[Qemu-ppc] [PATCH v4 07/20] ppc/pnv: add XSCOM handlers to PnvCore

[Cédric Le Goater]

Now that we are using real HW ids for the cores in PowerNV chips, we
can route the XSCOM accesses to them. We just need to attach a
specific XSCOM memory region to each core in the appropriate window
for the core number.

To start with, let's install the DTS (Digital Thermal Sensor) handlers
which should return 38°C for each core.

Signed-off-by: Cédric Le Goater <address@hidden>
---

 Changes since v3:

 - moved to new XSCOM model
 - kept the write op on the XSCOM memory region for later use

 Changes since v2:

 - added a XSCOM memory region to handle access to the EX core
   registers   
 - extended the PnvCore object with a XSCOM_INTERFACE so that we can
   use pnv_xscom_pcba() and pnv_xscom_addr() to handle XSCOM address
   translation.

 hw/ppc/pnv.c               |  4 ++++
 hw/ppc/pnv_core.c          | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/pnv_core.h  |  2 ++
 include/hw/ppc/pnv_xscom.h | 19 ++++++++++++++++++
 4 files changed, 75 insertions(+)

diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 5e19b6880387..ffe245fe59d2 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -620,6 +620,10 @@ static void pnv_chip_realize(DeviceState *dev, Error 
**errp)
                                  &error_fatal);
         object_unref(OBJECT(pnv_core));
         i++;
+
+        memory_region_add_subregion(&chip->xscom,
+                         PNV_XSCOM_EX_CORE_BASE(core_hwid) << 3,
+                         &PNV_CORE(pnv_core)->xscom_regs);
     }
     g_free(typename);
 }
diff --git a/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c
index d37788f142f4..a1c8a14f06b6 100644
--- a/hw/ppc/pnv_core.c
+++ b/hw/ppc/pnv_core.c
@@ -19,6 +19,7 @@
 #include "qemu/osdep.h"
 #include "sysemu/sysemu.h"
 #include "qapi/error.h"
+#include "qemu/log.h"
 #include "target-ppc/cpu.h"
 #include "hw/ppc/ppc.h"
 #include "hw/ppc/pnv.h"
@@ -64,6 +65,51 @@ static void powernv_cpu_init(PowerPCCPU *cpu, Error **errp)
     powernv_cpu_reset(cpu);
 }
 
+/*
+ * These values are read by the PowerNV HW monitors under Linux
+ */
+#define PNV_XSCOM_EX_DTS_RESULT0     0x50000
+#define PNV_XSCOM_EX_DTS_RESULT1     0x50001
+
+static uint64_t pnv_core_xscom_read(void *opaque, hwaddr addr,
+                                    unsigned int width)
+{
+    uint32_t offset = addr >> 3;
+    uint64_t val = 0;
+
+    /* The result should be 38 C */
+    switch (offset) {
+    case PNV_XSCOM_EX_DTS_RESULT0:
+        val = 0x26f024f023f0000ull;
+        break;
+    case PNV_XSCOM_EX_DTS_RESULT1:
+        val = 0x24f000000000000ull;
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "Warning: reading reg=0x%" HWADDR_PRIx,
+                  addr);
+    }
+
+    return val;
+}
+
+static void pnv_core_xscom_write(void *opaque, hwaddr addr, uint64_t val,
+                                 unsigned int width)
+{
+    qemu_log_mask(LOG_UNIMP, "Warning: writing to reg=0x%" HWADDR_PRIx,
+                  addr);
+}
+
+static const MemoryRegionOps pnv_core_xscom_ops = {
+    .read = pnv_core_xscom_read,
+    .write = pnv_core_xscom_write,
+    .valid.min_access_size = 8,
+    .valid.max_access_size = 8,
+    .impl.min_access_size = 8,
+    .impl.max_access_size = 8,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
 static void pnv_core_realize_child(Object *child, Error **errp)
 {
     Error *local_err = NULL;
@@ -119,6 +165,10 @@ static void pnv_core_realize(DeviceState *dev, Error 
**errp)
             goto err;
         }
     }
+
+    snprintf(name, sizeof(name), "xscom-core.%d", cc->core_id);
+    memory_region_init_io(&pc->xscom_regs, OBJECT(dev), &pnv_core_xscom_ops,
+                          pc, name,  PNV_XSCOM_EX_CORE_SIZE << 3);
     return;
 
 err:
diff --git a/include/hw/ppc/pnv_core.h b/include/hw/ppc/pnv_core.h
index a151e281c017..2955a41c901f 100644
--- a/include/hw/ppc/pnv_core.h
+++ b/include/hw/ppc/pnv_core.h
@@ -36,6 +36,8 @@ typedef struct PnvCore {
     /*< public >*/
     void *threads;
     uint32_t pir;
+
+    MemoryRegion xscom_regs;
 } PnvCore;
 
 typedef struct PnvCoreClass {
diff --git a/include/hw/ppc/pnv_xscom.h b/include/hw/ppc/pnv_xscom.h
index f50eb0bc4099..79975a6cbe46 100644
--- a/include/hw/ppc/pnv_xscom.h
+++ b/include/hw/ppc/pnv_xscom.h
@@ -41,6 +41,25 @@ typedef struct PnvXScomInterfaceClass {
     int (*populate)(PnvXScomInterface *dev, void *fdt, int offset);
 } PnvXScomInterfaceClass;
 
+/*
+ * Layout of the XSCOM PCB addresses of EX core 1
+ *
+ *   GPIO        0x1100xxxx
+ *   SCOM        0x1101xxxx
+ *   OHA         0x1102xxxx
+ *   CLOCK CTL   0x1103xxxx
+ *   FIR         0x1104xxxx
+ *   THERM       0x1105xxxx
+ *   <reserved>  0x1106xxxx
+ *               ..
+ *               0x110Exxxx
+ *   PCB SLAVE   0x110Fxxxx
+ */
+
+#define PNV_XSCOM_EX_BASE         0x10000000
+#define PNV_XSCOM_EX_CORE_BASE(i) (PNV_XSCOM_EX_BASE | (((uint64_t)i) << 24))
+#define PNV_XSCOM_EX_CORE_SIZE    0x100000
+
 extern void pnv_xscom_realize(PnvChip *chip, Error **errp);
 extern int pnv_xscom_populate(PnvChip *chip, void *fdt, int offset);
 
-- 
2.7.4