target/openrisc: implement shadow registers

Shadow registers are part of the openrisc spec along with sr[cid], as
part of the fast context switching feature.  When exceptions occur,
instead of having to save registers to the stack if enabled the CID will
increment and a new set of registers will be available.

This patch only implements shadow registers which can be used as extra
scratch registers via the mfspr and mtspr if required.  This is
implemented in a way where it would be easy to add on the fast context
switching, currently cid is hardcoded to 0.

This is need for openrisc linux smp kernels to boot correctly.

Signed-off-by: Stafford Horne <shorne@gmail.com>

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index f520d7723c04d31c27d9d54c38eb8d013978b723..ce77317e0965662b0738b2438facf11de61f8a2f 100644 (file)
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1052,7 +1052,7 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs,
     int i;
 
     for (i = 0; i < 32; i++) {
-        (*regs)[i] = tswapreg(env->gpr[i]);
+        (*regs)[i] = tswapreg(cpu_get_gpr(env, i));
     }
     (*regs)[32] = tswapreg(env->pc);
     (*regs)[33] = tswapreg(cpu_get_sr(env));

diff --git a/linux-user/main.c b/linux-user/main.c
index 10a3bb3a123830ddf50503df8b8b12308a1db563..79d621b87232eac567c15e78af9fe4ff4d9622b1 100644 (file)
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -2590,17 +2590,17 @@ void cpu_loop(CPUOpenRISCState *env)
         case EXCP_SYSCALL:
             env->pc += 4;   /* 0xc00; */
             ret = do_syscall(env,
-                             env->gpr[11], /* return value       */
-                             env->gpr[3],  /* r3 - r7 are params */
-                             env->gpr[4],
-                             env->gpr[5],
-                             env->gpr[6],
-                             env->gpr[7],
-                             env->gpr[8], 0, 0);
+                             cpu_get_gpr(env, 11), /* return value       */
+                             cpu_get_gpr(env, 3),  /* r3 - r7 are params */
+                             cpu_get_gpr(env, 4),
+                             cpu_get_gpr(env, 5),
+                             cpu_get_gpr(env, 6),
+                             cpu_get_gpr(env, 7),
+                             cpu_get_gpr(env, 8), 0, 0);
             if (ret == -TARGET_ERESTARTSYS) {
                 env->pc -= 4;
             } else if (ret != -TARGET_QEMU_ESIGRETURN) {
-                env->gpr[11] = ret;
+                cpu_set_gpr(env, 11, ret);
             }
             break;
         case EXCP_DPF:
@@ -4765,7 +4765,7 @@ int main(int argc, char **argv, char **envp)
         int i;
 
         for (i = 0; i < 32; i++) {
-            env->gpr[i] = regs->gpr[i];
+            cpu_set_gpr(env, i, regs->gpr[i]);
         }
         env->pc = regs->pc;
         cpu_set_sr(env, regs->sr);

diff --git a/linux-user/openrisc/target_cpu.h b/linux-user/openrisc/target_cpu.h
index f283d96a9353ed85b2316e5b1eddd8bab26fd41e..606ad6f69581f829dbaed125cf68c37705ec25df 100644 (file)
--- a/linux-user/openrisc/target_cpu.h
+++ b/linux-user/openrisc/target_cpu.h
@@ -23,14 +23,14 @@
 static inline void cpu_clone_regs(CPUOpenRISCState *env, target_ulong newsp)
 {
     if (newsp) {
-        env->gpr[1] = newsp;
+        cpu_set_gpr(env, 1, newsp);
     }
-    env->gpr[11] = 0;
+    cpu_set_gpr(env, 11, 0);
 }
 
 static inline void cpu_set_tls(CPUOpenRISCState *env, target_ulong newtls)
 {
-    env->gpr[10] = newtls;
+    cpu_set_gpr(env, 10, newtls);
 }
 
 #endif

diff --git a/linux-user/openrisc/target_signal.h b/linux-user/openrisc/target_signal.h
index 9f2c493f79c1a48772f273f4384f817ea96feed2..95a733e15af4aaa95027075f94e1e1541f7d4cac 100644 (file)
--- a/linux-user/openrisc/target_signal.h
+++ b/linux-user/openrisc/target_signal.h
@@ -20,7 +20,7 @@ typedef struct target_sigaltstack {
 
 static inline abi_ulong get_sp_from_cpustate(CPUOpenRISCState *state)
 {
-    return state->gpr[1];
+    return cpu_get_gpr(state, 1);
 }
 
 

diff --git a/linux-user/signal.c b/linux-user/signal.c
index a67db04e1a48c5f354d449c9387af5a6749d0f9e..3d18d1b3ee6069597a9b296de1042626bc1ff3b8 100644 (file)
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -4411,7 +4411,7 @@ static void setup_sigcontext(struct target_sigcontext *sc,
                              CPUOpenRISCState *regs,
                              unsigned long mask)
 {
-    unsigned long usp = regs->gpr[1];
+    unsigned long usp = cpu_get_gpr(regs, 1);
 
     /* copy the regs. they are first in sc so we can use sc directly */
 
@@ -4436,7 +4436,7 @@ static inline abi_ulong get_sigframe(struct target_sigaction *ka,
                                      CPUOpenRISCState *regs,
                                      size_t frame_size)
 {
-    unsigned long sp = regs->gpr[1];
+    unsigned long sp = cpu_get_gpr(regs, 1);
     int onsigstack = on_sig_stack(sp);
 
     /* redzone */
@@ -4489,7 +4489,8 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka,
     __put_user(0, &frame->uc.tuc_link);
     __put_user(target_sigaltstack_used.ss_sp,
                &frame->uc.tuc_stack.ss_sp);
-    __put_user(sas_ss_flags(env->gpr[1]), &frame->uc.tuc_stack.ss_flags);
+    __put_user(sas_ss_flags(cpu_get_gpr(env, 1)),
+               &frame->uc.tuc_stack.ss_flags);
     __put_user(target_sigaltstack_used.ss_size,
                &frame->uc.tuc_stack.ss_size);
     setup_sigcontext(&frame->sc, env, set->sig[0]);
@@ -4512,13 +4513,13 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka,
 
     /* Set up registers for signal handler */
     env->pc = (unsigned long)ka->_sa_handler; /* what we enter NOW */
-    env->gpr[9] = (unsigned long)return_ip;     /* what we enter LATER */
-    env->gpr[3] = (unsigned long)sig;           /* arg 1: signo */
-    env->gpr[4] = (unsigned long)&frame->info;  /* arg 2: (siginfo_t*) */
-    env->gpr[5] = (unsigned long)&frame->uc;    /* arg 3: ucontext */
+    cpu_set_gpr(env, 9, (unsigned long)return_ip);     /* what we enter LATER */
+    cpu_set_gpr(env, 3, (unsigned long)sig);           /* arg 1: signo */
+    cpu_set_gpr(env, 4, (unsigned long)&frame->info);  /* arg 2: (siginfo_t*) */
+    cpu_set_gpr(env, 5, (unsigned long)&frame->uc);    /* arg 3: ucontext */
 
     /* actually move the usp to reflect the stacked frame */
-    env->gpr[1] = (unsigned long)frame;
+    cpu_set_gpr(env, 1, (unsigned long)frame);
 
     return;
 

diff --git a/target/openrisc/cpu.c b/target/openrisc/cpu.c
index 1524ed981ae917c922d0505944b4470005bd7721..6c1ed07c165c8e65d4c37a6434f164cc215d5edb 100644 (file)
--- a/target/openrisc/cpu.c
+++ b/target/openrisc/cpu.c
@@ -52,7 +52,7 @@ static void openrisc_cpu_reset(CPUState *s)
     s->exception_index = -1;
 
     cpu->env.upr = UPR_UP | UPR_DMP | UPR_IMP | UPR_PICP | UPR_TTP;
-    cpu->env.cpucfgr = CPUCFGR_OB32S | CPUCFGR_OF32S;
+    cpu->env.cpucfgr = CPUCFGR_OB32S | CPUCFGR_OF32S | CPUCFGR_NSGF;
     cpu->env.dmmucfgr = (DMMUCFGR_NTW & (0 << 2)) | (DMMUCFGR_NTS & (6 << 2));
     cpu->env.immucfgr = (IMMUCFGR_NTW & (0 << 2)) | (IMMUCFGR_NTS & (6 << 2));
 
@@ -132,6 +132,7 @@ static void or1200_initfn(Object *obj)
 {
     OpenRISCCPU *cpu = OPENRISC_CPU(obj);
 
+    set_feature(cpu, OPENRISC_FEATURE_NSGF);
     set_feature(cpu, OPENRISC_FEATURE_OB32S);
     set_feature(cpu, OPENRISC_FEATURE_OF32S);
     set_feature(cpu, OPENRISC_FEATURE_EVBAR);
@@ -141,6 +142,7 @@ static void openrisc_any_initfn(Object *obj)
 {
     OpenRISCCPU *cpu = OPENRISC_CPU(obj);
 
+    set_feature(cpu, OPENRISC_FEATURE_NSGF);
     set_feature(cpu, OPENRISC_FEATURE_OB32S);
     set_feature(cpu, OPENRISC_FEATURE_EVBAR);
 }

diff --git a/target/openrisc/cpu.h b/target/openrisc/cpu.h
index 1958b72718cce0291abed9610370f193e8ee402d..e159b226a4676f26b9076947a4ea854a4fde6455 100644 (file)
--- a/target/openrisc/cpu.h
+++ b/target/openrisc/cpu.h
@@ -275,7 +275,8 @@ typedef struct CPUOpenRISCTLBContext {
 #endif
 
 typedef struct CPUOpenRISCState {
-    target_ulong gpr[32];     /* General registers */
+    target_ulong shadow_gpr[16][32]; /* Shadow registers */
+
     target_ulong pc;          /* Program counter */
     target_ulong ppc;         /* Prev PC */
     target_ulong jmp_pc;      /* Jump PC */
@@ -399,6 +400,16 @@ int cpu_openrisc_get_phys_data(OpenRISCCPU *cpu,
 #define TB_FLAGS_R0_0  2
 #define TB_FLAGS_OVE   SR_OVE
 
+static inline uint32_t cpu_get_gpr(const CPUOpenRISCState *env, int i)
+{
+    return env->shadow_gpr[0][i];
+}
+
+static inline void cpu_set_gpr(CPUOpenRISCState *env, int i, uint32_t val)
+{
+    env->shadow_gpr[0][i] = val;
+}
+
 static inline void cpu_get_tb_cpu_state(CPUOpenRISCState *env,
                                         target_ulong *pc,
                                         target_ulong *cs_base, uint32_t *flags)
@@ -406,7 +417,7 @@ static inline void cpu_get_tb_cpu_state(CPUOpenRISCState *env,
     *pc = env->pc;
     *cs_base = 0;
     *flags = (env->dflag
-              | (env->gpr[0] == 0 ? TB_FLAGS_R0_0 : 0)
+              | (cpu_get_gpr(env, 0) == 0 ? TB_FLAGS_R0_0 : 0)
               | (env->sr & SR_OVE));
 }
 

diff --git a/target/openrisc/gdbstub.c b/target/openrisc/gdbstub.c
index b18c7e9f05c14b8ce69a819d808ccc631f8ee868..f9af6507f3390edc3bd9f3a42735f99a69ca2f3d 100644 (file)
--- a/target/openrisc/gdbstub.c
+++ b/target/openrisc/gdbstub.c
@@ -28,7 +28,7 @@ int openrisc_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
     CPUOpenRISCState *env = &cpu->env;
 
     if (n < 32) {
-        return gdb_get_reg32(mem_buf, env->gpr[n]);
+        return gdb_get_reg32(mem_buf, cpu_get_gpr(env, n));
     } else {
         switch (n) {
         case 32:    /* PPC */
@@ -61,7 +61,7 @@ int openrisc_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
     tmp = ldl_p(mem_buf);
 
     if (n < 32) {
-        env->gpr[n] = tmp;
+        cpu_set_gpr(env, n, tmp);
     } else {
         switch (n) {
         case 32: /* PPC */

diff --git a/target/openrisc/machine.c b/target/openrisc/machine.c
index 686eaa30c93a54209f93bc7b02268ebe994e7f46..2bf71c352e7c12f2b36b39275fbc4b1325cb3a24 100644 (file)
--- a/target/openrisc/machine.c
+++ b/target/openrisc/machine.c
@@ -47,10 +47,10 @@ static const VMStateInfo vmstate_sr = {
 
 static const VMStateDescription vmstate_env = {
     .name = "env",
-    .version_id = 4,
-    .minimum_version_id = 4,
+    .version_id = 5,
+    .minimum_version_id = 5,
     .fields = (VMStateField[]) {
-        VMSTATE_UINTTL_ARRAY(gpr, CPUOpenRISCState, 32),
+        VMSTATE_UINTTL_2DARRAY(shadow_gpr, CPUOpenRISCState, 16, 32),
         VMSTATE_UINTTL(pc, CPUOpenRISCState),
         VMSTATE_UINTTL(ppc, CPUOpenRISCState),
         VMSTATE_UINTTL(jmp_pc, CPUOpenRISCState),

diff --git a/target/openrisc/sys_helper.c b/target/openrisc/sys_helper.c
index e13666bea0a869af4bf54ba8d0793776a9872472..fa3d6a436e5dae581e2ba691b567f9c350e4ce56 100644 (file)
--- a/target/openrisc/sys_helper.c
+++ b/target/openrisc/sys_helper.c
@@ -92,6 +92,11 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
     case TO_SPR(0, 64): /* ESR */
         env->esr = rb;
         break;
+
+    case TO_SPR(0, 1024) ... TO_SPR(0, 1024 + (16 * 32)): /* Shadow GPRs */
+        idx = (spr - 1024);
+        env->shadow_gpr[idx / 32][idx % 32] = rb;
+
     case TO_SPR(1, 512) ... TO_SPR(1, 512+DTLB_SIZE-1): /* DTLBW0MR 0-127 */
         idx = spr - TO_SPR(1, 512);
         if (!(rb & 1)) {
@@ -239,6 +244,10 @@ target_ulong HELPER(mfspr)(CPUOpenRISCState *env,
     case TO_SPR(0, 129): /* NUMCORES */
         return 1;
 
+    case TO_SPR(0, 1024) ... TO_SPR(0, 1024 + (16 * 32)): /* Shadow GPRs */
+        idx = (spr - 1024);
+        return env->shadow_gpr[idx / 32][idx % 32];
+
     case TO_SPR(1, 512) ... TO_SPR(1, 512+DTLB_SIZE-1): /* DTLBW0MR 0-127 */
         idx = spr - TO_SPR(1, 512);
         return env->tlb->dtlb[0][idx].mr;

diff --git a/target/openrisc/translate.c b/target/openrisc/translate.c
index 7c4cbf205f37a9b3ea64ed1f76bae6c55271b88f..e49518e893e934e63423fe79d17f094ba27f92c5 100644 (file)
--- a/target/openrisc/translate.c
+++ b/target/openrisc/translate.c
@@ -107,7 +107,8 @@ void openrisc_translate_init(void)
                                      "mac");
     for (i = 0; i < 32; i++) {
         cpu_R[i] = tcg_global_mem_new(cpu_env,
-                                      offsetof(CPUOpenRISCState, gpr[i]),
+                                      offsetof(CPUOpenRISCState,
+                                               shadow_gpr[0][i]),
                                       regnames[i]);
     }
     cpu_R0 = cpu_R[0];
@@ -1662,7 +1663,7 @@ void openrisc_cpu_dump_state(CPUState *cs, FILE *f,
 
     cpu_fprintf(f, "PC=%08x\n", env->pc);
     for (i = 0; i < 32; ++i) {
-        cpu_fprintf(f, "R%02d=%08x%c", i, env->gpr[i],
+        cpu_fprintf(f, "R%02d=%08x%c", i, cpu_get_gpr(env, i),
                     (i % 4) == 3 ? '\n' : ' ');
     }
 }