target/xtensa: implement MEMCTL SR

MEMCTL SR controls zero overhead loop buffer and number of ways enabled
in L1 caches.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

target/xtensa/cpu.c

@@ -66,6 +66,7 @@ static void xtensa_cpu_reset(CPUState *s)
             XTENSA_OPTION_INTERRUPT) ? 0x1f : 0x10;
     env->sregs[VECBASE] = env->config->vecbase;
     env->sregs[IBREAKENABLE] = 0;
+    env->sregs[MEMCTL] = MEMCTL_IL0EN & env->config->memctl_mask;
     env->sregs[CACHEATTR] = 0x22222222;
     env->sregs[ATOMCTL] = xtensa_option_enabled(env->config,
             XTENSA_OPTION_ATOMCTL) ? 0x28 : 0x15;

target/xtensa/cpu.h

@@ -129,6 +129,7 @@ enum {
     ITLBCFG = 91,
     DTLBCFG = 92,
     IBREAKENABLE = 96,
+    MEMCTL = 97,
     CACHEATTR = 98,
     ATOMCTL = 99,
     IBREAKA = 128,
@@ -189,6 +190,20 @@ enum {
 #define DBREAKC_SB_LB (DBREAKC_SB | DBREAKC_LB)
 #define DBREAKC_MASK 0x3f
 
+#define MEMCTL_INIT 0x00800000
+#define MEMCTL_IUSEWAYS_SHIFT 18
+#define MEMCTL_IUSEWAYS_LEN 5
+#define MEMCTL_IUSEWAYS_MASK 0x007c0000
+#define MEMCTL_DALLOCWAYS_SHIFT 13
+#define MEMCTL_DALLOCWAYS_LEN 5
+#define MEMCTL_DALLOCWAYS_MASK 0x0003e000
+#define MEMCTL_DUSEWAYS_SHIFT 8
+#define MEMCTL_DUSEWAYS_LEN 5
+#define MEMCTL_DUSEWAYS_MASK 0x00001f00
+#define MEMCTL_ISNP 0x4
+#define MEMCTL_DSNP 0x2
+#define MEMCTL_IL0EN 0x1
+
 #define MAX_NAREG 64
 #define MAX_NINTERRUPT 32
 #define MAX_NLEVEL 6
@@ -332,6 +347,10 @@ struct XtensaConfig {
     unsigned nibreak;
     unsigned ndbreak;
 
+    unsigned icache_ways;
+    unsigned dcache_ways;
+    uint32_t memctl_mask;
+
     uint32_t configid[2];
 
     uint32_t clock_freq_khz;

target/xtensa/helper.h

@@ -23,6 +23,7 @@ DEF_HELPER_2(wsr_ccount, void, env, i32)
 DEF_HELPER_2(update_ccompare, void, env, i32)
 DEF_HELPER_1(check_interrupts, void, env)
 DEF_HELPER_3(check_atomctl, void, env, i32, i32)
+DEF_HELPER_2(wsr_memctl, void, env, i32)
 
 DEF_HELPER_2(itlb_hit_test, void, env, i32)
 DEF_HELPER_2(wsr_rasid, void, env, i32)

target/xtensa/op_helper.c

@@ -506,6 +506,30 @@ void HELPER(check_atomctl)(CPUXtensaState *env, uint32_t pc, uint32_t vaddr)
     }
 }
 
+void HELPER(wsr_memctl)(CPUXtensaState *env, uint32_t v)
+{
+    if (xtensa_option_enabled(env->config, XTENSA_OPTION_ICACHE)) {
+        if (extract32(v, MEMCTL_IUSEWAYS_SHIFT, MEMCTL_IUSEWAYS_LEN) >
+            env->config->icache_ways) {
+            deposit32(v, MEMCTL_IUSEWAYS_SHIFT, MEMCTL_IUSEWAYS_LEN,
+                      env->config->icache_ways);
+        }
+    }
+    if (xtensa_option_enabled(env->config, XTENSA_OPTION_DCACHE)) {
+        if (extract32(v, MEMCTL_DUSEWAYS_SHIFT, MEMCTL_DUSEWAYS_LEN) >
+            env->config->dcache_ways) {
+            deposit32(v, MEMCTL_DUSEWAYS_SHIFT, MEMCTL_DUSEWAYS_LEN,
+                      env->config->dcache_ways);
+        }
+        if (extract32(v, MEMCTL_DALLOCWAYS_SHIFT, MEMCTL_DALLOCWAYS_LEN) >
+            env->config->dcache_ways) {
+            deposit32(v, MEMCTL_DALLOCWAYS_SHIFT, MEMCTL_DALLOCWAYS_LEN,
+                      env->config->dcache_ways);
+        }
+    }
+    env->sregs[MEMCTL] = v & env->config->memctl_mask;
+}
+
 void HELPER(wsr_rasid)(CPUXtensaState *env, uint32_t v)
 {
     XtensaCPU *cpu = xtensa_env_get_cpu(env);

target/xtensa/overlay_tool.h

@@ -59,6 +59,10 @@
 #define XCHAL_HW_MIN_VERSION 0
 #endif
 
+#ifndef XCHAL_LOOP_BUFFER_SIZE
+#define XCHAL_LOOP_BUFFER_SIZE 0
+#endif
+
 #define XCHAL_OPTION(xchal, qemu) ((xchal) ? XTENSA_OPTION_BIT(qemu) : 0)
 
 #define XTENSA_OPTIONS ( \
@@ -343,6 +347,16 @@
     .nibreak = XCHAL_NUM_IBREAK, \
     .ndbreak = XCHAL_NUM_DBREAK
 
+#define CACHE_SECTION \
+    .icache_ways = XCHAL_ICACHE_WAYS, \
+    .dcache_ways = XCHAL_DCACHE_WAYS, \
+    .memctl_mask = \
+        (XCHAL_ICACHE_SIZE ? MEMCTL_IUSEWAYS_MASK : 0) | \
+        (XCHAL_DCACHE_SIZE ? \
+         MEMCTL_DALLOCWAYS_MASK | MEMCTL_DUSEWAYS_MASK : 0) | \
+        MEMCTL_ISNP | MEMCTL_DSNP | \
+        (XCHAL_HAVE_LOOPS && XCHAL_LOOP_BUFFER_SIZE ? MEMCTL_IL0EN : 0)
+
 #define CONFIG_SECTION \
     .configid = { \
         XCHAL_HW_CONFIGID0, \
@@ -357,6 +371,7 @@
     INTERRUPTS_SECTION, \
     TLB_SECTION, \
     DEBUG_SECTION, \
+    CACHE_SECTION, \
     CONFIG_SECTION
 
 

target/xtensa/translate.c

@@ -133,6 +133,7 @@ static const XtensaReg sregnames[256] = {
     [ITLBCFG] = XTENSA_REG("ITLBCFG", XTENSA_OPTION_MMU),
     [DTLBCFG] = XTENSA_REG("DTLBCFG", XTENSA_OPTION_MMU),
     [IBREAKENABLE] = XTENSA_REG("IBREAKENABLE", XTENSA_OPTION_DEBUG),
+    [MEMCTL] = XTENSA_REG_BITS("MEMCTL", XTENSA_OPTION_ALL),
     [CACHEATTR] = XTENSA_REG("CACHEATTR", XTENSA_OPTION_CACHEATTR),
     [ATOMCTL] = XTENSA_REG("ATOMCTL", XTENSA_OPTION_ATOMCTL),
     [IBREAKA] = XTENSA_REG("IBREAKA0", XTENSA_OPTION_DEBUG),
@@ -637,6 +638,12 @@ static bool gen_wsr_ibreakenable(DisasContext *dc, uint32_t sr, TCGv_i32 v)
     return true;
 }
 
+static bool gen_wsr_memctl(DisasContext *dc, uint32_t sr, TCGv_i32 v)
+{
+    gen_helper_wsr_memctl(cpu_env, v);
+    return false;
+}
+
 static bool gen_wsr_atomctl(DisasContext *dc, uint32_t sr, TCGv_i32 v)
 {
     tcg_gen_andi_i32(cpu_SR[sr], v, 0x3f);
@@ -821,6 +828,7 @@ static bool gen_wsr(DisasContext *dc, uint32_t sr, TCGv_i32 s)
         [ITLBCFG] = gen_wsr_tlbcfg,
         [DTLBCFG] = gen_wsr_tlbcfg,
         [IBREAKENABLE] = gen_wsr_ibreakenable,
+        [MEMCTL] = gen_wsr_memctl,
         [ATOMCTL] = gen_wsr_atomctl,
         [IBREAKA] = gen_wsr_ibreaka,
         [IBREAKA + 1] = gen_wsr_ibreaka,