ppc/pnv: Add a PNOR model

On a POWERPC PowerNV system, the host firmware is stored in a PNOR
flash chip which contents is mapped on the LPC bus. This model adds a
simple dummy device to map the contents of a block device in the host
address space.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191021131215.3693-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/ppc/Makefile.objs

@@ -9,7 +9,9 @@ obj-$(CONFIG_PSERIES) += spapr_tpm_proxy.o
 obj-$(CONFIG_SPAPR_RNG) +=  spapr_rng.o
 # IBM PowerNV
 obj-$(CONFIG_POWERNV) += pnv.o pnv_xscom.o pnv_core.o pnv_lpc.o pnv_psi.o pnv_occ.o pnv_bmc.o
-obj-$(CONFIG_POWERNV) += pnv_homer.o
+obj-$(CONFIG_POWERNV) += pnv_homer.o pnv_pnor.o
+
+
 ifeq ($(CONFIG_PCI)$(CONFIG_PSERIES)$(CONFIG_LINUX), yyy)
 obj-y += spapr_pci_vfio.o spapr_pci_nvlink2.o
 endif

hw/ppc/pnv.c

@@ -44,6 +44,7 @@
 #include "hw/ppc/xics.h"
 #include "hw/qdev-properties.h"
 #include "hw/ppc/pnv_xscom.h"
+#include "hw/ppc/pnv_pnor.h"
 
 #include "hw/isa/isa.h"
 #include "hw/boards.h"
@@ -633,6 +634,8 @@ static void pnv_init(MachineState *machine)
     long fw_size;
     int i;
     char *chip_typename;
+    DriveInfo *pnor = drive_get(IF_MTD, 0, 0);
+    DeviceState *dev;
 
     /* allocate RAM */
     if (machine->ram_size < (1 * GiB)) {
@@ -644,6 +647,17 @@ static void pnv_init(MachineState *machine)
                                          machine->ram_size);
     memory_region_add_subregion(get_system_memory(), 0, ram);
 
+    /*
+     * Create our simple PNOR device
+     */
+    dev = qdev_create(NULL, TYPE_PNV_PNOR);
+    if (pnor) {
+        qdev_prop_set_drive(dev, "drive", blk_by_legacy_dinfo(pnor),
+                            &error_abort);
+    }
+    qdev_init_nofail(dev);
+    pnv->pnor = PNV_PNOR(dev);
+
     /* load skiboot firmware  */
     if (bios_name == NULL) {
         bios_name = FW_FILE_NAME;

hw/ppc/pnv_pnor.c

@@ -0,0 +1,135 @@
+/*
+ * QEMU PowerNV PNOR simple model
+ *
+ * Copyright (c) 2015-2019, IBM Corporation.
+ *
+ * This code is licensed under the GPL version 2 or later. See the
+ * COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/log.h"
+#include "sysemu/block-backend.h"
+#include "sysemu/blockdev.h"
+#include "hw/loader.h"
+#include "hw/ppc/pnv_pnor.h"
+#include "hw/qdev-properties.h"
+
+static uint64_t pnv_pnor_read(void *opaque, hwaddr addr, unsigned size)
+{
+    PnvPnor *s = PNV_PNOR(opaque);
+    uint64_t ret = 0;
+    int i;
+
+    for (i = 0; i < size; i++) {
+        ret |= (uint64_t) s->storage[addr + i] << (8 * (size - i - 1));
+    }
+
+    return ret;
+}
+
+static void pnv_pnor_update(PnvPnor *s, int offset, int size)
+{
+    int offset_end;
+
+    if (s->blk) {
+        return;
+    }
+
+    offset_end = offset + size;
+    offset = QEMU_ALIGN_DOWN(offset, BDRV_SECTOR_SIZE);
+    offset_end = QEMU_ALIGN_UP(offset_end, BDRV_SECTOR_SIZE);
+
+    blk_pwrite(s->blk, offset, s->storage + offset,
+               offset_end - offset, 0);
+}
+
+static void pnv_pnor_write(void *opaque, hwaddr addr, uint64_t data,
+                           unsigned size)
+{
+    PnvPnor *s = PNV_PNOR(opaque);
+    int i;
+
+    for (i = 0; i < size; i++) {
+        s->storage[addr + i] = (data >> (8 * (size - i - 1))) & 0xFF;
+    }
+    pnv_pnor_update(s, addr, size);
+}
+
+/*
+ * TODO: Check endianness: skiboot is BIG, Aspeed AHB is LITTLE, flash
+ * is BIG.
+ */
+static const MemoryRegionOps pnv_pnor_ops = {
+    .read = pnv_pnor_read,
+    .write = pnv_pnor_write,
+    .endianness = DEVICE_BIG_ENDIAN,
+    .valid = {
+        .min_access_size = 1,
+        .max_access_size = 4,
+    },
+};
+
+static void pnv_pnor_realize(DeviceState *dev, Error **errp)
+{
+    PnvPnor *s = PNV_PNOR(dev);
+    int ret;
+
+    if (s->blk) {
+        uint64_t perm = BLK_PERM_CONSISTENT_READ |
+                        (blk_is_read_only(s->blk) ? 0 : BLK_PERM_WRITE);
+        ret = blk_set_perm(s->blk, perm, BLK_PERM_ALL, errp);
+        if (ret < 0) {
+            return;
+        }
+
+        s->size = blk_getlength(s->blk);
+        if (s->size <= 0) {
+            error_setg(errp, "failed to get flash size");
+            return;
+        }
+
+        s->storage = blk_blockalign(s->blk, s->size);
+
+        if (blk_pread(s->blk, 0, s->storage, s->size) != s->size) {
+            error_setg(errp, "failed to read the initial flash content");
+            return;
+        }
+    } else {
+        s->storage = blk_blockalign(NULL, s->size);
+        memset(s->storage, 0xFF, s->size);
+    }
+
+    memory_region_init_io(&s->mmio, OBJECT(s), &pnv_pnor_ops, s,
+                          TYPE_PNV_PNOR, s->size);
+}
+
+static Property pnv_pnor_properties[] = {
+    DEFINE_PROP_UINT32("size", PnvPnor, size, 128 << 20),
+    DEFINE_PROP_DRIVE("drive", PnvPnor, blk),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void pnv_pnor_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = pnv_pnor_realize;
+    dc->props = pnv_pnor_properties;
+}
+
+static const TypeInfo pnv_pnor_info = {
+    .name          = TYPE_PNV_PNOR,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(PnvPnor),
+    .class_init    = pnv_pnor_class_init,
+};
+
+static void pnv_pnor_register_types(void)
+{
+    type_register_static(&pnv_pnor_info);
+}
+
+type_init(pnv_pnor_register_types)

include/hw/ppc/pnv.h

@@ -24,6 +24,7 @@
 #include "hw/sysbus.h"
 #include "hw/ipmi/ipmi.h"
 #include "hw/ppc/pnv_lpc.h"
+#include "hw/ppc/pnv_pnor.h"
 #include "hw/ppc/pnv_psi.h"
 #include "hw/ppc/pnv_occ.h"
 #include "hw/ppc/pnv_homer.h"
@@ -175,6 +176,8 @@ typedef struct PnvMachineState {
 
     IPMIBmc      *bmc;
     Notifier     powerdown_notifier;
+
+    PnvPnor      *pnor;
 } PnvMachineState;
 
 static inline bool pnv_chip_is_power9(const PnvChip *chip)

include/hw/ppc/pnv_pnor.h

@@ -0,0 +1,25 @@
+/*
+ * QEMU PowerNV PNOR simple model
+ *
+ * Copyright (c) 2019, IBM Corporation.
+ *
+ * This code is licensed under the GPL version 2 or later. See the
+ * COPYING file in the top-level directory.
+ */
+#ifndef _PPC_PNV_PNOR_H
+#define _PPC_PNV_PNOR_H
+
+#define TYPE_PNV_PNOR  "pnv-pnor"
+#define PNV_PNOR(obj)  OBJECT_CHECK(PnvPnor, (obj), TYPE_PNV_PNOR)
+
+typedef struct PnvPnor {
+    SysBusDevice   parent_obj;
+
+    BlockBackend   *blk;
+
+    uint8_t        *storage;
+    uint32_t       size;
+    MemoryRegion   mmio;
+} PnvPnor;
+
+#endif /* _PPC_PNV_PNOR_H */