[v3,4/4] target/arm: Add support for DC CVAP & DC CVADP ins

Commit Message

Beata Michalska Nov. 21, 2019, 12:08 a.m. UTC

ARMv8.2 introduced support for Data Cache Clean instructions
to PoP (point-of-persistence) - DC CVAP and PoDP (point-of-deep-persistence)
- DV CVADP. Both specify conceptual points in a memory system where all writes
that are to reach them are considered persistent.
The support provided considers both to be actually the same so there is no
distinction between the two. If none is available (there is no backing store
for given memory) both will result in Data Cache Clean up to the point of
coherency. Otherwise sync for the specified range shall be performed.

Signed-off-by: Beata Michalska <[e-mail]>
Reviewed-by: Richard Henderson <[e-mail]>
---
 linux-user/elfload.c |  2 ++
 target/arm/cpu.h     | 10 ++++++++++
 target/arm/cpu64.c   |  1 +
 target/arm/helper.c  | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 69 insertions(+)

Patch

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index f6693e5..07b16cc 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -656,6 +656,7 @@  static uint32_t get_elf_hwcap(void)
     GET_FEATURE_ID(aa64_jscvt, ARM_HWCAP_A64_JSCVT);
     GET_FEATURE_ID(aa64_sb, ARM_HWCAP_A64_SB);
     GET_FEATURE_ID(aa64_condm_4, ARM_HWCAP_A64_FLAGM);
+    GET_FEATURE_ID(aa64_dcpop, ARM_HWCAP_A64_DCPOP);
 
     return hwcaps;
 }
@@ -665,6 +666,7 @@  static uint32_t get_elf_hwcap2(void)
     ARMCPU *cpu = ARM_CPU(thread_cpu);
     uint32_t hwcaps = 0;
 
+    GET_FEATURE_ID(aa64_dcpodp, ARM_HWCAP2_A64_DCPODP);
     GET_FEATURE_ID(aa64_condm_5, ARM_HWCAP2_A64_FLAGM2);
     GET_FEATURE_ID(aa64_frint, ARM_HWCAP2_A64_FRINT);
 
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 83a809d..c3c0bf5 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -3616,6 +3616,16 @@  static inline bool isar_feature_aa64_frint(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64isar1, ID_AA64ISAR1, FRINTTS) != 0;
 }
 
+static inline bool isar_feature_aa64_dcpop(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64isar1, ID_AA64ISAR1, DPB) != 0;
+}
+
+static inline bool isar_feature_aa64_dcpodp(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64isar1, ID_AA64ISAR1, DPB) >= 2;
+}
+
 static inline bool isar_feature_aa64_fp16(const ARMISARegisters *id)
 {
     /* We always set the AdvSIMD and FP fields identically wrt FP16.  */
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index a39d6fc..61fd0ad 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -646,6 +646,7 @@  static void aarch64_max_initfn(Object *obj)
         cpu->isar.id_aa64isar0 = t;
 
         t = cpu->isar.id_aa64isar1;
+        t = FIELD_DP64(t, ID_AA64ISAR1, DPB, 2);
         t = FIELD_DP64(t, ID_AA64ISAR1, JSCVT, 1);
         t = FIELD_DP64(t, ID_AA64ISAR1, FCMA, 1);
         t = FIELD_DP64(t, ID_AA64ISAR1, APA, 1); /* PAuth, architected only */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index a089fb5..f90f3ec 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -5929,6 +5929,52 @@  static const ARMCPRegInfo rndr_reginfo[] = {
       .access = PL0_R, .readfn = rndr_readfn },
     REGINFO_SENTINEL
 };
+
+#ifndef CONFIG_USER_ONLY
+static void dccvap_writefn(CPUARMState *env, const ARMCPRegInfo *opaque,
+                          uint64_t value)
+{
+    ARMCPU *cpu = env_archcpu(env);
+    /* CTR_EL0 System register -> DminLine, bits [19:16] */
+    uint64_t dline_size = 4 << ((cpu->ctr >> 16) & 0xF);
+    uint64_t vaddr_in = (uint64_t) value;
+    uint64_t vaddr = vaddr_in & ~(dline_size - 1);
+    void *haddr;
+    int mem_idx = cpu_mmu_index(env, false);
+
+    /* This won't be crossing page boundaries */
+    haddr = probe_read(env, vaddr, dline_size, mem_idx, GETPC());
+    if (haddr) {
+
+        ram_addr_t offset;
+        MemoryRegion *mr;
+
+        /* RCU lock is already being held */
+        mr = memory_region_from_host(haddr, &offset);
+
+        if (mr) {
+            memory_region_do_writeback(mr, offset, dline_size);
+        }
+    }
+}
+
+static const ARMCPRegInfo dcpop_reg[] = {
+    { .name = "DC_CVAP", .state = ARM_CP_STATE_AA64,
+      .opc0 = 1, .opc1 = 3, .crn = 7, .crm = 12, .opc2 = 1,
+      .access = PL0_W, .type = ARM_CP_NO_RAW | ARM_CP_SUPPRESS_TB_END,
+      .accessfn = aa64_cacheop_access, .writefn = dccvap_writefn },
+    REGINFO_SENTINEL
+};
+
+static const ARMCPRegInfo dcpodp_reg[] = {
+    { .name = "DC_CVADP", .state = ARM_CP_STATE_AA64,
+      .opc0 = 1, .opc1 = 3, .crn = 7, .crm = 13, .opc2 = 1,
+      .access = PL0_W, .type = ARM_CP_NO_RAW | ARM_CP_SUPPRESS_TB_END,
+      .accessfn = aa64_cacheop_access, .writefn = dccvap_writefn },
+    REGINFO_SENTINEL
+};
+#endif /*CONFIG_USER_ONLY*/
+
 #endif
 
 static CPAccessResult access_predinv(CPUARMState *env, const ARMCPRegInfo *ri,
@@ -6889,6 +6935,16 @@  void register_cp_regs_for_features(ARMCPU *cpu)
     if (cpu_isar_feature(aa64_rndr, cpu)) {
         define_arm_cp_regs(cpu, rndr_reginfo);
     }
+#ifndef CONFIG_USER_ONLY
+    /* Data Cache clean instructions up to PoP */
+    if (cpu_isar_feature(aa64_dcpop, cpu)) {
+        define_one_arm_cp_reg(cpu, dcpop_reg);
+
+        if (cpu_isar_feature(aa64_dcpodp, cpu)) {
+            define_one_arm_cp_reg(cpu, dcpodp_reg);
+        }
+    }
+#endif /*CONFIG_USER_ONLY*/
 #endif
 
     /*