Re: [PATCH for-6.2 01/25] arm: Move M-profile RAS register block into its own device

[Luc Michel]

On 10:33 Thu 12 Aug     , Peter Maydell wrote:
> Currently we implement the RAS register block within the NVIC device.
> It isn't really very tightly coupled with the NVIC proper, so instead
> move it out into a sysbus device of its own and have the top level
> ARMv7M container create it and map it into memory at the right
> address.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Luc Michel <luc@lmichel.fr>

> ---
>  include/hw/arm/armv7m.h       |  2 +
>  include/hw/intc/armv7m_nvic.h |  1 -
>  include/hw/misc/armv7m_ras.h  | 37 ++++++++++++++
>  hw/arm/armv7m.c               | 12 +++++
>  hw/intc/armv7m_nvic.c         | 56 ---------------------
>  hw/misc/armv7m_ras.c          | 93 +++++++++++++++++++++++++++++++++++
>  MAINTAINERS                   |  2 +
>  hw/misc/meson.build           |  2 +
>  8 files changed, 148 insertions(+), 57 deletions(-)
>  create mode 100644 include/hw/misc/armv7m_ras.h
>  create mode 100644 hw/misc/armv7m_ras.c
> 
> diff --git a/include/hw/arm/armv7m.h b/include/hw/arm/armv7m.h
> index bc6733c5184..4cae0d7eeaa 100644
> --- a/include/hw/arm/armv7m.h
> +++ b/include/hw/arm/armv7m.h
> @@ -12,6 +12,7 @@
>  
>  #include "hw/sysbus.h"
>  #include "hw/intc/armv7m_nvic.h"
> +#include "hw/misc/armv7m_ras.h"
>  #include "target/arm/idau.h"
>  #include "qom/object.h"
>  
> @@ -58,6 +59,7 @@ struct ARMv7MState {
>      NVICState nvic;
>      BitBandState bitband[ARMV7M_NUM_BITBANDS];
>      ARMCPU *cpu;
> +    ARMv7MRAS ras;
>  
>      /* MemoryRegion we pass to the CPU, with our devices layered on
>       * top of the ones the board provides in board_memory.
> diff --git a/include/hw/intc/armv7m_nvic.h b/include/hw/intc/armv7m_nvic.h
> index 39c71e15936..33b6d8810c7 100644
> --- a/include/hw/intc/armv7m_nvic.h
> +++ b/include/hw/intc/armv7m_nvic.h
> @@ -83,7 +83,6 @@ struct NVICState {
>      MemoryRegion sysreg_ns_mem;
>      MemoryRegion systickmem;
>      MemoryRegion systick_ns_mem;
> -    MemoryRegion ras_mem;
>      MemoryRegion container;
>      MemoryRegion defaultmem;
>  
> diff --git a/include/hw/misc/armv7m_ras.h b/include/hw/misc/armv7m_ras.h
> new file mode 100644
> index 00000000000..f8773e65b14
> --- /dev/null
> +++ b/include/hw/misc/armv7m_ras.h
> @@ -0,0 +1,37 @@
> +/*
> + * Arm M-profile RAS block
> + *
> + * Copyright (c) 2021 Linaro Limited
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License version 2 or
> + *  (at your option) any later version.
> + */
> +
> +/*
> + * This is a model of the RAS register block of an M-profile CPU
> + * (the registers starting at 0xE0005000 with ERRFRn).
> + *
> + * QEMU interface:
> + *  + sysbus MMIO region 0: the register bank
> + *
> + * The QEMU implementation currently provides "minimal RAS" only.
> + */
> +
> +#ifndef HW_MISC_ARMV7M_RAS_H
> +#define HW_MISC_ARMV7M_RAS_H
> +
> +#include "hw/sysbus.h"
> +
> +#define TYPE_ARMV7M_RAS "armv7m-ras"
> +OBJECT_DECLARE_SIMPLE_TYPE(ARMv7MRAS, ARMV7M_RAS)
> +
> +struct ARMv7MRAS {
> +    /*< private >*/
> +    SysBusDevice parent_obj;
> +
> +    /*< public >*/
> +    MemoryRegion iomem;
> +};
> +
> +#endif
> diff --git a/hw/arm/armv7m.c b/hw/arm/armv7m.c
> index 9ce5c30cd5c..8964730d153 100644
> --- a/hw/arm/armv7m.c
> +++ b/hw/arm/armv7m.c
> @@ -231,6 +231,18 @@ static void armv7m_realize(DeviceState *dev, Error 
> **errp)
>      memory_region_add_subregion(&s->container, 0xe0000000,
>                                  sysbus_mmio_get_region(sbd, 0));
>  
> +    /* If the CPU has RAS support, create the RAS register block */
> +    if (cpu_isar_feature(aa32_ras, s->cpu)) {
> +        object_initialize_child(OBJECT(dev), "armv7m-ras",
> +                                &s->ras, TYPE_ARMV7M_RAS);
> +        sbd = SYS_BUS_DEVICE(&s->ras);
> +        if (!sysbus_realize(sbd, errp)) {
> +            return;
> +        }
> +        memory_region_add_subregion_overlap(&s->container, 0xe0005000,
> +                                            sysbus_mmio_get_region(sbd, 0), 
> 1);
> +    }
> +
>      for (i = 0; i < ARRAY_SIZE(s->bitband); i++) {
>          if (s->enable_bitband) {
>              Object *obj = OBJECT(&s->bitband[i]);
> diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
> index 1e7ddcb94cb..a5975592dfa 100644
> --- a/hw/intc/armv7m_nvic.c
> +++ b/hw/intc/armv7m_nvic.c
> @@ -2549,56 +2549,6 @@ static const MemoryRegionOps nvic_systick_ops = {
>      .endianness = DEVICE_NATIVE_ENDIAN,
>  };
>  
> -
> -static MemTxResult ras_read(void *opaque, hwaddr addr,
> -                            uint64_t *data, unsigned size,
> -                            MemTxAttrs attrs)
> -{
> -    if (attrs.user) {
> -        return MEMTX_ERROR;
> -    }
> -
> -    switch (addr) {
> -    case 0xe10: /* ERRIIDR */
> -        /* architect field = Arm; product/variant/revision 0 */
> -        *data = 0x43b;
> -        break;
> -    case 0xfc8: /* ERRDEVID */
> -        /* Minimal RAS: we implement 0 error record indexes */
> -        *data = 0;
> -        break;
> -    default:
> -        qemu_log_mask(LOG_UNIMP, "Read RAS register offset 0x%x\n",
> -                      (uint32_t)addr);
> -        *data = 0;
> -        break;
> -    }
> -    return MEMTX_OK;
> -}
> -
> -static MemTxResult ras_write(void *opaque, hwaddr addr,
> -                             uint64_t value, unsigned size,
> -                             MemTxAttrs attrs)
> -{
> -    if (attrs.user) {
> -        return MEMTX_ERROR;
> -    }
> -
> -    switch (addr) {
> -    default:
> -        qemu_log_mask(LOG_UNIMP, "Write to RAS register offset 0x%x\n",
> -                      (uint32_t)addr);
> -        break;
> -    }
> -    return MEMTX_OK;
> -}
> -
> -static const MemoryRegionOps ras_ops = {
> -    .read_with_attrs = ras_read,
> -    .write_with_attrs = ras_write,
> -    .endianness = DEVICE_NATIVE_ENDIAN,
> -};
> -
>  /*
>   * Unassigned portions of the PPB space are RAZ/WI for privileged
>   * accesses, and fault for non-privileged accesses.
> @@ -2946,12 +2896,6 @@ static void armv7m_nvic_realize(DeviceState *dev, 
> Error **errp)
>                                              &s->systick_ns_mem, 1);
>      }
>  
> -    if (cpu_isar_feature(aa32_ras, s->cpu)) {
> -        memory_region_init_io(&s->ras_mem, OBJECT(s),
> -                              &ras_ops, s, "nvic_ras", 0x1000);
> -        memory_region_add_subregion(&s->container, 0x5000, &s->ras_mem);
> -    }
> -
>      sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->container);
>  }
>  
> diff --git a/hw/misc/armv7m_ras.c b/hw/misc/armv7m_ras.c
> new file mode 100644
> index 00000000000..a2b4f4b8dc8
> --- /dev/null
> +++ b/hw/misc/armv7m_ras.c
> @@ -0,0 +1,93 @@
> +/*
> + * Arm M-profile RAS block
> + *
> + * Copyright (c) 2021 Linaro Limited
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License version 2 or
> + *  (at your option) any later version.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "hw/misc/armv7m_ras.h"
> +#include "qemu/log.h"
> +
> +static MemTxResult ras_read(void *opaque, hwaddr addr,
> +                            uint64_t *data, unsigned size,
> +                            MemTxAttrs attrs)
> +{
> +    if (attrs.user) {
> +        return MEMTX_ERROR;
> +    }
> +
> +    switch (addr) {
> +    case 0xe10: /* ERRIIDR */
> +        /* architect field = Arm; product/variant/revision 0 */
> +        *data = 0x43b;
> +        break;
> +    case 0xfc8: /* ERRDEVID */
> +        /* Minimal RAS: we implement 0 error record indexes */
> +        *data = 0;
> +        break;
> +    default:
> +        qemu_log_mask(LOG_UNIMP, "Read RAS register offset 0x%x\n",
> +                      (uint32_t)addr);
> +        *data = 0;
> +        break;
> +    }
> +    return MEMTX_OK;
> +}
> +
> +static MemTxResult ras_write(void *opaque, hwaddr addr,
> +                             uint64_t value, unsigned size,
> +                             MemTxAttrs attrs)
> +{
> +    if (attrs.user) {
> +        return MEMTX_ERROR;
> +    }
> +
> +    switch (addr) {
> +    default:
> +        qemu_log_mask(LOG_UNIMP, "Write to RAS register offset 0x%x\n",
> +                      (uint32_t)addr);
> +        break;
> +    }
> +    return MEMTX_OK;
> +}
> +
> +static const MemoryRegionOps ras_ops = {
> +    .read_with_attrs = ras_read,
> +    .write_with_attrs = ras_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +
> +static void armv7m_ras_init(Object *obj)
> +{
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
> +    ARMv7MRAS *s = ARMV7M_RAS(obj);
> +
> +    memory_region_init_io(&s->iomem, obj, &ras_ops,
> +                          s, "armv7m-ras", 0x1000);
> +    sysbus_init_mmio(sbd, &s->iomem);
> +}
> +
> +static void armv7m_ras_class_init(ObjectClass *klass, void *data)
> +{
> +    /* This device has no state: no need for vmstate or reset */
> +}
> +
> +static const TypeInfo armv7m_ras_info = {
> +    .name = TYPE_ARMV7M_RAS,
> +    .parent = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(ARMv7MRAS),
> +    .instance_init = armv7m_ras_init,
> +    .class_init = armv7m_ras_class_init,
> +};
> +
> +static void armv7m_ras_register_types(void)
> +{
> +    type_register_static(&armv7m_ras_info);
> +}
> +
> +type_init(armv7m_ras_register_types);
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 37b1a8e4428..3cac393bb48 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -617,6 +617,7 @@ F: hw/intc/gic_internal.h
>  F: hw/misc/a9scu.c
>  F: hw/misc/arm11scu.c
>  F: hw/misc/arm_l2x0.c
> +F: hw/misc/armv7m_ras.c
>  F: hw/timer/a9gtimer*
>  F: hw/timer/arm*
>  F: include/hw/arm/arm*.h
> @@ -626,6 +627,7 @@ F: include/hw/misc/arm11scu.h
>  F: include/hw/timer/a9gtimer.h
>  F: include/hw/timer/arm_mptimer.h
>  F: include/hw/timer/armv7m_systick.h
> +F: include/hw/misc/armv7m_ras.h
>  F: tests/qtest/test-arm-mptimer.c
>  
>  Exynos
> diff --git a/hw/misc/meson.build b/hw/misc/meson.build
> index a53b849a5a0..3f41a3a5b27 100644
> --- a/hw/misc/meson.build
> +++ b/hw/misc/meson.build
> @@ -17,6 +17,8 @@ softmmu_ss.add(when: 'CONFIG_INTEGRATOR_DEBUG', if_true: 
> files('arm_integrator_d
>  softmmu_ss.add(when: 'CONFIG_A9SCU', if_true: files('a9scu.c'))
>  softmmu_ss.add(when: 'CONFIG_ARM11SCU', if_true: files('arm11scu.c'))
>  
> +softmmu_ss.add(when: 'CONFIG_ARM_V7M', if_true: files('armv7m_ras.c'))
> +
>  # Mac devices
>  softmmu_ss.add(when: 'CONFIG_MOS6522', if_true: files('mos6522.c'))
>  
> -- 
> 2.20.1
> 

--