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, 74 insertions, 1 deletions

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 383be0a955..ac01c835e1 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -46,6 +46,10 @@ void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops)
 static int fs(CPURISCVState *env, int csrno)
 {
 #if !defined(CONFIG_USER_ONLY)
+    /* loose check condition for fcsr in vector extension */
+    if ((csrno == CSR_FCSR) && (env->misa & RVV)) {
+        return 0;
+    }
     if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
         return -1;
     }
@@ -53,6 +57,14 @@ static int fs(CPURISCVState *env, int csrno)
     return 0;
 }
 
+static int vs(CPURISCVState *env, int csrno)
+{
+    if (env->misa & RVV) {
+        return 0;
+    }
+    return -1;
+}
+
 static int ctr(CPURISCVState *env, int csrno)
 {
 #if !defined(CONFIG_USER_ONLY)
@@ -154,6 +166,10 @@ static int read_fcsr(CPURISCVState *env, int csrno, target_ulong *val)
 #endif
     *val = (riscv_cpu_get_fflags(env) << FSR_AEXC_SHIFT)
         | (env->frm << FSR_RD_SHIFT);
+    if (vs(env, csrno) >= 0) {
+        *val |= (env->vxrm << FSR_VXRM_SHIFT)
+                | (env->vxsat << FSR_VXSAT_SHIFT);
+    }
     return 0;
 }
 
@@ -166,10 +182,62 @@ static int write_fcsr(CPURISCVState *env, int csrno, target_ulong val)
     env->mstatus |= MSTATUS_FS;
 #endif
     env->frm = (val & FSR_RD) >> FSR_RD_SHIFT;
+    if (vs(env, csrno) >= 0) {
+        env->vxrm = (val & FSR_VXRM) >> FSR_VXRM_SHIFT;
+        env->vxsat = (val & FSR_VXSAT) >> FSR_VXSAT_SHIFT;
+    }
     riscv_cpu_set_fflags(env, (val & FSR_AEXC) >> FSR_AEXC_SHIFT);
     return 0;
 }
 
+static int read_vtype(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vtype;
+    return 0;
+}
+
+static int read_vl(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vl;
+    return 0;
+}
+
+static int read_vxrm(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vxrm;
+    return 0;
+}
+
+static int write_vxrm(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vxrm = val;
+    return 0;
+}
+
+static int read_vxsat(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vxsat;
+    return 0;
+}
+
+static int write_vxsat(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vxsat = val;
+    return 0;
+}
+
+static int read_vstart(CPURISCVState *env, int csrno, target_ulong *val)
+{
+    *val = env->vstart;
+    return 0;
+}
+
+static int write_vstart(CPURISCVState *env, int csrno, target_ulong val)
+{
+    env->vstart = val;
+    return 0;
+}
+
 /* User Timers and Counters */
 static int read_instret(CPURISCVState *env, int csrno, target_ulong *val)
 {
@@ -1183,7 +1251,12 @@ static riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_FFLAGS] =              { fs,   read_fflags,      write_fflags      },
     [CSR_FRM] =                 { fs,   read_frm,         write_frm         },
     [CSR_FCSR] =                { fs,   read_fcsr,        write_fcsr        },
-
+    /* Vector CSRs */
+    [CSR_VSTART] =              { vs,   read_vstart,      write_vstart      },
+    [CSR_VXSAT] =               { vs,   read_vxsat,       write_vxsat       },
+    [CSR_VXRM] =                { vs,   read_vxrm,        write_vxrm        },
+    [CSR_VL] =                  { vs,   read_vl                             },
+    [CSR_VTYPE] =               { vs,   read_vtype                          },
     /* User Timers and Counters */
     [CSR_CYCLE] =               { ctr,  read_instret                        },
     [CSR_INSTRET] =             { ctr,  read_instret                        },