pnv/xive2: Support ESB Escalation

Add support for XIVE ESB Interrupt Escalation.

Suggested-by: Michael Kowal <kowal@linux.ibm.com>
[This change was taken from a patch provided by Michael Kowal.]
Signed-off-by: Glenn Miles <milesg@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Michael Kowal <kowal@linux.ibm.com>
Reviewed-by: Caleb Schlossin <calebs@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Link: https://lore.kernel.org/qemu-devel/20250512031100.439842-18-npiggin@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

3 files changed, 59 insertions, 17 deletions

diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c
index cca121b..541b052 100644
--- a/hw/intc/xive2.c
+++ b/hw/intc/xive2.c
@@ -1552,18 +1552,39 @@ do_escalation:
         }
     }
 
-    /*
-     * The END trigger becomes an Escalation trigger
-     */
-    xive2_router_end_notify(xrtr,
-                           xive_get_field32(END2_W4_END_BLOCK,     end.w4),
-                           xive_get_field32(END2_W4_ESC_END_INDEX, end.w4),
-                           xive_get_field32(END2_W5_ESC_END_DATA,  end.w5));
+    if (xive2_end_is_escalate_end(&end)) {
+        /*
+         * Perform END Adaptive escalation processing
+         * The END trigger becomes an Escalation trigger
+         */
+        xive2_router_end_notify(xrtr,
+                               xive_get_field32(END2_W4_END_BLOCK,     end.w4),
+                               xive_get_field32(END2_W4_ESC_END_INDEX, end.w4),
+                               xive_get_field32(END2_W5_ESC_END_DATA,  end.w5));
+    } /* end END adaptive escalation */
+
+    else {
+        uint32_t lisn;              /* Logical Interrupt Source Number */
+
+        /*
+         *  Perform ESB escalation processing
+         *      E[N] == 1 --> N
+         *      Req[Block] <- E[ESB_Block]
+         *      Req[Index] <- E[ESB_Index]
+         *      Req[Offset] <- 0x000
+         *      Execute <ESB Store> Req command
+         */
+        lisn = XIVE_EAS(xive_get_field32(END2_W4_END_BLOCK,     end.w4),
+                        xive_get_field32(END2_W4_ESC_END_INDEX, end.w4));
+
+        xive2_notify(xrtr, lisn, true /* pq_checked */);
+    }
+
+    return;
 }
 
-void xive2_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked)
+void xive2_notify(Xive2Router *xrtr , uint32_t lisn, bool pq_checked)
 {
-    Xive2Router *xrtr = XIVE2_ROUTER(xn);
     uint8_t eas_blk = XIVE_EAS_BLOCK(lisn);
     uint32_t eas_idx = XIVE_EAS_INDEX(lisn);
     Xive2Eas eas;
@@ -1606,13 +1627,30 @@ void xive2_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked)
         return;
     }
 
+    /* TODO: add support for EAS resume */
+    if (xive2_eas_is_resume(&eas)) {
+        qemu_log_mask(LOG_UNIMP,
+                      "XIVE: EAS resume processing unimplemented - LISN %x\n",
+                      lisn);
+        return;
+    }
+
     /*
      * The event trigger becomes an END trigger
      */
     xive2_router_end_notify(xrtr,
-                             xive_get_field64(EAS2_END_BLOCK, eas.w),
-                             xive_get_field64(EAS2_END_INDEX, eas.w),
-                             xive_get_field64(EAS2_END_DATA,  eas.w));
+                            xive_get_field64(EAS2_END_BLOCK, eas.w),
+                            xive_get_field64(EAS2_END_INDEX, eas.w),
+                            xive_get_field64(EAS2_END_DATA,  eas.w));
+    return;
+}
+
+void xive2_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked)
+{
+    Xive2Router *xrtr = XIVE2_ROUTER(xn);
+
+    xive2_notify(xrtr, lisn, pq_checked);
+    return;
 }
 
 static const Property xive2_router_properties[] = {
diff --git a/include/hw/ppc/xive2.h b/include/hw/ppc/xive2.h
index 8cdf819..2436ddb 100644
--- a/include/hw/ppc/xive2.h
+++ b/include/hw/ppc/xive2.h
@@ -80,6 +80,7 @@ int xive2_router_write_nvgc(Xive2Router *xrtr, bool crowd,
 uint32_t xive2_router_get_config(Xive2Router *xrtr);
 
 void xive2_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked);
+void xive2_notify(Xive2Router *xrtr, uint32_t lisn, bool pq_checked);
 
 /*
  * XIVE2 Presenter (POWER10)
diff --git a/include/hw/ppc/xive2_regs.h b/include/hw/ppc/xive2_regs.h
index 3c28de8..2c535ec 100644
--- a/include/hw/ppc/xive2_regs.h
+++ b/include/hw/ppc/xive2_regs.h
@@ -39,15 +39,18 @@
 
 typedef struct Xive2Eas {
         uint64_t       w;
-#define EAS2_VALID                 PPC_BIT(0)
-#define EAS2_END_BLOCK             PPC_BITMASK(4, 7) /* Destination EQ block# */
-#define EAS2_END_INDEX             PPC_BITMASK(8, 31) /* Destination EQ index */
-#define EAS2_MASKED                PPC_BIT(32) /* Masked                 */
-#define EAS2_END_DATA              PPC_BITMASK(33, 63) /* written to the EQ */
+#define EAS2_VALID         PPC_BIT(0)
+#define EAS2_QOS           PPC_BIT(1, 2)       /* Quality of Service(unimp) */
+#define EAS2_RESUME        PPC_BIT(3)          /* END Resume(unimp) */
+#define EAS2_END_BLOCK     PPC_BITMASK(4, 7)   /* Destination EQ block# */
+#define EAS2_END_INDEX     PPC_BITMASK(8, 31)  /* Destination EQ index */
+#define EAS2_MASKED        PPC_BIT(32)         /* Masked */
+#define EAS2_END_DATA      PPC_BITMASK(33, 63) /* written to the EQ */
 } Xive2Eas;
 
 #define xive2_eas_is_valid(eas)   (be64_to_cpu((eas)->w) & EAS2_VALID)
 #define xive2_eas_is_masked(eas)  (be64_to_cpu((eas)->w) & EAS2_MASKED)
+#define xive2_eas_is_resume(eas)  (be64_to_cpu((eas)->w) & EAS2_RESUME)
 
 void xive2_eas_pic_print_info(Xive2Eas *eas, uint32_t lisn, GString *buf);