PPC: Bring EPR support closer to reality

We already used to support the external proxy facility of FSL MPICs,
but only implemented it halfway correctly.

This patch adds support for

  * dynamic enablement of the EPR facility
  * interrupt acknowledgement only when the interrupt is delivered

This way the implementation now is closer to real hardware.

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

8 files changed, 31 insertions, 46 deletions

diff --git a/hw/openpic.c b/hw/openpic.c
index e773d680f..3b20a39ab 100644
--- a/hw/openpic.c
+++ b/hw/openpic.c
@@ -131,6 +131,9 @@ static const int debug_openpic = 0;
 #define VIR_GENERIC      0x00000000 /* Generic Vendor ID */
 
 #define GCR_RESET        0x80000000
+#define GCR_MODE_PASS    0x00000000
+#define GCR_MODE_MIXED   0x20000000
+#define GCR_MODE_PROXY   0x60000000
 
 #define TBCR_CI           0x80000000 /* count inhibit */
 #define TCCR_TOG          0x80000000 /* toggles when decrement to zero */
@@ -233,6 +236,7 @@ typedef struct OpenPICState {
     uint32_t ivpr_reset;
     uint32_t idr_reset;
     uint32_t brr1;
+    uint32_t mpic_mode_mask;
 
     /* Sub-regions */
     MemoryRegion sub_io_mem[5];
@@ -667,6 +671,20 @@ static void openpic_gbl_write(void *opaque, hwaddr addr, uint64_t val,
     case 0x1020: /* GCR */
         if (val & GCR_RESET) {
             openpic_reset(&opp->busdev.qdev);
+        } else if (opp->mpic_mode_mask) {
+            CPUArchState *env;
+            int mpic_proxy = 0;
+
+            opp->gcr &= ~opp->mpic_mode_mask;
+            opp->gcr |= val & opp->mpic_mode_mask;
+
+            /* Set external proxy mode */
+            if ((val & opp->mpic_mode_mask) == GCR_MODE_PROXY) {
+                mpic_proxy = 1;
+            }
+            for (env = first_cpu; env != NULL; env = env->next_cpu) {
+                env->mpic_proxy = mpic_proxy;
+            }
         }
         break;
     case 0x1080: /* VIR */
@@ -1407,6 +1425,9 @@ static int openpic_init(SysBusDevice *dev)
         opp->irq_tim0 = FSL_MPIC_20_TMR_IRQ;
         opp->irq_msi = FSL_MPIC_20_MSI_IRQ;
         opp->brr1 = FSL_BRR1_IPID | FSL_BRR1_IPMJ | FSL_BRR1_IPMN;
+        /* XXX really only available as of MPIC 4.0 */
+        opp->mpic_mode_mask = GCR_MODE_PROXY;
+
         msi_supported = true;
         list = list_be;
 
diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
index 5d70618f7..3a9e1c7b4 100644
--- a/hw/ppc/e500.c
+++ b/hw/ppc/e500.c
@@ -497,8 +497,8 @@ void ppce500_init(PPCE500Params *params)
         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_CCSRBAR_BASE +
-                              MPC8544_MPIC_REGS_OFFSET + 0x20000;
+        env->mpic_iack = MPC8544_CCSRBAR_BASE +
+                         MPC8544_MPIC_REGS_OFFSET + 0x200A0;
 
         ppc_booke_timers_init(cpu, 400000000, PPC_TIMER_E500);
 
diff --git a/target-ppc/Makefile.objs b/target-ppc/Makefile.objs
index 237a0ed4f..6c11ef84b 100644
--- a/target-ppc/Makefile.objs
+++ b/target-ppc/Makefile.objs
@@ -9,4 +9,3 @@ 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 e88ebe00d..dc5145bf3 100644
--- a/target-ppc/cpu.h
+++ b/target-ppc/cpu.h
@@ -1067,7 +1067,9 @@ struct CPUPPCState {
     target_ulong ivor_mask;
     target_ulong ivpr_mask;
     target_ulong hreset_vector;
-    hwaddr mpic_cpu_base;
+    hwaddr mpic_iack;
+    /* true when the external proxy facility mode is enabled */
+    bool mpic_proxy;
 #endif
 
     /* Those resources are used only during code translation */
diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
index 41037a7e2..0a1ac86a4 100644
--- a/target-ppc/excp_helper.c
+++ b/target-ppc/excp_helper.c
@@ -178,6 +178,10 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
         if (lpes0 == 1) {
             new_msr |= (target_ulong)MSR_HVB;
         }
+        if (env->mpic_proxy) {
+            /* IACK the IRQ on delivery */
+            env->spr[SPR_BOOKE_EPR] = ldl_phys(env->mpic_iack);
+        }
         goto store_next;
     case POWERPC_EXCP_ALIGN:     /* Alignment exception                      */
         if (lpes1 == 0) {
diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index d2e9a55f2..83139d522 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -405,7 +405,6 @@ 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
deleted file mode 100644
index 2c6a4d30a..000000000
--- a/target-ppc/mpic_helper.c
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- *  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
diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 42ed748b5..e2eeb8765 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -4493,11 +4493,6 @@ static void spr_read_mas73(void *opaque, int gprn, int sprn)
     tcg_temp_free(mas7);
 }
 
-static void spr_load_epr(void *opaque, int gprn, int sprn)
-{
-    gen_helper_load_epr(cpu_gpr[gprn], cpu_env);
-}
-
 #endif
 
 enum fsl_e500_version {
@@ -4656,7 +4651,7 @@ static void init_proc_e500 (CPUPPCState *env, int version)
                  0x00000000);
     spr_register(env, SPR_BOOKE_EPR, "EPR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_load_epr, SPR_NOACCESS,
+                 &spr_read_generic, SPR_NOACCESS,
                  0x00000000);
     /* XXX better abstract into Emb.xxx features */
     if (version == fsl_e5500) {