hw/intc: GICv3 ITS Feature enablement

Added properties to enable ITS feature and define qemu system
address space memory in gicv3 common,setup distributor and
redistributor registers to indicate LPI support.

Signed-off-by: Shashi Mallela <shashi.mallela@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Message-id: 20210910143951.92242-6-shashi.mallela@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/intc/arm_gicv3_common.c

@@ -345,6 +345,11 @@ static void arm_gicv3_common_realize(DeviceState *dev, Error **errp)
         return;
     }
 
+    if (s->lpi_enable && !s->dma) {
+        error_setg(errp, "Redist-ITS: Guest 'sysmem' reference link not set");
+        return;
+    }
+
     s->cpu = g_new0(GICv3CPUState, s->num_cpu);
 
     for (i = 0; i < s->num_cpu; i++) {
@@ -381,6 +386,10 @@ static void arm_gicv3_common_realize(DeviceState *dev, Error **errp)
             (1 << 24) |
             (i << 8) |
             (last << 4);
+
+        if (s->lpi_enable) {
+            s->cpu[i].gicr_typer |= GICR_TYPER_PLPIS;
+        }
     }
 }
 
@@ -494,9 +503,12 @@ static Property arm_gicv3_common_properties[] = {
     DEFINE_PROP_UINT32("num-cpu", GICv3State, num_cpu, 1),
     DEFINE_PROP_UINT32("num-irq", GICv3State, num_irq, 32),
     DEFINE_PROP_UINT32("revision", GICv3State, revision, 3),
+    DEFINE_PROP_BOOL("has-lpi", GICv3State, lpi_enable, 0),
     DEFINE_PROP_BOOL("has-security-extensions", GICv3State, security_extn, 0),
     DEFINE_PROP_ARRAY("redist-region-count", GICv3State, nb_redist_regions,
                       redist_region_count, qdev_prop_uint32, uint32_t),
+    DEFINE_PROP_LINK("sysmem", GICv3State, dma, TYPE_MEMORY_REGION,
+                     MemoryRegion *),
     DEFINE_PROP_END_OF_LIST(),
 };
 

hw/intc/arm_gicv3_dist.c

@@ -384,7 +384,9 @@ static bool gicd_readl(GICv3State *s, hwaddr offset,
          * A3V == 1 (non-zero values of Affinity level 3 supported)
          * IDbits == 0xf (we support 16-bit interrupt identifiers)
          * DVIS == 0 (Direct virtual LPI injection not supported)
-         * LPIS == 0 (LPIs not supported)
+         * LPIS == 1 (LPIs are supported if affinity routing is enabled)
+         * num_LPIs == 0b00000 (bits [15:11],Number of LPIs as indicated
+         *                      by GICD_TYPER.IDbits)
          * MBIS == 0 (message-based SPIs not supported)
          * SecurityExtn == 1 if security extns supported
          * CPUNumber == 0 since for us ARE is always 1
@@ -399,6 +401,7 @@ static bool gicd_readl(GICv3State *s, hwaddr offset,
         bool sec_extn = !(s->gicd_ctlr & GICD_CTLR_DS);
 
         *data = (1 << 25) | (1 << 24) | (sec_extn << 10) |
+            (s->lpi_enable << GICD_TYPER_LPIS_SHIFT) |
             (0xf << 19) | itlinesnumber;
         return true;
     }

hw/intc/arm_gicv3_redist.c

@@ -248,10 +248,16 @@ static MemTxResult gicr_writel(GICv3CPUState *cs, hwaddr offset,
     case GICR_CTLR:
         /* For our implementation, GICR_TYPER.DPGS is 0 and so all
          * the DPG bits are RAZ/WI. We don't do anything asynchronously,
-         * so UWP and RWP are RAZ/WI. And GICR_TYPER.LPIS is 0 (we don't
+         * so UWP and RWP are RAZ/WI. GICR_TYPER.LPIS is 1 (we
-         * implement LPIs) so Enable_LPIs is RES0. So there are no writable
+         * implement LPIs) so Enable_LPIs is programmable.
-         * bits for us.
          */
+        if (cs->gicr_typer & GICR_TYPER_PLPIS) {
+            if (value & GICR_CTLR_ENABLE_LPIS) {
+                cs->gicr_ctlr |= GICR_CTLR_ENABLE_LPIS;
+            } else {
+                cs->gicr_ctlr &= ~GICR_CTLR_ENABLE_LPIS;
+            }
+        }
         return MEMTX_OK;
     case GICR_STATUSR:
         /* RAZ/WI for our implementation */

hw/intc/gicv3_internal.h

@@ -68,6 +68,8 @@
 #define GICD_CTLR_E1NWF             (1U << 7)
 #define GICD_CTLR_RWP               (1U << 31)
 
+#define GICD_TYPER_LPIS_SHIFT          17
+
 /* 16 bits EventId */
 #define GICD_TYPER_IDBITS            0xf
 

include/hw/intc/arm_gicv3_common.h

@@ -221,6 +221,7 @@ struct GICv3State {
     uint32_t num_cpu;
     uint32_t num_irq;
     uint32_t revision;
+    bool lpi_enable;
     bool security_extn;
     bool irq_reset_nonsecure;
     bool gicd_no_migration_shift_bug;