Re: [Qemu-devel] [PATCH v2 1/8] ppc/pnv: Add support for POWER8+ LPC Controller

[David Gibson <david@gibson.dropbear.id.au>]

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On Mon, Apr 10, 2017 at 03:56:51PM +0200, Cédric Le Goater wrote:
> From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
> It adds the Naples chip which supports proper LPC interrupts via the
> LPC controller rather than via an external CPLD.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> [clg: - updated for qemu-2.9
>       - ported on latest PowerNV patchset
>       - moved the IRQ handler in pnv_lpc.c
>       - introduced pnv_lpc_isa_irq_create() to create the ISA IRQs ]
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---
> 
>  Changes since v1:
> 
>  - moved the IRQ handler in pnv_lpc.c
>  - introduced pnv_lpc_isa_irq_create() to create the ISA IRQs 
> 
>  hw/ppc/pnv.c             | 45 +++-------------------
>  hw/ppc/pnv_lpc.c         | 97 +++++++++++++++++++++++++++++++++++++++++++++++-
>  include/hw/ppc/pnv_lpc.h |  8 ++++
>  3 files changed, 108 insertions(+), 42 deletions(-)
> 
> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
> index 16f32c9bbd9d..27589b91d1cf 100644
> --- a/hw/ppc/pnv.c
> +++ b/hw/ppc/pnv.c
> @@ -346,36 +346,6 @@ static void ppc_powernv_reset(void)
>      cpu_physical_memory_write(PNV_FDT_ADDR, fdt, fdt_totalsize(fdt));
>  }
>  
> -/* If we don't use the built-in LPC interrupt deserializer, we need
> - * to provide a set of qirqs for the ISA bus or things will go bad.
> - *
> - * Most machines using pre-Naples chips (without said deserializer)
> - * have a CPLD that will collect the SerIRQ and shoot them as a
> - * single level interrupt to the P8 chip. So let's setup a hook
> - * for doing just that.
> - */
> -static void pnv_lpc_isa_irq_handler_cpld(void *opaque, int n, int level)
> -{
> -    PnvMachineState *pnv = POWERNV_MACHINE(qdev_get_machine());
> -    uint32_t old_state = pnv->cpld_irqstate;
> -    PnvChip *chip = opaque;
> -
> -    if (level) {
> -        pnv->cpld_irqstate |= 1u << n;
> -    } else {
> -        pnv->cpld_irqstate &= ~(1u << n);
> -    }
> -    if (pnv->cpld_irqstate != old_state) {
> -        pnv_psi_irq_set(&chip->psi, PSIHB_IRQ_EXTERNAL,
> -                        pnv->cpld_irqstate != 0);
> -    }
> -}
> -
> -static void pnv_lpc_isa_irq_handler(void *opaque, int n, int level)
> -{
> -     /* XXX TODO */
> -}
> -
>  static ISABus *pnv_isa_create(PnvChip *chip)
>  {
>      PnvLpcController *lpc = &chip->lpc;
> @@ -390,16 +360,7 @@ static ISABus *pnv_isa_create(PnvChip *chip)
>      isa_bus = isa_bus_new(NULL, &lpc->isa_mem, &lpc->isa_io,
>                            &error_fatal);
>  
> -    /* Not all variants have a working serial irq decoder. If not,
> -     * handling of LPC interrupts becomes a platform issue (some
> -     * platforms have a CPLD to do it).
> -     */
> -    if (pcc->chip_type == PNV_CHIP_POWER8NVL) {
> -        irqs = qemu_allocate_irqs(pnv_lpc_isa_irq_handler, chip, ISA_NUM_IRQS);
> -    } else {
> -        irqs = qemu_allocate_irqs(pnv_lpc_isa_irq_handler_cpld, chip,
> -                                  ISA_NUM_IRQS);
> -    }
> +    irqs = pnv_lpc_isa_irq_create(lpc, pcc->chip_type, ISA_NUM_IRQS);
>  
>      isa_bus_irqs(isa_bus, irqs);
>      return isa_bus;
> @@ -699,6 +660,10 @@ static void pnv_chip_init(Object *obj)
>      object_property_add_child(obj, "occ", OBJECT(&chip->occ), NULL);
>      object_property_add_const_link(OBJECT(&chip->occ), "psi",
>                                     OBJECT(&chip->psi), &error_abort);
> +
> +    /* The LPC controller needs PSI to generate interrupts */
> +    object_property_add_const_link(OBJECT(&chip->lpc), "psi",
> +                                   OBJECT(&chip->psi), &error_abort);
>  }
>  
>  static void pnv_chip_icp_realize(PnvChip *chip, Error **errp)
> diff --git a/hw/ppc/pnv_lpc.c b/hw/ppc/pnv_lpc.c
> index 78db52415b11..baee366d386a 100644
> --- a/hw/ppc/pnv_lpc.c
> +++ b/hw/ppc/pnv_lpc.c
> @@ -250,6 +250,34 @@ static const MemoryRegionOps pnv_lpc_xscom_ops = {
>      .endianness = DEVICE_BIG_ENDIAN,
>  };
>  
> +static void pnv_lpc_eval_irqs(PnvLpcController *lpc)
> +{
> +    bool lpc_to_opb_irq = false;
> +
> +    /* Update LPC controller to OPB line */
> +    if (lpc->lpc_hc_irqser_ctrl & LPC_HC_IRQSER_EN) {
> +        uint32_t irqs;
> +
> +        irqs = lpc->lpc_hc_irqstat & lpc->lpc_hc_irqmask;
> +        lpc_to_opb_irq = (irqs != 0);
> +    }
> +
> +    /* We don't honor the polarity register, it's pointless and unused
> +     * anyway
> +     */
> +    if (lpc_to_opb_irq) {
> +        lpc->opb_irq_input |= OPB_MASTER_IRQ_LPC;
> +    } else {
> +        lpc->opb_irq_input &= ~OPB_MASTER_IRQ_LPC;
> +    }
> +
> +    /* Update OPB internal latch */
> +    lpc->opb_irq_stat |= lpc->opb_irq_input & lpc->opb_irq_mask;
> +
> +    /* Reflect the interrupt */
> +    pnv_psi_irq_set(lpc->psi, PSIHB_IRQ_LPC_I2C, lpc->opb_irq_stat != 0);
> +}
> +
>  static uint64_t lpc_hc_read(void *opaque, hwaddr addr, unsigned size)
>  {
>      PnvLpcController *lpc = opaque;
> @@ -300,12 +328,15 @@ static void lpc_hc_write(void *opaque, hwaddr addr, uint64_t val,
>          break;
>      case LPC_HC_IRQSER_CTRL:
>          lpc->lpc_hc_irqser_ctrl = val;
> +        pnv_lpc_eval_irqs(lpc);
>          break;
>      case LPC_HC_IRQMASK:
>          lpc->lpc_hc_irqmask = val;
> +        pnv_lpc_eval_irqs(lpc);
>          break;
>      case LPC_HC_IRQSTAT:
>          lpc->lpc_hc_irqstat &= ~val;
> +        pnv_lpc_eval_irqs(lpc);
>          break;
>      case LPC_HC_ERROR_ADDRESS:
>          break;
> @@ -363,14 +394,15 @@ static void opb_master_write(void *opaque, hwaddr addr,
>      switch (addr) {
>      case OPB_MASTER_LS_IRQ_STAT:
>          lpc->opb_irq_stat &= ~val;
> +        pnv_lpc_eval_irqs(lpc);
>          break;
>      case OPB_MASTER_LS_IRQ_MASK:
> -        /* XXX Filter out reserved bits */
>          lpc->opb_irq_mask = val;
> +        pnv_lpc_eval_irqs(lpc);
>          break;
>      case OPB_MASTER_LS_IRQ_POL:
> -        /* XXX Filter out reserved bits */
>          lpc->opb_irq_pol = val;
> +        pnv_lpc_eval_irqs(lpc);
>          break;
>      case OPB_MASTER_LS_IRQ_INPUT:
>          /* Read only */
> @@ -398,6 +430,8 @@ static const MemoryRegionOps opb_master_ops = {
>  static void pnv_lpc_realize(DeviceState *dev, Error **errp)
>  {
>      PnvLpcController *lpc = PNV_LPC(dev);
> +    Object *obj;
> +    Error *error = NULL;
>  
>      /* Reg inits */
>      lpc->lpc_hc_fw_rd_acc_size = LPC_HC_FW_RD_4B;
> @@ -441,6 +475,15 @@ static void pnv_lpc_realize(DeviceState *dev, Error **errp)
>      pnv_xscom_region_init(&lpc->xscom_regs, OBJECT(dev),
>                            &pnv_lpc_xscom_ops, lpc, "xscom-lpc",
>                            PNV_XSCOM_LPC_SIZE);
> +
> +    /* get PSI object from chip */
> +    obj = object_property_get_link(OBJECT(dev), "psi", &error);
> +    if (!obj) {
> +        error_setg(errp, "%s: required link 'psi' not found: %s",
> +                   __func__, error_get_pretty(error));
> +        return;
> +    }
> +    lpc->psi = PNV_PSI(obj);
>  }
>  
>  static void pnv_lpc_class_init(ObjectClass *klass, void *data)
> @@ -470,3 +513,53 @@ static void pnv_lpc_register_types(void)
>  }
>  
>  type_init(pnv_lpc_register_types)
> +
> +/* If we don't use the built-in LPC interrupt deserializer, we need
> + * to provide a set of qirqs for the ISA bus or things will go bad.
> + *
> + * Most machines using pre-Naples chips (without said deserializer)
> + * have a CPLD that will collect the SerIRQ and shoot them as a
> + * single level interrupt to the P8 chip. So let's setup a hook
> + * for doing just that.
> + */
> +static void pnv_lpc_isa_irq_handler_cpld(void *opaque, int n, int level)
> +{
> +    PnvMachineState *pnv = POWERNV_MACHINE(qdev_get_machine());
> +    uint32_t old_state = pnv->cpld_irqstate;
> +    PnvLpcController *lpc = opaque;

You can use the existing PNV_LPC() and similar macros here, rather
than hard casting from a void *.  That's a bit safer.

> +
> +    if (level) {
> +        pnv->cpld_irqstate |= 1u << n;
> +    } else {
> +        pnv->cpld_irqstate &= ~(1u << n);
> +    }
> +
> +    if (pnv->cpld_irqstate != old_state) {
> +        pnv_psi_irq_set(lpc->psi, PSIHB_IRQ_EXTERNAL, pnv->cpld_irqstate != 0);
> +    }
> +}
> +
> +static void pnv_lpc_isa_irq_handler(void *opaque, int n, int level)
> +{
> +    PnvLpcController *lpc = opaque;
> +
> +    /* The Naples HW latches the 1 levels, clearing is done by SW */
> +    if (level) {
> +        lpc->lpc_hc_irqstat |= LPC_HC_IRQ_SERIRQ0 >> n;
> +        pnv_lpc_eval_irqs(lpc);
> +    }
> +}
> +
> +qemu_irq *pnv_lpc_isa_irq_create(PnvLpcController *lpc, int chip_type,
> +                                 int nirqs)
> +{
> +    /* Not all variants have a working serial irq decoder. If not,
> +     * handling of LPC interrupts becomes a platform issue (some
> +     * platforms have a CPLD to do it).
> +     */
> +    if (chip_type == PNV_CHIP_POWER8NVL) {
> +        return qemu_allocate_irqs(pnv_lpc_isa_irq_handler, lpc, nirqs);
> +    } else {
> +        return qemu_allocate_irqs(pnv_lpc_isa_irq_handler_cpld, lpc, nirqs);
> +    }
> +}
> diff --git a/include/hw/ppc/pnv_lpc.h b/include/hw/ppc/pnv_lpc.h
> index 38e5506975aa..ccf969af9448 100644
> --- a/include/hw/ppc/pnv_lpc.h
> +++ b/include/hw/ppc/pnv_lpc.h
> @@ -23,6 +23,8 @@
>  #define PNV_LPC(obj) \
>       OBJECT_CHECK(PnvLpcController, (obj), TYPE_PNV_LPC)
>  
> +typedef struct PnvPsi PnvPsi;
> +
>  typedef struct PnvLpcController {
>      DeviceState parent;
>  
> @@ -62,6 +64,12 @@ typedef struct PnvLpcController {
>  
>      /* XSCOM registers */
>      MemoryRegion xscom_regs;
> +
> +    /* PSI to generate interrupts */
> +    PnvPsi *psi;
>  } PnvLpcController;
>  
> +qemu_irq *pnv_lpc_isa_irq_create(PnvLpcController *lpc, int chip_type,
> +                                 int nirqs);
> +
>  #endif /* _PPC_PNV_LPC_H */

-- 
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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