diff mbox series

[for-7.1,v6,42/51] target/nios2: Implement rdprs, wrprs

Message ID 20220317050538.924111-43-richard.henderson@linaro.org
State New
Headers show
Series target/nios2: Shadow register set, EIC and VIC | expand

Commit Message

Richard Henderson March 17, 2022, 5:05 a.m. UTC 
Implement these out of line, so that tcg global temps
(aka the architectural registers) are synced back to
tcg storage as required.  This makes sure that we get
the proper results when status.PRS == status.CRS.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/nios2/cpu.h       |  1 +
 target/nios2/helper.h    |  2 ++
 target/nios2/op_helper.c | 12 ++++++++++
 target/nios2/translate.c | 47 ++++++++++++++++++++++++++++++++++++++--
 4 files changed, 60 insertions(+), 2 deletions(-)

Comments

Peter Maydell March 17, 2022, 6:47 p.m. UTC | #1 
On Thu, 17 Mar 2022 at 05:55, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Implement these out of line, so that tcg global temps
> (aka the architectural registers) are synced back to
> tcg storage as required.  This makes sure that we get
> the proper results when status.PRS == status.CRS.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


> +void helper_wrprs(CPUNios2State *env, uint32_t regno, uint32_t val)
> +{
> +    unsigned prs = FIELD_EX32(env->ctrl[CR_STATUS], CR_STATUS, PRS);
> +    env->shadow_regs[prs][regno] = val;
> +}

If we have the TB flag for "r0 is 0", then we'd need to make
wrprs writes to r0 in the current register set end the TB.
(If I'd been designing the ISA, I'd have made attempts to
use wrprs/rdprs with CRS == PRS cause an exception.)

Otherwise
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM
diff mbox series

Patch

diff --git a/target/nios2/cpu.h b/target/nios2/cpu.h
index e32bebe9b7..26d4dcfe12 100644
--- a/target/nios2/cpu.h
+++ b/target/nios2/cpu.h
@@ -220,6 +220,7 @@  struct ArchCPU {
 
     bool diverr_present;
     bool mmu_present;
+    bool eic_present;
 
     uint32_t pid_num_bits;
     uint32_t tlb_num_ways;
diff --git a/target/nios2/helper.h b/target/nios2/helper.h
index 6f5ec60b0d..1648d76ade 100644
--- a/target/nios2/helper.h
+++ b/target/nios2/helper.h
@@ -24,6 +24,8 @@  DEF_HELPER_FLAGS_3(divu, TCG_CALL_NO_WG, i32, env, i32, i32)
 
 #if !defined(CONFIG_USER_ONLY)
 DEF_HELPER_3(eret, noreturn, env, i32, i32)
+DEF_HELPER_FLAGS_2(rdprs, TCG_CALL_NO_WG, i32, env, i32)
+DEF_HELPER_3(wrprs, void, env, i32, i32)
 DEF_HELPER_2(mmu_write_tlbacc, void, env, i32)
 DEF_HELPER_2(mmu_write_tlbmisc, void, env, i32)
 DEF_HELPER_2(mmu_write_pteaddr, void, env, i32)
diff --git a/target/nios2/op_helper.c b/target/nios2/op_helper.c
index 849867becd..e5e70268da 100644
--- a/target/nios2/op_helper.c
+++ b/target/nios2/op_helper.c
@@ -83,4 +83,16 @@  void helper_eret(CPUNios2State *env, uint32_t new_status, uint32_t new_pc)
     env->pc = new_pc;
     cpu_loop_exit(cs);
 }
+
+uint32_t helper_rdprs(CPUNios2State *env, uint32_t regno)
+{
+    unsigned prs = FIELD_EX32(env->ctrl[CR_STATUS], CR_STATUS, PRS);
+    return env->shadow_regs[prs][regno];
+}
+
+void helper_wrprs(CPUNios2State *env, uint32_t regno, uint32_t val)
+{
+    unsigned prs = FIELD_EX32(env->ctrl[CR_STATUS], CR_STATUS, PRS);
+    env->shadow_regs[prs][regno] = val;
+}
 #endif /* !CONFIG_USER_ONLY */
diff --git a/target/nios2/translate.c b/target/nios2/translate.c
index 525df7b023..2b2f528e00 100644
--- a/target/nios2/translate.c
+++ b/target/nios2/translate.c
@@ -103,6 +103,7 @@  typedef struct DisasContext {
     bool              crs0;
     TCGv              sink;
     const ControlRegState *cr_state;
+    bool              eic_present;
 } DisasContext;
 
 static TCGv cpu_R[NUM_GP_REGS];
@@ -326,6 +327,27 @@  gen_i_math_logic(andhi, andi, 0, instr.imm16.u << 16)
 gen_i_math_logic(orhi , ori,  1, instr.imm16.u << 16)
 gen_i_math_logic(xorhi, xori, 1, instr.imm16.u << 16)
 
+/* rB <- prs.rA + sigma(IMM16) */
+static void rdprs(DisasContext *dc, uint32_t code, uint32_t flags)
+{
+    if (!dc->eic_present) {
+        t_gen_helper_raise_exception(dc, EXCP_ILLEGAL);
+        return;
+    }
+    if (!gen_check_supervisor(dc)) {
+        return;
+    }
+
+#ifdef CONFIG_USER_ONLY
+    g_assert_not_reached();
+#else
+    I_TYPE(instr, code);
+    TCGv dest = dest_gpr(dc, instr.b);
+    gen_helper_rdprs(dest, cpu_env, tcg_constant_i32(instr.a));
+    tcg_gen_addi_tl(dest, dest, instr.imm16.s);
+#endif
+}
+
 /* Prototype only, defined below */
 static void handle_r_type_instr(DisasContext *dc, uint32_t code,
                                 uint32_t flags);
@@ -387,7 +409,7 @@  static const Nios2Instruction i_type_instructions[] = {
     INSTRUCTION_FLG(gen_stx, MO_SL),                  /* stwio */
     INSTRUCTION_FLG(gen_bxx, TCG_COND_LTU),           /* bltu */
     INSTRUCTION_FLG(gen_ldx, MO_UL),                  /* ldwio */
-    INSTRUCTION_UNIMPLEMENTED(),                      /* rdprs */
+    INSTRUCTION(rdprs),                               /* rdprs */
     INSTRUCTION_ILLEGAL(),
     INSTRUCTION_FLG(handle_r_type_instr, 0),          /* R-Type */
     INSTRUCTION_NOP(),                                /* flushd */
@@ -587,6 +609,26 @@  static void wrctl(DisasContext *dc, uint32_t code, uint32_t flags)
 #endif
 }
 
+/* prs.rC <- rA */
+static void wrprs(DisasContext *dc, uint32_t code, uint32_t flags)
+{
+    if (!dc->eic_present) {
+        t_gen_helper_raise_exception(dc, EXCP_ILLEGAL);
+        return;
+    }
+    if (!gen_check_supervisor(dc)) {
+        return;
+    }
+
+#ifdef CONFIG_USER_ONLY
+    g_assert_not_reached();
+#else
+    R_TYPE(instr, code);
+    gen_helper_wrprs(cpu_env, tcg_constant_i32(instr.c),
+                     load_gpr(dc, instr.a));
+#endif
+}
+
 /* Comparison instructions */
 static void gen_cmpxx(DisasContext *dc, uint32_t code, uint32_t flags)
 {
@@ -711,7 +753,7 @@  static const Nios2Instruction r_type_instructions[] = {
     INSTRUCTION_ILLEGAL(),
     INSTRUCTION(slli),                                /* slli */
     INSTRUCTION(sll),                                 /* sll */
-    INSTRUCTION_UNIMPLEMENTED(),                      /* wrprs */
+    INSTRUCTION(wrprs),                               /* wrprs */
     INSTRUCTION_ILLEGAL(),
     INSTRUCTION(or),                                  /* or */
     INSTRUCTION(mulxsu),                              /* mulxsu */
@@ -812,6 +854,7 @@  static void nios2_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
 
     dc->mem_idx = cpu_mmu_index(env, false);
     dc->cr_state = cpu->cr_state;
+    dc->eic_present = cpu->eic_present;
     dc->crs0 = FIELD_EX32(dc->base.tb->flags, TBFLAGS, CRS0);
 
     /* Bound the number of insns to execute to those left on the page.  */