1 files changed, 135 insertions, 0 deletions

diff --git a/scripts/gdb/linux/cpus.py b/scripts/gdb/linux/cpus.py
new file mode 100644
index 000000000000..4297b83fedef
--- /dev/null
+++ b/scripts/gdb/linux/cpus.py
@@ -0,0 +1,135 @@
+#
+# gdb helper commands and functions for Linux kernel debugging
+#
+#  per-cpu tools
+#
+# Copyright (c) Siemens AG, 2011-2013
+#
+# Authors:
+#  Jan Kiszka <jan.kiszka@siemens.com>
+#
+# This work is licensed under the terms of the GNU GPL version 2.
+#
+
+import gdb
+
+from linux import tasks, utils
+
+
+MAX_CPUS = 4096
+
+
+def get_current_cpu():
+    if utils.get_gdbserver_type() == utils.GDBSERVER_QEMU:
+        return gdb.selected_thread().num - 1
+    elif utils.get_gdbserver_type() == utils.GDBSERVER_KGDB:
+        tid = gdb.selected_thread().ptid[2]
+        if tid > (0x100000000 - MAX_CPUS - 2):
+            return 0x100000000 - tid - 2
+        else:
+            return tasks.get_thread_info(tasks.get_task_by_pid(tid))['cpu']
+    else:
+        raise gdb.GdbError("Sorry, obtaining the current CPU is not yet "
+                           "supported with this gdb server.")
+
+
+def per_cpu(var_ptr, cpu):
+    if cpu == -1:
+        cpu = get_current_cpu()
+    if utils.is_target_arch("sparc:v9"):
+        offset = gdb.parse_and_eval(
+            "trap_block[{0}].__per_cpu_base".format(str(cpu)))
+    else:
+        try:
+            offset = gdb.parse_and_eval(
+                "__per_cpu_offset[{0}]".format(str(cpu)))
+        except gdb.error:
+            # !CONFIG_SMP case
+            offset = 0
+    pointer = var_ptr.cast(utils.get_long_type()) + offset
+    return pointer.cast(var_ptr.type).dereference()
+
+
+cpu_mask = {}
+
+
+def cpu_mask_invalidate(event):
+    global cpu_mask
+    cpu_mask = {}
+    gdb.events.stop.disconnect(cpu_mask_invalidate)
+    if hasattr(gdb.events, 'new_objfile'):
+        gdb.events.new_objfile.disconnect(cpu_mask_invalidate)
+
+
+def cpu_list(mask_name):
+    global cpu_mask
+    mask = None
+    if mask_name in cpu_mask:
+        mask = cpu_mask[mask_name]
+    if mask is None:
+        mask = gdb.parse_and_eval(mask_name + ".bits")
+        if hasattr(gdb, 'events'):
+            cpu_mask[mask_name] = mask
+            gdb.events.stop.connect(cpu_mask_invalidate)
+            if hasattr(gdb.events, 'new_objfile'):
+                gdb.events.new_objfile.connect(cpu_mask_invalidate)
+    bits_per_entry = mask[0].type.sizeof * 8
+    num_entries = mask.type.sizeof * 8 / bits_per_entry
+    entry = -1
+    bits = 0
+
+    while True:
+        while bits == 0:
+            entry += 1
+            if entry == num_entries:
+                return
+            bits = mask[entry]
+            if bits != 0:
+                bit = 0
+                break
+
+        while bits & 1 == 0:
+            bits >>= 1
+            bit += 1
+
+        cpu = entry * bits_per_entry + bit
+
+        bits >>= 1
+        bit += 1
+
+        yield cpu
+
+
+class PerCpu(gdb.Function):
+    """Return per-cpu variable.
+
+$lx_per_cpu("VAR"[, CPU]): Return the per-cpu variable called VAR for the
+given CPU number. If CPU is omitted, the CPU of the current context is used.
+Note that VAR has to be quoted as string."""
+
+    def __init__(self):
+        super(PerCpu, self).__init__("lx_per_cpu")
+
+    def invoke(self, var_name, cpu=-1):
+        var_ptr = gdb.parse_and_eval("&" + var_name.string())
+        return per_cpu(var_ptr, cpu)
+
+
+PerCpu()
+
+
+class LxCurrentFunc(gdb.Function):
+    """Return current task.
+
+$lx_current([CPU]): Return the per-cpu task variable for the given CPU
+number. If CPU is omitted, the CPU of the current context is used."""
+
+    def __init__(self):
+        super(LxCurrentFunc, self).__init__("lx_current")
+
+    def invoke(self, cpu=-1):
+        var_ptr = gdb.parse_and_eval("&current_task")
+        return per_cpu(var_ptr, cpu).dereference()
+
+
+LxCurrentFunc()