1 files changed, 67 insertions, 0 deletions
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index d0217b6a98..84ee018f7d 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -191,6 +191,73 @@ void helper_cbo_zero(CPURISCVState *env, target_ulong address)
     }
 }
 
+/*
+ * check_zicbom_access
+ *
+ * Check access permissions (LOAD, STORE or FETCH as specified in
+ * section 2.5.2 of the CMO specification) for Zicbom, raising
+ * either store page-fault (non-virtualized) or store guest-page
+ * fault (virtualized).
+ */
+static void check_zicbom_access(CPURISCVState *env,
+                                target_ulong address,
+                                uintptr_t ra)
+{
+    RISCVCPU *cpu = env_archcpu(env);
+    int mmu_idx = cpu_mmu_index(env, false);
+    uint16_t cbomlen = cpu->cfg.cbom_blocksize;
+    void *phost;
+    int ret;
+
+    /* Mask off low-bits to align-down to the cache-block. */
+    address &= ~(cbomlen - 1);
+
+    /*
+     * Section 2.5.2 of cmobase v1.0.1:
+     *
+     * "A cache-block management instruction is permitted to
+     * access the specified cache block whenever a load instruction
+     * or store instruction is permitted to access the corresponding
+     * physical addresses. If neither a load instruction nor store
+     * instruction is permitted to access the physical addresses,
+     * but an instruction fetch is permitted to access the physical
+     * addresses, whether a cache-block management instruction is
+     * permitted to access the cache block is UNSPECIFIED."
+     */
+    ret = probe_access_flags(env, address, cbomlen, MMU_DATA_LOAD,
+                             mmu_idx, true, &phost, ra);
+    if (ret != TLB_INVALID_MASK) {
+        /* Success: readable */
+        return;
+    }
+
+    /*
+     * Since not readable, must be writable. On failure, store
+     * fault/store guest amo fault will be raised by
+     * riscv_cpu_tlb_fill(). PMP exceptions will be caught
+     * there as well.
+     */
+    probe_write(env, address, cbomlen, mmu_idx, ra);
+}
+
+void helper_cbo_clean_flush(CPURISCVState *env, target_ulong address)
+{
+    uintptr_t ra = GETPC();
+    check_zicbo_envcfg(env, MENVCFG_CBCFE, ra);
+    check_zicbom_access(env, address, ra);
+
+    /* We don't emulate the cache-hierarchy, so we're done. */
+}
+
+void helper_cbo_inval(CPURISCVState *env, target_ulong address)
+{
+    uintptr_t ra = GETPC();
+    check_zicbo_envcfg(env, MENVCFG_CBIE, ra);
+    check_zicbom_access(env, address, ra);
+
+    /* We don't emulate the cache-hierarchy, so we're done. */
+}
+
 #ifndef CONFIG_USER_ONLY
 
 target_ulong helper_sret(CPURISCVState *env)