linker: Split out CacheFlush logic

Test Plan: Validate

Reviewers: erikd, austin, simonmar

Reviewed By: erikd

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2643

1 files changed, 71 insertions, 0 deletions

diff --git a/rts/linker/CacheFlush.c b/rts/linker/CacheFlush.c
new file mode 100644
index 0000000000..206b2ef7ef
--- /dev/null
+++ b/rts/linker/CacheFlush.c
@@ -0,0 +1,71 @@
+/* Platform-dependent cache flushing logic */
+
+#include "Rts.h"
+#include "linker/CacheFlush.h"
+
+#if defined(arm_HOST_ARCH)
+
+void
+ocFlushInstructionCache( ObjectCode *oc )
+{
+    int i;
+    // Object code
+    for (i=0; i < oc->n_sections; i++) {
+        Section *s = &oc->sections[i];
+        // This is a bit too broad but we don't have any way to determine what
+        // is certainly code
+        if (s->kind == SECTIONKIND_CODE_OR_RODATA)
+            __clear_cache(s->start, (void*) ((uintptr_t) s->start + s->size));
+    }
+
+    // Jump islands
+    // Note the (+1) to ensure that the last symbol extra is covered by the
+    // flush.
+    __clear_cache(oc->symbol_extras, &oc->symbol_extras[oc->n_symbol_extras+1]);
+}
+
+#elif defined(powerpc_HOST_ARCH)
+/*
+   ocFlushInstructionCache
+
+   Flush the data & instruction caches.
+   Because the PPC has split data/instruction caches, we have to
+   do that whenever we modify code at runtime.
+ */
+
+static void
+ocFlushInstructionCacheFrom(void* begin, size_t length)
+{
+    size_t         n = (length + 3) / 4;
+    unsigned long* p = begin;
+
+    while (n--)
+    {
+        __asm__ volatile ( "dcbf 0,%0\n\t"
+                           "sync\n\t"
+                           "icbi 0,%0"
+                           :
+                           : "r" (p)
+                         );
+        p++;
+    }
+    __asm__ volatile ( "sync\n\t"
+                       "isync"
+                     );
+}
+
+void
+ocFlushInstructionCache( ObjectCode *oc )
+{
+    /* The main object code */
+    ocFlushInstructionCacheFrom(oc->image + oc->misalignment, oc->fileSize);
+
+    /* Jump Islands */
+    ocFlushInstructionCacheFrom(oc->symbol_extras, sizeof(SymbolExtra) * oc->n_symbol_extras);
+}
+
+#else
+
+void ocFlushInstructionCache( ObjectCode *oc STG_UNUSED ) {}
+
+#endif /* powerpc_HOST_ARCH */