arm: Clean up the GIC implementation

Lots of minor cleaups:
  * Make cached params const
  * Don't serialize params
  * Use AddrRange to represent the distributor and CPU address spaces
  * Store a const AddrRangeList of all PIO ranges

Change-Id: I40a17bc3a38868fb3b8af247790e852cf99ddf1d
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2330
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

2 files changed, 41 insertions, 69 deletions

diff --git a/src/dev/arm/gic_pl390.cc b/src/dev/arm/gic_pl390.cc
index e7dc8e907..f21d5c518 100644
--- a/src/dev/arm/gic_pl390.cc
+++ b/src/dev/arm/gic_pl390.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2013, 2015-2016 ARM Limited
+ * Copyright (c) 2010, 2013, 2015-2017 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -63,8 +63,11 @@ const AddrRange Pl390::GICD_ITARGETSR (0x800, 0xbff);
 const AddrRange Pl390::GICD_ICFGR     (0xc00, 0xcff);
 
 Pl390::Pl390(const Params *p)
-    : BaseGic(p), distAddr(p->dist_addr),
-      cpuAddr(p->cpu_addr), distPioDelay(p->dist_pio_delay),
+    : BaseGic(p),
+      distRange(RangeSize(p->dist_addr, DIST_SIZE)),
+      cpuRange(RangeSize(p->cpu_addr, CPU_SIZE)),
+      addrRanges{distRange, cpuRange},
+      distPioDelay(p->dist_pio_delay),
       cpuPioDelay(p->cpu_pio_delay), intLatency(p->int_latency),
       enabled(false), haveGem5Extensions(p->gem5_extensions),
       itLines(p->it_lines),
@@ -93,12 +96,11 @@ Pl390::Pl390(const Params *p)
 Tick
 Pl390::read(PacketPtr pkt)
 {
+    const Addr addr = pkt->getAddr();
 
-    Addr addr = pkt->getAddr();
-
-    if (addr >= distAddr && addr < distAddr + DIST_SIZE)
+    if (distRange.contains(addr))
         return readDistributor(pkt);
-    else if (addr >= cpuAddr && addr < cpuAddr + CPU_SIZE)
+    else if (cpuRange.contains(addr))
         return readCpu(pkt);
     else
         panic("Read to unknown address %#x\n", pkt->getAddr());
@@ -108,12 +110,11 @@ Pl390::read(PacketPtr pkt)
 Tick
 Pl390::write(PacketPtr pkt)
 {
+    const Addr addr = pkt->getAddr();
 
-    Addr addr = pkt->getAddr();
-
-    if (addr >= distAddr && addr < distAddr + DIST_SIZE)
+    if (distRange.contains(addr))
         return writeDistributor(pkt);
-    else if (addr >= cpuAddr && addr < cpuAddr + CPU_SIZE)
+    else if (cpuRange.contains(addr))
         return writeCpu(pkt);
     else
         panic("Write to unknown address %#x\n", pkt->getAddr());
@@ -122,9 +123,8 @@ Pl390::write(PacketPtr pkt)
 Tick
 Pl390::readDistributor(PacketPtr pkt)
 {
-    Addr daddr = pkt->getAddr() - distAddr;
-
-    ContextID ctx = pkt->req->contextId();
+    const Addr daddr = pkt->getAddr() - distRange.start();
+    const ContextID ctx = pkt->req->contextId();
 
     DPRINTF(GIC, "gic distributor read register %#x\n", daddr);
 
@@ -267,10 +267,10 @@ done:
 Tick
 Pl390::readCpu(PacketPtr pkt)
 {
-    Addr daddr = pkt->getAddr() - cpuAddr;
+    const Addr daddr = pkt->getAddr() - cpuRange.start();
 
     assert(pkt->req->hasContextId());
-    ContextID ctx = pkt->req->contextId();
+    const ContextID ctx = pkt->req->contextId();
     assert(ctx < sys->numRunningContexts());
 
     DPRINTF(GIC, "gic cpu read register %#x cpu context: %d\n", daddr,
@@ -361,10 +361,10 @@ Pl390::readCpu(PacketPtr pkt)
 Tick
 Pl390::writeDistributor(PacketPtr pkt)
 {
-    Addr daddr = pkt->getAddr() - distAddr;
+    const Addr daddr = pkt->getAddr() - distRange.start();
 
     assert(pkt->req->hasContextId());
-    ContextID ctx = pkt->req->contextId();
+    const ContextID ctx = pkt->req->contextId();
 
     uint32_t pkt_data M5_VAR_USED;
     switch (pkt->getSize())
@@ -520,10 +520,10 @@ done:
 Tick
 Pl390::writeCpu(PacketPtr pkt)
 {
-    Addr daddr = pkt->getAddr() - cpuAddr;
+    const Addr daddr = pkt->getAddr() - cpuRange.start();
 
     assert(pkt->req->hasContextId());
-    ContextID ctx = pkt->req->contextId();
+    const ContextID ctx = pkt->req->contextId();
     IAR iar;
 
     DPRINTF(GIC, "gic cpu write register cpu:%d %#x val: %#x\n",
@@ -816,25 +816,12 @@ Pl390::postInt(uint32_t cpu, Tick when)
         eventq->schedule(postIntEvent[cpu], when);
 }
 
-AddrRangeList
-Pl390::getAddrRanges() const
-{
-    AddrRangeList ranges;
-    ranges.push_back(RangeSize(distAddr, DIST_SIZE));
-    ranges.push_back(RangeSize(cpuAddr, CPU_SIZE));
-    return ranges;
-}
-
 
 void
 Pl390::serialize(CheckpointOut &cp) const
 {
     DPRINTF(Checkpoint, "Serializing Arm GIC\n");
 
-    SERIALIZE_SCALAR(distAddr);
-    SERIALIZE_SCALAR(cpuAddr);
-    SERIALIZE_SCALAR(distPioDelay);
-    SERIALIZE_SCALAR(cpuPioDelay);
     SERIALIZE_SCALAR(enabled);
     SERIALIZE_SCALAR(itLines);
     SERIALIZE_ARRAY(intEnabled, INT_BITS_MAX-1);
@@ -887,10 +874,6 @@ Pl390::unserialize(CheckpointIn &cp)
 {
     DPRINTF(Checkpoint, "Unserializing Arm GIC\n");
 
-    UNSERIALIZE_SCALAR(distAddr);
-    UNSERIALIZE_SCALAR(cpuAddr);
-    UNSERIALIZE_SCALAR(distPioDelay);
-    UNSERIALIZE_SCALAR(cpuPioDelay);
     UNSERIALIZE_SCALAR(enabled);
     UNSERIALIZE_SCALAR(itLines);
     UNSERIALIZE_ARRAY(intEnabled, INT_BITS_MAX-1);
diff --git a/src/dev/arm/gic_pl390.hh b/src/dev/arm/gic_pl390.hh
index 7c5511227..533a0f318 100644
--- a/src/dev/arm/gic_pl390.hh
+++ b/src/dev/arm/gic_pl390.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2013, 2015-2016 ARM Limited
+ * Copyright (c) 2010, 2013, 2015-2017 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -122,22 +122,26 @@ class Pl390 : public BaseGic
         Bitfield<12,10> cpu_id;
     EndBitUnion(IAR)
 
-    /** Distributor address GIC listens at */
-    Addr distAddr;
+  protected: /* Params */
+    /** Address range for the distributor interface */
+    const AddrRange distRange;
 
-    /** CPU address GIC listens at */
-    /** @todo is this one per cpu? */
-    Addr cpuAddr;
+    /** Address range for the CPU interfaces */
+    const AddrRange cpuRange;
+
+    /** All address ranges used by this GIC */
+    const AddrRangeList addrRanges;
 
     /** Latency for a distributor operation */
-    Tick distPioDelay;
+    const Tick distPioDelay;
 
     /** Latency for a cpu operation */
-    Tick cpuPioDelay;
+    const Tick cpuPioDelay;
 
     /** Latency for a interrupt to get to CPU */
-    Tick intLatency;
+    const Tick intLatency;
 
+  protected:
     /** Gic enabled */
     bool enabled;
 
@@ -343,11 +347,11 @@ class Pl390 : public BaseGic
     }
     Pl390(const Params *p);
 
-    /** @{ */
-    /** Return the address ranges used by the Gic
-     * This is the distributor address + all cpu addresses
-     */
-    AddrRangeList getAddrRanges() const override;
+    void serialize(CheckpointOut &cp) const override;
+    void unserialize(CheckpointIn &cp) override;
+
+  public: /* PioDevice */
+    AddrRangeList getAddrRanges() const { return addrRanges; }
 
     /** A PIO read to the device, immediately split up into
      * readDistributor() or readCpu()
@@ -358,27 +362,15 @@ class Pl390 : public BaseGic
      * writeDistributor() or writeCpu()
      */
     Tick write(PacketPtr pkt) override;
-    /** @} */
 
-    /** @{ */
-    /** Post an interrupt from a device that is connected to the Gic.
-     * Depending on the configuration, the gic will pass this interrupt
-     * on through to a CPU.
-     * @param number number of interrupt to send */
+  public: /* BaseGic */
     void sendInt(uint32_t number) override;
-
-    /** Interface call for private peripheral interrupts  */
-    void sendPPInt(uint32_t num, uint32_t cpu) override;
-
-    /** Clear an interrupt from a device that is connected to the Gic
-     * Depending on the configuration, the gic may de-assert it's cpu line
-     * @param number number of interrupt to send */
     void clearInt(uint32_t number) override;
 
-    /** Clear a (level-sensitive) PPI */
+    void sendPPInt(uint32_t num, uint32_t cpu) override;
     void clearPPInt(uint32_t num, uint32_t cpu) override;
-    /** @} */
 
+  public: // Test & debug intefaces
     /** @{ */
     /* Various functions fer testing and debugging */
     void driveSPI(uint32_t spi);
@@ -387,9 +379,6 @@ class Pl390 : public BaseGic
     void driveIrqEn(bool state);
     /** @} */
 
-    void serialize(CheckpointOut &cp) const override;
-    void unserialize(CheckpointIn &cp) override;
-
   protected:
     /** Handle a read to the distributor portion of the GIC
      * @param pkt packet to respond to