[Qemu-devel] [PATCH v2 06/17] ppc/xive: Provide unconditional escalation support

["Cédric Le Goater" <clg@kaod.org>]

When the 'u' bit is set the escalation is said to be 'unconditional'
which means that the ESe PQ bits are not used. Introduce a
xive_router_end_es_notify() routine to share code with the ESn
notification.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 include/hw/ppc/xive_regs.h |  2 ++
 hw/intc/xive.c             | 44 ++++++++++++++++++++++++++++++--------
 2 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/include/hw/ppc/xive_regs.h b/include/hw/ppc/xive_regs.h
index 1a8c5b5e64f0..5d02ccfeff16 100644
--- a/include/hw/ppc/xive_regs.h
+++ b/include/hw/ppc/xive_regs.h
@@ -207,6 +207,8 @@ typedef struct XiveEND {
 #define xive_end_is_notify(end)   (be32_to_cpu((end)->w0) & END_W0_UCOND_NOTIFY)
 #define xive_end_is_backlog(end)  (be32_to_cpu((end)->w0) & END_W0_BACKLOG)
 #define xive_end_is_escalate(end) (be32_to_cpu((end)->w0) & END_W0_ESCALATE_CTL)
+#define xive_end_is_uncond_escalation(end)              \
+    (be32_to_cpu((end)->w0) & END_W0_UNCOND_ESCALATE)
 
 static inline uint64_t xive_end_qaddr(XiveEND *end)
 {
diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index 89a09dde060b..c2e7e2d4c9a9 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -1407,6 +1407,27 @@ static bool xive_presenter_notify(XiveRouter *xrtr, uint8_t format,
     return found;
 }
 
+/*
+ * Notification using the END ESe/ESn bit (Event State Buffer for
+ * escalation and notification). Profide futher coalescing in the
+ * Router.
+ */
+static bool xive_router_end_es_notify(XiveRouter *xrtr, uint8_t end_blk,
+                                      uint32_t end_idx, XiveEND *end,
+                                      uint32_t end_esmask)
+{
+    uint8_t pq = xive_get_field32(end_esmask, end->w1);
+    bool notify = xive_esb_trigger(&pq);
+
+    if (pq != xive_get_field32(end_esmask, end->w1)) {
+        end->w1 = xive_set_field32(end_esmask, end->w1, pq);
+        xive_router_write_end(xrtr, end_blk, end_idx, end, 1);
+    }
+
+    /* ESe/n[Q]=1 : end of notification */
+    return notify;
+}
+
 /*
  * An END trigger can come from an event trigger (IPI or HW) or from
  * another chip. We don't model the PowerBus but the END trigger
@@ -1463,16 +1484,9 @@ static void xive_router_end_notify(XiveRouter *xrtr, uint8_t end_blk,
      * even futher coalescing in the Router
      */
     if (!xive_end_is_notify(&end)) {
-        uint8_t pq = xive_get_field32(END_W1_ESn, end.w1);
-        bool notify = xive_esb_trigger(&pq);
-
-        if (pq != xive_get_field32(END_W1_ESn, end.w1)) {
-            end.w1 = xive_set_field32(END_W1_ESn, end.w1, pq);
-            xive_router_write_end(xrtr, end_blk, end_idx, &end, 1);
-        }
-
         /* ESn[Q]=1 : end of notification */
-        if (!notify) {
+        if (!xive_router_end_es_notify(xrtr, end_blk, end_idx,
+                                       &end, END_W1_ESn)) {
             return;
         }
     }
@@ -1536,6 +1550,18 @@ static void xive_router_end_notify(XiveRouter *xrtr, uint8_t end_blk,
         return;
     }
 
+    /*
+     * Check the END ESe (Event State Buffer for escalation) for even
+     * futher coalescing in the Router
+     */
+    if (!xive_end_is_uncond_escalation(&end)) {
+        /* ESe[Q]=1 : end of notification */
+        if (!xive_router_end_es_notify(xrtr, end_blk, end_idx,
+                                       &end, END_W1_ESe)) {
+            return;
+        }
+    }
+
     /*
      * The END trigger becomes an Escalation trigger
      */
-- 
2.21.0