[PATCH 4/5] [RISCV_PM] Add address masking functions required for RISC-V Pointer Masking extension

[Alexey Baturo <baturo.alexey@gmail.com>]

From: Anatoly Parshintsev <kupokupokupopo@gmail.com>

Signed-off-by: Anatoly Parshintsev <kupokupokupopo@gmail.com>
---
 target/riscv/translate.c | 65 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 79dca2291b..338a967e0c 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -63,6 +63,10 @@ typedef struct DisasContext {
     uint16_t vlen;
     uint16_t mlen;
     bool vl_eq_vlmax;
+    /* PointerMasking extension */
+    uint8_t pm_enabled;
+    target_ulong pm_mask;
+    target_ulong pm_base;
 } DisasContext;
 
 #ifdef TARGET_RISCV64
@@ -90,6 +94,38 @@ static inline bool has_ext(DisasContext *ctx, uint32_t ext)
     return ctx->misa & ext;
 }
 
+/* Generates address adjustment for PointerMasking */
+static void gen_pm_adjust_address(DisasContext *s,
+                                  TCGv_i64      dst,
+                                  TCGv_i64      src)
+{
+    if (s->pm_enabled == 0) {
+        /* Load unmodified address */
+        tcg_gen_mov_i64(dst, src);
+    } else {
+        TCGv_i64 mask_neg = tcg_const_i64(~s->pm_mask);
+        TCGv_i64 base     = tcg_const_i64(s->pm_base);
+        /* calculate (addr & ~mask) */
+        TCGv res1 = tcg_temp_new();
+        tcg_gen_and_tl(res1, mask_neg, src);
+        /* calculate (1) | (base) */
+        TCGv res2 = tcg_temp_new();
+        tcg_gen_or_tl(res2, res1, base);
+        /* move result to dst */
+        tcg_gen_mov_i64(dst, res2);
+        /* free allocated temps */
+        tcg_temp_free(res1);
+        tcg_temp_free(res2);
+        tcg_temp_free_i64(mask_neg);
+        tcg_temp_free_i64(base);
+    }
+}
+
+static TCGv_i64 apply_pointer_masking(DisasContext *s, TCGv_i64 addr)
+{
+    gen_pm_adjust_address(s, addr, addr);
+    return addr;
+}
 /*
  * RISC-V requires NaN-boxing of narrower width floating point values.
  * This applies when a 32-bit value is assigned to a 64-bit FP register.
@@ -800,8 +836,36 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     } else {
         ctx->virt_enabled = false;
     }
+    if (riscv_has_ext(env, RVJ)) {
+        switch (env->priv) {
+        case PRV_U:
+            ctx->pm_enabled = get_field(env->mmte, UMTE_U_PM_ENABLE);
+            ctx->pm_mask = env->upmmask;
+            ctx->pm_base = env->upmbase;
+            break;
+        case PRV_S:
+            ctx->pm_enabled = get_field(env->mmte, SMTE_S_PM_ENABLE);
+            ctx->pm_mask = env->spmmask;
+            ctx->pm_base = env->spmbase;
+            break;
+        case PRV_M:
+            ctx->pm_enabled = get_field(env->mmte, MMTE_M_PM_ENABLE);
+            ctx->pm_mask = env->mpmmask;
+            ctx->pm_base = env->mpmbase;
+            break;
+        default:
+            assert(0 && "Unreachable");
+        }
+    } else {
+        ctx->pm_enabled = 0;
+        ctx->pm_mask = 0;
+        ctx->pm_base = 0;
+    }
 #else
     ctx->virt_enabled = false;
+    ctx->pm_enabled = 0;
+    ctx->pm_mask = 0;
+    ctx->pm_base = 0;
 #endif
     ctx->misa = env->misa;
     ctx->frm = -1;  /* unknown rounding mode */
@@ -932,3 +996,4 @@ void riscv_translate_init(void)
     load_val = tcg_global_mem_new(cpu_env, offsetof(CPURISCVState, load_val),
                              "load_val");
 }
+
-- 
2.20.1