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>

4 files changed, 38 insertions, 0 deletions

diff --git a/target-ppc/Makefile.objs b/target-ppc/Makefile.objs
index 6c11ef8..237a0ed 100644
--- a/target-ppc/Makefile.objs
+++ b/target-ppc/Makefile.objs
@@ -9,3 +9,4 @@ obj-y += mmu_helper.o
 obj-y += timebase_helper.o
 obj-y += misc_helper.o
 obj-y += mem_helper.o
+obj-y += mpic_helper.o
diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
index 7a77fff..652a35a 100644
--- a/target-ppc/cpu.h
+++ b/target-ppc/cpu.h
@@ -1066,6 +1066,7 @@ struct CPUPPCState {
     target_ulong ivor_mask;
     target_ulong ivpr_mask;
     target_ulong hreset_vector;
+    target_phys_addr_t mpic_cpu_base;
 #endif
 
     /* Those resources are used only during code translation */
diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index ddab97b..fd04c06 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -405,6 +405,7 @@ DEF_HELPER_2(store_40x_dbcr0, void, env, tl)
 DEF_HELPER_2(store_40x_sler, void, env, tl)
 DEF_HELPER_2(store_booke_tcr, void, env, tl)
 DEF_HELPER_2(store_booke_tsr, void, env, tl)
+DEF_HELPER_1(load_epr, tl, env)
 DEF_HELPER_3(store_ibatl, void, env, i32, tl)
 DEF_HELPER_3(store_ibatu, void, env, i32, tl)
 DEF_HELPER_3(store_dbatl, void, env, i32, tl)
diff --git a/target-ppc/mpic_helper.c b/target-ppc/mpic_helper.c
new file mode 100644
index 0000000..2c6a4d3
--- /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