[Qemu-devel] [PATCH 0/2] hw/mips: implement Cluster Power Controller

[Qemu-devel] [PATCH 0/2] hw/mips: implement Cluster Power Controller

[Leon Alrae]

This minimal CPC support is one of the elements required to allow R6 Linux to
bring up Virtual Processors on Malta board. This patch applies on top of
Yongbok's GIC/GCR patchset which still requires updating/fixing (that
probably will also affect CPC, in particular when we come up with a wrapper
for the CPU, GIC, GCR, etc.). Hopefully this will get sorted out soon so
we could include these functionalities in 2.6 release.

Next step can be extending the feature to support multi-core. Also,
these features will be handy for testing MIPS with MTTCG which is
something I hope to start in near future.

Thanks,
Leon

Leon Alrae (2):
  hw/mips: add initial Cluster Power Controller support
  hw/mips_malta: add CPC to the Malta board

 default-configs/mips-softmmu.mak     |   1 +
 default-configs/mips64-softmmu.mak   |   1 +
 default-configs/mips64el-softmmu.mak |   1 +
 default-configs/mipsel-softmmu.mak   |   1 +
 hw/mips/mips_malta.c                 |  30 +++++++++
 hw/misc/Makefile.objs                |   1 +
 hw/misc/mips_cpc.c                   | 124 +++++++++++++++++++++++++++++++++++
 include/hw/misc/mips_cpc.h           |  45 +++++++++++++
 8 files changed, 204 insertions(+)
 create mode 100644 hw/misc/mips_cpc.c
 create mode 100644 include/hw/misc/mips_cpc.h

-- 
2.1.0

[Qemu-devel] [PATCH 1/2] hw/mips: add initial Cluster Power Controller support

[Leon Alrae]

Cluster Power Controller (CPC) is responsible for power management in
multiprocessing system. It provides registers to control the power and the
clock frequency of the individual elements in the system.

This patch implements only three registers that are used to control the
power state of each VP on a single core:
* VP Run is a write-only register used to set each VP to the run state
* VP Stop is a write-only register used to set each VP to the suspend state
* VP Running is a read-only register indicating the run state of each VP

Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
---
 default-configs/mips-softmmu.mak     |   1 +
 default-configs/mips64-softmmu.mak   |   1 +
 default-configs/mips64el-softmmu.mak |   1 +
 default-configs/mipsel-softmmu.mak   |   1 +
 hw/misc/Makefile.objs                |   1 +
 hw/misc/mips_cpc.c                   | 124 +++++++++++++++++++++++++++++++++++
 include/hw/misc/mips_cpc.h           |  45 +++++++++++++
 7 files changed, 174 insertions(+)
 create mode 100644 hw/misc/mips_cpc.c
 create mode 100644 include/hw/misc/mips_cpc.h

diff --git a/default-configs/mips-softmmu.mak b/default-configs/mips-softmmu.mak
index a784644..8a9482e 100644
--- a/default-configs/mips-softmmu.mak
+++ b/default-configs/mips-softmmu.mak
@@ -31,3 +31,4 @@ CONFIG_MC146818RTC=y
 CONFIG_ISA_TESTDEV=y
 CONFIG_EMPTY_SLOT=y
 CONFIG_MIPS_GIC=y
+CONFIG_MIPS_CPC=y
diff --git a/default-configs/mips64-softmmu.mak b/default-configs/mips64-softmmu.mak
index 957508d..27ca662 100644
--- a/default-configs/mips64-softmmu.mak
+++ b/default-configs/mips64-softmmu.mak
@@ -37,3 +37,4 @@ CONFIG_MC146818RTC=y
 CONFIG_ISA_TESTDEV=y
 CONFIG_EMPTY_SLOT=y
 CONFIG_MIPS_GIC=y
+CONFIG_MIPS_CPC=y
diff --git a/default-configs/mips64el-softmmu.mak b/default-configs/mips64el-softmmu.mak
index 6c1065f..7dfc4cb 100644
--- a/default-configs/mips64el-softmmu.mak
+++ b/default-configs/mips64el-softmmu.mak
@@ -40,3 +40,4 @@ CONFIG_VT82C686=y
 CONFIG_ISA_TESTDEV=y
 CONFIG_EMPTY_SLOT=y
 CONFIG_MIPS_GIC=y
+CONFIG_MIPS_CPC=y
diff --git a/default-configs/mipsel-softmmu.mak b/default-configs/mipsel-softmmu.mak
index 4633b0b..e02599d 100644
--- a/default-configs/mipsel-softmmu.mak
+++ b/default-configs/mipsel-softmmu.mak
@@ -31,3 +31,4 @@ CONFIG_MC146818RTC=y
 CONFIG_ISA_TESTDEV=y
 CONFIG_EMPTY_SLOT=y
 CONFIG_MIPS_GIC=y
+CONFIG_MIPS_CPC=y
diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 7bb14ed..46b3e71 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -43,6 +43,7 @@ obj-$(CONFIG_ZYNQ) += zynq_slcr.o
 obj-$(CONFIG_ZYNQ) += zynq-xadc.o
 obj-$(CONFIG_STM32F2XX_SYSCFG) += stm32f2xx_syscfg.o
 obj-$(CONFIG_MIPS_GIC) += mips_gcr.o
+obj-$(CONFIG_MIPS_CPC) += mips_cpc.o
 
 obj-$(CONFIG_PVPANIC) += pvpanic.o
 obj-$(CONFIG_EDU) += edu.o
diff --git a/hw/misc/mips_cpc.c b/hw/misc/mips_cpc.c
new file mode 100644
index 0000000..3ea55fb
--- /dev/null
+++ b/hw/misc/mips_cpc.c
@@ -0,0 +1,124 @@
+/*
+ * Cluster Power Controller emulation
+ *
+ * Copyright (c) 2016 Imagination Technologies
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+
+#include "hw/misc/mips_cpc.h"
+
+#define CPC_VP_PER_CORE_MAX 4
+#define CPC_VP_RUN_MASK ((1 << CPC_VP_PER_CORE_MAX) - 1)
+
+static void cpc_run_vp(MIPSCPCState *cpc, uint64_t vp_run)
+{
+    CPUState *cs = first_cpu;
+
+    CPU_FOREACH(cs) {
+        uint64_t i = 1ULL << cs->cpu_index;
+        if (i & vp_run & ~cpc->vp_running) {
+            cpu_interrupt(cs, CPU_INTERRUPT_WAKE);
+            cpc->vp_running |= i;
+        }
+    }
+}
+
+static void cpc_stop_vp(MIPSCPCState *cpc, uint64_t vp_stop)
+{
+    CPUState *cs = first_cpu;
+
+    CPU_FOREACH(cs) {
+        uint64_t i = 1ULL << cs->cpu_index;
+        if (i & vp_stop & cpc->vp_running) {
+            cs->halted = 1;
+            cpu_reset_interrupt(cs, CPU_INTERRUPT_WAKE);
+            cpc->vp_running &= ~i;
+        }
+    }
+}
+
+static void cpc_write(void *opaque, hwaddr offset, uint64_t data,
+                      unsigned size)
+{
+    MIPSCPCState *s = opaque;
+
+    switch (offset) {
+    case CPC_CL_BASE_OFS + CPC_VP_RUN_OFS:
+    case CPC_CO_BASE_OFS + CPC_VP_RUN_OFS:
+        cpc_run_vp(s, data & CPC_VP_RUN_MASK);
+        break;
+    case CPC_CL_BASE_OFS + CPC_VP_STOP_OFS:
+    case CPC_CO_BASE_OFS + CPC_VP_STOP_OFS:
+        cpc_stop_vp(s, data & CPC_VP_RUN_MASK);
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP,
+                      "%s: Bad offset 0x%x\n",  __func__, (int)offset);
+        break;
+    }
+
+    return;
+}
+
+static uint64_t cpc_read(void *opaque, hwaddr offset, unsigned size)
+{
+    MIPSCPCState *s = opaque;
+
+    switch (offset) {
+    case CPC_CL_BASE_OFS + CPC_VP_RUNNING_OFS:
+    case CPC_CO_BASE_OFS + CPC_VP_RUNNING_OFS:
+        return s->vp_running;
+    default:
+        qemu_log_mask(LOG_UNIMP,
+                      "%s: Bad offset 0x%x\n",  __func__, (int)offset);
+        return 0;
+    }
+}
+
+static const MemoryRegionOps cpc_ops = {
+    .read = cpc_read,
+    .write = cpc_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .impl = {
+        .max_access_size = 8,
+    },
+};
+
+static void mips_cpc_init(Object *obj)
+{
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+    MIPSCPCState *s = MIPS_CPC(obj);
+
+    memory_region_init_io(&s->mr, OBJECT(s), &cpc_ops, s, "mips-cpc",
+                          CPC_ADDRSPACE_SZ);
+    sysbus_init_mmio(sbd, &s->mr);
+}
+
+static const TypeInfo mips_cpc_info = {
+    .name          = TYPE_MIPS_CPC,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(MIPSCPCState),
+    .instance_init = mips_cpc_init,
+};
+
+static void mips_cpc_register_types(void)
+{
+    type_register_static(&mips_cpc_info);
+}
+
+type_init(mips_cpc_register_types)
diff --git a/include/hw/misc/mips_cpc.h b/include/hw/misc/mips_cpc.h
new file mode 100644
index 0000000..2f7f84e
--- /dev/null
+++ b/include/hw/misc/mips_cpc.h
@@ -0,0 +1,45 @@
+/*
+ * Cluster Power Controller emulation
+ *
+ * Copyright (c) 2016 Imagination Technologies
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef MIPS_CPC_H
+#define MIPS_CPC_H
+
+#define CPC_BASE_ADDR       0x1bde0000ULL
+#define CPC_ADDRSPACE_SZ    0x6000
+
+/* CPC blocks offsets relative to base address */
+#define CPC_CL_BASE_OFS     0x2000
+#define CPC_CO_BASE_OFS     0x4000
+
+/* CPC register offsets relative to block offsets */
+#define CPC_VP_STOP_OFS     0x20
+#define CPC_VP_RUN_OFS      0x28
+#define CPC_VP_RUNNING_OFS  0x30
+
+#define TYPE_MIPS_CPC "mips-cpc"
+#define MIPS_CPC(obj) OBJECT_CHECK(MIPSCPCState, (obj), TYPE_MIPS_CPC)
+
+typedef struct MIPSCPCState {
+    SysBusDevice parent_obj;
+
+    MemoryRegion mr;
+    uint64_t vp_running; /* Indicates which VP's are in the run state */
+} MIPSCPCState;
+
+#endif /* MIPS_CPC_H */
-- 
2.1.0

[Qemu-devel] [PATCH 2/2] hw/mips_malta: add CPC to the Malta board

[Leon Alrae]

On Malta, after reset, only VP0 on Core0 starts the execution. Other VPs
are halted until VP0 powers them up using Cluster Power Controller.

Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
---
 hw/mips/mips_malta.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c
index 1fb17fb..34cc4cb 100644
--- a/hw/mips/mips_malta.c
+++ b/hw/mips/mips_malta.c
@@ -57,6 +57,7 @@
 #include "exec/semihost.h"
 #include "hw/misc/mips_gcr.h"
 #include "hw/intc/mips_gic.h"
+#include "hw/misc/mips_cpc.h"
 
 //#define DEBUG_BOARD_INIT
 
@@ -97,6 +98,7 @@ typedef struct {
 
     MIPSGCRState gcr;
     MIPSGICState gic;
+    MIPSCPCState cpc;
     qemu_irq *i8259;
 } MaltaState;
 
@@ -617,6 +619,19 @@ static void gic_init(MaltaState *s, Error **err)
     sysbus_mmio_map(gicbusdev, 0, gicbase);
 }
 
+static void cpc_init(MaltaState *s, Error **err)
+{
+    object_initialize(&s->cpc, sizeof(s->cpc), TYPE_MIPS_CPC);
+    qdev_set_parent_bus(DEVICE(&s->cpc), sysbus_get_default());
+
+    object_property_set_bool(OBJECT(&s->cpc), true, "realized", err);
+    if (*err != NULL) {
+        return;
+    }
+
+    sysbus_mmio_map(SYS_BUS_DEVICE(&s->cpc), 0, CPC_BASE_ADDR);
+}
+
 /* Network support */
 static void network_init(PCIBus *pci_bus)
 {
@@ -937,6 +952,7 @@ static void malta_mips_config(MIPSCPU *cpu)
 static void main_cpu_reset(void *opaque)
 {
     MIPSCPU *cpu = opaque;
+    CPUState *cs = CPU(cpu);
     CPUMIPSState *env = &cpu->env;
 
     cpu_reset(CPU(cpu));
@@ -954,6 +970,15 @@ static void main_cpu_reset(void *opaque)
         /* Start running from the bootloader we wrote to end of RAM */
         env->active_tc.PC = 0x40000000 + loaderparams.ram_low_size;
     }
+
+    /* At reset only VP0 on Core0 will start executing the code, other
+       VPs are halted until VP0 powers them up through Cluster Power
+       Controller. */
+    if ((env->CP0_Config5 & (1 << CP0C5_VP)) &&
+        (env->CP0_Config3 & (1 << CP0C3_CMGCR)) &&
+        (cs->cpu_index != 0)) {
+        cs->halted = 1;
+    }
 }
 
 static
@@ -1200,6 +1225,11 @@ void mips_malta_init(MachineState *machine)
             error_report("%s", error_get_pretty(err));
             exit(1);
         }
+        cpc_init(s, &err);
+        if (err != NULL) {
+            error_report("%s", error_get_pretty(err));
+            exit(1);
+        }
     }
 
     /*
-- 
2.1.0

Re: [Qemu-devel] [PATCH 1/2] hw/mips: add initial Cluster Power Controller support

[Peter Maydell]

On 26 February 2016 at 16:19, Leon Alrae <leon.alrae@imgtec.com> wrote:
> Cluster Power Controller (CPC) is responsible for power management in
> multiprocessing system. It provides registers to control the power and the
> clock frequency of the individual elements in the system.
>
> This patch implements only three registers that are used to control the
> power state of each VP on a single core:
> * VP Run is a write-only register used to set each VP to the run state
> * VP Stop is a write-only register used to set each VP to the suspend state
> * VP Running is a read-only register indicating the run state of each VP
>
> Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
> ---
>  default-configs/mips-softmmu.mak     |   1 +
>  default-configs/mips64-softmmu.mak   |   1 +
>  default-configs/mips64el-softmmu.mak |   1 +
>  default-configs/mipsel-softmmu.mak   |   1 +

A separate thing, but maybe it would be worth having a mips-softmmu-common.mak
that all the mips*-softmmu.mak include to avoid having to repeat CONFIG defines
in four places like this.

> +static void mips_cpc_init(Object *obj)
> +{
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
> +    MIPSCPCState *s = MIPS_CPC(obj);
> +
> +    memory_region_init_io(&s->mr, OBJECT(s), &cpc_ops, s, "mips-cpc",
> +                          CPC_ADDRSPACE_SZ);
> +    sysbus_init_mmio(sbd, &s->mr);
> +}
> +
> +static const TypeInfo mips_cpc_info = {
> +    .name          = TYPE_MIPS_CPC,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(MIPSCPCState),
> +    .instance_init = mips_cpc_init,
> +};

I suspect you need a reset method.

> +
> +static void mips_cpc_register_types(void)
> +{
> +    type_register_static(&mips_cpc_info);
> +}
> +
> +type_init(mips_cpc_register_types)

> +typedef struct MIPSCPCState {
> +    SysBusDevice parent_obj;
> +
> +    MemoryRegion mr;
> +    uint64_t vp_running; /* Indicates which VP's are in the run state */

This is state, so you need a VMState structure to migrate it correctly.

> +} MIPSCPCState;
> +
> +#endif /* MIPS_CPC_H */
> --
> 2.1.0

thanks
-- PMM

Re: [Qemu-devel] [PATCH 1/2] hw/mips: add initial Cluster Power Controller support

[Leon Alrae]

On 26/02/16 16:49, Peter Maydell wrote:
> On 26 February 2016 at 16:19, Leon Alrae <leon.alrae@imgtec.com> wrote:
>> Cluster Power Controller (CPC) is responsible for power management in
>> multiprocessing system. It provides registers to control the power and the
>> clock frequency of the individual elements in the system.
>>
>> This patch implements only three registers that are used to control the
>> power state of each VP on a single core:
>> * VP Run is a write-only register used to set each VP to the run state
>> * VP Stop is a write-only register used to set each VP to the suspend state
>> * VP Running is a read-only register indicating the run state of each VP
>>
>> Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
>> ---
>>  default-configs/mips-softmmu.mak     |   1 +
>>  default-configs/mips64-softmmu.mak   |   1 +
>>  default-configs/mips64el-softmmu.mak |   1 +
>>  default-configs/mipsel-softmmu.mak   |   1 +
> 
> A separate thing, but maybe it would be worth having a mips-softmmu-common.mak
> that all the mips*-softmmu.mak include to avoid having to repeat CONFIG defines
> in four places like this.

Good idea. I'll prepare a separate patch for that.

And the comments below will be addressed in v2 (it'll also include few
extra changes).

Thanks,
Leon

> 
>> +static void mips_cpc_init(Object *obj)
>> +{
>> +    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
>> +    MIPSCPCState *s = MIPS_CPC(obj);
>> +
>> +    memory_region_init_io(&s->mr, OBJECT(s), &cpc_ops, s, "mips-cpc",
>> +                          CPC_ADDRSPACE_SZ);
>> +    sysbus_init_mmio(sbd, &s->mr);
>> +}
>> +
>> +static const TypeInfo mips_cpc_info = {
>> +    .name          = TYPE_MIPS_CPC,
>> +    .parent        = TYPE_SYS_BUS_DEVICE,
>> +    .instance_size = sizeof(MIPSCPCState),
>> +    .instance_init = mips_cpc_init,
>> +};
> 
> I suspect you need a reset method.
> 
>> +
>> +static void mips_cpc_register_types(void)
>> +{
>> +    type_register_static(&mips_cpc_info);
>> +}
>> +
>> +type_init(mips_cpc_register_types)
> 
>> +typedef struct MIPSCPCState {
>> +    SysBusDevice parent_obj;
>> +
>> +    MemoryRegion mr;
>> +    uint64_t vp_running; /* Indicates which VP's are in the run state */
> 
> This is state, so you need a VMState structure to migrate it correctly.
> 
>> +} MIPSCPCState;
>> +
>> +#endif /* MIPS_CPC_H */
>> --
>> 2.1.0
> 
> thanks
> -- PMM
>