#25: fix reading device tree nodes

coresight-tools/cs_topology.py

@@ -125,7 +125,7 @@ def __init__(self, platform, device_type, is_hidden=False, name=None, type_name=
         self.part_vendor = None
         self.part_number = None     # e.g. 0x906
         self.cpu_number = None      # CPU (PE) number within the system, e.g. as seen by Linux
-        self.affine_cpu = None
+        self.affine_cpu = None      # a CS_DEVTYPE_CORE Device object we are affine to
         self.type = device_type
         if device_type == CS_DEVTYPE_CORE:
             self.affine_cpu = self
@@ -156,13 +156,26 @@ def type_str(self):
             return str(self.type)
 
     def __str__(self):
+        """
+        Generate a string representation for the device, including its name (if known)
+        and base address. This could unfortunately duplicate the address, if the naming
+        convention includes the address, e.g.
+           etm2@0x80000
+        but
+           etm@0x0080000@0x80000
+        So we try to be clever and only append the base address if it's not already
+        in the name.
+        """
         s = ""
         if self.name is not None:
             s = self.name
         else:
             s += "<%s>" % self.type_str()
         if self.is_memory_mapped():
-            s += "@" + self.address_str()
+            if self.name is not None and '@' in self.name:
+                pass
+            else:
+                s += "@" + self.address_str()
         return s
 
     def links(self, type, end=None):
@@ -208,7 +221,7 @@ def set_affine_cpu(self, cpu_dev):
         """
         if self.affine_cpu != cpu_dev:
             assert self.affine_cpu is None, "set_affine_cpu() called twice with different devices"
-            assert cpu_dev.type == CS_DEVTYPE_CORE
+            assert cpu_dev.type == CS_DEVTYPE_CORE, "set_affine_cpu needs a core device: %s" % cpu_dev
             self.affine_cpu = cpu_dev
             cpu_dev.affine_devices.append(self)
             if self.cpu_number is None:
@@ -218,9 +231,22 @@ def set_cpu_number(self, n):
         self.cpu_number = n
         if n > self.platform.max_cpu_number:
             self.platform.max_cpu_number = n
-        if type == CS_DEVTYPE_CORE:
+        if self.type == CS_DEVTYPE_CORE:
+            # Core cpu number is now known, so update all its affine devices
+            # to get the same CPU number.
             for d in self.affine_devices:
+                assert d.affine_cpu == self
                 d.cpu_number = n
+            # Some devices may already have got a CPU number, but because the core
+            # has only just got its own number, they're not tied together.
+            # Do that now.
+            for d in self.platform.devices:
+                if d.cpu_number == n and d.affine_cpu is not self:
+                    d.set_affine_cpu(self)
+        elif self.affine_cpu is None:
+            cpu_dev = self.platform.device_by_cpu(n)
+            if cpu_dev is not None:
+                self.set_affine_cpu(cpu_dev)
 
     def set_arm_part_number(self, pid):
         assert pid <= 0xfff, "expected 3 hex digit part number: 0x%x" % pid
@@ -552,10 +578,10 @@ def show(self):
             print("  %20s" % name, end="")
             print("  %12s" % (d.type_str()), end="")
             if d.is_affine_to_cpu():
+                if d.cpu_number is not None:
+                    print(" %4u" % d.cpu_number, end="")
                 if d.affine_cpu is not None:
-                    print("%5s" % str(d.affine_cpu), end="")
-                else:
-                    print("%5u" % d.cpu_number, end="")
+                    print(" %4s" % str(d.affine_cpu), end="")
             else:
                 print("     ", end="")
             if d.is_hidden:
@@ -651,6 +677,7 @@ def test():
     Link(df1, ds2, CS_LINK_ATB)
     p.show()
     p.check()
+    print("Self-tests completed.")
 
 
 if __name__ == "__main__":

coresight-tools/cs_topology_sysfs.py

@@ -40,6 +40,8 @@
     "ptm":        CS_DEVTYPE_TRACE_CORE,
     "etm":        CS_DEVTYPE_TRACE_CORE,
     "stm":        CS_DEVTYPE_TRACE_SW,
+    "cti_cpu":    CS_DEVTYPE_CTI,
+    "cti_sys":    CS_DEVTYPE_CTI,
 }
 
 
@@ -113,6 +115,7 @@ def get_cs_from_sysfs(p=None):
         devtype = devtypes[base]
         d = Device(p, devtype, name=sd)
         d.sysfs_path = dp
+        # See if the device is affine to a (single) CPU
         try:
             cn = int(read_file(os.path.join(dp, "cpu")))
             d.set_cpu_number(cn)
@@ -128,7 +131,10 @@ def get_cs_from_sysfs(p=None):
         of_node = os.path.join(os.path.dirname(rp), "of_node")
         if os.path.exists(of_node):
             d.of_node = os.path.realpath(of_node)      # /sys/firmware/devicetree
-            d.set_mem_address(device_tree_node_address(d.of_node))
+            addr = device_tree_node_address(d.of_node)
+            if addr == 0:
+                print("warning: %s has zero address" % (d.of_node), file=sys.stderr)
+            d.set_mem_address(addr)
         firmware_node = os.path.join(os.path.dirname(rp), "firmware_node")
         if os.path.exists(firmware_node):
             firmware_node = os.path.realpath(firmware_node)
@@ -172,6 +178,9 @@ def get_cs_from_sysfs(p=None):
 
 
 def device_tree_node_compatibility(dtn):
+    """
+    Get the list of compatibility strings for a device tree node
+    """
     compat = read_file(os.path.join(dtn, "compatible")).split(",")
     cl = []
     for s in compat:
@@ -206,11 +215,14 @@ def device_tree_node_reg(dtn, reg_name="reg"):
 
 
 def device_tree_node_property_length(dtn, prop):
+    """
+    For a device tree node, find the #size-cells or #address-cells value,
+    by looking exactly one level upwards in its directory hierarchy.
+    (Note that if #address-cells file exists in a node, it indicates the
+    size of the address field in any childrens' "reg", not its own "reg".)
+    """
     prop = "#" + prop + "-cells"
-    assert dtn.startswith("/proc/device-tree/"), "unexpected device tree node: %s" % dtn
-    while len(dtn) > 18 and not os.path.isfile(os.path.join(dtn, prop)):
-        dtn = os.path.dirname(dtn)
-    assert dtn != "/proc/device-tree"
+    dtn = os.path.dirname(dtn)    # Go exactly one level up
     alen = device_tree_node_reg(dtn, reg_name=prop)
     alen = alen * 4    # it's counted in words
     return alen
@@ -240,7 +252,9 @@ def device_tree_node_size_length(dtn):
 
 def device_tree_nodes():
     """
-    Iterate through nodes in /proc/device-tree
+    Iterate through nodes in the device tree.
+    The device tree is exported at /sys/firmware/devicetree/base
+    and as an alias at /proc/device-tree .
     """
     for root, dirs, files in os.walk("/proc/device-tree"):
         for d in dirs:
@@ -265,6 +279,9 @@ def compat_is_coresight(dcompat):
     return None
 
 
+#
+# Map device-tree compatibility strings (minus "coresight-") into device types.
+#
 cs_device_tree_types = {
     "etm3x":               CS_DEVTYPE_TRACE_CORE,
     "ptm":                 CS_DEVTYPE_TRACE_CORE,
@@ -276,6 +293,9 @@ def compat_is_coresight(dcompat):
     "tpiu":                CS_DEVTYPE_PORT,
     "etb10":               CS_DEVTYPE_BUFFER,
     "tmc":                 CS_DEVTYPE_BUFFER,
+    "cti":                 CS_DEVTYPE_CTI,
+    "cti-v8-arch":         CS_DEVTYPE_CTI,
+    "cpu-debug":           CS_DEVTYPE_CORE,
 }
 
 
@@ -399,6 +419,20 @@ def get_cs_from_device_tree(p=None):
     return p
 
 
+def list_device_tree_nodes():
+    """
+    Debugging: just list the device tree nodes.
+    """
+    for (dp, phandle, dcompat) in device_tree_nodes():
+        dc = compat_is_coresight(dcompat)
+        if not dc:
+            continue
+        print("  %-20s  %4s  %-40s" % (dc, phandle, dp), end="")
+        reg = read_binary_file(os.path.join(dp, "reg"))
+        print(" reg:%3u" % len(reg), end="")
+        print("  %s" % str(os.listdir(dp)))
+
+
 if __name__ == "__main__":
     p = get_cs_from_sysfs()
     if True or p is None or not p.links: