MIPS patches 2015-10-30

Changes:
 * R6 CPU can be woken up by non-enabled interrupts
 * PC fix in KVM
 * Coprocessor 0 XContext calculation fix
 * various MIPS R6 updates
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Merge remote-tracking branch 'remotes/lalrae/tags/mips-20151030' into staging

MIPS patches 2015-10-30

Changes:
* R6 CPU can be woken up by non-enabled interrupts
* PC fix in KVM
* Coprocessor 0 XContext calculation fix
* various MIPS R6 updates

# gpg: Signature made Fri 30 Oct 2015 14:51:56 GMT using RSA key ID 0B29DA6B
# gpg: Good signature from "Leon Alrae <leon.alrae@imgtec.com>"

* remotes/lalrae/tags/mips-20151030:
  target-mips: fix updating XContext on mmu exception
  target-mips: add SIGRIE instruction
  target-mips: Set Config5.XNP for R6 cores
  target-mips: add PC, XNP reg numbers to RDHWR
  hw/mips_malta: Fix KVM PC initialisation
  target-mips: Add enum for BREAK32
  target-mips: update writing to CP0.Status.KX/SX/UX in MIPS Release R6
  target-mips: implement the CPU wake-up on non-enabled interrupts in R6
  target-mips: move the test for enabled interrupts to a separate function

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

hw/mips/mips_malta.c

@@ -901,7 +901,7 @@ static void main_cpu_reset(void *opaque)
 
     if (kvm_enabled()) {
         /* Start running from the bootloader we wrote to end of RAM */
-        env->active_tc.PC = 0x40000000 + loaderparams.ram_size;
+        env->active_tc.PC = 0x40000000 + loaderparams.ram_low_size;
     }
 }
 

target-mips/cpu.c

@@ -53,12 +53,15 @@ static bool mips_cpu_has_work(CPUState *cs)
     CPUMIPSState *env = &cpu->env;
     bool has_work = false;
 
-    /* It is implementation dependent if non-enabled interrupts
+    /* Prior to MIPS Release 6 it is implementation dependent if non-enabled
-       wake-up the CPU, however most of the implementations only
+       interrupts wake-up the CPU, however most of the implementations only
        check for interrupts that can be taken. */
     if ((cs->interrupt_request & CPU_INTERRUPT_HARD) &&
         cpu_mips_hw_interrupts_pending(env)) {
-        has_work = true;
+        if (cpu_mips_hw_interrupts_enabled(env) ||
+            (env->insn_flags & ISA_MIPS32R6)) {
+            has_work = true;
+        }
     }
 
     /* MIPS-MT has the ability to halt the CPU.  */

target-mips/cpu.h

@@ -469,6 +469,7 @@ struct CPUMIPSState {
 #define CP0C5_CV         29
 #define CP0C5_EVA        28
 #define CP0C5_MSAEn      27
+#define CP0C5_XNP        13
 #define CP0C5_UFE        9
 #define CP0C5_FRE        8
 #define CP0C5_SBRI       6
@@ -637,23 +638,24 @@ static inline int cpu_mmu_index (CPUMIPSState *env, bool ifetch)
     return env->hflags & MIPS_HFLAG_KSU;
 }
 
-static inline int cpu_mips_hw_interrupts_pending(CPUMIPSState *env)
+static inline bool cpu_mips_hw_interrupts_enabled(CPUMIPSState *env)
 {
-    int32_t pending;
+    return (env->CP0_Status & (1 << CP0St_IE)) &&
-    int32_t status;
+        !(env->CP0_Status & (1 << CP0St_EXL)) &&
-    int r;
+        !(env->CP0_Status & (1 << CP0St_ERL)) &&
-
+        !(env->hflags & MIPS_HFLAG_DM) &&
-    if (!(env->CP0_Status & (1 << CP0St_IE)) ||
-        (env->CP0_Status & (1 << CP0St_EXL)) ||
-        (env->CP0_Status & (1 << CP0St_ERL)) ||
         /* Note that the TCStatus IXMT field is initialized to zero,
            and only MT capable cores can set it to one. So we don't
            need to check for MT capabilities here.  */
-        (env->active_tc.CP0_TCStatus & (1 << CP0TCSt_IXMT)) ||
+        !(env->active_tc.CP0_TCStatus & (1 << CP0TCSt_IXMT));
-        (env->hflags & MIPS_HFLAG_DM)) {
+}
-        /* Interrupts are disabled */
+
-        return 0;
+/* Check if there is pending and not masked out interrupt */
-    }
+static inline bool cpu_mips_hw_interrupts_pending(CPUMIPSState *env)
+{
+    int32_t pending;
+    int32_t status;
+    bool r;
 
     pending = env->CP0_Cause & CP0Ca_IP_mask;
     status = env->CP0_Status & CP0Ca_IP_mask;
@@ -667,7 +669,7 @@ static inline int cpu_mips_hw_interrupts_pending(CPUMIPSState *env)
         /* A MIPS configured with compatibility or VInt (Vectored Interrupts)
            treats the pending lines as individual interrupt lines, the status
            lines are individual masks.  */
-        r = pending & status;
+        r = (pending & status) != 0;
     }
     return r;
 }
@@ -1000,7 +1002,12 @@ static inline void cpu_mips_store_status(CPUMIPSState *env, target_ulong val)
 
     if (env->insn_flags & ISA_MIPS32R6) {
         bool has_supervisor = extract32(mask, CP0St_KSU, 2) == 0x3;
-
+#if defined(TARGET_MIPS64)
+        uint32_t ksux = (1 << CP0St_KX) & val;
+        ksux |= (ksux >> 1) & val; /* KX = 0 forces SX to be 0 */
+        ksux |= (ksux >> 1) & val; /* SX = 0 forces UX to be 0 */
+        val = (val & ~(7 << CP0St_UX)) | ksux;
+#endif
         if (has_supervisor && extract32(val, CP0St_KSU, 2) == 0x3) {
             mask &= ~(3 << CP0St_KSU);
         }

target-mips/helper.c

@@ -293,9 +293,10 @@ static void raise_mmu_exception(CPUMIPSState *env, target_ulong address,
         (env->CP0_EntryHi & 0xFF) | (address & (TARGET_PAGE_MASK << 1));
 #if defined(TARGET_MIPS64)
     env->CP0_EntryHi &= env->SEGMask;
-    env->CP0_XContext = (env->CP0_XContext & ((~0ULL) << (env->SEGBITS - 7))) |
+    env->CP0_XContext =
-                        ((address & 0xC00000000000ULL) >> (55 - env->SEGBITS)) |
+        /* PTEBase */   (env->CP0_XContext & ((~0ULL) << (env->SEGBITS - 7))) |
-                        ((address & ((1ULL << env->SEGBITS) - 1) & 0xFFFFFFFFFFFFE000ULL) >> 9);
+        /* R */         (extract64(address, 62, 2) << (env->SEGBITS - 9)) |
+        /* BadVPN2 */   (extract64(address, 13, env->SEGBITS - 13) << 4);
 #endif
     cs->exception_index = exception;
     env->error_code = error_code;
@@ -759,7 +760,8 @@ bool mips_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
         MIPSCPU *cpu = MIPS_CPU(cs);
         CPUMIPSState *env = &cpu->env;
 
-        if (cpu_mips_hw_interrupts_pending(env)) {
+        if (cpu_mips_hw_interrupts_enabled(env) &&
+            cpu_mips_hw_interrupts_pending(env)) {
             /* Raise it */
             cs->exception_index = EXCP_EXT_INTERRUPT;
             env->error_code = 0;

target-mips/helper.h

@@ -358,6 +358,8 @@ DEF_HELPER_1(rdhwr_cpunum, tl, env)
 DEF_HELPER_1(rdhwr_synci_step, tl, env)
 DEF_HELPER_1(rdhwr_cc, tl, env)
 DEF_HELPER_1(rdhwr_ccres, tl, env)
+DEF_HELPER_1(rdhwr_performance, tl, env)
+DEF_HELPER_1(rdhwr_xnp, tl, env)
 DEF_HELPER_2(pmon, void, env, int)
 DEF_HELPER_1(wait, void, env)
 

target-mips/op_helper.c

@@ -1357,6 +1357,13 @@ void helper_mtc0_hwrena(CPUMIPSState *env, target_ulong arg1)
 {
     uint32_t mask = 0x0000000F;
 
+    if ((env->CP0_Config1 & (1 << CP0C1_PC)) &&
+        (env->insn_flags & ISA_MIPS32R6)) {
+        mask |= (1 << 4);
+    }
+    if (env->insn_flags & ISA_MIPS32R6) {
+        mask |= (1 << 5);
+    }
     if (env->CP0_Config3 & (1 << CP0C3_ULRI)) {
         mask |= (1 << 29);
 
@@ -2185,53 +2192,52 @@ void helper_deret(CPUMIPSState *env)
 }
 #endif /* !CONFIG_USER_ONLY */
 
+static inline void check_hwrena(CPUMIPSState *env, int reg)
+{
+    if ((env->hflags & MIPS_HFLAG_CP0) || (env->CP0_HWREna & (1 << reg))) {
+        return;
+    }
+    do_raise_exception(env, EXCP_RI, GETPC());
+}
+
 target_ulong helper_rdhwr_cpunum(CPUMIPSState *env)
 {
-    if ((env->hflags & MIPS_HFLAG_CP0) ||
+    check_hwrena(env, 0);
-        (env->CP0_HWREna & (1 << 0)))
+    return env->CP0_EBase & 0x3ff;
-        return env->CP0_EBase & 0x3ff;
-    else
-        do_raise_exception(env, EXCP_RI, GETPC());
-
-    return 0;
 }
 
 target_ulong helper_rdhwr_synci_step(CPUMIPSState *env)
 {
-    if ((env->hflags & MIPS_HFLAG_CP0) ||
+    check_hwrena(env, 1);
-        (env->CP0_HWREna & (1 << 1)))
+    return env->SYNCI_Step;
-        return env->SYNCI_Step;
-    else
-        do_raise_exception(env, EXCP_RI, GETPC());
-
-    return 0;
 }
 
 target_ulong helper_rdhwr_cc(CPUMIPSState *env)
 {
-    if ((env->hflags & MIPS_HFLAG_CP0) ||
+    check_hwrena(env, 2);
-        (env->CP0_HWREna & (1 << 2))) {
 #ifdef CONFIG_USER_ONLY
-        return env->CP0_Count;
+    return env->CP0_Count;
 #else
-        return (int32_t)cpu_mips_get_count(env);
+    return (int32_t)cpu_mips_get_count(env);
 #endif
-    } else {
-        do_raise_exception(env, EXCP_RI, GETPC());
-    }
-
-    return 0;
 }
 
 target_ulong helper_rdhwr_ccres(CPUMIPSState *env)
 {
-    if ((env->hflags & MIPS_HFLAG_CP0) ||
+    check_hwrena(env, 3);
-        (env->CP0_HWREna & (1 << 3)))
+    return env->CCRes;
-        return env->CCRes;
+}
-    else
-        do_raise_exception(env, EXCP_RI, GETPC());
 
-    return 0;
+target_ulong helper_rdhwr_performance(CPUMIPSState *env)
+{
+    check_hwrena(env, 4);
+    return env->CP0_Performance0;
+}
+
+target_ulong helper_rdhwr_xnp(CPUMIPSState *env)
+{
+    check_hwrena(env, 5);
+    return (env->CP0_Config5 >> CP0C5_XNP) & 1;
 }
 
 void helper_pmon(CPUMIPSState *env, int function)

target-mips/translate.c

@@ -323,6 +323,7 @@ enum {
     OPC_TLTIU    = (0x0B << 16) | OPC_REGIMM,
     OPC_TEQI     = (0x0C << 16) | OPC_REGIMM,
     OPC_TNEI     = (0x0E << 16) | OPC_REGIMM,
+    OPC_SIGRIE   = (0x17 << 16) | OPC_REGIMM,
     OPC_SYNCI    = (0x1F << 16) | OPC_REGIMM,
 
     OPC_DAHI     = (0x06 << 16) | OPC_REGIMM,
@@ -10333,7 +10334,7 @@ static void gen_flt3_arith (DisasContext *ctx, uint32_t opc,
     }
 }
 
-static void gen_rdhwr(DisasContext *ctx, int rt, int rd)
+static void gen_rdhwr(DisasContext *ctx, int rt, int rd, int sel)
 {
     TCGv t0;
 
@@ -10361,6 +10362,22 @@ static void gen_rdhwr(DisasContext *ctx, int rt, int rd)
         gen_helper_rdhwr_ccres(t0, cpu_env);
         gen_store_gpr(t0, rt);
         break;
+    case 4:
+        check_insn(ctx, ISA_MIPS32R6);
+        if (sel != 0) {
+            /* Performance counter registers are not implemented other than
+             * control register 0.
+             */
+            generate_exception(ctx, EXCP_RI);
+        }
+        gen_helper_rdhwr_performance(t0, cpu_env);
+        gen_store_gpr(t0, rt);
+        break;
+    case 5:
+        check_insn(ctx, ISA_MIPS32R6);
+        gen_helper_rdhwr_xnp(t0, cpu_env);
+        gen_store_gpr(t0, rt);
+        break;
     case 29:
 #if defined(CONFIG_USER_ONLY)
         tcg_gen_ld_tl(t0, cpu_env,
@@ -11979,6 +11996,7 @@ enum {
     ROTR = 0x3,
     SELEQZ = 0x5,
     SELNEZ = 0x6,
+    R6_RDHWR = 0x7,
 
     SLLV = 0x0,
     SRLV = 0x1,
@@ -12009,11 +12027,13 @@ enum {
     MODU = 0x7,
 
     /* The following can be distinguished by their lower 6 bits. */
+    BREAK32 = 0x07,
     INS = 0x0c,
     LSA = 0x0f,
     ALIGN = 0x1f,
     EXT = 0x2c,
-    POOL32AXF = 0x3c
+    POOL32AXF = 0x3c,
+    SIGRIE = 0x3f
 };
 
 /* POOL32AXF encoding of minor opcode field extension */
@@ -12931,7 +12951,8 @@ static void gen_pool32axf (CPUMIPSState *env, DisasContext *ctx, int rt, int rs)
             gen_cl(ctx, mips32_op, rt, rs);
             break;
         case RDHWR:
-            gen_rdhwr(ctx, rt, rs);
+            check_insn_opc_removed(ctx, ISA_MIPS32R6);
+            gen_rdhwr(ctx, rt, rs, 0);
             break;
         case WSBH:
             gen_bshfl(ctx, OPC_WSBH, rs, rt);
@@ -13486,6 +13507,10 @@ static void decode_micromips32_opc(CPUMIPSState *env, DisasContext *ctx)
                 check_insn(ctx, ISA_MIPS32R6);
                 gen_cond_move(ctx, OPC_SELNEZ, rd, rs, rt);
                 break;
+            case R6_RDHWR:
+                check_insn(ctx, ISA_MIPS32R6);
+                gen_rdhwr(ctx, rt, rs, extract32(ctx->opcode, 11, 3));
+                break;
             default:
                 goto pool32a_invalid;
             }
@@ -13629,9 +13654,13 @@ static void decode_micromips32_opc(CPUMIPSState *env, DisasContext *ctx)
         case POOL32AXF:
             gen_pool32axf(env, ctx, rt, rs);
             break;
-        case 0x07:
+        case BREAK32:
             generate_exception_end(ctx, EXCP_BREAK);
             break;
+        case SIGRIE:
+            check_insn(ctx, ISA_MIPS32R6);
+            generate_exception_end(ctx, EXCP_RI);
+            break;
         default:
         pool32a_invalid:
                 MIPS_INVAL("pool32a");
@@ -17732,7 +17761,7 @@ static void decode_opc_special3(CPUMIPSState *env, DisasContext *ctx)
         break;
 #endif
     case OPC_RDHWR:
-        gen_rdhwr(ctx, rt, rd);
+        gen_rdhwr(ctx, rt, rd, extract32(ctx->opcode, 6, 3));
         break;
     case OPC_FORK:
         check_insn(ctx, ASE_MT);
@@ -18950,6 +18979,10 @@ static void decode_opc(CPUMIPSState *env, DisasContext *ctx)
             check_insn_opc_removed(ctx, ISA_MIPS32R6);
             gen_trap(ctx, op1, rs, -1, imm);
             break;
+        case OPC_SIGRIE:
+            check_insn(ctx, ISA_MIPS32R6);
+            generate_exception_end(ctx, EXCP_RI);
+            break;
         case OPC_SYNCI:
             check_insn(ctx, ISA_MIPS32R2);
             /* Break the TB to be able to sync copied instructions

target-mips/translate_init.c

@@ -447,7 +447,7 @@ static const mips_def_t mips_defs[] =
                        (1 << CP0C3_RXI) | (1U << CP0C3_M),
         .CP0_Config4 = MIPS_CONFIG4 | (0xfc << CP0C4_KScrExist) |
                        (3 << CP0C4_IE) | (1U << CP0C4_M),
-        .CP0_Config5 = MIPS_CONFIG5 | (1 << CP0C5_LLB),
+        .CP0_Config5 = MIPS_CONFIG5 | (1 << CP0C5_XNP) | (1 << CP0C5_LLB),
         .CP0_Config5_rw_bitmask = (1 << CP0C5_SBRI) | (1 << CP0C5_FRE) |
                                   (1 << CP0C5_UFE),
         .CP0_LLAddr_rw_bitmask = 0,
@@ -665,7 +665,7 @@ static const mips_def_t mips_defs[] =
                        (1 << CP0C3_RXI) | (1 << CP0C3_LPA),
         .CP0_Config4 = MIPS_CONFIG4 | (1U << CP0C4_M) | (3 << CP0C4_IE) |
                        (0xfc << CP0C4_KScrExist),
-        .CP0_Config5 = MIPS_CONFIG5 | (1 << CP0C5_LLB),
+        .CP0_Config5 = MIPS_CONFIG5 | (1 << CP0C5_XNP) | (1 << CP0C5_LLB),
         .CP0_Config5_rw_bitmask = (1 << CP0C5_MSAEn) | (1 << CP0C5_SBRI) |
                                   (1 << CP0C5_FRE) | (1 << CP0C5_UFE),
         .CP0_LLAddr_rw_bitmask = 0,