pnv/xive2: Add definition for the ESB cache configuration register

Add basic read/write support for the ESB cache configuration register
on P10. We don't model the ESB cache in qemu so reading/writing the
register won't do anything, but it avoids logging a guest error when
skiboot configures it:

qemu-system-ppc64 -machine powernv10 ... -d guest_errors
      ...
XIVE[0] - VC: invalid read @240
XIVE[0] - VC: invalid write @240

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20230601121331.487207-3-fbarrat@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

hw/intc/pnv_xive2.c

@@ -955,6 +955,10 @@ static uint64_t pnv_xive2_ic_vc_read(void *opaque, hwaddr offset,
         val = xive->vc_regs[reg];
         break;
 
+    case VC_ESBC_CFG:
+        val = xive->vc_regs[reg];
+        break;
+
     /*
      * EAS cache updates (not modeled)
      */
@@ -1046,6 +1050,9 @@ static void pnv_xive2_ic_vc_write(void *opaque, hwaddr offset,
         /* ESB update */
         break;
 
+    case VC_ESBC_CFG:
+        break;
+
     /*
      * EAS cache updates (not modeled)
      */

hw/intc/pnv_xive2_regs.h

@@ -232,6 +232,10 @@
 #define  VC_ESBC_FLUSH_POLL_BLOCK_ID_MASK       PPC_BITMASK(32, 35)
 #define  VC_ESBC_FLUSH_POLL_OFFSET_MASK         PPC_BITMASK(36, 63) /* 28-bit */
 
+/* ESBC configuration */
+#define X_VC_ESBC_CFG                           0x148
+#define VC_ESBC_CFG                             0x240
+
 /* EASC flush control register */
 #define X_VC_EASC_FLUSH_CTRL                    0x160
 #define VC_EASC_FLUSH_CTRL                      0x300