Re: [Qemu-devel] [PATCH for-2.10 4/8] ppc/pnv: add memory regions for the ICP registers

[David Gibson]

On Wed, Mar 08, 2017 at 11:52:47AM +0100, Cédric Le Goater wrote:
> This provides to a PowerNV chip (POWER8) access to the Interrupt
> Management area, which contains the registers of the Interrupt Control
> Presenters of each thread. These are used to accept, return, forward
> interrupts in the system.
> 
> This area is modeled with a per-chip container memory region holding
> all the ICP registers. Each thread of a chip is then associated with
> its ICP registers using a memory subregion indexed by its PIR number
> in the overall region.
> 
> Signed-off-by: Cédric Le Goater <address@hidden>

Putting the MMIO stuff into the PNV code seems wrong.  Instead I'd
expect a subclass of TYPE_ICP which implements the MMIO stuff locally,
and exposes an already construct MR, which the pnv code can then
insert into the overall address space.

> ---
>  hw/ppc/pnv.c              |  20 +++++++
>  hw/ppc/pnv_core.c         | 146 
> ++++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/ppc/pnv.h      |  20 +++++++
>  include/hw/ppc/pnv_core.h |   1 +
>  include/hw/ppc/xics.h     |   3 +
>  5 files changed, 190 insertions(+)
> 
> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
> index 461d3535e99c..7b13b08deadf 100644
> --- a/hw/ppc/pnv.c
> +++ b/hw/ppc/pnv.c
> @@ -658,6 +658,16 @@ static void pnv_chip_init(Object *obj)
>      object_property_add_child(obj, "lpc", OBJECT(&chip->lpc), NULL);
>  }
>  
> +static void pnv_chip_icp_realize(PnvChip *chip, Error **errp)
> +{
> +    char *name;
> +
> +    name = g_strdup_printf("icp-%x", chip->chip_id);
> +    memory_region_init(&chip->icp_mmio, OBJECT(chip), name, PNV_ICP_SIZE);
> +    sysbus_init_mmio(SYS_BUS_DEVICE(chip), &chip->icp_mmio);
> +    g_free(name);
> +}
> +
>  static void pnv_chip_realize(DeviceState *dev, Error **errp)
>  {
>      PnvChip *chip = PNV_CHIP(dev);
> @@ -680,6 +690,14 @@ static void pnv_chip_realize(DeviceState *dev, Error 
> **errp)
>      }
>      sysbus_mmio_map(SYS_BUS_DEVICE(chip), 0, PNV_XSCOM_BASE(chip));
>  
> +    /* Interrupt Management Area. This is the memory region holding
> +     * all the Interrupt Control Presenter (ICP) registers */
> +    pnv_chip_icp_realize(chip, &error);
> +    if (error) {
> +        error_propagate(errp, error);
> +        return;
> +    }
> +
>      /* Cores */
>      pnv_chip_core_sanitize(chip, &error);
>      if (error) {
> @@ -709,6 +727,8 @@ static void pnv_chip_realize(DeviceState *dev, Error 
> **errp)
>          object_property_set_int(OBJECT(pnv_core),
>                                  pcc->core_pir(chip, core_hwid),
>                                  "pir", &error_fatal);
> +        object_property_add_const_link(OBJECT(pnv_core), "xics",
> +                                       qdev_get_machine(), &error_fatal);
>          object_property_set_bool(OBJECT(pnv_core), true, "realized",
>                                   &error_fatal);
>          object_unref(OBJECT(pnv_core));
> diff --git a/hw/ppc/pnv_core.c b/hw/ppc/pnv_core.c
> index d79d530b4881..8633afbff795 100644
> --- a/hw/ppc/pnv_core.c
> +++ b/hw/ppc/pnv_core.c
> @@ -26,6 +26,128 @@
>  #include "hw/ppc/pnv_core.h"
>  #include "hw/ppc/pnv_xscom.h"
>  
> +static uint64_t pnv_core_icp_read(void *opaque, hwaddr addr, unsigned width)
> +{
> +    ICPState *icp = opaque;
> +    bool byte0 = (width == 1 && (addr & 0x3) == 0);
> +    uint64_t val = 0xffffffff;
> +
> +    switch (addr & 0xffc) {
> +    case 0: /* poll */
> +        val = icp_ipoll(icp, NULL);
> +        if (byte0) {
> +            val >>= 24;
> +        } else if (width != 4) {
> +            goto bad_access;
> +        }
> +        break;
> +    case 4: /* xirr */
> +        if (byte0) {
> +            val = icp_ipoll(icp, NULL) >> 24;
> +        } else if (width == 4) {
> +            val = icp_accept(icp);
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    case 12:
> +        if (byte0) {
> +            val = icp->mfrr;
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    case 16:
> +        if (width == 4) {
> +            val = icp->links[0];
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    case 20:
> +        if (width == 4) {
> +            val = icp->links[1];
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    case 24:
> +        if (width == 4) {
> +            val = icp->links[2];
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    default:
> +bad_access:
> +        qemu_log_mask(LOG_GUEST_ERROR, "XICS: Bad ICP access 0x%"
> +                      HWADDR_PRIx"/%d\n", addr, width);
> +    }
> +
> +    return val;
> +}
> +
> +static void pnv_core_icp_write(void *opaque, hwaddr addr, uint64_t val,
> +                              unsigned width)
> +{
> +    ICPState *icp = opaque;
> +    bool byte0 = (width == 1 && (addr & 0x3) == 0);
> +
> +    switch (addr & 0xffc) {
> +    case 4: /* xirr */
> +        if (byte0) {
> +            icp_set_cppr(icp, val);
> +        } else if (width == 4) {
> +            icp_eoi(icp, val);
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    case 12:
> +        if (byte0) {
> +            icp_set_mfrr(icp, val);
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    case 16:
> +        if (width == 4) {
> +            icp->links[0] = val;
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    case 20:
> +        if (width == 4) {
> +            icp->links[1] = val;
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    case 24:
> +        if (width == 4) {
> +            icp->links[2] = val;
> +        } else {
> +            goto bad_access;
> +        }
> +        break;
> +    default:
> +bad_access:
> +        qemu_log_mask(LOG_GUEST_ERROR, "XICS: Bad ICP access 0x%"
> +                      HWADDR_PRIx"/%d\n", addr, width);
> +    }
> +}
> +
> +static const MemoryRegionOps pnv_core_icp_ops = {
> +    .read = pnv_core_icp_read,
> +    .write = pnv_core_icp_write,
> +    .valid.min_access_size = 1,
> +    .valid.max_access_size = 4,
> +    .impl.min_access_size = 1,
> +    .impl.max_access_size = 4,
> +    .endianness = DEVICE_BIG_ENDIAN,
> +};
> +
>  static void powernv_cpu_reset(void *opaque)
>  {
>      PowerPCCPU *cpu = opaque;
> @@ -129,6 +251,14 @@ static void pnv_core_realize_child(Object *child, Error 
> **errp)
>      }
>  }
>  
> +static ICPState *xics_get_icp_per_pir(XICSFabric *xi, int pir)
> +{
> +    int index = xics_get_cpu_index_by_pir(pir);
> +    assert(index != -1);
> +
> +    return xics_icp_get(xi, index);
> +}
> +
>  static void pnv_core_realize(DeviceState *dev, Error **errp)
>  {
>      PnvCore *pc = PNV_CORE(OBJECT(dev));
> @@ -140,6 +270,14 @@ static void pnv_core_realize(DeviceState *dev, Error 
> **errp)
>      void *obj;
>      int i, j;
>      char name[32];
> +    Object *xi;
> +
> +    xi = object_property_get_link(OBJECT(dev), "xics", &local_err);
> +    if (!xi) {
> +        error_setg(errp, "%s: required link 'xics' not found: %s",
> +                   __func__, error_get_pretty(local_err));
> +        return;
> +    }
>  
>      pc->threads = g_malloc0(size * cc->nr_threads);
>      for (i = 0; i < cc->nr_threads; i++) {
> @@ -169,6 +307,14 @@ static void pnv_core_realize(DeviceState *dev, Error 
> **errp)
>      snprintf(name, sizeof(name), "xscom-core.%d", cc->core_id);
>      pnv_xscom_region_init(&pc->xscom_regs, OBJECT(dev), &pnv_core_xscom_ops,
>                            pc, name, PNV_XSCOM_EX_CORE_SIZE);
> +
> +    pc->icp_mmios = g_new0(MemoryRegion, cc->nr_threads);
> +    for (i = 0; i < cc->nr_threads; i++) {
> +        ICPState *icp = xics_get_icp_per_pir(XICS_FABRIC(xi), pc->pir + i);
> +        snprintf(name, sizeof(name), "icp-core.%d", cc->core_id);
> +        memory_region_init_io(&pc->icp_mmios[i], OBJECT(dev),
> +                              &pnv_core_icp_ops, icp, name, 0x1000);
> +    }
>      return;
>  
>  err:
> diff --git a/include/hw/ppc/pnv.h b/include/hw/ppc/pnv.h
> index 6a0b004cea93..f11215ea31f2 100644
> --- a/include/hw/ppc/pnv.h
> +++ b/include/hw/ppc/pnv.h
> @@ -55,6 +55,7 @@ typedef struct PnvChip {
>      MemoryRegion xscom_mmio;
>      MemoryRegion xscom;
>      AddressSpace xscom_as;
> +    MemoryRegion icp_mmio;
>  
>      PnvLpcController lpc;
>  } PnvChip;
> @@ -130,4 +131,23 @@ typedef struct PnvMachineState {
>  #define PNV_XSCOM_BASE(chip)                                            \
>      (chip->xscom_base + ((uint64_t)(chip)->chip_id) * PNV_XSCOM_SIZE)
>  
> +/*
> + * XSCOM 0x20109CA defines the ICP BAR:
> + *
> + * 0:29   : bits 14 to 43 of address to define 1 MB region.
> + * 30     : 1 to enable ICP to receive loads/stores against its BAR region
> + * 31:63  : Constant 0
> + *
> + * Usually defined as :
> + *
> + *      0xffffe00200000000 -> 0x0003ffff80000000
> + *      0xffffe00600000000 -> 0x0003ffff80100000
> + *      0xffffe02200000000 -> 0x0003ffff80800000
> + *      0xffffe02600000000 -> 0x0003ffff80900000
> + *
> + * TODO: make a macro using the chip hw id
> + */
> +#define PNV_ICP_BASE(chip)   0x0003ffff80000000ull
> +#define PNV_ICP_SIZE         0x0000000000100000ull
> +
>  #endif /* _PPC_PNV_H */
> diff --git a/include/hw/ppc/pnv_core.h b/include/hw/ppc/pnv_core.h
> index 2955a41c901f..f2fad8f6361b 100644
> --- a/include/hw/ppc/pnv_core.h
> +++ b/include/hw/ppc/pnv_core.h
> @@ -38,6 +38,7 @@ typedef struct PnvCore {
>      uint32_t pir;
>  
>      MemoryRegion xscom_regs;
> +    MemoryRegion *icp_mmios;
>  } PnvCore;
>  
>  typedef struct PnvCoreClass {
> diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h
> index c2032cac55f6..a3dcdf93bbe3 100644
> --- a/include/hw/ppc/xics.h
> +++ b/include/hw/ppc/xics.h
> @@ -78,6 +78,9 @@ struct ICPState {
>      bool cap_irq_xics_enabled;
>  
>      XICSFabric *xics;
> +
> +    /* for the PowerNV ICP registers (not used by Linux). */
> +    uint32_t links[3];
>  };
>  
>  #define TYPE_ICS_BASE "ics-base"

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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