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: NAlexander Graf <agraf@suse.de>

hw/ppce500_mpc8544ds.c

@@ -469,6 +469,7 @@ static void mpc8544ds_init(ram_addr_t ram_size,
         irqs[i][OPENPIC_OUTPUT_INT] = input[PPCE500_INPUT_INT];
         irqs[i][OPENPIC_OUTPUT_CINT] = input[PPCE500_INPUT_CINT];
         env->spr[SPR_BOOKE_PIR] = env->cpu_index = i;
+        env->mpic_cpu_base = MPC8544_MPIC_REGS_BASE + 0x20000;
 
         ppc_booke_timers_init(env, 400000000, PPC_TIMER_E500);
 

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

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 */

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)

target-ppc/mpic_helper.c

+/*
+ *  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