Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpregs.h            |  2 ++
 target/arm/cpregs-gcs.c        | 17 ++++++++++++++++
 target/arm/tcg/translate-a64.c | 37 ++++++++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+)

diff --git a/target/arm/cpregs.h b/target/arm/cpregs.h
index 9b19520346..3d76afd20b 100644
--- a/target/arm/cpregs.h
+++ b/target/arm/cpregs.h
@@ -49,6 +49,7 @@ enum {
     /* Special: gcs instructions */
     ARM_CP_GCSPUSHM              = 0x0008,
     ARM_CP_GCSPOPM               = 0x0009,
+    ARM_CP_GCSPUSHX              = 0x000a,
 
     /* Flag: reads produce resetvalue; writes ignored. */
     ARM_CP_CONST                 = 1 << 4,
@@ -865,6 +866,7 @@ typedef enum FGTBit {
     DO_BIT(HFGITR, CPPRCTX),
     DO_BIT(HFGITR, DCCVAC),
     DO_REV_BIT(HFGITR, NGCSPUSHM_EL1),
+    DO_REV_BIT(HFGITR, NGCSEPP),
     DO_BIT(HFGITR, ATS1E1A),
 } FGTBit;
 
diff --git a/target/arm/cpregs-gcs.c b/target/arm/cpregs-gcs.c
index fdefb2e17a..c688d0c391 100644
--- a/target/arm/cpregs-gcs.c
+++ b/target/arm/cpregs-gcs.c
@@ -53,6 +53,19 @@ static CPAccessResult access_gcspushm(CPUARMState *env, const ARMCPRegInfo *ri,
     return CP_ACCESS_OK;
 }
 
+static CPAccessResult access_gcspushx(CPUARMState *env, const ARMCPRegInfo *ri,
+                                      bool isread)
+{
+    /* Trap if lock taken, and enabled. */
+    if (!(env->pstate & PSTATE_EXLOCK)) {
+        int el = arm_current_el(env);
+        if (env->cp15.gcscr_el[el] & GCSCR_EXLOCKEN) {
+            return CP_ACCESS_EXLOCK;
+        }
+    }
+    return CP_ACCESS_OK;
+}
+
 static const ARMCPRegInfo gcs_reginfo[] = {
     { .name = "GCSCRE0_EL1", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 0, .crn = 2, .crm = 5, .opc2 = 2,
@@ -99,6 +112,10 @@ static const ARMCPRegInfo gcs_reginfo[] = {
     { .name = "GCSPOPM", .state = ARM_CP_STATE_AA64,
       .opc0 = 1, .opc1 = 3, .crn = 7, .crm = 7, .opc2 = 1,
       .access = PL0_R, .type = ARM_CP_GCSPOPM },
+    { .name = "GCSPUSHX", .state = ARM_CP_STATE_AA64,
+      .opc0 = 1, .opc1 = 0, .crn = 7, .crm = 7, .opc2 = 4,
+      .access = PL1_W, .accessfn = access_gcspushx, .fgt = FGT_NGCSEPP,
+      .type = ARM_CP_GCSPUSHX },
 };
 
 void define_gcs_cpregs(ARMCPU *cpu)
diff --git a/target/arm/tcg/translate-a64.c b/target/arm/tcg/translate-a64.c
index badc24d2a5..e5d9a6e837 100644
--- a/target/arm/tcg/translate-a64.c
+++ b/target/arm/tcg/translate-a64.c
@@ -2531,6 +2531,35 @@ static void gen_gcspopm(DisasContext *s, int rt)
     tcg_gen_mov_i64(cpu_reg(s, rt), value);
 }
 
+static void gen_gcspushx(DisasContext *s)
+{
+    TCGv_i64 gcspr = cpu_gcspr[s->current_el];
+    int spsr_idx = aarch64_banked_spsr_index(s->current_el);
+    int spsr_off = offsetof(CPUARMState, banked_spsr[spsr_idx]);
+    int elr_off = offsetof(CPUARMState, elr_el[s->current_el]);
+    int mmuidx = core_gcs_mem_index(s->mmu_idx);
+    MemOp mop = finalize_memop(s, MO_64 | MO_ALIGN);
+    TCGv_i64 addr = tcg_temp_new_i64();
+    TCGv_i64 tmp = tcg_temp_new_i64();
+
+    tcg_gen_addi_i64(addr, gcspr, -8);
+    tcg_gen_qemu_st_i64(cpu_reg(s, 30), addr, mmuidx, mop);
+
+    tcg_gen_ld_i64(tmp, tcg_env, spsr_off);
+    tcg_gen_addi_i64(addr, addr, -8);
+    tcg_gen_qemu_st_i64(tmp, addr, mmuidx, mop);
+
+    tcg_gen_ld_i64(tmp, tcg_env, elr_off);
+    tcg_gen_addi_i64(addr, addr, -8);
+    tcg_gen_qemu_st_i64(tmp, addr, mmuidx, mop);
+
+    tcg_gen_addi_i64(addr, addr, -8);
+    tcg_gen_qemu_st_i64(tcg_constant_i64(0b1001), addr, mmuidx, mop);
+
+    tcg_gen_mov_i64(gcspr, addr);
+    clear_pstate_bits(PSTATE_EXLOCK);
+}
+
 /* MRS - move from system register
  * MSR (register) - move to system register
  * SYS
@@ -2818,6 +2847,14 @@ static void handle_sys(DisasContext *s, bool isread,
             gen_gcspopm(s, rt);
         }
         return;
+    case ARM_CP_GCSPUSHX:
+        /* Choose the CONSTRAINED UNPREDICTABLE for UNDEF. */
+        if (rt != 31) {
+            unallocated_encoding(s);
+        } else if (s->gcs_en) {
+            gen_gcspushx(s);
+        }
+        return;
     default:
         g_assert_not_reached();
     }
-- 
2.43.0