Merge remote-tracking branch 'remotes/alistair/tags/pull-riscv-to-apply-20200702-1' into staging

This PR contains two patches to improve PLIC support in QEMU.

It also contains one patch that fixes CLINT accesses for RISC-V. This
fixes a regression for most RISC-V boards.

The rest of the PR is adding support for the v0.7.1 RISC-V vector
extensions. This is experimental support as the vector extensions are
still in a draft state.

This is a v2 pull request that has fixed the building on big endian
machines failure.

# gpg: Signature made Thu 02 Jul 2020 17:21:54 BST
# gpg:                using RSA key F6C4AC46D4934868D3B8CE8F21E10D29DF977054
# gpg: Good signature from "Alistair Francis <alistair@alistair23.me>" [full]
# Primary key fingerprint: F6C4 AC46 D493 4868 D3B8  CE8F 21E1 0D29 DF97 7054

* remotes/alistair/tags/pull-riscv-to-apply-20200702-1: (64 commits)
  target/riscv: configure and turn on vector extension from command line
  target/riscv: vector compress instruction
  target/riscv: vector register gather instruction
  target/riscv: vector slide instructions
  target/riscv: floating-point scalar move instructions
  target/riscv: integer scalar move instruction
  target/riscv: integer extract instruction
  target/riscv: vector element index instruction
  target/riscv: vector iota instruction
  target/riscv: set-X-first mask bit
  target/riscv: vmfirst find-first-set mask bit
  target/riscv: vector mask population count vmpopc
  target/riscv: vector mask-register logical instructions
  target/riscv: vector widening floating-point reduction instructions
  target/riscv: vector single-width floating-point reduction instructions
  target/riscv: vector wideing integer reduction instructions
  target/riscv: vector single-width integer reduction instructions
  target/riscv: narrowing floating-point/integer type-convert instructions
  target/riscv: widening floating-point/integer type-convert instructions
  target/riscv: vector floating-point/integer type-convert instructions
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 14 insertions, 6 deletions

diff --git a/hw/riscv/sifive_plic.c b/hw/riscv/sifive_plic.c
index 4f216c5585..c20c192034 100644
--- a/hw/riscv/sifive_plic.c
+++ b/hw/riscv/sifive_plic.c
@@ -166,6 +166,9 @@ static void sifive_plic_update(SiFivePLICState *plic)
 static uint32_t sifive_plic_claim(SiFivePLICState *plic, uint32_t addrid)
 {
     int i, j;
+    uint32_t max_irq = 0;
+    uint32_t max_prio = plic->target_priority[addrid];
+
     for (i = 0; i < plic->bitfield_words; i++) {
         uint32_t pending_enabled_not_claimed =
             (plic->pending[i] & ~plic->claimed[i]) &
@@ -177,14 +180,18 @@ static uint32_t sifive_plic_claim(SiFivePLICState *plic, uint32_t addrid)
             int irq = (i << 5) + j;
             uint32_t prio = plic->source_priority[irq];
             int enabled = pending_enabled_not_claimed & (1 << j);
-            if (enabled && prio > plic->target_priority[addrid]) {
-                sifive_plic_set_pending(plic, irq, false);
-                sifive_plic_set_claimed(plic, irq, true);
-                return irq;
+            if (enabled && prio > max_prio) {
+                max_irq = irq;
+                max_prio = prio;
             }
         }
     }
-    return 0;
+
+    if (max_irq) {
+        sifive_plic_set_pending(plic, max_irq, false);
+        sifive_plic_set_claimed(plic, max_irq, true);
+    }
+    return max_irq;
 }
 
 static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size)
@@ -248,8 +255,8 @@ static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size)
                     plic->addr_config[addrid].hartid,
                     mode_to_char(plic->addr_config[addrid].mode),
                     value);
-                sifive_plic_print_state(plic);
             }
+            sifive_plic_update(plic);
             return value;
         }
     }
@@ -280,6 +287,7 @@ static void sifive_plic_write(void *opaque, hwaddr addr, uint64_t value,
             qemu_log("plic: write priority: irq=%d priority=%d\n",
                 irq, plic->source_priority[irq]);
         }
+        sifive_plic_update(plic);
         return;
     } else if (addr >= plic->pending_base && /* 1 bit per source */
                addr < plic->pending_base + (plic->num_sources >> 3))