Hi Serge,
> From: Serge Semin, Sent: Tuesday, May 2, 2023 4:25 AM
>
> On Wed, Apr 26, 2023 at 01:55:44PM +0900, Yoshihiro Shimoda wrote:
> > Add support for triggering INTx IRQs by using outbound iATU.
> > Outbound iATU is utilized to send assert and de-assert INTx TLPs.
> > The message is generated based on the payloadless Msg TLP with type
> > 0x14, where 0x4 is the routing code implying the Terminate at
> > Receiver message. The message code is specified as b1000xx for
> > the INTx assertion and b1001xx for the INTx de-assertion.
>
> [PATCH v14 08/21] PCI: dwc: Add support for triggering INTx IRQs from endpoint drivers
>
> What about shortening the subject out a bit:
> "PCI: designware-ep: Add INTx IRQs support"
> ?
Thank you for the suggestion. I'll modify the subject.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > ---
> > .../pci/controller/dwc/pcie-designware-ep.c | 71 +++++++++++++++++--
> > drivers/pci/controller/dwc/pcie-designware.h | 2 +
> > 2 files changed, 69 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > index 96375b0aba82..b35ed2b06193 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > @@ -6,6 +6,7 @@
> > * Author: Kishon Vijay Abraham I <kishon@xxxxxx>
> > */
> >
> > +#include <linux/delay.h>
> > #include <linux/of.h>
> > #include <linux/platform_device.h>
> >
> > @@ -485,14 +486,63 @@ static const struct pci_epc_ops epc_ops = {
> > .get_features = dw_pcie_ep_get_features,
> > };
> >
> > +static int dw_pcie_ep_send_msg(struct dw_pcie_ep *ep, u8 func_no, u8 code,
> > + u8 routing)
> > +{
> > + struct dw_pcie_outbound_atu atu = { 0 };
> > + struct pci_epc *epc = ep->epc;
> > + int ret;
> > +
> > + atu.func_no = func_no;
> > + atu.code = code;
> > + atu.routing = routing;
> > + atu.type = PCIE_ATU_TYPE_MSG;
> > + atu.cpu_addr = ep->intx_mem_phys;
> > + atu.size = epc->mem->window.page_size;
> > +
> > + ret = dw_pcie_ep_outbound_atu(ep, &atu);
> > + if (ret)
> > + return ret;
> > +
> > + writel(0, ep->intx_mem);
> > +
> > + dw_pcie_ep_unmap_addr(epc, func_no, 0, ep->intx_mem_phys);
> > +
> > + return 0;
> > +}
> > +
>
> > +static int __dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no,
> > + int intx)
> > +{
> > + int ret;
> > +
> > + ret = dw_pcie_ep_send_msg(ep, func_no, PCI_CODE_ASSERT_INTA + intx,
> > + PCI_MSG_ROUTING_LOCAL);
> > + if (ret)
> > + return ret;
> > +
> > + /*
> > + * The documents of PCIe and the controller don't mention how long
> > + * the INTx should be asserted. If 10 usec, sometimes it failed.
> > + * So, asserted for 50 usec.
> > + */
> > + usleep_range(50, 100);
> > +
> > + return dw_pcie_ep_send_msg(ep, func_no, PCI_CODE_DEASSERT_INTA + intx,
> > + PCI_MSG_ROUTING_LOCAL);
> > +}
>
> Why do you need the underscored version of the method? I don't see it
> being utilized anywhere but in the dw_pcie_ep_raise_intx_irq()
> function.
I thought that readability can be improved a bit if a function was separated.
But, it seemed wrong.
> Thus its body can be completely moved to
> dw_pcie_ep_raise_intx_irq().
I got it.
Best regards,
Yoshihiro Shimoda
> -Serge(y)
>
> > +
> > int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
> > {
> > struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > struct device *dev = pci->dev;
> >
> > - dev_err(dev, "EP cannot trigger INTx IRQs\n");
> > + if (!ep->intx_mem) {
> > + dev_err(dev, "INTx not supported\n");
> > + return -EOPNOTSUPP;
> > + }
> >
> > - return -EINVAL;
> > + return __dw_pcie_ep_raise_intx_irq(ep, func_no, 0);
> > }
> > EXPORT_SYMBOL_GPL(dw_pcie_ep_raise_intx_irq);
> >
> > @@ -623,6 +673,10 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
> >
> > dw_pcie_edma_remove(pci);
> >
> > + if (ep->intx_mem)
> > + pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
> > + epc->mem->window.page_size);
> > +
> > pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
> > epc->mem->window.page_size);
> >
> > @@ -794,9 +848,14 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> > goto err_exit_epc_mem;
> > }
> >
> > + ep->intx_mem = pci_epc_mem_alloc_addr(epc, &ep->intx_mem_phys,
> > + epc->mem->window.page_size);
> > + if (!ep->intx_mem)
> > + dev_warn(dev, "Failed to reserve memory for INTx\n");
> > +
> > ret = dw_pcie_edma_detect(pci);
> > if (ret)
> > - goto err_free_epc_mem;
> > + goto err_free_epc_mem_intx;
> >
> > if (ep->ops->get_features) {
> > epc_features = ep->ops->get_features(ep);
> > @@ -813,7 +872,11 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> > err_remove_edma:
> > dw_pcie_edma_remove(pci);
> >
> > -err_free_epc_mem:
> > +err_free_epc_mem_intx:
> > + if (ep->intx_mem)
> > + pci_epc_mem_free_addr(epc, ep->intx_mem_phys, ep->intx_mem,
> > + epc->mem->window.page_size);
> > +
> > pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
> > epc->mem->window.page_size);
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> > index 954d504890a1..8c08159ea08e 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -369,6 +369,8 @@ struct dw_pcie_ep {
> > unsigned long *ob_window_map;
> > void __iomem *msi_mem;
> > phys_addr_t msi_mem_phys;
> > + void __iomem *intx_mem;
> > + phys_addr_t intx_mem_phys;
> > struct pci_epf_bar *epf_bar[PCI_STD_NUM_BARS];
> > };
> >
> > --
> > 2.25.1
> >
