hw/{misc, riscv}: pfsoc: add system controller as unimplemented

The system controller on PolarFire SoC is access via a mailbox. The
control registers for this mailbox lie in the "IOSCB" region & the
interrupt is cleared via write to the "SYSREG" region. It also has a
QSPI controller, usually connected to a flash chip, that is used for
storing FPGA bitstreams and used for In-Application Programming (IAP).

Linux has an implementation of the system controller, through which the
hwrng is accessed, leading to load/store access faults.

Add the QSPI as unimplemented and a very basic (effectively
unimplemented) version of the system controller's mailbox. Rather than
purely marking the regions as unimplemented, service the mailbox
requests by reporting failures and raising the interrupt so a guest can
better handle the lack of support.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221117225518.4102575-4-conor@kernel.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

2 files changed, 84 insertions, 6 deletions

diff --git a/hw/misc/mchp_pfsoc_ioscb.c b/hw/misc/mchp_pfsoc_ioscb.c
index f976e42..a71d134 100644
--- a/hw/misc/mchp_pfsoc_ioscb.c
+++ b/hw/misc/mchp_pfsoc_ioscb.c
@@ -24,6 +24,7 @@
 #include "qemu/bitops.h"
 #include "qemu/log.h"
 #include "qapi/error.h"
+#include "hw/irq.h"
 #include "hw/sysbus.h"
 #include "hw/misc/mchp_pfsoc_ioscb.h"
 
@@ -34,6 +35,9 @@
 #define IOSCB_WHOLE_REG_SIZE        0x10000000
 #define IOSCB_SUBMOD_REG_SIZE       0x1000
 #define IOSCB_CCC_REG_SIZE          0x2000000
+#define IOSCB_CTRL_REG_SIZE         0x800
+#define IOSCB_QSPIXIP_REG_SIZE      0x200
+
 
 /*
  * There are many sub-modules in the IOSCB module.
@@ -45,6 +49,8 @@
 #define IOSCB_LANE01_BASE           0x06500000
 #define IOSCB_LANE23_BASE           0x06510000
 #define IOSCB_CTRL_BASE             0x07020000
+#define IOSCB_QSPIXIP_BASE          0x07020100
+#define IOSCB_MAILBOX_BASE          0x07020800
 #define IOSCB_CFG_BASE              0x07080000
 #define IOSCB_CCC_BASE              0x08000000
 #define IOSCB_PLL_MSS_BASE          0x0E001000
@@ -143,6 +149,58 @@ static const MemoryRegionOps mchp_pfsoc_io_calib_ddr_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
+#define SERVICES_CR             0x50
+#define SERVICES_SR             0x54
+#define SERVICES_STATUS_SHIFT   16
+
+static uint64_t mchp_pfsoc_ctrl_read(void *opaque, hwaddr offset,
+                                     unsigned size)
+{
+    uint32_t val = 0;
+
+    switch (offset) {
+    case SERVICES_SR:
+        /*
+         * Although some services have no error codes, most do. All services
+         * that do implement errors, begin their error codes at 1. Treat all
+         * service requests as failures & return 1.
+         * See the "PolarFire® FPGA and PolarFire SoC FPGA System Services"
+         * user guide for more information on service error codes.
+         */
+        val = 1u << SERVICES_STATUS_SHIFT;
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "%s: unimplemented device read "
+                      "(size %d, offset 0x%" HWADDR_PRIx ")\n",
+                      __func__, size, offset);
+    }
+
+    return val;
+}
+
+static void mchp_pfsoc_ctrl_write(void *opaque, hwaddr offset,
+                                  uint64_t value, unsigned size)
+{
+    MchpPfSoCIoscbState *s = opaque;
+
+    switch (offset) {
+    case SERVICES_CR:
+        qemu_irq_raise(s->irq);
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "%s: unimplemented device write "
+                      "(size %d, value 0x%" PRIx64
+                      ", offset 0x%" HWADDR_PRIx ")\n",
+                      __func__, size, value, offset);
+    }
+}
+
+static const MemoryRegionOps mchp_pfsoc_ctrl_ops = {
+    .read = mchp_pfsoc_ctrl_read,
+    .write = mchp_pfsoc_ctrl_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 static void mchp_pfsoc_ioscb_realize(DeviceState *dev, Error **errp)
 {
     MchpPfSoCIoscbState *s = MCHP_PFSOC_IOSCB(dev);
@@ -162,10 +220,18 @@ static void mchp_pfsoc_ioscb_realize(DeviceState *dev, Error **errp)
                           "mchp.pfsoc.ioscb.lane23", IOSCB_SUBMOD_REG_SIZE);
     memory_region_add_subregion(&s->container, IOSCB_LANE23_BASE, &s->lane23);
 
-    memory_region_init_io(&s->ctrl, OBJECT(s), &mchp_pfsoc_dummy_ops, s,
-                          "mchp.pfsoc.ioscb.ctrl", IOSCB_SUBMOD_REG_SIZE);
+    memory_region_init_io(&s->ctrl, OBJECT(s), &mchp_pfsoc_ctrl_ops, s,
+                          "mchp.pfsoc.ioscb.ctrl", IOSCB_CTRL_REG_SIZE);
     memory_region_add_subregion(&s->container, IOSCB_CTRL_BASE, &s->ctrl);
 
+    memory_region_init_io(&s->qspixip, OBJECT(s), &mchp_pfsoc_dummy_ops, s,
+                          "mchp.pfsoc.ioscb.qspixip", IOSCB_QSPIXIP_REG_SIZE);
+    memory_region_add_subregion(&s->container, IOSCB_QSPIXIP_BASE, &s->qspixip);
+
+    memory_region_init_io(&s->mailbox, OBJECT(s), &mchp_pfsoc_dummy_ops, s,
+                          "mchp.pfsoc.ioscb.mailbox", IOSCB_SUBMOD_REG_SIZE);
+    memory_region_add_subregion(&s->container, IOSCB_MAILBOX_BASE, &s->mailbox);
+
     memory_region_init_io(&s->cfg, OBJECT(s), &mchp_pfsoc_dummy_ops, s,
                           "mchp.pfsoc.ioscb.cfg", IOSCB_SUBMOD_REG_SIZE);
     memory_region_add_subregion(&s->container, IOSCB_CFG_BASE, &s->cfg);
@@ -222,6 +288,8 @@ static void mchp_pfsoc_ioscb_realize(DeviceState *dev, Error **errp)
                           IOSCB_SUBMOD_REG_SIZE);
     memory_region_add_subregion(&s->container, IOSCB_IO_CALIB_SGMII_BASE,
                                 &s->io_calib_sgmii);
+
+    sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
 }
 
 static void mchp_pfsoc_ioscb_class_init(ObjectClass *klass, void *data)
diff --git a/hw/misc/mchp_pfsoc_sysreg.c b/hw/misc/mchp_pfsoc_sysreg.c
index 89571ed..7876fe0 100644
--- a/hw/misc/mchp_pfsoc_sysreg.c
+++ b/hw/misc/mchp_pfsoc_sysreg.c
@@ -24,10 +24,12 @@
 #include "qemu/bitops.h"
 #include "qemu/log.h"
 #include "qapi/error.h"
+#include "hw/irq.h"
 #include "hw/sysbus.h"
 #include "hw/misc/mchp_pfsoc_sysreg.h"
 
 #define ENVM_CR         0xb8
+#define MESSAGE_INT     0x118c
 
 static uint64_t mchp_pfsoc_sysreg_read(void *opaque, hwaddr offset,
                                        unsigned size)
@@ -52,10 +54,17 @@ static uint64_t mchp_pfsoc_sysreg_read(void *opaque, hwaddr offset,
 static void mchp_pfsoc_sysreg_write(void *opaque, hwaddr offset,
                                     uint64_t value, unsigned size)
 {
-    qemu_log_mask(LOG_UNIMP, "%s: unimplemented device write "
-                  "(size %d, value 0x%" PRIx64
-                  ", offset 0x%" HWADDR_PRIx ")\n",
-                  __func__, size, value, offset);
+    MchpPfSoCSysregState *s = opaque;
+    switch (offset) {
+    case MESSAGE_INT:
+        qemu_irq_lower(s->irq);
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "%s: unimplemented device write "
+                      "(size %d, value 0x%" PRIx64
+                      ", offset 0x%" HWADDR_PRIx ")\n",
+                      __func__, size, value, offset);
+    }
 }
 
 static const MemoryRegionOps mchp_pfsoc_sysreg_ops = {
@@ -73,6 +82,7 @@ static void mchp_pfsoc_sysreg_realize(DeviceState *dev, Error **errp)
                           "mchp.pfsoc.sysreg",
                           MCHP_PFSOC_SYSREG_REG_SIZE);
     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->sysreg);
+    sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
 }
 
 static void mchp_pfsoc_sysreg_class_init(ObjectClass *klass, void *data)