ppc/xive: Introduce a xive_tctx_ipb_update() helper

We will use it to resend missed interrupts when a vCPU context is
pushed on a HW thread.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191125065820.927-17-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/intc/xive.c

@@ -47,12 +47,6 @@ static uint8_t ipb_to_pipr(uint8_t ibp)
     return ibp ? clz32((uint32_t)ibp << 24) : 0xff;
 }
 
-static void ipb_update(uint8_t *regs, uint8_t priority)
-{
-    regs[TM_IPB] |= priority_to_ipb(priority);
-    regs[TM_PIPR] = ipb_to_pipr(regs[TM_IPB]);
-}
-
 static uint8_t exception_mask(uint8_t ring)
 {
     switch (ring) {
@@ -135,6 +129,15 @@ static void xive_tctx_set_cppr(XiveTCTX *tctx, uint8_t ring, uint8_t cppr)
     xive_tctx_notify(tctx, ring);
 }
 
+void xive_tctx_ipb_update(XiveTCTX *tctx, uint8_t ring, uint8_t ipb)
+{
+    uint8_t *regs = &tctx->regs[ring];
+
+    regs[TM_IPB] |= ipb;
+    regs[TM_PIPR] = ipb_to_pipr(regs[TM_IPB]);
+    xive_tctx_notify(tctx, ring);
+}
+
 static inline uint32_t xive_tctx_word2(uint8_t *ring)
 {
     return *((uint32_t *) &ring[TM_WORD2]);
@@ -336,8 +339,7 @@ static void xive_tm_set_os_cppr(XivePresenter *xptr, XiveTCTX *tctx,
 static void xive_tm_set_os_pending(XivePresenter *xptr, XiveTCTX *tctx,
                                    hwaddr offset, uint64_t value, unsigned size)
 {
-    ipb_update(&tctx->regs[TM_QW1_OS], value & 0xff);
-    xive_tctx_notify(tctx, TM_QW1_OS);
+    xive_tctx_ipb_update(tctx, TM_QW1_OS, priority_to_ipb(value & 0xff));
 }
 
 static void xive_os_cam_decode(uint32_t cam, uint8_t *nvt_blk,
@@ -1429,8 +1431,7 @@ static bool xive_presenter_notify(uint8_t format,
 
     /* handle CPU exception delivery */
     if (count) {
-        ipb_update(&match.tctx->regs[match.ring], priority);
-        xive_tctx_notify(match.tctx, match.ring);
+        xive_tctx_ipb_update(match.tctx, match.ring, priority_to_ipb(priority));
     }
 
     return !!count;

include/hw/ppc/xive.h

@@ -469,6 +469,7 @@ void xive_tctx_pic_print_info(XiveTCTX *tctx, Monitor *mon);
 Object *xive_tctx_create(Object *cpu, XiveRouter *xrtr, Error **errp);
 void xive_tctx_reset(XiveTCTX *tctx);
 void xive_tctx_destroy(XiveTCTX *tctx);
+void xive_tctx_ipb_update(XiveTCTX *tctx, uint8_t ring, uint8_t ipb);
 
 /*
  * KVM XIVE device helpers