Re: [PATCH v2 3/3] hw/sd: Add Cadence SDHCI emulation

[Philippe Mathieu-Daudé]

On 8/17/20 12:05 PM, Bin Meng wrote:
> Cadence SD/SDIO/eMMC Host Controller (SD4HC) is an SDHCI compatible
> controller. The SDHCI compatible registers start from offset 0x200,
> which are called Slot Register Set (SRS) in its datasheet.
> 
> This creates a Cadence SDHCI model built on top of the existing
> generic SDHCI model. Cadence specific Host Register Set (HRS) is
> implemented to make guest software happy.
> 
> Signed-off-by: Bin Meng <bin.meng@windriver.com>
> 
> ---
> 
> Changes in v2:
> - use 's' for the model state
> - call device_cold_reset() in cadence_sdhci_reset()
> - add .impl in cadence_sdhci_ops
> - move Cadence specific register defines to cadence_sdhci.c
> - use 'sdhci' instead of 'slot' to represent SDHCIState
> - use sysbus_mmio_get_region() to access SDHCI model's memory region
> - initialize TYPE_SYSBUS_SDHCI in the instance_init() so that users
>   of Cadence SDHCI do not have to do that themselves
> - propergate irq and 'sd-bus' from generic-sdhci
> 
>  hw/sd/Kconfig                 |   4 +
>  hw/sd/Makefile.objs           |   1 +
>  hw/sd/cadence_sdhci.c         | 200 
> ++++++++++++++++++++++++++++++++++++++++++
>  include/hw/sd/cadence_sdhci.h |  46 ++++++++++
>  4 files changed, 251 insertions(+)
>  create mode 100644 hw/sd/cadence_sdhci.c
>  create mode 100644 include/hw/sd/cadence_sdhci.h

Consider using scripts/git.orderfile ;)
> 
> diff --git a/hw/sd/Kconfig b/hw/sd/Kconfig
> index c5e1e55..633b9af 100644
> --- a/hw/sd/Kconfig
> +++ b/hw/sd/Kconfig
> @@ -19,3 +19,7 @@ config SDHCI_PCI
>      default y if PCI_DEVICES
>      depends on PCI
>      select SDHCI
> +
> +config CADENCE_SDHCI
> +    bool
> +    select SDHCI
> diff --git a/hw/sd/Makefile.objs b/hw/sd/Makefile.objs
> index 0d1df17..4d500a6 100644
> --- a/hw/sd/Makefile.objs
> +++ b/hw/sd/Makefile.objs
> @@ -10,3 +10,4 @@ common-obj-$(CONFIG_OMAP) += omap_mmc.o
>  common-obj-$(CONFIG_PXA2XX) += pxa2xx_mmci.o
>  common-obj-$(CONFIG_RASPI) += bcm2835_sdhost.o
>  common-obj-$(CONFIG_ASPEED_SOC) += aspeed_sdhci.o
> +common-obj-$(CONFIG_CADENCE_SDHCI) += cadence_sdhci.o
> diff --git a/hw/sd/cadence_sdhci.c b/hw/sd/cadence_sdhci.c
> new file mode 100644
> index 0000000..4f01d63
> --- /dev/null
> +++ b/hw/sd/cadence_sdhci.c
> @@ -0,0 +1,200 @@
> +/*
> + * Cadence SDHCI emulation
> + *
> + * Copyright (c) 2020 Wind River Systems, Inc.
> + *
> + * Author:
> + *   Bin Meng <bin.meng@windriver.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 or
> + * (at your option) version 3 of the License.
> + *
> + * This program 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 General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qemu/bitops.h"
> +#include "qemu/error-report.h"
> +#include "qemu/log.h"
> +#include "qapi/error.h"
> +#include "migration/vmstate.h"
> +#include "hw/irq.h"
> +#include "hw/sd/cadence_sdhci.h"
> +#include "sdhci-internal.h"
> +
> +/* HRS - Host Register Set (specific to Cadence) */
> +
> +#define CADENCE_SDHCI_HRS00             0x00    /* general information */
> +#define CADENCE_SDHCI_HRS00_SWR             BIT(0)
> +#define CADENCE_SDHCI_HRS00_POR_VAL         0x00010000
> +
> +#define CADENCE_SDHCI_HRS04             0x10    /* PHY access port */
> +#define CADENCE_SDHCI_HRS04_WR              BIT(24)
> +#define CADENCE_SDHCI_HRS04_RD              BIT(25)
> +#define CADENCE_SDHCI_HRS04_ACK             BIT(26)
> +
> +#define CADENCE_SDHCI_HRS06             0x18    /* eMMC control */
> +#define CADENCE_SDHCI_HRS06_TUNE_UP         BIT(15)
> +
> +/* SRS - Slot Register Set (SDHCI-compatible) */
> +
> +#define CADENCE_SDHCI_SRS_BASE          0x200
> +
> +#define TO_REG(addr)    ((addr) / sizeof(uint32_t))
> +
> +static void cadence_sdhci_instance_init(Object *obj)
> +{
> +    CadenceSDHCIState *s = CADENCE_SDHCI(obj);
> +
> +    object_initialize_child(OBJECT(s), "cadence-sdhci.sdhci",

"generic-sdhci"?

> +                            &s->sdhci, TYPE_SYSBUS_SDHCI);
> +}
> +
> +static void cadence_sdhci_reset(DeviceState *dev)
> +{
> +    CadenceSDHCIState *s = CADENCE_SDHCI(dev);
> +
> +    memset(s->regs, 0, CADENCE_SDHCI_REG_SIZE);
> +    s->regs[TO_REG(CADENCE_SDHCI_HRS00)] = CADENCE_SDHCI_HRS00_POR_VAL;
> +
> +    device_cold_reset(DEVICE(&s->sdhci));
> +}
> +
> +static uint64_t cadence_sdhci_read(void *opaque, hwaddr addr, unsigned int 
> size)
> +{
> +    uint32_t val = 0;
> +    CadenceSDHCIState *s = opaque;
> +
> +    if (addr < CADENCE_SDHCI_REG_SIZE) {
> +        val = s->regs[TO_REG(addr)];
> +    } else {
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Out-of-bounds read at 0x%" HWADDR_PRIx "\n",
> +                      __func__, addr);
> +    }
> +
> +    return (uint64_t)val;
> +}
> +
> +static void cadence_sdhci_write(void *opaque, hwaddr addr, uint64_t val,
> +                                unsigned int size)
> +{
> +    CadenceSDHCIState *s = opaque;
> +    uint32_t val32 = (uint32_t)val;
> +
> +    switch (addr) {
> +    case CADENCE_SDHCI_HRS00:
> +        /*
> +         * The only writable bit is SWR (software reset) and it automatically
> +         * clears to zero, so essentially this register remains unchanged.
> +         */
> +        if (val32 & CADENCE_SDHCI_HRS00_SWR) {
> +            cadence_sdhci_reset(DEVICE(s));
> +        }
> +
> +        break;
> +    case CADENCE_SDHCI_HRS04:
> +        /*
> +         * Only emulate the ACK bit behavior when read or write transaction
> +         * are requested.
> +         */
> +        if (val32 & (CADENCE_SDHCI_HRS04_WR | CADENCE_SDHCI_HRS04_RD)) {
> +            val32 |= CADENCE_SDHCI_HRS04_ACK;
> +        } else {
> +            val32 &= ~CADENCE_SDHCI_HRS04_ACK;
> +        }
> +
> +        s->regs[TO_REG(addr)] = val32;
> +        break;
> +    case CADENCE_SDHCI_HRS06:
> +        if (val32 & CADENCE_SDHCI_HRS06_TUNE_UP) {
> +            val32 &= ~CADENCE_SDHCI_HRS06_TUNE_UP;
> +        }
> +
> +        s->regs[TO_REG(addr)] = val32;
> +        break;
> +    default:
> +        if (addr < CADENCE_SDHCI_REG_SIZE) {
> +            s->regs[TO_REG(addr)] = val32;
> +        } else {
> +            qemu_log_mask(LOG_GUEST_ERROR,
> +                          "%s: Out-of-bounds write at 0x%" HWADDR_PRIx "\n",
> +                          __func__, addr);
> +        }
> +    }
> +}
> +
> +static const MemoryRegionOps cadence_sdhci_ops = {
> +    .read = cadence_sdhci_read,
> +    .write = cadence_sdhci_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +    .impl = {
> +        .min_access_size = 4,
> +        .max_access_size = 4,
> +    },
> +    .valid = {
> +        .min_access_size = 4,
> +        .max_access_size = 4,
> +    }
> +};
> +
> +static void cadence_sdhci_realize(DeviceState *dev, Error **errp)
> +{
> +    CadenceSDHCIState *s = CADENCE_SDHCI(dev);
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
> +    SysBusDevice *sbd_sdhci = SYS_BUS_DEVICE(&s->sdhci);
> +
> +    memory_region_init_io(&s->iomem, OBJECT(s), &cadence_sdhci_ops,
> +                          s, TYPE_CADENCE_SDHCI, 0x1000);

I/O Region of 0x1000 but you only uses 0x100 for the Cadence part
and 0x100 for the generic part.

Consider creating a container of 0x1000, and map 2 subregions?

  memory_region_init(&s->container, OBJECT(s), 0x1000);
  memory_region_init_io(&s->iomem, OBJECT(s), &cadence_sdhci_ops,
                         s, TYPE_CADENCE_SDHCI, CADENCE_SDHCI_REG_SIZE);
  memory_region_add_subregion(&s->container, 0x000, &s->iomem);

You can then simplify your out-of-bounds access checks for
cadence_sdhci_ops's read/write.

> +    sysbus_init_mmio(sbd, &s->iomem);

Replace by:

  sysbus_init_mmio(sbd, &s->container);

Using a container seems cleaner, but your patch is fine:
Acked-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> +
> +    sysbus_realize(sbd_sdhci, errp);
> +    memory_region_add_subregion(&s->iomem, CADENCE_SDHCI_SRS_BASE,
> +                                sysbus_mmio_get_region(sbd_sdhci, 0));
> +
> +    /* propagate irq and "sd-bus" from generic-sdhci */
> +    sysbus_pass_irq(sbd, sbd_sdhci);
> +    s->bus = qdev_get_child_bus(DEVICE(sbd_sdhci), "sd-bus");
> +}
> +
> +static const VMStateDescription vmstate_cadence_sdhci = {
> +    .name = TYPE_CADENCE_SDHCI,
> +    .version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT32_ARRAY(regs, CadenceSDHCIState, 
> CADENCE_SDHCI_NUM_REGS),
> +        VMSTATE_END_OF_LIST(),
> +    },
> +};
> +
> +static void cadence_sdhci_class_init(ObjectClass *classp, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(classp);
> +
> +    dc->desc = "Cadence SD/SDIO/eMMC Host Controller (SD4HC)";
> +    dc->realize = cadence_sdhci_realize;
> +    dc->reset = cadence_sdhci_reset;
> +    dc->vmsd = &vmstate_cadence_sdhci;
> +}
> +
> +static TypeInfo cadence_sdhci_info = {
> +    .name          = TYPE_CADENCE_SDHCI,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(CadenceSDHCIState),
> +    .instance_init = cadence_sdhci_instance_init,
> +    .class_init    = cadence_sdhci_class_init,
> +};
> +
> +static void cadence_sdhci_register_types(void)
> +{
> +    type_register_static(&cadence_sdhci_info);
> +}
> +
> +type_init(cadence_sdhci_register_types)
> diff --git a/include/hw/sd/cadence_sdhci.h b/include/hw/sd/cadence_sdhci.h
> new file mode 100644
> index 0000000..9b52115
> --- /dev/null
> +++ b/include/hw/sd/cadence_sdhci.h
> @@ -0,0 +1,46 @@
> +/*
> + * Cadence SDHCI emulation
> + *
> + * Copyright (c) 2020 Wind River Systems, Inc.
> + *
> + * Author:
> + *   Bin Meng <bin.meng@windriver.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 or
> + * (at your option) version 3 of the License.
> + *
> + * This program 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 General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef CADENCE_SDHCI_H
> +#define CADENCE_SDHCI_H
> +
> +#include "hw/sd/sdhci.h"
> +
> +#define CADENCE_SDHCI_REG_SIZE  0x100
> +#define CADENCE_SDHCI_NUM_REGS  (CADENCE_SDHCI_REG_SIZE / sizeof(uint32_t))
> +
> +typedef struct CadenceSDHCIState {
> +    SysBusDevice parent;
> +
> +    MemoryRegion iomem;
> +    BusState *bus;
> +
> +    uint32_t regs[CADENCE_SDHCI_NUM_REGS];
> +
> +    SDHCIState sdhci;
> +} CadenceSDHCIState;
> +
> +#define TYPE_CADENCE_SDHCI  "cadence.sdhci"
> +#define CADENCE_SDHCI(obj)  OBJECT_CHECK(CadenceSDHCIState, (obj), \
> +                                         TYPE_CADENCE_SDHCI)
> +
> +#endif /* CADENCE_SDHCI_H */
>