Re: [Qemu-devel] [Qemu-ppc] [PATCH 48/77] ppc/pnv: Add model for Power8 PHB3 PCIe Host bridge

[Cédric Le Goater]

Ben,

Quick question,

> +/* This is called whenever the PHB LSI, MSI source ID register or
> + * the PBCQ irq filters are written.
> + */
> +void pnv_phb3_remap_irqs(PnvPhb3State *phb)
> +{
> +    uint32_t local, global, count, mask, comp;
> +    uint64_t baren;
> +
> +    /* First check if we are enabled. Unlike real HW we don't separate TX 
> and RX
> +     * so we enable if both are set
> +     */
> +    baren = phb->pbcq->nest_regs[PBCQ_NEST_BAR_EN];
> +    if (!(baren & PBCQ_NEST_BAR_EN_IRSN_RX) ||
> +        !(baren & PBCQ_NEST_BAR_EN_IRSN_TX)) {
> +        phb->lsi_ics->offset = 0;
> +        return;
> +    }
> +
> +    /* Grab local LSI source ID */
> +    local = GETFIELD(PHB_LSI_SRC_ID, phb->regs[PHB_LSI_SOURCE_ID >> 3]) << 3;
> +
> +    /* Grab global one and compare */
> +    global = GETFIELD(PBCQ_NEST_LSI_SRC,
> +                      phb->pbcq->nest_regs[PBCQ_NEST_LSI_SRC_ID]) << 3;
> +    if (global != local) {
> +        /* This happens during initialization, let's come back when we
> +         * are properly configured
> +         */
> +        phb->lsi_ics->offset = 0;
> +        return;
> +    }
> +
> +    /* Get the base on the powerbus */
> +    comp = GETFIELD(PBCQ_NEST_IRSN_COMP,
> +                    phb->pbcq->nest_regs[PBCQ_NEST_IRSN_COMPARE]);
> +    mask = GETFIELD(PBCQ_NEST_IRSN_COMP,
> +                    phb->pbcq->nest_regs[PBCQ_NEST_IRSN_MASK]);
> +    count = ((~mask) + 1) & 0x7ffff;
> +    phb->total_irq = count;
> +
> +    /* Sanity checks */
> +    if ((global + 8) > count) {
> +        DBG_MAP(phb, "LSIs out of reach: LSI base=%d total irq=%d",
> +                global, count);
> +    }
> +    if (count > 2048) {
> +        DBG_MAP(phb, "More interrupts than supported: %d", count);
> +    }
> +    if ((comp & mask) != comp) {
> +        DBG_MAP(phb, "IRQ compare bits not in mask: comp=0x%x mask=0x%x",
> +                comp, mask);
> +        comp &= mask;
> +    }
> +    /* Setup LSI offset */
> +    phb->lsi_ics->offset = comp + global;
> +
> +    /* Setup MSI offset */
> +    pnv_phb3_msi_update_config(phb->msis, comp, count);

I changed that to :

    pnv_phb3_msi_update_config(phb->msis, comp, count - PHB_NUM_LSI);

else the IRQ numbers overlap with the LSI and I think this why we were 
uselessly looping on the EOI.

Correct ? 

C.
 
> +
> +    DBG_MAP(phb, "Initialized for %d interrupts @0x%x, LSI off=%d",
> +            count, comp, global);
> +}
> +