dev-arm: Add GICv4 extension switch in GICv3

This is currently used only for determining which is the correct
size of redistributors in memory (256KB in GICv4 and 128KB in GICv3)

Change-Id: I2c07005e97167fde03548313c9927176788f31dd
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18391
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/dev/arm/Gic.py

@@ -182,3 +182,5 @@ class Gicv3(BaseGic):
     cpu_max = Param.Unsigned(256,
         "Maximum number of PE. This is affecting the maximum number of "
         "redistributors")
+
+    gicv4 = Param.Bool(True, "GICv4 extension available")

src/dev/arm/gic_v3.cc

@@ -48,12 +48,6 @@ Gicv3::Gicv3(const Params * p)
 void
 Gicv3::init()
 {
-    distRange = RangeSize(params()->dist_addr,
-                          Gicv3Distributor::ADDR_RANGE_SIZE - 1);
-    redistRange = RangeSize(params()->redist_addr,
-        Gicv3Redistributor::ADDR_RANGE_SIZE * sys->numContexts() - 1);
-    addrRanges = {distRange, redistRange};
-    BaseGic::init();
     distributor = new Gicv3Distributor(this, params()->it_lines);
     redistributors.resize(sys->numContexts(), nullptr);
     cpuInterfaces.resize(sys->numContexts(), nullptr);
@@ -68,12 +62,23 @@ Gicv3::init()
         cpuInterfaces[i] = new Gicv3CPUInterface(this, i);
     }
 
+    distRange = RangeSize(params()->dist_addr,
+        Gicv3Distributor::ADDR_RANGE_SIZE - 1);
+
+    redistSize = redistributors[0]->addrRangeSize;
+    redistRange = RangeSize(params()->redist_addr,
+         redistSize * sys->numContexts() - 1);
+
+    addrRanges = {distRange, redistRange};
+
     distributor->init();
 
     for (int i = 0; i < sys->numContexts(); i++) {
         redistributors[i]->init();
         cpuInterfaces[i]->init();
     }
+
+    BaseGic::init();
 }
 
 void
@@ -107,8 +112,8 @@ Gicv3::read(PacketPtr pkt)
     } else if (redistRange.contains(addr)) {
         Addr daddr = addr - redistRange.start();
         uint32_t redistributor_id =
-            daddr / Gicv3Redistributor::ADDR_RANGE_SIZE;
-        daddr = daddr % Gicv3Redistributor::ADDR_RANGE_SIZE;
+            daddr / redistSize;
+        daddr = daddr % redistSize;
         panic_if(redistributor_id >= redistributors.size(),
                  "Invalid redistributor_id!");
         panic_if(!redistributors[redistributor_id], "Redistributor is null!");
@@ -148,8 +153,8 @@ Gicv3::write(PacketPtr pkt)
     } else if (redistRange.contains(addr)) {
         Addr daddr = addr - redistRange.start();
         uint32_t redistributor_id =
-            daddr / Gicv3Redistributor::ADDR_RANGE_SIZE;
-        daddr = daddr % Gicv3Redistributor::ADDR_RANGE_SIZE;
+            daddr / redistSize;
+        daddr = daddr % redistSize;
         panic_if(redistributor_id >= redistributors.size(),
                  "Invalid redistributor_id!");
         panic_if(!redistributors[redistributor_id], "Redistributor is null!");

src/dev/arm/gic_v3.hh

@@ -42,6 +42,7 @@ class Gicv3 : public BaseGic
 {
   protected:
     friend class Gicv3CPUInterface;
+    friend class Gicv3Redistributor;
 
     typedef Gicv3Params Params;
     Gicv3Distributor * distributor;
@@ -50,6 +51,7 @@ class Gicv3 : public BaseGic
     AddrRange distRange;
     AddrRange redistRange;
     AddrRangeList addrRanges;
+    uint64_t redistSize;
 
   public:
 

src/dev/arm/gic_v3_redistributor.cc

@@ -51,7 +51,8 @@ Gicv3Redistributor::Gicv3Redistributor(Gicv3 * gic, uint32_t cpu_id)
       irqPriority(Gicv3::SGI_MAX + Gicv3::PPI_MAX),
       irqConfig(Gicv3::SGI_MAX + Gicv3::PPI_MAX),
       irqGrpmod(Gicv3::SGI_MAX + Gicv3::PPI_MAX),
-      irqNsacr(Gicv3::SGI_MAX + Gicv3::PPI_MAX)
+      irqNsacr(Gicv3::SGI_MAX + Gicv3::PPI_MAX),
+      addrRangeSize(gic->params()->gicv4 ? 0x40000 : 0x20000)
 {
 }
 

src/dev/arm/gic_v3_redistributor.hh

@@ -177,7 +177,7 @@ class Gicv3Redistributor : public Serializable
      * Note this must match with DTB/DTS GIC node definition and boot
      * loader code.
      */
-    static const uint32_t ADDR_RANGE_SIZE = 0x40000;
+    const uint32_t addrRangeSize;
 
     static const uint32_t SMALLEST_LPI_ID = 8192;