwlocks" add the SMP locking infrastructure as needed. Using the qspinlocks and qrwlocks as suggested by Peter Z while reviewing the original spinlocks implementation. - The "support for ompic" adds a new irqchip device which is used for IPI communication to support SMP. - The "initial SMP support" adds smp.c and makes changes to all of the necessary data-structures to be per-cpu. The remaining patches are bug fixes and debug helpers which I wanted to keep separate from the "initial SMP support" in order to allow them to be reviewed on their own. This includes: - add cacheflush support to fix icache aliasing - fix initial preempt state for secondary cpu tasks - sleep instead of spin on secondary wait - support framepointers and STACKTRACE_SUPPORT - enable LOCKDEP_SUPPORT and irqflags tracing - timer sync: Add tick timer sync logic - fix possible deadlock in timer sync, pointed out by mips guys Note: the irqchip patch was reviewed with Marc and we agreed to push it together with these patches" * tag 'for-linus' of git://github.com/openrisc/linux: openrisc: fix possible deadlock scenario during timer sync openrisc: pass endianness info to sparse openrisc: add tick timer multi-core sync logic openrisc: enable LOCKDEP_SUPPORT and irqflags tracing openrisc: support framepointers and STACKTRACE_SUPPORT openrisc: add simple_smp dts and defconfig for simulators openrisc: add cacheflush support to fix icache aliasing openrisc: sleep instead of spin on secondary wait openrisc: fix initial preempt state for secondary cpu tasks openrisc: initial SMP support irqchip: add initial support for ompic dt-bindings: add openrisc to vendor prefixes list openrisc: use qspinlocks and qrwlocks openrisc: add 1 and 2 byte cmpxchg support openrisc: use shadow registers to save regs on exception dt-bindings: openrisc: Add OpenRISC platform SoC Documentation: openrisc: Updates to README Documentation: Move OpenRISC docs out of arch/ MAINTAINERS: Add OpenRISC pic maintainer openrisc: dts: or1ksim: Add stdout-path
Diffstat (limited to 'arch/openrisc/kernel/stacktrace.c')
-rw-r--r--arch/openrisc/kernel/stacktrace.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/openrisc/kernel/stacktrace.c b/arch/openrisc/kernel/stacktrace.c
new file mode 100644
index 000000000000..43f140a28bc7
--- /dev/null
+++ b/arch/openrisc/kernel/stacktrace.c
@@ -0,0 +1,86 @@
+/*
+ * Stack trace utility for OpenRISC
+ *
+ * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ *
+ * Losely based on work from sh and powerpc.
+ */
+
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/stacktrace.h>
+
+#include <asm/processor.h>
+#include <asm/unwinder.h>
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+static void
+save_stack_address(void *data, unsigned long addr, int reliable)
+{
+ struct stack_trace *trace = data;
+
+ if (!reliable)
+ return;
+
+ if (trace->skip > 0) {
+ trace->skip--;
+ return;
+ }
+
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = addr;
+}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+ unwind_stack(trace, (unsigned long *) &trace, save_stack_address);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+static void
+save_stack_address_nosched(void *data, unsigned long addr, int reliable)
+{
+ struct stack_trace *trace = (struct stack_trace *)data;
+
+ if (!reliable)
+ return;
+
+ if (in_sched_functions(addr))
+ return;
+
+ if (trace->skip > 0) {
+ trace->skip--;
+ return;
+ }
+
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = addr;
+}
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ unsigned long *sp = NULL;
+
+ if (tsk == current)
+ sp = (unsigned long *) &sp;
+ else
+ sp = (unsigned long *) KSTK_ESP(tsk);
+
+ unwind_stack(trace, sp, save_stack_address_nosched);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+void
+save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+ unwind_stack(trace, (unsigned long *) regs->sp,
+ save_stack_address_nosched);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_regs);