[Qemu-devel] [PATCH target-arm v3 2/7] target-arm: Add registers for PMSAv7

[Peter Crosthwaite]

Define the arm CP registers for PMSAv7 and their accessor functions.
RGNR serves as a shared index that indexes into arrays storing the
DRBAR, DRSR and DRACR registers. DRBAR and friends have to be VMSDd
separately from the CP interface using a new PMSA specific VMSD
subsection.

Reviewed-by: Peter Maydell <address@hidden>
Signed-off-by: Peter Crosthwaite <address@hidden>
---
changed since v2 (PMM review):
conditionalise pointer allocation on non-zero regions
Handle 0 regions in CP accessors
Tweak RGNR GUEST_ERROR message with s/>/>=
Resolve conflict with VSMD subsection.needed refactor
changed since v1 (PMM review):
Use raw_ptr
Implement reset as memset
Implement VMSD support
Add out-of-bounds guard or rgnr_write
Dynamically allocate registers
Move arrays out of cp15 struct into dedicated substruct

 target-arm/cpu.c     |  6 ++++
 target-arm/cpu.h     | 10 ++++++
 target-arm/helper.c  | 90 ++++++++++++++++++++++++++++++++++++++++++++++++----
 target-arm/machine.c | 34 ++++++++++++++++++++
 4 files changed, 133 insertions(+), 7 deletions(-)

diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index a3d702f..4010d81 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -596,6 +596,12 @@ static void arm_cpu_realizefn(DeviceState *dev, Error 
**errp)
             error_setg(errp, "PMSAv7 MPU #regions invalid %" PRIu32 "\n", nr);
             return;
         }
+
+        if (nr) {
+            env->pmsav7.drbar = g_new0(uint32_t, nr);
+            env->pmsav7.drsr = g_new0(uint32_t, nr);
+            env->pmsav7.dracr = g_new0(uint32_t, nr);
+        }
     }
 
     register_cp_regs_for_features(cpu);
diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index c9d2330..6e82893 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -284,6 +284,9 @@ typedef struct CPUARMState {
             };
             uint64_t par_el[4];
         };
+
+        uint32_t c6_rgnr;
+
         uint32_t c9_insn; /* Cache lockdown registers.  */
         uint32_t c9_data;
         uint64_t c9_pmcr; /* performance monitor control register */
@@ -482,6 +485,13 @@ typedef struct CPUARMState {
     /* Internal CPU feature flags.  */
     uint64_t features;
 
+    /* PMSAv7 MPU */
+    struct {
+        uint32_t *drbar;
+        uint32_t *drsr;
+        uint32_t *dracr;
+    } pmsav7;
+
     void *nvic;
     const struct arm_boot_info *boot_info;
 } CPUARMState;
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 685f972..0384c79 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -1710,6 +1710,81 @@ static uint64_t pmsav5_insn_ap_read(CPUARMState *env, 
const ARMCPRegInfo *ri)
     return simple_mpu_ap_bits(env->cp15.pmsav5_insn_ap);
 }
 
+static uint64_t pmsav7_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    uint32_t *u32p = *(uint32_t **)raw_ptr(env, ri);
+
+    if (!u32p) {
+        return 0;
+    }
+
+    u32p += env->cp15.c6_rgnr;
+    return *u32p;
+}
+
+static void pmsav7_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                         uint64_t value)
+{
+    ARMCPU *cpu = arm_env_get_cpu(env);
+    uint32_t *u32p = *(uint32_t **)raw_ptr(env, ri);
+
+    if (!u32p) {
+        return;
+    }
+
+    u32p += env->cp15.c6_rgnr;
+    tlb_flush(CPU(cpu), 1); /* Mappings may have changed - purge! */
+    *u32p = value;
+}
+
+static void pmsav7_reset(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    ARMCPU *cpu = arm_env_get_cpu(env);
+    uint32_t *u32p = *(uint32_t **)raw_ptr(env, ri);
+
+    if (!u32p) {
+        return;
+    }
+
+    memset(u32p, 0, sizeof(*u32p) * cpu->pmsav7_dregion);
+}
+
+static void pmsav7_rgnr_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                              uint64_t value)
+{
+    ARMCPU *cpu = arm_env_get_cpu(env);
+    uint32_t nrgs = cpu->pmsav7_dregion;
+
+    if (value >= nrgs) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "PMSAv7 RGNR write >= # supported regions, %" PRIu32
+                      " > %" PRIu32 "\n", (uint32_t)value, nrgs);
+        return;
+    }
+
+    raw_write(env, ri, value);
+}
+
+static const ARMCPRegInfo pmsav7_cp_reginfo[] = {
+    { .name = "DRBAR", .cp = 15, .crn = 6, .opc1 = 0, .crm = 1, .opc2 = 0,
+      .access = PL1_RW, .type = ARM_CP_NO_RAW,
+      .fieldoffset = offsetof(CPUARMState, pmsav7.drbar),
+      .readfn = pmsav7_read, .writefn = pmsav7_write, .resetfn = pmsav7_reset 
},
+    { .name = "DRSR", .cp = 15, .crn = 6, .opc1 = 0, .crm = 1, .opc2 = 2,
+      .access = PL1_RW, .type = ARM_CP_NO_RAW,
+      .fieldoffset = offsetof(CPUARMState, pmsav7.drsr),
+      .readfn = pmsav7_read, .writefn = pmsav7_write, .resetfn = pmsav7_reset 
},
+    { .name = "DRACR", .cp = 15, .crn = 6, .opc1 = 0, .crm = 1, .opc2 = 4,
+      .access = PL1_RW, .type = ARM_CP_NO_RAW,
+      .fieldoffset = offsetof(CPUARMState, pmsav7.dracr),
+      .readfn = pmsav7_read, .writefn = pmsav7_write, .resetfn = pmsav7_reset 
},
+    { .name = "RGNR", .cp = 15, .crn = 6, .opc1 = 0, .crm = 2, .opc2 = 0,
+      .access = PL1_RW,
+      .fieldoffset = offsetof(CPUARMState, cp15.c6_rgnr),
+      .writefn = pmsav7_rgnr_write },
+    REGINFO_SENTINEL
+};
+
 static const ARMCPRegInfo pmsav5_cp_reginfo[] = {
     { .name = "DATA_AP", .cp = 15, .crn = 5, .crm = 0, .opc1 = 0, .opc2 = 0,
       .access = PL1_RW, .type = ARM_CP_ALIAS,
@@ -3345,13 +3420,14 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         define_one_arm_cp_reg(cpu, &rvbar);
     }
     if (arm_feature(env, ARM_FEATURE_MPU)) {
-        /* These are the MPU registers prior to PMSAv6. Any new
-         * PMSA core later than the ARM946 will require that we
-         * implement the PMSAv6 or PMSAv7 registers, which are
-         * completely different.
-         */
-        assert(!arm_feature(env, ARM_FEATURE_V6));
-        define_arm_cp_regs(cpu, pmsav5_cp_reginfo);
+        if (arm_feature(env, ARM_FEATURE_V6)) {
+            /* PMSAv6 not implemented */
+            assert(arm_feature(env, ARM_FEATURE_V7));
+            define_arm_cp_regs(cpu, vmsa_pmsa_cp_reginfo);
+            define_arm_cp_regs(cpu, pmsav7_cp_reginfo);
+        } else {
+            define_arm_cp_regs(cpu, pmsav5_cp_reginfo);
+        }
     } else {
         define_arm_cp_regs(cpu, vmsa_pmsa_cp_reginfo);
         define_arm_cp_regs(cpu, vmsa_cp_reginfo);
diff --git a/target-arm/machine.c b/target-arm/machine.c
index 36365a5..9eb51df 100644
--- a/target-arm/machine.c
+++ b/target-arm/machine.c
@@ -125,6 +125,39 @@ static const VMStateDescription vmstate_thumb2ee = {
     }
 };
 
+static bool pmsav7_needed(void *opaque)
+{
+    ARMCPU *cpu = opaque;
+    CPUARMState *env = &cpu->env;
+
+    return arm_feature(env, ARM_FEATURE_MPU) &&
+           arm_feature(env, ARM_FEATURE_V7);
+}
+
+static bool pmsav7_rgnr_vmstate_validate(void *opaque, int version_id)
+{
+    ARMCPU *cpu = opaque;
+
+    return cpu->env.cp15.c6_rgnr < cpu->pmsav7_dregion;
+}
+
+static const VMStateDescription vmstate_pmsav7 = {
+    .name = "cpu/pmsav7",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = pmsav7_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_VARRAY_UINT32(env.pmsav7.drbar, ARMCPU, pmsav7_dregion, 0,
+                              vmstate_info_uint32, uint32_t),
+        VMSTATE_VARRAY_UINT32(env.pmsav7.drsr, ARMCPU, pmsav7_dregion, 0,
+                              vmstate_info_uint32, uint32_t),
+        VMSTATE_VARRAY_UINT32(env.pmsav7.dracr, ARMCPU, pmsav7_dregion, 0,
+                              vmstate_info_uint32, uint32_t),
+        VMSTATE_VALIDATE("rgnr is valid", pmsav7_rgnr_vmstate_validate),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static int get_cpsr(QEMUFile *f, void *opaque, size_t size)
 {
     ARMCPU *cpu = opaque;
@@ -291,6 +324,7 @@ const VMStateDescription vmstate_arm_cpu = {
         &vmstate_iwmmxt,
         &vmstate_m,
         &vmstate_thumb2ee,
+        &vmstate_pmsav7,
         NULL
     }
 };
-- 
2.4.3.3.g905f831