[PATCH 04/39] target/hexagon: Implement start/stop helpers

[Brian Cain <brian.cain@oss.qualcomm.com>]

From: Brian Cain <bcain@quicinc.com>

Signed-off-by: Brian Cain <brian.cain@oss.qualcomm.com>
---
 target/hexagon/cpu.h        |  3 ++
 target/hexagon/cpu_bits.h   |  1 +
 target/hexagon/cpu_helper.h |  3 ++
 target/hexagon/cpu.c        | 14 +++++-
 target/hexagon/cpu_helper.c | 94 +++++++++++++++++++++++++++++++++++++
 target/hexagon/op_helper.c  |  4 +-
 6 files changed, 116 insertions(+), 3 deletions(-)

diff --git a/target/hexagon/cpu.h b/target/hexagon/cpu.h
index 894219fd20..1549c4f1f0 100644
--- a/target/hexagon/cpu.h
+++ b/target/hexagon/cpu.h
@@ -41,6 +41,7 @@ typedef struct CPUHexagonTLBContext CPUHexagonTLBContext;
 #define REG_WRITES_MAX 32
 #define PRED_WRITES_MAX 5                   /* 4 insns + endloop */
 #define VSTORES_MAX 2
+#define VECTOR_UNIT_MAX 8
 
 #ifndef CONFIG_USER_ONLY
 #define CPU_INTERRUPT_SWI      CPU_INTERRUPT_TGT_INT_0
@@ -178,6 +179,7 @@ struct ArchCPU {
 #ifndef CONFIG_USER_ONLY
     uint32_t num_tlbs;
     uint32_t l2vic_base_addr;
+    uint32_t hvx_contexts;
 #endif
 };
 
@@ -194,6 +196,7 @@ G_NORETURN void hexagon_raise_exception_err(CPUHexagonState *env,
 uint32_t hexagon_greg_read(CPUHexagonState *env, uint32_t reg);
 uint32_t hexagon_sreg_read(CPUHexagonState *env, uint32_t reg);
 void hexagon_gdb_sreg_write(CPUHexagonState *env, uint32_t reg, uint32_t val);
+void hexagon_cpu_soft_reset(CPUHexagonState *env);
 #endif
 
 #include "exec/cpu-all.h"
diff --git a/target/hexagon/cpu_bits.h b/target/hexagon/cpu_bits.h
index b559a7ba88..610094a759 100644
--- a/target/hexagon/cpu_bits.h
+++ b/target/hexagon/cpu_bits.h
@@ -52,6 +52,7 @@ enum hex_event {
 
 enum hex_cause {
     HEX_CAUSE_NONE = -1,
+    HEX_CAUSE_RESET = 0x000,
     HEX_CAUSE_TRAP0 = 0x172,
     HEX_CAUSE_FETCH_NO_UPAGE =  0x012,
     HEX_CAUSE_INVALID_PACKET =  0x015,
diff --git a/target/hexagon/cpu_helper.h b/target/hexagon/cpu_helper.h
index 6f0c6697ad..95a0cc0788 100644
--- a/target/hexagon/cpu_helper.h
+++ b/target/hexagon/cpu_helper.h
@@ -17,6 +17,9 @@ void hexagon_set_sys_pcycle_count_high(CPUHexagonState *env, uint32_t);
 void hexagon_modify_ssr(CPUHexagonState *env, uint32_t new, uint32_t old);
 int get_exe_mode(CPUHexagonState *env);
 void clear_wait_mode(CPUHexagonState *env);
+void hexagon_ssr_set_cause(CPUHexagonState *env, uint32_t cause);
+void hexagon_start_threads(CPUHexagonState *env, uint32_t mask);
+void hexagon_stop_thread(CPUHexagonState *env);
 
 static inline void arch_set_thread_reg(CPUHexagonState *env, uint32_t reg,
                                        uint32_t val)
diff --git a/target/hexagon/cpu.c b/target/hexagon/cpu.c
index cb56b929cf..84a96a194b 100644
--- a/target/hexagon/cpu.c
+++ b/target/hexagon/cpu.c
@@ -32,6 +32,7 @@
 
 #ifndef CONFIG_USER_ONLY
 #include "sys_macros.h"
+#include "qemu/main-loop.h"
 #endif
 
 static void hexagon_v66_cpu_init(Object *obj) { }
@@ -61,6 +62,7 @@ static const Property hexagon_cpu_properties[] = {
     DEFINE_PROP_UINT32("jtlb-entries", HexagonCPU, num_tlbs, MAX_TLB_ENTRIES),
     DEFINE_PROP_UINT32("l2vic-base-addr", HexagonCPU, l2vic_base_addr,
         0xffffffffULL),
+    DEFINE_PROP_UINT32("hvx-contexts", HexagonCPU, hvx_contexts, 0),
 #endif
     DEFINE_PROP_BOOL("lldb-compat", HexagonCPU, lldb_compat, false),
     DEFINE_PROP_UNSIGNED("lldb-stack-adjust", HexagonCPU, lldb_stack_adjust, 0,
@@ -295,9 +297,18 @@ static void mmu_reset(CPUHexagonState *env)
         memset(env->hex_tlb, 0, sizeof(*env->hex_tlb));
     }
 }
+
+void hexagon_cpu_soft_reset(CPUHexagonState *env)
+{
+    BQL_LOCK_GUARD();
+    arch_set_system_reg(env, HEX_SREG_SSR, 0);
+    hexagon_ssr_set_cause(env, HEX_CAUSE_RESET);
+
+    target_ulong evb = arch_get_system_reg(env, HEX_SREG_EVB);
+    arch_set_thread_reg(env, HEX_REG_PC, evb);
+}
 #endif
 
-
 static void hexagon_cpu_reset_hold(Object *obj, ResetType type)
 {
     CPUState *cs = CPU(obj);
@@ -327,6 +338,7 @@ static void hexagon_cpu_reset_hold(Object *obj, ResetType type)
     }
     mmu_reset(env);
     arch_set_system_reg(env, HEX_SREG_HTID, cs->cpu_index);
+    hexagon_cpu_soft_reset(env);
     memset(env->t_sreg, 0, sizeof(target_ulong) * NUM_SREGS);
     memset(env->greg, 0, sizeof(target_ulong) * NUM_GREGS);
     env->threadId = cs->cpu_index;
diff --git a/target/hexagon/cpu_helper.c b/target/hexagon/cpu_helper.c
index 9373e491d6..e151c6335a 100644
--- a/target/hexagon/cpu_helper.c
+++ b/target/hexagon/cpu_helper.c
@@ -84,8 +84,102 @@ void clear_wait_mode(CPUHexagonState *env)
     SET_SYSTEM_FIELD(env, HEX_SREG_MODECTL, MODECTL_W, thread_wait_mask);
 }
 
+void hexagon_ssr_set_cause(CPUHexagonState *env, uint32_t cause)
+{
+    g_assert(bql_locked());
+
+    const uint32_t old = arch_get_system_reg(env, HEX_SREG_SSR);
+    SET_SYSTEM_FIELD(env, HEX_SREG_SSR, SSR_EX, 1);
+    SET_SYSTEM_FIELD(env, HEX_SREG_SSR, SSR_CAUSE, cause);
+    const uint32_t new = arch_get_system_reg(env, HEX_SREG_SSR);
+
+    hexagon_modify_ssr(env, new, old);
+}
+
+
 int get_exe_mode(CPUHexagonState *env)
 {
     g_assert_not_reached();
 }
+
+static void set_enable_mask(CPUHexagonState *env)
+{
+    g_assert(bql_locked());
+
+    const uint32_t modectl = arch_get_system_reg(env, HEX_SREG_MODECTL);
+    uint32_t thread_enabled_mask = GET_FIELD(MODECTL_E, modectl);
+    thread_enabled_mask |= 0x1 << env->threadId;
+    SET_SYSTEM_FIELD(env, HEX_SREG_MODECTL, MODECTL_E, thread_enabled_mask);
+}
+
+static uint32_t clear_enable_mask(CPUHexagonState *env)
+{
+    g_assert(bql_locked());
+
+    const uint32_t modectl = arch_get_system_reg(env, HEX_SREG_MODECTL);
+    uint32_t thread_enabled_mask = GET_FIELD(MODECTL_E, modectl);
+    thread_enabled_mask &= ~(0x1 << env->threadId);
+    SET_SYSTEM_FIELD(env, HEX_SREG_MODECTL, MODECTL_E, thread_enabled_mask);
+    return thread_enabled_mask;
+}
+static void do_start_thread(CPUState *cs, run_on_cpu_data tbd)
+{
+    BQL_LOCK_GUARD();
+
+    CPUHexagonState *env = cpu_env(cs);
+
+    hexagon_cpu_soft_reset(env);
+
+    set_enable_mask(env);
+
+    cs->halted = 0;
+    cs->exception_index = HEX_EVENT_NONE;
+    cpu_resume(cs);
+}
+
+void hexagon_start_threads(CPUHexagonState *current_env, uint32_t mask)
+{
+    CPUState *cs;
+    CPU_FOREACH(cs) {
+        CPUHexagonState *env = cpu_env(cs);
+        if (!(mask & (0x1 << env->threadId))) {
+            continue;
+        }
+
+        if (current_env->threadId != env->threadId) {
+            async_safe_run_on_cpu(cs, do_start_thread, RUN_ON_CPU_NULL);
+        }
+    }
+}
+
+/*
+ * When we have all threads stopped, the return
+ * value to the shell is register 2 from thread 0.
+ */
+static target_ulong get_thread0_r2(void)
+{
+    CPUState *cs;
+    CPU_FOREACH(cs) {
+        CPUHexagonState *thread = cpu_env(cs);
+        if (thread->threadId == 0) {
+            return thread->gpr[2];
+        }
+    }
+    g_assert_not_reached();
+}
+
+void hexagon_stop_thread(CPUHexagonState *env)
+
+{
+    BQL_LOCK_GUARD();
+
+    uint32_t thread_enabled_mask = clear_enable_mask(env);
+    CPUState *cs = env_cpu(env);
+    cpu_interrupt(cs, CPU_INTERRUPT_HALT);
+    if (!thread_enabled_mask) {
+        /* All threads are stopped, exit */
+        exit(get_thread0_r2());
+    }
+}
+
 #endif
diff --git a/target/hexagon/op_helper.c b/target/hexagon/op_helper.c
index ded6c80d62..9f79b1a20c 100644
--- a/target/hexagon/op_helper.c
+++ b/target/hexagon/op_helper.c
@@ -1448,12 +1448,12 @@ uint32_t HELPER(iassignr)(CPUHexagonState *env, uint32_t src)
 
 void HELPER(start)(CPUHexagonState *env, uint32_t imask)
 {
-    g_assert_not_reached();
+    hexagon_start_threads(env, imask);
 }
 
 void HELPER(stop)(CPUHexagonState *env)
 {
-    g_assert_not_reached();
+    hexagon_stop_thread(env);
 }
 
 void HELPER(wait)(CPUHexagonState *env, target_ulong PC)
-- 
2.34.1