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

[Cédric Le Goater]

On 04/11/2017 04:23 AM, David Gibson wrote:
> On Mon, Apr 10, 2017 at 03:56:51PM +0200, Cédric Le Goater wrote:
>> From: Benjamin Herrenschmidt <address@hidden>
>>
>> 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 <address@hidden>
>> [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 <address@hidden>
>> ---
>>
>>  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.

ah yes. I missed that. 

Thanks,

C. 

>> +
>> +    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 */
>