lrdp: iommulib: Refactor methods to find iommu domains

There are several different methods to find all iommu domains.
Reorganaize them into different functions.

Stop treating iommu_debug_attachments as a pointer (since
it is not a pointer but a struct list_head), by replacing:

    list_head_attachments = ramdump.read_pointer(
                                           'iommu_debug_attachments')
    list_head_arm_addr = self.ramdump.read_structure_field(
        list_head_attachments, 'struct list_head', 'prev')

with:

    list_head_attachments = ramdump.address_of(
                                           'iommu_debug_attachments')

Change-Id: I096ba602cf374229a0c2d1090899b91e04852885

linux-ramdump-parser-v2/iommulib.py

-# Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
+# Copyright (c) 2014-2019, The Linux Foundation. All rights reserved.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 and
@@ -12,6 +12,7 @@
 import rb_tree
 import linux_list as llist
 from mm import phys_to_virt
+from print_out import print_out_str
 
 ARM_SMMU_DOMAIN = 0
 MSM_SMMU_DOMAIN = 1
@@ -38,47 +39,48 @@ class IommuLib(object):
         self.ramdump = ramdump
         self.domain_list = []
 
-        root = self.ramdump.read_word('domain_root')
+        if self.find_iommu_domains_msm_iommu():
+            pass
+        elif self.find_iommu_domains_debug_attachments():
+            pass
+        else:
+            print_out_str("Unable to find any iommu domains")
 
-        list_head_attachments = self.ramdump.read_pointer(
-                                                    'iommu_debug_attachments')
+    """
+    legacy code - pre-8996/kernel 4.4?
+    """
+    def find_iommu_domains_msm_iommu(self):
+        domains = list()
+        root = self.ramdump.read_word('domain_root')
+        if root is None:
+            return False
 
-        if list_head_attachments is not None:
-            list_head_arm_addr = self.ramdump.read_structure_field(
-                list_head_attachments, 'struct list_head', 'prev')
-            list_walker = llist.ListWalker(
-                self.ramdump, list_head_arm_addr,
-                self.ramdump.field_offset('struct iommu_debug_attachment',
-                                          'list'))
-            list_walker.walk(list_head_attachments,
-                             self._iommu_domain_find_default,
-                             self.domain_list)
-
-        if root is not None:
         rb_walker = rb_tree.RbTreeWalker(self.ramdump)
         rb_walker.walk(root, self._iommu_domain_func, self.domain_list)
+        return True
 
-    def _iommu_domain_find_default(self, node, domain_list):
-        domain_ptr = self.ramdump.read_structure_field(
-            node, 'struct iommu_debug_attachment', 'domain')
-
-        if not domain_ptr:
-            return
+    """
+    depends on CONFIG_IOMMU_DEBUG_TRACKING
+    """
+    def find_iommu_domains_debug_attachments(self):
+        list_head_attachments = self.ramdump.address_of(
+                                                    'iommu_debug_attachments')
+        if list_head_attachments is None:
+            return False
 
-        if self.ramdump.field_offset('struct iommu_domain', 'priv') \
-                is not None:
-            priv_ptr = self.ramdump.read_structure_field(
-                domain_ptr, 'struct iommu_domain', 'priv')
+        offset = self.ramdump.field_offset('struct iommu_debug_attachment',
+                                          'list')
+        list_walker = llist.ListWalker(self.ramdump, list_head_attachments, offset)
 
-            if not priv_ptr:
-                return
-        else:
-            priv_ptr = None
+        for debug_attachment in list_walker:
+            domain_ptr = self.ramdump.read_structure_field(
+                            debug_attachment, 'struct iommu_debug_attachment', 'domain')
 
-        arm_smmu_ops = self.ramdump.address_of('arm_smmu_ops')
+            if not domain_ptr:
+                continue
 
             ptr = self.ramdump.read_structure_field(
-            node, 'struct iommu_debug_attachment', 'group')
+                debug_attachment, 'struct iommu_debug_attachment', 'group')
             if ptr is not None:
                 dev_list = ptr + self.ramdump.field_offset(
                     'struct iommu_group', 'devices')
@@ -95,11 +97,30 @@ class IommuLib(object):
                 instead of 'iommu_group'.
                 """
                 ptr = self.ramdump.read_structure_field(
-                node, 'struct iommu_debug_attachment', 'dev')
+                    debug_attachment, 'struct iommu_debug_attachment', 'dev')
                 kobj_ptr = ptr + self.ramdump.field_offset('struct device', 'kobj')
                 client_name = self.ramdump.read_structure_cstring(
                     kobj_ptr, 'struct kobject', 'name')
 
+
+            self._find_iommu_domains_arm_smmu(domain_ptr, client_name, self.domain_list)
+
+        return True
+
+
+    def _find_iommu_domains_arm_smmu(self, domain_ptr, client_name, domain_list):
+        if self.ramdump.field_offset('struct iommu_domain', 'priv') \
+                is not None:
+            priv_ptr = self.ramdump.read_structure_field(
+                domain_ptr, 'struct iommu_domain', 'priv')
+
+            if not priv_ptr:
+                return
+        else:
+            priv_ptr = None
+
+        arm_smmu_ops = self.ramdump.address_of('arm_smmu_ops')
+
         iommu_domain_ops = self.ramdump.read_structure_field(
             domain_ptr, 'struct iommu_domain', 'ops')
         if iommu_domain_ops is None or iommu_domain_ops == 0: