[PATCH for-6.2 01/25] arm: Move M-profile RAS register block into its own device

[Peter Maydell <peter.maydell@linaro.org>]

Currently we implement the RAS register block within the NVIC device.
It isn't really very tightly coupled with the NVIC proper, so instead
move it out into a sysbus device of its own and have the top level
ARMv7M container create it and map it into memory at the right
address.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/hw/arm/armv7m.h       |  2 +
 include/hw/intc/armv7m_nvic.h |  1 -
 include/hw/misc/armv7m_ras.h  | 37 ++++++++++++++
 hw/arm/armv7m.c               | 12 +++++
 hw/intc/armv7m_nvic.c         | 56 ---------------------
 hw/misc/armv7m_ras.c          | 93 +++++++++++++++++++++++++++++++++++
 MAINTAINERS                   |  2 +
 hw/misc/meson.build           |  2 +
 8 files changed, 148 insertions(+), 57 deletions(-)
 create mode 100644 include/hw/misc/armv7m_ras.h
 create mode 100644 hw/misc/armv7m_ras.c

diff --git a/include/hw/arm/armv7m.h b/include/hw/arm/armv7m.h
index bc6733c5184..4cae0d7eeaa 100644
--- a/include/hw/arm/armv7m.h
+++ b/include/hw/arm/armv7m.h
@@ -12,6 +12,7 @@
 
 #include "hw/sysbus.h"
 #include "hw/intc/armv7m_nvic.h"
+#include "hw/misc/armv7m_ras.h"
 #include "target/arm/idau.h"
 #include "qom/object.h"
 
@@ -58,6 +59,7 @@ struct ARMv7MState {
     NVICState nvic;
     BitBandState bitband[ARMV7M_NUM_BITBANDS];
     ARMCPU *cpu;
+    ARMv7MRAS ras;
 
     /* MemoryRegion we pass to the CPU, with our devices layered on
      * top of the ones the board provides in board_memory.
diff --git a/include/hw/intc/armv7m_nvic.h b/include/hw/intc/armv7m_nvic.h
index 39c71e15936..33b6d8810c7 100644
--- a/include/hw/intc/armv7m_nvic.h
+++ b/include/hw/intc/armv7m_nvic.h
@@ -83,7 +83,6 @@ struct NVICState {
     MemoryRegion sysreg_ns_mem;
     MemoryRegion systickmem;
     MemoryRegion systick_ns_mem;
-    MemoryRegion ras_mem;
     MemoryRegion container;
     MemoryRegion defaultmem;
 
diff --git a/include/hw/misc/armv7m_ras.h b/include/hw/misc/armv7m_ras.h
new file mode 100644
index 00000000000..f8773e65b14
--- /dev/null
+++ b/include/hw/misc/armv7m_ras.h
@@ -0,0 +1,37 @@
+/*
+ * Arm M-profile RAS block
+ *
+ * Copyright (c) 2021 Linaro Limited
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 or
+ *  (at your option) any later version.
+ */
+
+/*
+ * This is a model of the RAS register block of an M-profile CPU
+ * (the registers starting at 0xE0005000 with ERRFRn).
+ *
+ * QEMU interface:
+ *  + sysbus MMIO region 0: the register bank
+ *
+ * The QEMU implementation currently provides "minimal RAS" only.
+ */
+
+#ifndef HW_MISC_ARMV7M_RAS_H
+#define HW_MISC_ARMV7M_RAS_H
+
+#include "hw/sysbus.h"
+
+#define TYPE_ARMV7M_RAS "armv7m-ras"
+OBJECT_DECLARE_SIMPLE_TYPE(ARMv7MRAS, ARMV7M_RAS)
+
+struct ARMv7MRAS {
+    /*< private >*/
+    SysBusDevice parent_obj;
+
+    /*< public >*/
+    MemoryRegion iomem;
+};
+
+#endif
diff --git a/hw/arm/armv7m.c b/hw/arm/armv7m.c
index 9ce5c30cd5c..8964730d153 100644
--- a/hw/arm/armv7m.c
+++ b/hw/arm/armv7m.c
@@ -231,6 +231,18 @@ static void armv7m_realize(DeviceState *dev, Error **errp)
     memory_region_add_subregion(&s->container, 0xe0000000,
                                 sysbus_mmio_get_region(sbd, 0));
 
+    /* If the CPU has RAS support, create the RAS register block */
+    if (cpu_isar_feature(aa32_ras, s->cpu)) {
+        object_initialize_child(OBJECT(dev), "armv7m-ras",
+                                &s->ras, TYPE_ARMV7M_RAS);
+        sbd = SYS_BUS_DEVICE(&s->ras);
+        if (!sysbus_realize(sbd, errp)) {
+            return;
+        }
+        memory_region_add_subregion_overlap(&s->container, 0xe0005000,
+                                            sysbus_mmio_get_region(sbd, 0), 1);
+    }
+
     for (i = 0; i < ARRAY_SIZE(s->bitband); i++) {
         if (s->enable_bitband) {
             Object *obj = OBJECT(&s->bitband[i]);
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
index 1e7ddcb94cb..a5975592dfa 100644
--- a/hw/intc/armv7m_nvic.c
+++ b/hw/intc/armv7m_nvic.c
@@ -2549,56 +2549,6 @@ static const MemoryRegionOps nvic_systick_ops = {
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
-
-static MemTxResult ras_read(void *opaque, hwaddr addr,
-                            uint64_t *data, unsigned size,
-                            MemTxAttrs attrs)
-{
-    if (attrs.user) {
-        return MEMTX_ERROR;
-    }
-
-    switch (addr) {
-    case 0xe10: /* ERRIIDR */
-        /* architect field = Arm; product/variant/revision 0 */
-        *data = 0x43b;
-        break;
-    case 0xfc8: /* ERRDEVID */
-        /* Minimal RAS: we implement 0 error record indexes */
-        *data = 0;
-        break;
-    default:
-        qemu_log_mask(LOG_UNIMP, "Read RAS register offset 0x%x\n",
-                      (uint32_t)addr);
-        *data = 0;
-        break;
-    }
-    return MEMTX_OK;
-}
-
-static MemTxResult ras_write(void *opaque, hwaddr addr,
-                             uint64_t value, unsigned size,
-                             MemTxAttrs attrs)
-{
-    if (attrs.user) {
-        return MEMTX_ERROR;
-    }
-
-    switch (addr) {
-    default:
-        qemu_log_mask(LOG_UNIMP, "Write to RAS register offset 0x%x\n",
-                      (uint32_t)addr);
-        break;
-    }
-    return MEMTX_OK;
-}
-
-static const MemoryRegionOps ras_ops = {
-    .read_with_attrs = ras_read,
-    .write_with_attrs = ras_write,
-    .endianness = DEVICE_NATIVE_ENDIAN,
-};
-
 /*
  * Unassigned portions of the PPB space are RAZ/WI for privileged
  * accesses, and fault for non-privileged accesses.
@@ -2946,12 +2896,6 @@ static void armv7m_nvic_realize(DeviceState *dev, Error **errp)
                                             &s->systick_ns_mem, 1);
     }
 
-    if (cpu_isar_feature(aa32_ras, s->cpu)) {
-        memory_region_init_io(&s->ras_mem, OBJECT(s),
-                              &ras_ops, s, "nvic_ras", 0x1000);
-        memory_region_add_subregion(&s->container, 0x5000, &s->ras_mem);
-    }
-
     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->container);
 }
 
diff --git a/hw/misc/armv7m_ras.c b/hw/misc/armv7m_ras.c
new file mode 100644
index 00000000000..a2b4f4b8dc8
--- /dev/null
+++ b/hw/misc/armv7m_ras.c
@@ -0,0 +1,93 @@
+/*
+ * Arm M-profile RAS block
+ *
+ * Copyright (c) 2021 Linaro Limited
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 or
+ *  (at your option) any later version.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/misc/armv7m_ras.h"
+#include "qemu/log.h"
+
+static MemTxResult ras_read(void *opaque, hwaddr addr,
+                            uint64_t *data, unsigned size,
+                            MemTxAttrs attrs)
+{
+    if (attrs.user) {
+        return MEMTX_ERROR;
+    }
+
+    switch (addr) {
+    case 0xe10: /* ERRIIDR */
+        /* architect field = Arm; product/variant/revision 0 */
+        *data = 0x43b;
+        break;
+    case 0xfc8: /* ERRDEVID */
+        /* Minimal RAS: we implement 0 error record indexes */
+        *data = 0;
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "Read RAS register offset 0x%x\n",
+                      (uint32_t)addr);
+        *data = 0;
+        break;
+    }
+    return MEMTX_OK;
+}
+
+static MemTxResult ras_write(void *opaque, hwaddr addr,
+                             uint64_t value, unsigned size,
+                             MemTxAttrs attrs)
+{
+    if (attrs.user) {
+        return MEMTX_ERROR;
+    }
+
+    switch (addr) {
+    default:
+        qemu_log_mask(LOG_UNIMP, "Write to RAS register offset 0x%x\n",
+                      (uint32_t)addr);
+        break;
+    }
+    return MEMTX_OK;
+}
+
+static const MemoryRegionOps ras_ops = {
+    .read_with_attrs = ras_read,
+    .write_with_attrs = ras_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+
+static void armv7m_ras_init(Object *obj)
+{
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+    ARMv7MRAS *s = ARMV7M_RAS(obj);
+
+    memory_region_init_io(&s->iomem, obj, &ras_ops,
+                          s, "armv7m-ras", 0x1000);
+    sysbus_init_mmio(sbd, &s->iomem);
+}
+
+static void armv7m_ras_class_init(ObjectClass *klass, void *data)
+{
+    /* This device has no state: no need for vmstate or reset */
+}
+
+static const TypeInfo armv7m_ras_info = {
+    .name = TYPE_ARMV7M_RAS,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(ARMv7MRAS),
+    .instance_init = armv7m_ras_init,
+    .class_init = armv7m_ras_class_init,
+};
+
+static void armv7m_ras_register_types(void)
+{
+    type_register_static(&armv7m_ras_info);
+}
+
+type_init(armv7m_ras_register_types);
diff --git a/MAINTAINERS b/MAINTAINERS
index 37b1a8e4428..3cac393bb48 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -617,6 +617,7 @@ F: hw/intc/gic_internal.h
 F: hw/misc/a9scu.c
 F: hw/misc/arm11scu.c
 F: hw/misc/arm_l2x0.c
+F: hw/misc/armv7m_ras.c
 F: hw/timer/a9gtimer*
 F: hw/timer/arm*
 F: include/hw/arm/arm*.h
@@ -626,6 +627,7 @@ F: include/hw/misc/arm11scu.h
 F: include/hw/timer/a9gtimer.h
 F: include/hw/timer/arm_mptimer.h
 F: include/hw/timer/armv7m_systick.h
+F: include/hw/misc/armv7m_ras.h
 F: tests/qtest/test-arm-mptimer.c
 
 Exynos
diff --git a/hw/misc/meson.build b/hw/misc/meson.build
index a53b849a5a0..3f41a3a5b27 100644
--- a/hw/misc/meson.build
+++ b/hw/misc/meson.build
@@ -17,6 +17,8 @@ softmmu_ss.add(when: 'CONFIG_INTEGRATOR_DEBUG', if_true: files('arm_integrator_d
 softmmu_ss.add(when: 'CONFIG_A9SCU', if_true: files('a9scu.c'))
 softmmu_ss.add(when: 'CONFIG_ARM11SCU', if_true: files('arm11scu.c'))
 
+softmmu_ss.add(when: 'CONFIG_ARM_V7M', if_true: files('armv7m_ras.c'))
+
 # Mac devices
 softmmu_ss.add(when: 'CONFIG_MOS6522', if_true: files('mos6522.c'))
 
-- 
2.20.1