From 7271ebf96d6f2606682b0279e27744f4571adf31 Mon Sep 17 00:00:00 2001
From: Peter Maydell <peter.maydell@linaro.org>
Date: Sun, 22 Mar 2020 00:17:34 -0400
Subject: [PATCH] target/arm: Implement ARMv8.3-CCIDX

The ARMv8.3-CCIDX extension makes the CCSIDR_EL1 system ID registers
have a format that uses the full 64 bit width of the register, and
adds a new CCSIDR2 register so AArch32 can get at the high 32 bits.

QEMU doesn't implement caches, so we just treat these ID registers as
opaque values that are set to the correct constant values for each
CPU. The only thing we need to do is allow 64-bit values in our
cssidr[] array and provide the CCSIDR2 accessors.

We don't set the CCIDX field in our 'max' CPU because the CCSIDR
constant values we use are the same as the ones used by the
Cortex-A57 and they are in the old 32-bit format. This means
that the extra regdef added here is unused currently, but it
means that whenever in the future we add a CPU that does need
the new 64-bit format it will just work when we set the cssidr
values and the ID registers for it.

Backports commit 957e615503bd0de22393fd8dbcb22a5064fd2b5c from qemu
---
 qemu/target/arm/cpu.h    | 17 ++++++++++++++++-
 qemu/target/arm/helper.c | 19 +++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/qemu/target/arm/cpu.h b/qemu/target/arm/cpu.h
index 955ccad9..d89852bc 100644
--- a/qemu/target/arm/cpu.h
+++ b/qemu/target/arm/cpu.h
@@ -871,7 +871,7 @@ struct ARMCPU {
     /* The elements of this array are the CCSIDR values for each cache,
      * in the order L1DCache, L1ICache, L2DCache, L2ICache, etc.
      */
-    uint32_t ccsidr[16];
+    uint64_t ccsidr[16];
     uint64_t reset_cbar;
     uint32_t reset_auxcr;
     bool reset_hivecs;
@@ -3450,6 +3450,11 @@ static inline bool isar_feature_aa32_ac2(const ARMISARegisters *id)
     return FIELD_EX32(id->id_mmfr4, ID_MMFR4, AC2) != 0;
 }
 
+static inline bool isar_feature_aa32_ccidx(const ARMISARegisters *id)
+{
+    return FIELD_EX32(id->id_mmfr4, ID_MMFR4, CCIDX) != 0;
+}
+
 /*
  * 64-bit feature tests via id registers.
  */
@@ -3657,6 +3662,11 @@ static inline bool isar_feature_aa64_rcpc_8_4(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64isar1, ID_AA64ISAR1, LRCPC) >= 2;
 }
 
+static inline bool isar_feature_aa64_ccidx(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR2, CCIDX) != 0;
+}
+
 /*
  * Feature tests for "does this exist in either 32-bit or 64-bit?"
  */
@@ -3680,6 +3690,11 @@ static inline bool isar_feature_any_pmu_8_4(const ARMISARegisters *id)
     return isar_feature_aa64_pmu_8_4(id) || isar_feature_aa32_pmu_8_4(id);
 }
 
+static inline bool isar_feature_any_ccidx(const ARMISARegisters *id)
+{
+    return isar_feature_aa64_ccidx(id) || isar_feature_aa32_ccidx(id);
+}
+
 /*
  * Forward to the above feature tests given an ARMCPU pointer.
  */
diff --git a/qemu/target/arm/helper.c b/qemu/target/arm/helper.c
index 375acd92..5c3acbf2 100644
--- a/qemu/target/arm/helper.c
+++ b/qemu/target/arm/helper.c
@@ -6527,6 +6527,21 @@ static const ARMCPRegInfo predinv_reginfo[] = {
     REGINFO_SENTINEL
 };
 
+static uint64_t ccsidr2_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    /* Read the high 32 bits of the current CCSIDR */
+    return extract64(ccsidr_read(env, ri), 32, 32);
+}
+
+static const ARMCPRegInfo ccsidr2_reginfo[] = {
+    { .name = "CCSIDR2", .state = ARM_CP_STATE_BOTH,
+      .opc0 = 3, .opc1 = 1, .crn = 0, .crm = 0, .opc2 = 2,
+      .access = PL1_R,
+      .accessfn = access_aa64_tid2,
+      .readfn = ccsidr2_read, .type = ARM_CP_NO_RAW },
+    REGINFO_SENTINEL
+};
+
 static CPAccessResult access_aa64_tid3(CPUARMState *env, const ARMCPRegInfo *ri,
                                        bool isread)
 {
@@ -7575,6 +7590,10 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         define_arm_cp_regs(cpu, predinv_reginfo);
     }
 
+    if (cpu_isar_feature(any_ccidx, cpu)) {
+        define_arm_cp_regs(cpu, ccsidr2_reginfo);
+    }
+
 #ifndef CONFIG_USER_ONLY
     /*
      * Register redirections and aliases must be done last,