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>

1 files changed, 135 insertions, 0 deletions

diff --git a/hw/ppc/pnv_pnor.c b/hw/ppc/pnv_pnor.c
new file mode 100644
index 0000000000..bfb1e92b03
--- /dev/null
+++ b/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)