[PATCH 0/2] MIPS: Enable Loongson-3A4000 TCG for system emulation

[PATCH 0/2] MIPS: Enable Loongson-3A4000 TCG for system emulation

[Jiaxun Yang]

Hi there,

This series enables Loongson-3A4000 TCG for system emulation.
It Implemented Loongson CSR insertions which is required for
Linux Kernel to probe CPU features and removed CPU type restrictions
for loongson3_virt board.

This series is based on two of my previous series[1] [2]. However it's
just a soft dependency for me to do boot test, feel free to apply this
series without them.

Note that loongarch_ipi is still not hooked up in IOCSR. I've sucessfully
done it locally but I just want to confirm some details on hardware.

Thanks
- Jiaxun

[1]: https://lore.kernel.org/qemu-devel/20230521102307.87081-1-jiaxun.yang@flygoat.com/T/#t
[2]: https://lore.kernel.org/qemu-devel/0bb0cded-8450-536e-b90f-1a9d33311c2a@linaro.org/T/#t

Jiaxun Yang (2):
  target/mips: Implement Loongson CSR instructions
  hw/mips/loongson3_virt: Remove CPU restrictions for TCG

 hw/mips/loongson3_virt.c             |  4 --
 target/mips/cpu-defs.c.inc           |  9 ++++
 target/mips/cpu.c                    |  8 ++++
 target/mips/cpu.h                    | 40 ++++++++++++++++
 target/mips/helper.h                 |  4 ++
 target/mips/internal.h               |  2 +
 target/mips/tcg/lcsr.decode          | 17 +++++++
 target/mips/tcg/lcsr_translate.c     | 69 ++++++++++++++++++++++++++++
 target/mips/tcg/meson.build          |  2 +
 target/mips/tcg/op_helper.c          | 16 +++++++
 target/mips/tcg/sysemu/lcsr_helper.c | 45 ++++++++++++++++++
 target/mips/tcg/sysemu/meson.build   |  4 ++
 target/mips/tcg/sysemu_helper.h.inc  |  8 ++++
 target/mips/tcg/translate.c          |  3 ++
 target/mips/tcg/translate.h          |  7 +++
 15 files changed, 234 insertions(+), 4 deletions(-)
 create mode 100644 target/mips/tcg/lcsr.decode
 create mode 100644 target/mips/tcg/lcsr_translate.c
 create mode 100644 target/mips/tcg/sysemu/lcsr_helper.c

-- 
2.39.2 (Apple Git-143)

[PATCH 1/2] target/mips: Implement Loongson CSR instructions

[Jiaxun Yang]

Loongson introduced CSR instructions since 3A4000, which looks
similar to IOCSR and CPUCFG instructions we seen in LoongArch.

Unfortunately we don't have much document about those instructions,
bit fields of CPUCFG instructions and IOCSR registers can be found
at 3A4000's user manual, while instruction encodings can be found
at arch/mips/include/asm/mach-loongson64/loongson_regs.h from
Linux Kernel.

Our predefined CPUCFG bits are differ from actual 3A4000, since
we can't emulate all CPUCFG features present in 3A4000 for now,
we just enable bits for what we have in TCG.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 target/mips/cpu-defs.c.inc           |  9 ++++
 target/mips/cpu.c                    |  8 ++++
 target/mips/cpu.h                    | 40 ++++++++++++++++
 target/mips/helper.h                 |  4 ++
 target/mips/internal.h               |  2 +
 target/mips/tcg/lcsr.decode          | 17 +++++++
 target/mips/tcg/lcsr_translate.c     | 69 ++++++++++++++++++++++++++++
 target/mips/tcg/meson.build          |  2 +
 target/mips/tcg/op_helper.c          | 16 +++++++
 target/mips/tcg/sysemu/lcsr_helper.c | 45 ++++++++++++++++++
 target/mips/tcg/sysemu/meson.build   |  4 ++
 target/mips/tcg/sysemu_helper.h.inc  |  8 ++++
 target/mips/tcg/translate.c          |  3 ++
 target/mips/tcg/translate.h          |  7 +++
 14 files changed, 234 insertions(+)
 create mode 100644 target/mips/tcg/lcsr.decode
 create mode 100644 target/mips/tcg/lcsr_translate.c
 create mode 100644 target/mips/tcg/sysemu/lcsr_helper.c

diff --git a/target/mips/cpu-defs.c.inc b/target/mips/cpu-defs.c.inc
index d45f245a6718..167c96cb2748 100644
--- a/target/mips/cpu-defs.c.inc
+++ b/target/mips/cpu-defs.c.inc
@@ -895,6 +895,15 @@ const mips_def_t mips_defs[] =
         .CP1_fcr31 = 0,
         .CP1_fcr31_rw_bitmask = 0xFF83FFFF,
         .MSAIR = (0x01 << MSAIR_ProcID) | (0x40 << MSAIR_Rev),
+        .lcsr_cpucfg1 = (1 << CPUCFG1_FP) | (2 << CPUCFG1_FPREV) |
+                    (1 << CPUCFG1_MSA1) | (1 << CPUCFG1_LSLDR0) |
+                    (1 << CPUCFG1_LSPERF) | (1 << CPUCFG1_LSPERFX) |
+                    (1 << CPUCFG1_LSSYNCI) | (1 << CPUCFG1_LLEXC) |
+                    (1 << CPUCFG1_SCRAND) | (1 << CPUCFG1_MUALP) |
+                    (1 << CPUCFG1_KMUALEN) | (1 << CPUCFG1_ITLBT) |
+                    (1 << CPUCFG1_SFBP) | (1 << CPUCFG1_CDMAP),
+        .lcsr_cpucfg2 = (1 << CPUCFG2_LEXT1) | (1 << CPUCFG2_LCSRP) |
+                    (1 << CPUCFG2_LDISBLIKELY),
         .SEGBITS = 48,
         .PABITS = 48,
         .insn_flags = CPU_MIPS64R2 | INSN_LOONGSON3A |
diff --git a/target/mips/cpu.c b/target/mips/cpu.c
index b7119cbbb459..e675b9178192 100644
--- a/target/mips/cpu.c
+++ b/target/mips/cpu.c
@@ -244,6 +244,8 @@ static void mips_cpu_reset_hold(Object *obj)
     env->CP0_PageGrain_rw_bitmask = env->cpu_model->CP0_PageGrain_rw_bitmask;
     env->CP0_PageGrain = env->cpu_model->CP0_PageGrain;
     env->CP0_EBaseWG_rw_bitmask = env->cpu_model->CP0_EBaseWG_rw_bitmask;
+    env->lcsr_cpucfg1 = env->cpu_model->lcsr_cpucfg1;
+    env->lcsr_cpucfg2 = env->cpu_model->lcsr_cpucfg2;
     env->active_fpu.fcr0 = env->cpu_model->CP1_fcr0;
     env->active_fpu.fcr31_rw_bitmask = env->cpu_model->CP1_fcr31_rw_bitmask;
     env->active_fpu.fcr31 = env->cpu_model->CP1_fcr31;
@@ -507,6 +509,12 @@ static void mips_cpu_initfn(Object *obj)
     cpu->count_div = clock_new(OBJECT(obj), "clk-div-count");
     env->count_clock = clock_new(OBJECT(obj), "clk-count");
     env->cpu_model = mcc->cpu_def;
+    if (mcc->cpu_def->lcsr_cpucfg2 & (1 << CPUCFG2_LCSRP)) {
+        memory_region_init_io(&env->system_iocsr, OBJECT(cpu), NULL,
+                                env, "iocsr", UINT64_MAX);
+        address_space_init(&env->address_space_iocsr,
+                            &env->system_iocsr, "IOCSR");
+    }
 }
 
 static char *mips_cpu_type_name(const char *cpu_model)
diff --git a/target/mips/cpu.h b/target/mips/cpu.h
index 1b8107b0af86..f63b128ff3d3 100644
--- a/target/mips/cpu.h
+++ b/target/mips/cpu.h
@@ -3,6 +3,9 @@
 
 #include "cpu-qom.h"
 #include "exec/cpu-defs.h"
+#ifndef CONFIG_USER_ONLY
+#include "exec/memory.h"
+#endif
 #include "fpu/softfloat-types.h"
 #include "hw/clock.h"
 #include "mips-defs.h"
@@ -1068,6 +1071,33 @@ typedef struct CPUArchState {
  */
     int32_t CP0_DESAVE;
     target_ulong CP0_KScratch[MIPS_KSCRATCH_NUM];
+/*
+ * Loongson CSR CPUCFG registers
+ */
+    uint32_t lcsr_cpucfg1;
+#define CPUCFG1_FP     0
+#define CPUCFG1_FPREV  1
+#define CPUCFG1_MMI    4
+#define CPUCFG1_MSA1   5
+#define CPUCFG1_MSA2   6
+#define CPUCFG1_LSLDR0 16
+#define CPUCFG1_LSPERF 17
+#define CPUCFG1_LSPERFX 18
+#define CPUCFG1_LSSYNCI 19
+#define CPUCFG1_LLEXC   20
+#define CPUCFG1_SCRAND  21
+#define CPUCFG1_MUALP   25
+#define CPUCFG1_KMUALEN 26
+#define CPUCFG1_ITLBT   27
+#define CPUCFG1_SFBP    29
+#define CPUCFG1_CDMAP   30
+    uint32_t lcsr_cpucfg2;
+#define CPUCFG2_LEXT1   0
+#define CPUCFG2_LEXT2   1
+#define CPUCFG2_LEXT3   2
+#define CPUCFG2_LSPW    3
+#define CPUCFG2_LCSRP   27
+#define CPUCFG2_LDISBLIKELY 28
 
     /* We waste some space so we can handle shadow registers like TCs. */
     TCState tcs[MIPS_SHADOW_SET_MAX];
@@ -1162,6 +1192,10 @@ typedef struct CPUArchState {
     QEMUTimer *timer; /* Internal timer */
     Clock *count_clock; /* CP0_Count clock */
     target_ulong exception_base; /* ExceptionBase input to the core */
+
+    /* Loongson IOCSR memory */
+    AddressSpace address_space_iocsr;
+    MemoryRegion system_iocsr;
 } CPUMIPSState;
 
 /**
@@ -1281,6 +1315,12 @@ static inline bool ase_msa_available(CPUMIPSState *env)
     return env->CP0_Config3 & (1 << CP0C3_MSAP);
 }
 
+/* Check presence of Loongson CSR instructions */
+static inline bool ase_lcsr_available(CPUMIPSState *env)
+{
+    return env->lcsr_cpucfg1 & (1 << CPUCFG2_LCSRP);
+}
+
 /* Check presence of multi-threading ASE implementation */
 static inline bool ase_mt_available(CPUMIPSState *env)
 {
diff --git a/target/mips/helper.h b/target/mips/helper.h
index de32d82e980e..0f8462febb57 100644
--- a/target/mips/helper.h
+++ b/target/mips/helper.h
@@ -196,6 +196,10 @@ DEF_HELPER_1(rdhwr_xnp, tl, env)
 DEF_HELPER_2(pmon, void, env, int)
 DEF_HELPER_1(wait, void, env)
 
+#ifdef TARGET_MIPS64
+DEF_HELPER_FLAGS_2(lcsr_cpucfg, TCG_CALL_NO_RWG_SE, tl, env, tl)
+#endif
+
 /* Loongson multimedia functions.  */
 DEF_HELPER_FLAGS_2(paddsh, TCG_CALL_NO_RWG_SE, i64, i64, i64)
 DEF_HELPER_FLAGS_2(paddush, TCG_CALL_NO_RWG_SE, i64, i64, i64)
diff --git a/target/mips/internal.h b/target/mips/internal.h
index 4b0031d10d34..1d0c026c7d0d 100644
--- a/target/mips/internal.h
+++ b/target/mips/internal.h
@@ -79,6 +79,8 @@ struct mips_def_t {
     int32_t CP0_PageGrain_rw_bitmask;
     int32_t CP0_PageGrain;
     target_ulong CP0_EBaseWG_rw_bitmask;
+    uint32_t lcsr_cpucfg1;
+    uint32_t lcsr_cpucfg2;
     uint64_t insn_flags;
     enum mips_mmu_types mmu_type;
     int32_t SAARP;
diff --git a/target/mips/tcg/lcsr.decode b/target/mips/tcg/lcsr.decode
new file mode 100644
index 000000000000..960ef8b6f99b
--- /dev/null
+++ b/target/mips/tcg/lcsr.decode
@@ -0,0 +1,17 @@
+# Loongson CSR instructions
+#
+# Copyright (C) 2023 Jiaxun Yang <jiaxun.yang@flygoat.com>
+#
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+
+&r           rs rt rd sa
+
+@rs_rd       ...... rs:5 ..... rd:5 ..... ...... &r rt=0 sa=0
+
+CPUCFG       110010 ..... 01000 ..... 00100 011000 @rs_rd
+
+RDCSR        110010 ..... 00000 ..... 00100 011000 @rs_rd
+WRCSR        110010 ..... 00001 ..... 00100 011000 @rs_rd
+DRDCSR       110010 ..... 00010 ..... 00100 011000 @rs_rd
+DWRCSR       110010 ..... 00011 ..... 00100 011000 @rs_rd
diff --git a/target/mips/tcg/lcsr_translate.c b/target/mips/tcg/lcsr_translate.c
new file mode 100644
index 000000000000..0ca6f2e7f8db
--- /dev/null
+++ b/target/mips/tcg/lcsr_translate.c
@@ -0,0 +1,69 @@
+/*
+ * Loongson CSR instructions translation routines
+ *
+ *  Copyright (c) 2023 Jiaxun Yang <jiaxun.yang@flygoat.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "tcg/tcg-op.h"
+#include "tcg/tcg-op-gvec.h"
+#include "exec/helper-gen.h"
+#include "translate.h"
+
+/* Include the auto-generated decoder.  */
+#include "decode-lcsr.c.inc"
+
+static bool trans_CPUCFG(DisasContext *ctx, arg_CPUCFG *a)
+{
+    TCGv dest = tcg_temp_new();
+    TCGv src1 = tcg_temp_new();
+
+    gen_load_gpr(src1, a->rs);
+    gen_helper_lcsr_cpucfg(dest, cpu_env, src1);
+    gen_store_gpr(dest, a->rd);
+
+    return true;
+}
+
+#ifndef CONFIG_USER_ONLY
+static bool gen_rdcsr(DisasContext *ctx, arg_r *a,
+                        void (*func)(TCGv, TCGv_ptr, TCGv))
+{
+    TCGv dest = tcg_temp_new();
+    TCGv src1 = tcg_temp_new();
+
+    check_cp0_enabled(ctx);
+    gen_load_gpr(src1, a->rs);
+    func(dest, cpu_env, src1);
+    gen_store_gpr(dest, a->rd);
+
+    return true;
+}
+
+static bool gen_wrcsr(DisasContext *ctx, arg_r *a,
+                        void (*func)(TCGv_ptr, TCGv, TCGv))
+{
+    TCGv val = tcg_temp_new();
+    TCGv addr = tcg_temp_new();
+
+    check_cp0_enabled(ctx);
+    gen_load_gpr(addr, a->rs);
+    func(cpu_env, addr, val);
+    gen_store_gpr(val, a->rd);
+
+    return true;
+}
+
+TRANS(RDCSR, gen_rdcsr, gen_helper_lcsr_rdcsr)
+TRANS(DRDCSR, gen_rdcsr, gen_helper_lcsr_drdcsr)
+TRANS(WRCSR, gen_wrcsr, gen_helper_lcsr_wrcsr)
+TRANS(DWRCSR, gen_wrcsr, gen_helper_lcsr_wrcsr)
+#else
+GEN_FALSE_TRANS(RDCSR)
+GEN_FALSE_TRANS(DRDCSR)
+GEN_FALSE_TRANS(WRCSR)
+GEN_FALSE_TRANS(DWRCSR)
+#endif
diff --git a/target/mips/tcg/meson.build b/target/mips/tcg/meson.build
index 7ee969ec8f23..ea7fb582f2ab 100644
--- a/target/mips/tcg/meson.build
+++ b/target/mips/tcg/meson.build
@@ -4,6 +4,7 @@ gen = [
   decodetree.process('tx79.decode', extra_args: '--static-decode=decode_tx79'),
   decodetree.process('vr54xx.decode', extra_args: '--decode=decode_ext_vr54xx'),
   decodetree.process('octeon.decode', extra_args: '--decode=decode_ext_octeon'),
+  decodetree.process('lcsr.decode', extra_args: '--decode=decode_ase_lcsr'),
 ]
 
 mips_ss.add(gen)
@@ -26,6 +27,7 @@ mips_ss.add(files(
 mips_ss.add(when: 'TARGET_MIPS64', if_true: files(
   'tx79_translate.c',
   'octeon_translate.c',
+  'lcsr_translate.c',
 ), if_false: files(
   'mxu_translate.c',
 ))
diff --git a/target/mips/tcg/op_helper.c b/target/mips/tcg/op_helper.c
index ef3dafcbb3fd..98935b5e6418 100644
--- a/target/mips/tcg/op_helper.c
+++ b/target/mips/tcg/op_helper.c
@@ -257,6 +257,22 @@ void helper_pmon(CPUMIPSState *env, int function)
     }
 }
 
+#ifdef TARGET_MIPS64
+target_ulong helper_lcsr_cpucfg(CPUMIPSState *env, target_ulong rs)
+{
+    switch (rs) {
+    case 0:
+        return env->CP0_PRid;
+    case 1:
+        return env->lcsr_cpucfg1;
+    case 2:
+        return env->lcsr_cpucfg2;
+    default:
+        return 0;
+    }
+}
+#endif
+
 #if !defined(CONFIG_USER_ONLY)
 
 void mips_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
diff --git a/target/mips/tcg/sysemu/lcsr_helper.c b/target/mips/tcg/sysemu/lcsr_helper.c
new file mode 100644
index 000000000000..1152695ba2c1
--- /dev/null
+++ b/target/mips/tcg/sysemu/lcsr_helper.c
@@ -0,0 +1,45 @@
+/*
+ * Loongson CSR instructions translation routines
+ *
+ *  Copyright (c) 2023 Jiaxun Yang <jiaxun.yang@flygoat.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "cpu.h"
+#include "internal.h"
+#include "qemu/host-utils.h"
+#include "exec/helper-proto.h"
+#include "exec/exec-all.h"
+#include "exec/cpu_ldst.h"
+
+#define GET_MEMTXATTRS(cas) \
+        ((MemTxAttrs){.requester_id = env_cpu(cas)->cpu_index})
+
+uint64_t helper_lcsr_rdcsr(CPUMIPSState *env, target_ulong r_addr)
+{
+    return address_space_ldl(&env->address_space_iocsr, r_addr,
+                             GET_MEMTXATTRS(env), NULL);
+}
+
+uint64_t helper_lcsr_drdcsr(CPUMIPSState *env, target_ulong r_addr)
+{
+    return address_space_ldq(&env->address_space_iocsr, r_addr,
+                             GET_MEMTXATTRS(env), NULL);
+}
+
+void helper_lcsr_wrcsr(CPUMIPSState *env, target_ulong w_addr,
+                      target_ulong val)
+{
+    address_space_stl(&env->address_space_iocsr, w_addr,
+                      val, GET_MEMTXATTRS(env), NULL);
+}
+
+void helper_lcsr_dwrcsr(CPUMIPSState *env, target_ulong w_addr,
+                      target_ulong val)
+{
+    address_space_stq(&env->address_space_iocsr, w_addr,
+                      val, GET_MEMTXATTRS(env), NULL);
+}
diff --git a/target/mips/tcg/sysemu/meson.build b/target/mips/tcg/sysemu/meson.build
index 4da2c577b203..098b6069159b 100644
--- a/target/mips/tcg/sysemu/meson.build
+++ b/target/mips/tcg/sysemu/meson.build
@@ -4,3 +4,7 @@ mips_softmmu_ss.add(files(
   'special_helper.c',
   'tlb_helper.c',
 ))
+
+mips_softmmu_ss.add(when: 'TARGET_MIPS64', if_true: files(
+  'lcsr_helper.c',
+))
diff --git a/target/mips/tcg/sysemu_helper.h.inc b/target/mips/tcg/sysemu_helper.h.inc
index af585b5d9c13..f163af1eac75 100644
--- a/target/mips/tcg/sysemu_helper.h.inc
+++ b/target/mips/tcg/sysemu_helper.h.inc
@@ -181,3 +181,11 @@ DEF_HELPER_1(eret, void, env)
 DEF_HELPER_1(eretnc, void, env)
 DEF_HELPER_1(deret, void, env)
 DEF_HELPER_3(cache, void, env, tl, i32)
+
+#ifdef TARGET_MIPS64
+/* Longson CSR */
+DEF_HELPER_2(lcsr_rdcsr, i64, env, tl)
+DEF_HELPER_2(lcsr_drdcsr, i64, env, tl)
+DEF_HELPER_3(lcsr_wrcsr, void, env, tl, tl)
+DEF_HELPER_3(lcsr_dwrcsr, void, env, tl, tl)
+#endif
diff --git a/target/mips/tcg/translate.c b/target/mips/tcg/translate.c
index a6ca2e5a3b96..45558899229a 100644
--- a/target/mips/tcg/translate.c
+++ b/target/mips/tcg/translate.c
@@ -15361,6 +15361,9 @@ static void decode_opc(CPUMIPSState *env, DisasContext *ctx)
         return;
     }
 #if defined(TARGET_MIPS64)
+    if (ase_lcsr_available(env) && decode_ase_lcsr(ctx, ctx->opcode)) {
+        return;
+    }
     if (cpu_supports_isa(env, INSN_OCTEON) && decode_ext_octeon(ctx, ctx->opcode)) {
         return;
     }
diff --git a/target/mips/tcg/translate.h b/target/mips/tcg/translate.h
index 69f85841d213..99f7a404ba7e 100644
--- a/target/mips/tcg/translate.h
+++ b/target/mips/tcg/translate.h
@@ -218,6 +218,7 @@ bool decode_isa_rel6(DisasContext *ctx, uint32_t insn);
 bool decode_ase_msa(DisasContext *ctx, uint32_t insn);
 bool decode_ext_txx9(DisasContext *ctx, uint32_t insn);
 #if defined(TARGET_MIPS64)
+bool decode_ase_lcsr(DisasContext *ctx, uint32_t insn);
 bool decode_ext_tx79(DisasContext *ctx, uint32_t insn);
 bool decode_ext_octeon(DisasContext *ctx, uint32_t insn);
 #endif
@@ -231,6 +232,12 @@ bool decode_ext_vr54xx(DisasContext *ctx, uint32_t insn);
     static bool trans_##NAME(DisasContext *ctx, arg_##NAME *a) \
     { return FUNC(ctx, a, __VA_ARGS__); }
 
+#define GEN_FALSE_TRANS(name)   \
+static bool trans_##name(DisasContext *ctx, arg_##name * a)  \
+{   \
+    return false;   \
+}
+
 static inline bool cpu_is_bigendian(DisasContext *ctx)
 {
     return extract32(ctx->CP0_Config0, CP0C0_BE, 1);
-- 
2.39.2 (Apple Git-143)

[PATCH 2/2] hw/mips/loongson3_virt: Remove CPU restrictions for TCG

[Jiaxun Yang]

After implemented CPUCFG and CSR, we are now able to boot Linux
kernel with Loongson-3A4000 CPU, so there is no point to restrict
CPU type for TCG.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 hw/mips/loongson3_virt.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
index a57245012598..47289fb6bf85 100644
--- a/hw/mips/loongson3_virt.c
+++ b/hw/mips/loongson3_virt.c
@@ -488,10 +488,6 @@ static void mips_loongson3_virt_init(MachineState *machine)
         if (!machine->cpu_type) {
             machine->cpu_type = MIPS_CPU_TYPE_NAME("Loongson-3A1000");
         }
-        if (!strstr(machine->cpu_type, "Loongson-3A1000")) {
-            error_report("Loongson-3/TCG needs cpu type Loongson-3A1000");
-            exit(1);
-        }
     } else {
         if (!machine->cpu_type) {
             machine->cpu_type = MIPS_CPU_TYPE_NAME("Loongson-3A4000");
-- 
2.39.2 (Apple Git-143)

Re: [PATCH 1/2] target/mips: Implement Loongson CSR instructions

[Philippe Mathieu-Daudé]

Hi Jiaxun,

On 21/5/23 23:48, Jiaxun Yang wrote:
> Loongson introduced CSR instructions since 3A4000, which looks
> similar to IOCSR and CPUCFG instructions we seen in LoongArch.
> 
> Unfortunately we don't have much document about those instructions,
> bit fields of CPUCFG instructions and IOCSR registers can be found
> at 3A4000's user manual, while instruction encodings can be found
> at arch/mips/include/asm/mach-loongson64/loongson_regs.h from
> Linux Kernel.
> 
> Our predefined CPUCFG bits are differ from actual 3A4000, since
> we can't emulate all CPUCFG features present in 3A4000 for now,
> we just enable bits for what we have in TCG.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>   target/mips/cpu-defs.c.inc           |  9 ++++
>   target/mips/cpu.c                    |  8 ++++
>   target/mips/cpu.h                    | 40 ++++++++++++++++
>   target/mips/helper.h                 |  4 ++
>   target/mips/internal.h               |  2 +
>   target/mips/tcg/lcsr.decode          | 17 +++++++
>   target/mips/tcg/lcsr_translate.c     | 69 ++++++++++++++++++++++++++++
>   target/mips/tcg/meson.build          |  2 +
>   target/mips/tcg/op_helper.c          | 16 +++++++
>   target/mips/tcg/sysemu/lcsr_helper.c | 45 ++++++++++++++++++
>   target/mips/tcg/sysemu/meson.build   |  4 ++
>   target/mips/tcg/sysemu_helper.h.inc  |  8 ++++
>   target/mips/tcg/translate.c          |  3 ++
>   target/mips/tcg/translate.h          |  7 +++
>   14 files changed, 234 insertions(+)
>   create mode 100644 target/mips/tcg/lcsr.decode
>   create mode 100644 target/mips/tcg/lcsr_translate.c
>   create mode 100644 target/mips/tcg/sysemu/lcsr_helper.c


>   static char *mips_cpu_type_name(const char *cpu_model)
> diff --git a/target/mips/cpu.h b/target/mips/cpu.h
> index 1b8107b0af86..f63b128ff3d3 100644
> --- a/target/mips/cpu.h
> +++ b/target/mips/cpu.h
> @@ -3,6 +3,9 @@
>   
>   #include "cpu-qom.h"
>   #include "exec/cpu-defs.h"
> +#ifndef CONFIG_USER_ONLY
> +#include "exec/memory.h"
> +#endif
>   #include "fpu/softfloat-types.h"
>   #include "hw/clock.h"
>   #include "mips-defs.h"
> @@ -1068,6 +1071,33 @@ typedef struct CPUArchState {
>    */
>       int32_t CP0_DESAVE;
>       target_ulong CP0_KScratch[MIPS_KSCRATCH_NUM];
> +/*
> + * Loongson CSR CPUCFG registers
> + */
> +    uint32_t lcsr_cpucfg1;
> +#define CPUCFG1_FP     0
> +#define CPUCFG1_FPREV  1
> +#define CPUCFG1_MMI    4
> +#define CPUCFG1_MSA1   5
> +#define CPUCFG1_MSA2   6
> +#define CPUCFG1_LSLDR0 16
> +#define CPUCFG1_LSPERF 17
> +#define CPUCFG1_LSPERFX 18
> +#define CPUCFG1_LSSYNCI 19
> +#define CPUCFG1_LLEXC   20
> +#define CPUCFG1_SCRAND  21
> +#define CPUCFG1_MUALP   25
> +#define CPUCFG1_KMUALEN 26
> +#define CPUCFG1_ITLBT   27
> +#define CPUCFG1_SFBP    29
> +#define CPUCFG1_CDMAP   30
> +    uint32_t lcsr_cpucfg2;
> +#define CPUCFG2_LEXT1   0
> +#define CPUCFG2_LEXT2   1
> +#define CPUCFG2_LEXT3   2
> +#define CPUCFG2_LSPW    3
> +#define CPUCFG2_LCSRP   27
> +#define CPUCFG2_LDISBLIKELY 28
>   
>       /* We waste some space so we can handle shadow registers like TCs. */
>       TCState tcs[MIPS_SHADOW_SET_MAX];
> @@ -1162,6 +1192,10 @@ typedef struct CPUArchState {
>       QEMUTimer *timer; /* Internal timer */
>       Clock *count_clock; /* CP0_Count clock */
>       target_ulong exception_base; /* ExceptionBase input to the core */
> +
> +    /* Loongson IOCSR memory */

Preferrably:

    struct {

> +    AddressSpace address_space_iocsr;

        AddressSpace as;

> +    MemoryRegion system_iocsr;

        MemoryRegion mr;

     } iocsr;

>   } CPUMIPSState;
>   
>   /**
> @@ -1281,6 +1315,12 @@ static inline bool ase_msa_available(CPUMIPSState *env)
>       return env->CP0_Config3 & (1 << CP0C3_MSAP);
>   }
>   
> +/* Check presence of Loongson CSR instructions */
> +static inline bool ase_lcsr_available(CPUMIPSState *env)
> +{
> +    return env->lcsr_cpucfg1 & (1 << CPUCFG2_LCSRP);

You are checking CPUCFG1_ITLBT. Surely you want lcsr_cpucfg2 instead.

> +}

> --- a/target/mips/tcg/translate.h
> +++ b/target/mips/tcg/translate.h
> @@ -218,6 +218,7 @@ bool decode_isa_rel6(DisasContext *ctx, uint32_t insn);
>   bool decode_ase_msa(DisasContext *ctx, uint32_t insn);
>   bool decode_ext_txx9(DisasContext *ctx, uint32_t insn);
>   #if defined(TARGET_MIPS64)
> +bool decode_ase_lcsr(DisasContext *ctx, uint32_t insn);
>   bool decode_ext_tx79(DisasContext *ctx, uint32_t insn);
>   bool decode_ext_octeon(DisasContext *ctx, uint32_t insn);
>   #endif
> @@ -231,6 +232,12 @@ bool decode_ext_vr54xx(DisasContext *ctx, uint32_t insn);
>       static bool trans_##NAME(DisasContext *ctx, arg_##NAME *a) \
>       { return FUNC(ctx, a, __VA_ARGS__); }
>   
> +#define GEN_FALSE_TRANS(name)   \
> +static bool trans_##name(DisasContext *ctx, arg_##name * a)  \
> +{   \
> +    return false;   \
> +}

I'm not a big fan of this generic GEN_FALSE_TRANS() macro.

Otherwise LGTM!

Re: [PATCH 2/2] hw/mips/loongson3_virt: Remove CPU restrictions for TCG

[Philippe Mathieu-Daudé]

On 21/5/23 23:48, Jiaxun Yang wrote:
> After implemented CPUCFG and CSR, we are now able to boot Linux
> kernel with Loongson-3A4000 CPU, so there is no point to restrict
> CPU type for TCG.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>   hw/mips/loongson3_virt.c | 4 ----
>   1 file changed, 4 deletions(-)
> 
> diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
> index a57245012598..47289fb6bf85 100644
> --- a/hw/mips/loongson3_virt.c
> +++ b/hw/mips/loongson3_virt.c
> @@ -488,10 +488,6 @@ static void mips_loongson3_virt_init(MachineState *machine)
>           if (!machine->cpu_type) {
>               machine->cpu_type = MIPS_CPU_TYPE_NAME("Loongson-3A1000");
>           }
> -        if (!strstr(machine->cpu_type, "Loongson-3A1000")) {
> -            error_report("Loongson-3/TCG needs cpu type Loongson-3A1000");

Hmm, shouldn't we check for CPUs supporting the INSN_LOONGSON3A
insn_flags at least?

> -            exit(1);
> -        }
>       } else {
>           if (!machine->cpu_type) {
>               machine->cpu_type = MIPS_CPU_TYPE_NAME("Loongson-3A4000");

Re: [PATCH 2/2] hw/mips/loongson3_virt: Remove CPU restrictions for TCG

[Philippe Mathieu-Daudé]

On 21/5/23 23:48, Jiaxun Yang wrote:
> After implemented CPUCFG and CSR, we are now able to boot Linux
> kernel with Loongson-3A4000 CPU, so there is no point to restrict
> CPU type for TCG.
> 

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1639
?

> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>   hw/mips/loongson3_virt.c | 4 ----
>   1 file changed, 4 deletions(-)

Re: [PATCH 2/2] hw/mips/loongson3_virt: Remove CPU restrictions for TCG

[Jiaxun Yang]

> 2023年5月22日 13:08，Philippe Mathieu-Daudé <philmd@linaro.org> 写道：
> 
> On 21/5/23 23:48, Jiaxun Yang wrote:
>> After implemented CPUCFG and CSR, we are now able to boot Linux
>> kernel with Loongson-3A4000 CPU, so there is no point to restrict
>> CPU type for TCG.
> 
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1639
> ?

Potentially yes, although I think the issue itself is just a question on usage
of the board.

Thanks
- Jiaxun

> 
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> ---
>>  hw/mips/loongson3_virt.c | 4 ----
>>  1 file changed, 4 deletions(-)
> 
> 

Re: [PATCH 1/2] target/mips: Implement Loongson CSR instructions

[Philippe Mathieu-Daudé]

On 22/5/23 08:00, Philippe Mathieu-Daudé wrote:
> Hi Jiaxun,
> 
> On 21/5/23 23:48, Jiaxun Yang wrote:
>> Loongson introduced CSR instructions since 3A4000, which looks
>> similar to IOCSR and CPUCFG instructions we seen in LoongArch.
>>
>> Unfortunately we don't have much document about those instructions,
>> bit fields of CPUCFG instructions and IOCSR registers can be found
>> at 3A4000's user manual, while instruction encodings can be found
>> at arch/mips/include/asm/mach-loongson64/loongson_regs.h from
>> Linux Kernel.
>>
>> Our predefined CPUCFG bits are differ from actual 3A4000, since
>> we can't emulate all CPUCFG features present in 3A4000 for now,
>> we just enable bits for what we have in TCG.
>>
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> ---
>>   target/mips/cpu-defs.c.inc           |  9 ++++
>>   target/mips/cpu.c                    |  8 ++++
>>   target/mips/cpu.h                    | 40 ++++++++++++++++
>>   target/mips/helper.h                 |  4 ++
>>   target/mips/internal.h               |  2 +
>>   target/mips/tcg/lcsr.decode          | 17 +++++++
>>   target/mips/tcg/lcsr_translate.c     | 69 ++++++++++++++++++++++++++++
>>   target/mips/tcg/meson.build          |  2 +
>>   target/mips/tcg/op_helper.c          | 16 +++++++
>>   target/mips/tcg/sysemu/lcsr_helper.c | 45 ++++++++++++++++++
>>   target/mips/tcg/sysemu/meson.build   |  4 ++
>>   target/mips/tcg/sysemu_helper.h.inc  |  8 ++++
>>   target/mips/tcg/translate.c          |  3 ++
>>   target/mips/tcg/translate.h          |  7 +++
>>   14 files changed, 234 insertions(+)
>>   create mode 100644 target/mips/tcg/lcsr.decode
>>   create mode 100644 target/mips/tcg/lcsr_translate.c
>>   create mode 100644 target/mips/tcg/sysemu/lcsr_helper.c


>> @@ -1281,6 +1315,12 @@ static inline bool 
>> ase_msa_available(CPUMIPSState *env)
>>       return env->CP0_Config3 & (1 << CP0C3_MSAP);
>>   }
>> +/* Check presence of Loongson CSR instructions */
>> +static inline bool ase_lcsr_available(CPUMIPSState *env)
>> +{
>> +    return env->lcsr_cpucfg1 & (1 << CPUCFG2_LCSRP);
> 
> You are checking CPUCFG1_ITLBT. Surely you want lcsr_cpucfg2 instead.

Ping?

Anyhow:

Applying: target/mips: Implement Loongson CSR instructions
error: patch failed: target/mips/cpu.c:507
error: target/mips/cpu.c: patch does not apply
error: patch failed: target/mips/cpu.h:1162
error: target/mips/cpu.h: patch does not apply
Patch failed at 0001 target/mips: Implement Loongson CSR instructions

Re: [PATCH 0/2] MIPS: Enable Loongson-3A4000 TCG for system emulation

[Philippe Mathieu-Daudé]

On 21/5/23 23:48, Jiaxun Yang wrote:
> Hi there,
> 
> This series enables Loongson-3A4000 TCG for system emulation.
> It Implemented Loongson CSR insertions which is required for
> Linux Kernel to probe CPU features and removed CPU type restrictions
> for loongson3_virt board.
> 
> This series is based on two of my previous series[1] [2]. However it's
> just a soft dependency for me to do boot test, feel free to apply this
> series without them.
> 
> Note that loongarch_ipi is still not hooked up in IOCSR. I've sucessfully
> done it locally but I just want to confirm some details on hardware.
> 
> Thanks
> - Jiaxun
> 
> [1]: https://lore.kernel.org/qemu-devel/20230521102307.87081-1-jiaxun.yang@flygoat.com/T/#t
> [2]: https://lore.kernel.org/qemu-devel/0bb0cded-8450-536e-b90f-1a9d33311c2a@linaro.org/T/#t
> 
> Jiaxun Yang (2):
>    target/mips: Implement Loongson CSR instructions
>    hw/mips/loongson3_virt: Remove CPU restrictions for TCG

Thanks, queued to mips-next addressing the review comments.

Re: [PATCH 1/2] target/mips: Implement Loongson CSR instructions

[Philippe Mathieu-Daudé]

On 21/5/23 23:48, Jiaxun Yang wrote:
> Loongson introduced CSR instructions since 3A4000, which looks
> similar to IOCSR and CPUCFG instructions we seen in LoongArch.
> 
> Unfortunately we don't have much document about those instructions,
> bit fields of CPUCFG instructions and IOCSR registers can be found
> at 3A4000's user manual, while instruction encodings can be found
> at arch/mips/include/asm/mach-loongson64/loongson_regs.h from
> Linux Kernel.
> 
> Our predefined CPUCFG bits are differ from actual 3A4000, since
> we can't emulate all CPUCFG features present in 3A4000 for now,
> we just enable bits for what we have in TCG.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>   target/mips/cpu-defs.c.inc           |  9 ++++
>   target/mips/cpu.c                    |  8 ++++
>   target/mips/cpu.h                    | 40 ++++++++++++++++
>   target/mips/helper.h                 |  4 ++
>   target/mips/internal.h               |  2 +
>   target/mips/tcg/lcsr.decode          | 17 +++++++
>   target/mips/tcg/lcsr_translate.c     | 69 ++++++++++++++++++++++++++++
>   target/mips/tcg/meson.build          |  2 +
>   target/mips/tcg/op_helper.c          | 16 +++++++
>   target/mips/tcg/sysemu/lcsr_helper.c | 45 ++++++++++++++++++
>   target/mips/tcg/sysemu/meson.build   |  4 ++
>   target/mips/tcg/sysemu_helper.h.inc  |  8 ++++
>   target/mips/tcg/translate.c          |  3 ++
>   target/mips/tcg/translate.h          |  7 +++
>   14 files changed, 234 insertions(+)
>   create mode 100644 target/mips/tcg/lcsr.decode
>   create mode 100644 target/mips/tcg/lcsr_translate.c
>   create mode 100644 target/mips/tcg/sysemu/lcsr_helper.c


> diff --git a/target/mips/tcg/lcsr.decode b/target/mips/tcg/lcsr.decode
> new file mode 100644
> index 000000000000..960ef8b6f99b
> --- /dev/null
> +++ b/target/mips/tcg/lcsr.decode
> @@ -0,0 +1,17 @@
> +# Loongson CSR instructions
> +#
> +# Copyright (C) 2023 Jiaxun Yang <jiaxun.yang@flygoat.com>
> +#
> +# SPDX-License-Identifier: LGPL-2.1-or-later
> +#


> diff --git a/target/mips/tcg/lcsr_translate.c b/target/mips/tcg/lcsr_translate.c
> new file mode 100644
> index 000000000000..0ca6f2e7f8db
> --- /dev/null
> +++ b/target/mips/tcg/lcsr_translate.c
> @@ -0,0 +1,69 @@
> +/*
> + * Loongson CSR instructions translation routines
> + *
> + *  Copyright (c) 2023 Jiaxun Yang <jiaxun.yang@flygoat.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +


> diff --git a/target/mips/tcg/sysemu/lcsr_helper.c b/target/mips/tcg/sysemu/lcsr_helper.c
> new file mode 100644
> index 000000000000..1152695ba2c1
> --- /dev/null
> +++ b/target/mips/tcg/sysemu/lcsr_helper.c
> @@ -0,0 +1,45 @@
> +/*
> + * Loongson CSR instructions translation routines
> + *
> + *  Copyright (c) 2023 Jiaxun Yang <jiaxun.yang@flygoat.com>
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */

You have a mix of LGPL/GPL. I suppose you want LGPL.

> diff --git a/target/mips/tcg/sysemu/meson.build b/target/mips/tcg/sysemu/meson.build
> index 4da2c577b203..098b6069159b 100644
> --- a/target/mips/tcg/sysemu/meson.build
> +++ b/target/mips/tcg/sysemu/meson.build
> @@ -4,3 +4,7 @@ mips_softmmu_ss.add(files(
>     'special_helper.c',
>     'tlb_helper.c',
>   ))
> +
> +mips_softmmu_ss.add(when: 'TARGET_MIPS64', if_true: files(

Now s/mips_softmmu_ss/mips_system_ss/.

> +  'lcsr_helper.c',
> +))

Re: [PATCH 1/2] target/mips: Implement Loongson CSR instructions

[Philippe Mathieu-Daudé]

On 21/5/23 23:48, Jiaxun Yang wrote:
> Loongson introduced CSR instructions since 3A4000, which looks
> similar to IOCSR and CPUCFG instructions we seen in LoongArch.
> 
> Unfortunately we don't have much document about those instructions,
> bit fields of CPUCFG instructions and IOCSR registers can be found
> at 3A4000's user manual, while instruction encodings can be found
> at arch/mips/include/asm/mach-loongson64/loongson_regs.h from
> Linux Kernel.
> 
> Our predefined CPUCFG bits are differ from actual 3A4000, since
> we can't emulate all CPUCFG features present in 3A4000 for now,
> we just enable bits for what we have in TCG.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>   target/mips/cpu-defs.c.inc           |  9 ++++
>   target/mips/cpu.c                    |  8 ++++
>   target/mips/cpu.h                    | 40 ++++++++++++++++
>   target/mips/helper.h                 |  4 ++
>   target/mips/internal.h               |  2 +
>   target/mips/tcg/lcsr.decode          | 17 +++++++
>   target/mips/tcg/lcsr_translate.c     | 69 ++++++++++++++++++++++++++++
>   target/mips/tcg/meson.build          |  2 +
>   target/mips/tcg/op_helper.c          | 16 +++++++
>   target/mips/tcg/sysemu/lcsr_helper.c | 45 ++++++++++++++++++
>   target/mips/tcg/sysemu/meson.build   |  4 ++
>   target/mips/tcg/sysemu_helper.h.inc  |  8 ++++
>   target/mips/tcg/translate.c          |  3 ++
>   target/mips/tcg/translate.h          |  7 +++
>   14 files changed, 234 insertions(+)
>   create mode 100644 target/mips/tcg/lcsr.decode
>   create mode 100644 target/mips/tcg/lcsr_translate.c
>   create mode 100644 target/mips/tcg/sysemu/lcsr_helper.c


> @@ -1162,6 +1192,10 @@ typedef struct CPUArchState {
>       QEMUTimer *timer; /* Internal timer */
>       Clock *count_clock; /* CP0_Count clock */
>       target_ulong exception_base; /* ExceptionBase input to the core */
> +
> +    /* Loongson IOCSR memory */
> +    AddressSpace address_space_iocsr;
> +    MemoryRegion system_iocsr;
>   } CPUMIPSState;

Guarding to avoid on user emulation:

../target/mips/cpu.h:1198:22: error: field ‘as’ has incomplete type
  1198 |         AddressSpace as;
       |                      ^~
../target/mips/cpu.h:1199:22: error: field ‘mr’ has incomplete type
  1199 |         MemoryRegion mr;
       |                      ^~

Re: [PATCH 1/2] target/mips: Implement Loongson CSR instructions

[Philippe Mathieu-Daudé]

On 10/7/23 22:11, Philippe Mathieu-Daudé wrote:
> On 21/5/23 23:48, Jiaxun Yang wrote:
>> Loongson introduced CSR instructions since 3A4000, which looks
>> similar to IOCSR and CPUCFG instructions we seen in LoongArch.
>>
>> Unfortunately we don't have much document about those instructions,
>> bit fields of CPUCFG instructions and IOCSR registers can be found
>> at 3A4000's user manual, while instruction encodings can be found
>> at arch/mips/include/asm/mach-loongson64/loongson_regs.h from
>> Linux Kernel.
>>
>> Our predefined CPUCFG bits are differ from actual 3A4000, since
>> we can't emulate all CPUCFG features present in 3A4000 for now,
>> we just enable bits for what we have in TCG.
>>
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> ---
>>   target/mips/cpu-defs.c.inc           |  9 ++++
>>   target/mips/cpu.c                    |  8 ++++
>>   target/mips/cpu.h                    | 40 ++++++++++++++++
>>   target/mips/helper.h                 |  4 ++
>>   target/mips/internal.h               |  2 +
>>   target/mips/tcg/lcsr.decode          | 17 +++++++
>>   target/mips/tcg/lcsr_translate.c     | 69 ++++++++++++++++++++++++++++
>>   target/mips/tcg/meson.build          |  2 +
>>   target/mips/tcg/op_helper.c          | 16 +++++++
>>   target/mips/tcg/sysemu/lcsr_helper.c | 45 ++++++++++++++++++
>>   target/mips/tcg/sysemu/meson.build   |  4 ++
>>   target/mips/tcg/sysemu_helper.h.inc  |  8 ++++
>>   target/mips/tcg/translate.c          |  3 ++
>>   target/mips/tcg/translate.h          |  7 +++
>>   14 files changed, 234 insertions(+)
>>   create mode 100644 target/mips/tcg/lcsr.decode
>>   create mode 100644 target/mips/tcg/lcsr_translate.c
>>   create mode 100644 target/mips/tcg/sysemu/lcsr_helper.c
> 
> 
>> @@ -1162,6 +1192,10 @@ typedef struct CPUArchState {
>>       QEMUTimer *timer; /* Internal timer */
>>       Clock *count_clock; /* CP0_Count clock */
>>       target_ulong exception_base; /* ExceptionBase input to the core */
>> +
>> +    /* Loongson IOCSR memory */
>> +    AddressSpace address_space_iocsr;
>> +    MemoryRegion system_iocsr;
>>   } CPUMIPSState;
> 
> Guarding to avoid on user emulation:
> 
> ../target/mips/cpu.h:1198:22: error: field ‘as’ has incomplete type
>   1198 |         AddressSpace as;
>        |                      ^~
> ../target/mips/cpu.h:1199:22: error: field ‘mr’ has incomplete type
>   1199 |         MemoryRegion mr;
>        |                      ^~
> 

and:

../../target/mips/cpu.c: In function ‘mips_cpu_initfn’:
../../target/mips/cpu.c:513:9: error: implicit declaration of function 
‘memory_region_init_io’ [-Werror=implicit-function-declaration]
   513 |         memory_region_init_io(&env->iocsr.mr, OBJECT(cpu), NULL,
       |         ^~~~~~~~~~~~~~~~~~~~~
../../target/mips/cpu.c:513:9: error: nested extern declaration of 
‘memory_region_init_io’ [-Werror=nested-externs]
../../target/mips/cpu.c:513:35: error: ‘CPUMIPSState’ {aka ‘struct 
CPUArchState’} has no member named ‘iocsr’
   513 |         memory_region_init_io(&env->iocsr.mr, OBJECT(cpu), NULL,
       |                                   ^~
../../target/mips/cpu.c:515:9: error: implicit declaration of function 
‘address_space_init’ [-Werror=implicit-function-declaration]
   515 |         address_space_init(&env->iocsr.as,
       |         ^~~~~~~~~~~~~~~~~~
../../target/mips/cpu.c:515:9: error: nested extern declaration of 
‘address_space_init’ [-Werror=nested-externs]
../../target/mips/cpu.c:515:32: error: ‘CPUMIPSState’ {aka ‘struct 
CPUArchState’} has no member named ‘iocsr’
   515 |         address_space_init(&env->iocsr.as,
       |                                ^~
../../target/mips/cpu.c:516:33: error: ‘CPUMIPSState’ {aka ‘struct 
CPUArchState’} has no member named ‘iocsr’
   516 |                             &env->iocsr.mr, "IOCSR");
       |                                 ^~
cc1: all warnings being treated as errors

:(