> On Wed, 11 Nov 2015 12:03:39 +0530
> Bharat Kumar Gogada <bharat.kumar.gogada@xxxxxxxxxx> wrote:
>
> > Adding PCIe Root Port driver for Xilinx PCIe NWL bridge IP.
> >
> > Signed-off-by: Bharat Kumar Gogada <bharatku@xxxxxxxxxx>
> > Signed-off-by: Ravi Kiran Gummaluri <rgummal@xxxxxxxxxx>
> > ---
> > Added logic to allocate contiguous hwirq in nwl_irq_domain_alloc function.
> > Moved MSI functionality to separate functions.
> > Changed error return values.
> > ---
> > .../devicetree/bindings/pci/xilinx-nwl-pcie.txt | 68 ++
> > drivers/pci/host/Kconfig | 16 +-
> > drivers/pci/host/Makefile | 1 +
> > drivers/pci/host/pcie-xilinx-nwl.c | 1062 ++++++++++++++++++++
> > 4 files changed, 1144 insertions(+), 3 deletions(-) create mode
> > 100644 Documentation/devicetree/bindings/pci/xilinx-nwl-pcie.txt
> > create mode 100644 drivers/pci/host/pcie-xilinx-nwl.c
> >
> > diff --git a/drivers/pci/host/pcie-xilinx-nwl.c
> > b/drivers/pci/host/pcie-xilinx-nwl.c
> > new file mode 100644
> > index 0000000..8bc509c
> > --- /dev/null
> > +++ b/drivers/pci/host/pcie-xilinx-nwl.c
>
> [...]
>
> > +static struct msi_domain_info nwl_msi_domain_info = {
> > + .flags = (MSI_FLAG_USE_DEF_DOM_OPS |
> MSI_FLAG_USE_DEF_CHIP_OPS |
> > + MSI_FLAG_MULTI_PCI_MSI),
>
> Given that you claim to support multi-MSI...
>
> [...]
>
> > +static int nwl_irq_domain_alloc(struct irq_domain *domain, unsigned int
> virq,
> > + unsigned int nr_irqs, void *args) {
> > + struct nwl_pcie *pcie = domain->host_data;
> > + struct nwl_msi *msi = &pcie->msi;
> > + unsigned long bit;
> > + int i;
> > +
> > + mutex_lock(&msi->lock);
> > + for (i = 0; i < nr_irqs; i++) {
> > + bit = find_first_zero_bit(msi->used, INT_PCI_MSI_NR);
> > + if (bit < INT_PCI_MSI_NR)
> > + set_bit(bit, msi->used);
> > + else
> > + bit = -ENOSPC;
> > +
> > + if (bit < 0) {
> > + mutex_unlock(&msi->lock);
> > + return bit;
> > + }
> > +
> > + irq_domain_set_info(domain, virq, bit, &nwl_irq_chip,
> > + domain->host_data, handle_simple_irq,
> > + NULL, NULL);
> > + virq = virq + 1;
> > + }
>
> I really don't see how this allocator guarantees that all hwirqs are contiguous.
> I already mentioned this when reviewing v7, and you still haven't got it right.
> So either you allocate *contiguous* hwirqs in an atomic fashion, or you drop
> support for multi-MSI.
>
Yes, I understood now there is no check for allocating contiguous hwirq, I will address this in the next patch.
Regards,
Bharat
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