pseries: Make the PAPR RTC a qdev device

At present the PAPR RTC isn't a "device" as such - it's accessed only via
firmware/hypervisor calls, and is handled in the sPAPR core code.  This
becomes inconvenient as we extend it in various ways.

This patch makes the PAPR RTC a separate device in the qemu device model.

For now, the only piece of device state - the rtc_offset - is still kept in
the global sPAPREnvironment structure.  That's clearly wrong, but leaving
it to be fixed in a following patch makes for a clearer separation between
the internal re-organization of the device, and the behavioural changes
(because the migration stream format needs to change slightly when the
offset is moved into the device's own state).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>

hw/ppc/spapr.c

@@ -994,6 +994,14 @@ static void spapr_create_nvram(sPAPREnvironment *spapr)
     spapr->nvram = (struct sPAPRNVRAM *)dev;
 }
 
+static void spapr_rtc_create(sPAPREnvironment *spapr)
+{
+    DeviceState *dev = qdev_create(NULL, TYPE_SPAPR_RTC);
+
+    qdev_init_nofail(dev);
+    spapr->rtc = dev;
+}
+
 /* Returns whether we want to use VGA or not */
 static int spapr_vga_init(PCIBus *pci_bus)
 {
@@ -1492,7 +1500,7 @@ static void ppc_spapr_init(MachineState *machine)
     spapr_events_init(spapr);
 
     /* Set up the RTC RTAS interfaces */
-    spapr_rtc_init();
+    spapr_rtc_create(spapr);
 
     /* Set up VIO bus */
     spapr->vio_bus = spapr_vio_bus_init();

hw/ppc/spapr_events.c

@@ -246,7 +246,7 @@ static void spapr_powerdown_req(Notifier *n, void *opaque)
     maina->hdr.section_id = cpu_to_be16(RTAS_LOG_V6_SECTION_ID_MAINA);
     maina->hdr.section_length = cpu_to_be16(sizeof(*maina));
     /* FIXME: section version, subtype and creator id? */
-    spapr_rtc_read(spapr, &tm, NULL);
+    spapr_rtc_read(spapr->rtc, &tm, NULL);
     year = tm.tm_year + 1900;
     maina->creation_date = cpu_to_be32((to_bcd(year / 100) << 24)
                                        | (to_bcd(year % 100) << 16)

hw/ppc/spapr_rtc.c

@@ -30,13 +30,25 @@
 #include "hw/ppc/spapr.h"
 #include "qapi-event.h"
 
+#define SPAPR_RTC(obj) \
+    OBJECT_CHECK(sPAPRRTCState, (obj), TYPE_SPAPR_RTC)
+
+typedef struct sPAPRRTCState sPAPRRTCState;
+struct sPAPRRTCState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+};
+
 #define NSEC_PER_SEC    1000000000LL
 
-void spapr_rtc_read(sPAPREnvironment *spapr, struct tm *tm, uint32_t *ns)
+void spapr_rtc_read(DeviceState *dev, struct tm *tm, uint32_t *ns)
 {
+    sPAPRRTCState *rtc = SPAPR_RTC(dev);
     int64_t host_ns = qemu_clock_get_ns(rtc_clock);
     time_t guest_s;
 
+    assert(rtc);
+
     guest_s = host_ns / NSEC_PER_SEC + spapr->rtc_offset;
 
     if (tm) {
@@ -60,7 +72,12 @@ static void rtas_get_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
         return;
     }
 
-    spapr_rtc_read(spapr, &tm, &ns);
+    if (!spapr->rtc) {
+        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
+        return;
+    }
+
+    spapr_rtc_read(spapr->rtc, &tm, &ns);
 
     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
     rtas_st(rets, 1, tm.tm_year + 1900);
@@ -86,6 +103,11 @@ static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
         return;
     }
 
+    if (!spapr->rtc) {
+        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
+        return;
+    }
+
     tm.tm_year = rtas_ld(args, 0) - 1900;
     tm.tm_mon = rtas_ld(args, 1) - 1;
     tm.tm_mday = rtas_ld(args, 2);
@@ -109,7 +131,7 @@ static void rtas_set_time_of_day(PowerPCCPU *cpu, sPAPREnvironment *spapr,
     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
 }
 
-void spapr_rtc_init(void)
+static void spapr_rtc_realize(DeviceState *dev, Error **errp)
 {
     struct tm tm;
     time_t host_s;
@@ -121,9 +143,30 @@ void spapr_rtc_init(void)
     host_s = mktimegm(&tm);
     rtc_ns = qemu_clock_get_ns(rtc_clock);
     spapr->rtc_offset = host_s - rtc_ns / NSEC_PER_SEC;
+}
+
+static void spapr_rtc_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->realize = spapr_rtc_realize;
 
     spapr_rtas_register(RTAS_GET_TIME_OF_DAY, "get-time-of-day",
                         rtas_get_time_of_day);
     spapr_rtas_register(RTAS_SET_TIME_OF_DAY, "set-time-of-day",
                         rtas_set_time_of_day);
 }
+
+static const TypeInfo spapr_rtc_info = {
+    .name          = TYPE_SPAPR_RTC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(sPAPRRTCState),
+    .class_size = sizeof(XICSStateClass),
+    .class_init    = spapr_rtc_class_init,
+};
+
+static void spapr_rtc_register_types(void)
+{
+    type_register_static(&spapr_rtc_info);
+}
+type_init(spapr_rtc_register_types)

include/hw/ppc/spapr.h

@@ -15,6 +15,7 @@ typedef struct sPAPREnvironment {
     QLIST_HEAD(, sPAPRPHBState) phbs;
     struct sPAPRNVRAM *nvram;
     XICSState *icp;
+    DeviceState *rtc;
 
     hwaddr ram_limit;
     void *htab;
@@ -480,7 +481,9 @@ int spapr_dma_dt(void *fdt, int node_off, const char *propname,
                  uint32_t liobn, uint64_t window, uint32_t size);
 int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname,
                       sPAPRTCETable *tcet);
-void spapr_rtc_init(void);
-void spapr_rtc_read(sPAPREnvironment *spapr, struct tm *tm, uint32_t *ns);
+
+#define TYPE_SPAPR_RTC "spapr-rtc"
+
+void spapr_rtc_read(DeviceState *dev, struct tm *tm, uint32_t *ns);
 
 #endif /* !defined (__HW_SPAPR_H__) */