arm: Add support for memory-mapped m5ops

Add support for a memory mapped m5op interface. When enabled, the TLB
intercepts accesses in the 64KiB region designated by the
ArmTLB.m5ops_base parameter. An access to this range maps to a
specific m5op call. The upper 8 bits of the offset into the range
denote the m5op function to call and the lower 8 bits denote the
subfunction.

Change-Id: I55fd8ac1afef4c3cc423b973870c9fe600a843a2
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2964

1 files changed, 12 insertions, 0 deletions

diff --git a/src/arch/arm/system.hh b/src/arch/arm/system.hh
index ee286d23a..97769337a 100644
--- a/src/arch/arm/system.hh
+++ b/src/arch/arm/system.hh
@@ -116,6 +116,12 @@ class ArmSystem : public System
      */
     const bool _haveLargeAsid64;
 
+    /**
+     * Range for memory-mapped m5 pseudo ops. The range will be
+     * invalid/empty if disabled.
+     */
+    const AddrRange _m5opRange;
+
   protected:
     /**
      * Get a boot loader that matches the kernel.
@@ -216,6 +222,12 @@ class ArmSystem : public System
         return mask(physAddrRange());
     }
 
+    /**
+     * Range used by memory-mapped m5 pseudo-ops if enabled. Returns
+     * an invalid/empty range if disabled.
+     */
+    const AddrRange &m5opRange() const { return _m5opRange; }
+
     /** Returns true if the system of a specific thread context implements the
      * Security Extensions
      */