Hi Lorenzo, On 14/02/19 4:01 PM, Lorenzo Pieralisi wrote: > [CC'ed MarcZ] > > On Thu, Feb 14, 2019 at 10:27:19AM +0530, Kishon Vijay Abraham I wrote: >> Hi Lorenzo, >> >> On 13/02/19 10:27 PM, Lorenzo Pieralisi wrote: >>> On Wed, Feb 13, 2019 at 06:56:23PM +0530, Kishon Vijay Abraham I wrote: >>>> ks_pcie_legacy_irq_handler() uses 'virq' to get the IRQ number offset. >>>> This offset is used to get the correct IRQ_STATUS register >>>> corresponding to the IRQ line that raised the interrupt. >>>> There is no guarantee that 'virq' assigned for consecutive hardware >>>> IRQ will be contiguous. And this might get us an incorrect IRQ number >>>> offset. >>>> >>>> Fix it here by using 'hwirq' to get the IRQ number offset. >>>> >>>> Link: https://lkml.kernel.org/r/bb081d21-7c03-0357-4294-7e92d95d838c@xxxxxxx >>>> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx> >>>> --- >>>> drivers/pci/controller/dwc/pci-keystone.c | 17 +++++++++++++---- >>>> 1 file changed, 13 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c >>>> index e8b1d8eca78e..d35ac712a9f8 100644 >>>> --- a/drivers/pci/controller/dwc/pci-keystone.c >>>> +++ b/drivers/pci/controller/dwc/pci-keystone.c >>>> @@ -87,7 +87,7 @@ struct keystone_pcie { >>>> struct dw_pcie *pci; >>>> /* PCI Device ID */ >>>> u32 device_id; >>>> - int legacy_host_irqs[PCI_NUM_INTX]; >>>> + int legacy_host_irq; >>>> struct device_node *legacy_intc_np; >>>> >>>> int msi_host_irqs[MAX_MSI_HOST_IRQS]; >>>> @@ -582,11 +582,11 @@ static void ks_pcie_msi_irq_handler(struct irq_desc *desc) >>>> */ >>>> static void ks_pcie_legacy_irq_handler(struct irq_desc *desc) >>>> { >>>> - unsigned int irq = irq_desc_get_irq(desc); >>>> + unsigned int irq = desc->irq_data.hwirq; >>>> struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc); >>>> struct dw_pcie *pci = ks_pcie->pci; >>>> struct device *dev = pci->dev; >>>> - u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0]; >>>> + u32 irq_offset = irq - ks_pcie->legacy_host_irq; >>> >>> I think you should use the plain hwirq number (that if I understand >>> correctly range in [0,3]) and drop legacy_host_irq. >> >> The hwirq is [80, 83] for Keystone. We store legacy_host_irq (for Keystone it >> is 80) to get the correct offset in the range [0, 3]. > > IIUC the _parent_ hw_irq number should be what you need here, Marc (if > he has time) can correct me if I am wrong (or what I am suggesting is > a violation of IRQ domain bstraction usage). > >>> >>> See below. >>> >>>> struct irq_chip *chip = irq_desc_get_chip(desc); >>>> >>>> dev_dbg(dev, ": Handling legacy irq %d\n", irq); >>>> @@ -657,6 +657,7 @@ static int ks_pcie_config_legacy_irq(struct keystone_pcie *ks_pcie) >>>> struct device_node *np = ks_pcie->np; >>>> struct device_node *intc_np; >>>> int irq_count, irq, ret, i; >>>> + struct irq_data *irq_data; >>>> >>>> intc_np = of_get_child_by_name(np, "legacy-interrupt-controller"); >>>> if (!intc_np) { >>>> @@ -677,7 +678,15 @@ static int ks_pcie_config_legacy_irq(struct keystone_pcie *ks_pcie) >>>> ret = -EINVAL; >>>> goto err; >>>> } >>>> - ks_pcie->legacy_host_irqs[i] = irq; >>>> + >>>> + if (!ks_pcie->legacy_host_irq) { >>>> + irq_data = irq_get_irq_data(irq); >>>> + if (!irq_data) { >>>> + ret = -EINVAL; >>>> + goto err; >>>> + } >>>> + ks_pcie->legacy_host_irq = irq_data->hwirq; >>> >>> This depends on DT property ordering and may well be wrong. On top >>> of that as I said above I do not think it is even needed. >> >> right, it depends on the ordering of the entries in the "interrupts" property. >> Right now we have something like below >> >> interrupts = <GIC_SPI 48 IRQ_TYPE_EDGE_RISING>, >> <GIC_SPI 49 IRQ_TYPE_EDGE_RISING>, >> <GIC_SPI 50 IRQ_TYPE_EDGE_RISING>, >> <GIC_SPI 51 IRQ_TYPE_EDGE_RISING>; >> >> And changing the order will make legacy_host_irq store the wrong hwirq. With >> this patch we solve the problem of assuming virq to be contiguous for >> contiguous hwirq however we do expect the hwirqs to be populated in the DT in >> the correct order. >> >> Ordering entries within a property is also followed in other >> properties like "reg" where the drivers use platform_get_resource with >> index as argument. I'm not sure if there's a way to get rid of the >> ordering requirement in DT for the "interrupts" property. > > I am not sure there is an ordering requirement in place but hopefully we > should not need it, see above. > > The 1:1 relationship between GIC-IRQ<->PCI-host-bridge-controller-IRQ is > what the kernel IRQ domain abstraction is there to implement, so a > reverse look-up should be feasible without adding anything else, lest > we duplicate IRQ domain data structures. I got legacy interrupt working using hierarchy domain. With that we don't need to have chained irq handler here. I'll post v4 soon. Thanks Kishon
