PPC: BookE: Implement EPR SPR

On the e500 series, accessing SPR_EPR magically turns into an access at
that CPU's IACK register on the MPIC. Implement that logic to get kernels
that make use of that feature work.

Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 35 insertions, 0 deletions

diff --git a/target-ppc/mpic_helper.c b/target-ppc/mpic_helper.c
new file mode 100644
index 0000000000..2c6a4d30a9
--- /dev/null
+++ b/target-ppc/mpic_helper.c
@@ -0,0 +1,35 @@
+/*
+ *  PowerPC emulation helpers for QEMU.
+ *
+ *  Copyright (c) 2003-2007 Jocelyn Mayer
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+#include "cpu.h"
+#include "helper.h"
+
+/*****************************************************************************/
+/* SPR accesses */
+
+#if !defined(CONFIG_USER_ONLY)
+/*
+ * This is an ugly helper for EPR, which is basically the same as accessing
+ * the IACK (PIAC) register on the MPIC. Because we model the MPIC as a device
+ * that can only talk to the CPU through MMIO, let's access it that way!
+ */
+target_ulong helper_load_epr(CPUPPCState *env)
+{
+    return ldl_phys(env->mpic_cpu_base + 0xA0);
+}
+#endif