Add copyregion support for mapping a frame into the VSpace.

Add a "copyregion" object that supports a named page-aligned memory
region where page frames can be mapped. A copyregion has a name used to
construct the C symbol name and an optional size that specifies how
large a window to create (default is one "small page").  Any specified
size must be a multiple of the base page size (4096 on RISCV). Multiple
regions can be created per component by using different names. Note
there is no synchronization copyregion accesses (e.g. if used by multiple
threads).  A copy region is setup before any pre_init method is called;
any attempt to use it before then is undefined.

A copy region is implemented "under the covers" by creating a C array
named who's pages are unmapped at startup to create a hole in the VSpace.

Change-Id: I78c99441869860c55a80f8c1d93e3a31107af8d1
GitOrigin-RevId: 0dbaa9886d988ff622e8d96188023c0ec8440589

camkes/ast/__init__.py

@@ -21,7 +21,7 @@
 from .location import SourceLocation
 from .objects import Assembly, Attribute, AttributeReference, Component, \
     Composition, Configuration, Connection, ConnectionEnd, Connector, \
-    Consumes, Dataport, DictLookup, Emits, Export, Group, Include, Instance, Interface, \
+    Consumes, CopyRegion, Dataport, DictLookup, Emits, Export, Group, Include, Instance, Interface, \
     Method, Mutex, Parameter, Procedure, Provides, Reference, Semaphore, \
     BinarySemaphore, Setting, Uses, Struct, QueryObject
 from .traversal import SimpleTraversalContext, TraversalAction, \

camkes/ast/objects.py

@@ -609,17 +609,19 @@ def freeze(self):
               all(isinstance_fallback(x, "Semaphore") for x in s))
 @ast_property("binary_semaphores", lambda b: isinstance(b, (list, tuple)) and
               all(isinstance_fallback(x, "BinarySemaphore") for x in b))
+@ast_property("copyregions", lambda c: isinstance(c, (list, tuple)) and
+              all(isinstance_fallback(x, "CopyRegion") for x in c))
 @ast_property("composition", Composition)
 @ast_property("configuration", Configuration)
 class Component(MapLike):
     child_fields = ('attributes', 'includes', 'provides', 'uses', 'emits',
-                    'consumes', 'dataports', 'mutexes', 'semaphores', 'binary_semaphores', 'composition',
-                    'configuration')
+                    'consumes', 'dataports', 'mutexes', 'semaphores', 'binary_semaphores', 'copyregions',
+                    'composition', 'configuration')
 
     def __init__(self, name=None, includes=None, control=False, hardware=False,
                  provides=None, uses=None, emits=None, consumes=None, dataports=None,
-                 attributes=None, mutexes=None, semaphores=None, binary_semaphores=None, composition=None,
-                 configuration=None, location=None):
+                 attributes=None, mutexes=None, semaphores=None, binary_semaphores=None, copyregions=None,
+                 composition=None, configuration=None, location=None):
         super(Component, self).__init__(location)
         self.name = name
         self.includes = list(includes or [])
@@ -634,6 +636,7 @@ def __init__(self, name=None, includes=None, control=False, hardware=False,
         self.mutexes = list(mutexes or [])
         self.semaphores = list(semaphores or [])
         self.binary_semaphores = list(binary_semaphores or [])
+        self.copyregions = list(copyregions or [])
         if composition is not None:
             self.composition = composition
         else:
@@ -655,6 +658,7 @@ def claim_children(self):
         [self.adopt(m) for m in self.mutexes]
         [self.adopt(s) for s in self.semaphores]
         [self.adopt(b) for b in self.binary_semaphores]
+        [self.adopt(b) for b in self.copyregions]
         if self.composition is not None:
             self.adopt(self.composition)
         if self.configuration is not None:
@@ -777,6 +781,15 @@ def __init__(self, name, location=None):
         self.name = name
 
 
+@ast_property("name", six.string_types)
+@ast_property("size", lambda x: isinstance(x, six.integer_types) and x >= 0)
+class CopyRegion(ASTObject):
+    def __init__(self, name, size, location=None):
+        super(CopyRegion, self).__init__(location)
+        self.name = name
+        self.size = size
+
+
 @ast_property("name", lambda x: x is None or isinstance(x, six.string_types))
 @ast_property("from_type", lambda x: isinstance(x, six.string_types) and
               x in ('Dataport', 'Event', 'Procedure'))

camkes/parser/camkes.g

@@ -66,6 +66,7 @@ ID: '[a-zA-Z_]\w*'
             REFIN: 'refin';
             SEMAPHORE: 'semaphore';
             BINARY_SEMAPHORE: 'binary_semaphore';
+            COPYREGION: 'copyregion';
             SIGNED: 'signed';
             STRUCT: 'struct';
             STRING: 'string';
@@ -98,7 +99,7 @@ attribute_decl: attribute_parameter ('=' item)? ;
 component_decl: COMPONENT id? component_defn;
 component_defn: '\{' (attribute | consumes | control | dataport | emits |
                       hardware | include | mutex | provides | semaphore | binary_semaphore |
-                      uses)*
+                      copyregion | uses)*
                     ((composition_sing configuration_sing?) | configuration_sing composition_sing)? '\}';
 component_ref: reference | component_defn;
 
@@ -116,6 +117,8 @@ mutex: HAS MUTEX id ';';
 provides: PROVIDES reference id ';';
 semaphore: HAS SEMAPHORE id ';';
 binary_semaphore: HAS BINARY_SEMAPHORE id ';';
+copyregion_size: '\(' numeric_expr '\)';
+copyregion: HAS COPYREGION id copyregion_size? ';';
 uses: maybe? USES reference id ';';
 maybe: MAYBE;
 

camkes/parser/stage3.py

@@ -27,7 +27,7 @@
 
 from camkes.ast import Assembly, Attribute, AttributeReference, Component, \
     Composition, Configuration, Connection, ConnectionEnd, Connector, \
-    Consumes, Dataport, DictLookup, Emits, Export, Group, Include, Instance, Interface, \
+    Consumes, CopyRegion, Dataport, DictLookup, Emits, Export, Group, Include, Instance, Interface, \
     LiftedAST, Method, Mutex, normalise_type, Parameter, Procedure, Provides, \
     Reference, Semaphore, BinarySemaphore, QueryObject, Setting, SourceLocation, Uses, Struct
 from .base import Parser
@@ -240,6 +240,7 @@ def _lift_component_decl(location, *args):
                      attributes=component_defn.attributes, mutexes=component_defn.mutexes,
                      semaphores=component_defn.semaphores,
                      binary_semaphores=component_defn.binary_semaphores,
+                     copyregions=component_defn.copyregions,
                      composition=component_defn.composition,
                      configuration=component_defn.configuration, location=location)
 
@@ -263,6 +264,7 @@ def _lift_component_defn(location, *args):
                      mutexes=[x for x in args if isinstance(x, Mutex)],
                      semaphores=[x for x in args if isinstance(x, Semaphore)],
                      binary_semaphores=[x for x in args if isinstance(x, BinarySemaphore)],
+                     copyregions=[x for x in args if isinstance(x, CopyRegion)],
                      composition=composition, configuration=configuration,
                      location=location)
 
@@ -688,6 +690,19 @@ def _lift_binary_semaphore(location, id):
     return BinarySemaphore(id, location)
 
 
+def _lift_copyregion(location, *args):
+    if len(args) == 2:
+        name, size = args
+        return CopyRegion(name, size, location)
+    else:
+        # XXX use pagesize?
+        return CopyRegion(args[0], 4096, location)
+
+
+def _lift_copyregion_size(location, arg):
+    return arg
+
+
 def _lift_setting(location, id, id2, item):
     item = strip_quotes(item)
     return Setting(id, id2, item, location)
@@ -838,6 +853,8 @@ def _collapse(location, content):
     'reference': _lift_reference,
     'semaphore': _lift_semaphore,
     'binary_semaphore': _lift_binary_semaphore,
+    'copyregion': _lift_copyregion,
+    'copyregion_size': _lift_copyregion_size,
     'setting': _lift_setting,
     'signed_char': _lift_signed_char,
     'signed_int': _lift_signed_int,

camkes/templates/component.common.c

@@ -80,6 +80,26 @@ const char *get_instance_name(void) {
     return name;
 }
 
+/*- set copy_region_caps = [] -*/
+/*- for c in me.type.copyregions -*/
+    /*# Setup any per-component copy regions. The pre_init (or similar) routine
+      * is expected to unmap the pages using copy_region_caps. This leaves each
+      * COPY_REGION as a "hole" in the component's VSpace where it can map page
+      * frames. Users are required to implement any necessary synchronization. #*/
+    /*- set copy_region_size = c.size -*/
+    /*- set page_size = macros.get_page_size(copy_region_size, options.architecture) -*/
+    /*- if page_size == 0 -*/
+      /*? raise(TemplateError('Invalid %s copy_region size %d: must be a multiple of %d' % (c.name, copy_region_size, 4096))) ?*/
+    /*- endif -*/
+    /*- set page_size_bits = int(math.log(page_size, 2)) -*/
+    /*# set copy_region_symbol = '%s_COPY_REGION' % c.name #*/
+    /*- set copy_region_symbol = c.name -*/
+        char /*? copy_region_symbol ?*/[ROUND_UP_UNSAFE(/*? copy_region_size ?*/, /*? page_size ?*/)]
+        ALIGN(/*? page_size ?*/)
+        SECTION("align_/*? page_size_bits ?*/bit");
+    /*? register_shared_variable('%s_copy_region_%s' % (me.name, c.name), copy_region_symbol, copy_region_size, frame_size=page_size, perm='RW', with_mapping_caps=copy_region_caps) ?*/
+/*- endfor -*/
+
 /*- set cnode_size = configuration[me.address_space].get('cnode_size_bits') -*/
 /*- if cnode_size -*/
         /*- if isinstance(cnode_size, six.string_types) -*/
@@ -791,6 +811,19 @@ static int post_main(int thread_id) {
                     ZF_LOGF_IF(tls_regions[i] == NULL, "Failed to create tls");
                 }
             }
+            /*- for cap in copy_region_caps -*/
+                /*# Would otherwise put this in pre_init... #*/
+                ret = seL4_ARCH_Page_Unmap(/*? cap ?*/);
+                ERR_IF(ret != 0, camkes_error, ((camkes_error_t){
+                    .type = CE_SYSCALL_FAILED,
+                    .instance = "/*? me.name ?*/",
+                    .description = "failed to unmap copy_region frame /*? cap ?*/",
+                    .syscall = 0, /* XXX no ARCHPageUnmap */
+                    .error = ret,
+                }), ({
+                    return -1;
+                }));
+            /*- endfor -*/
             ret = component_control_main();
             sync_sem_bare_wait(/*? interface_init_ep ?*/, &interface_init_lock);
             return ret;