Re: [PATCH V3 5/5] PCI: pci-epf-test: Add support to defer core initialization

From: Lorenzo Pieralisi
Date: Wed Feb 26 2020 - 05:07:58 EST

On Tue, Feb 25, 2020 at 11:43:07PM +0530, Vidya Sagar wrote:
>
>
> On 2/25/2020 5:38 PM, Lorenzo Pieralisi wrote:
> > External email: Use caution opening links or attachments
> >
> >
> > On Mon, Feb 17, 2020 at 05:40:36PM +0530, Vidya Sagar wrote:
> > > Add support to defer core initialization and to receive a notifier
> > > when core is ready to accommodate platforms where core is not for
> > > initialization untile reference clock from host is available.
> >
> > I don't understand this commit log, please reword it and fix
> > the typos, I would merge it then, thanks.
> Would the following be ok?
>
> Add support to defer DWC core initialization for the endpoint mode of

I removed "DWC" since this is not what this patch is actually doing.

> operation. Initialization would resume based on the notifier
> mechanism. This would enable support for implementations like Tegra194
> for endpoint mode operation, where the core initialization needs to be
> deferred until the PCIe reference clock is available from the host
> system.
>
> If it is ok, I'll send new patch series with this commit log.

No need, merged in pci/endpoint for v5.7, thanks.

Lorenzo

> Thanks,
> Vidya Sagar
> >
> > Lorenzo
> >
> > > Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
> > > Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> > > ---
> > > V3:
> > > * Added Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> > >
> > > V2:
> > > * Addressed review comments from Kishon
> > >
> > > drivers/pci/endpoint/functions/pci-epf-test.c | 118 ++++++++++++------
> > > 1 file changed, 77 insertions(+), 41 deletions(-)
> > >
> > > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> > > index bddff15052cc..be04c6220265 100644
> > > --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> > > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> > > @@ -360,18 +360,6 @@ static void pci_epf_test_cmd_handler(struct work_struct *work)
> > > msecs_to_jiffies(1));
> > > }
> > >
> > > -static int pci_epf_test_notifier(struct notifier_block *nb, unsigned long val,
> > > - void *data)
> > > -{
> > > - struct pci_epf *epf = container_of(nb, struct pci_epf, nb);
> > > - struct pci_epf_test *epf_test = epf_get_drvdata(epf);
> > > -
> > > - queue_delayed_work(kpcitest_workqueue, &epf_test->cmd_handler,
> > > - msecs_to_jiffies(1));
> > > -
> > > - return NOTIFY_OK;
> > > -}
> > > -
> > > static void pci_epf_test_unbind(struct pci_epf *epf)
> > > {
> > > struct pci_epf_test *epf_test = epf_get_drvdata(epf);
> > > @@ -428,6 +416,78 @@ static int pci_epf_test_set_bar(struct pci_epf *epf)
> > > return 0;
> > > }
> > >
> > > +static int pci_epf_test_core_init(struct pci_epf *epf)
> > > +{
> > > + struct pci_epf_header *header = epf->header;
> > > + const struct pci_epc_features *epc_features;
> > > + struct pci_epc *epc = epf->epc;
> > > + struct device *dev = &epf->dev;
> > > + bool msix_capable = false;
> > > + bool msi_capable = true;
> > > + int ret;
> > > +
> > > + epc_features = pci_epc_get_features(epc, epf->func_no);
> > > + if (epc_features) {
> > > + msix_capable = epc_features->msix_capable;
> > > + msi_capable = epc_features->msi_capable;
> > > + }
> > > +
> > > + ret = pci_epc_write_header(epc, epf->func_no, header);
> > > + if (ret) {
> > > + dev_err(dev, "Configuration header write failed\n");
> > > + return ret;
> > > + }
> > > +
> > > + ret = pci_epf_test_set_bar(epf);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + if (msi_capable) {
> > > + ret = pci_epc_set_msi(epc, epf->func_no, epf->msi_interrupts);
> > > + if (ret) {
> > > + dev_err(dev, "MSI configuration failed\n");
> > > + return ret;
> > > + }
> > > + }
> > > +
> > > + if (msix_capable) {
> > > + ret = pci_epc_set_msix(epc, epf->func_no, epf->msix_interrupts);
> > > + if (ret) {
> > > + dev_err(dev, "MSI-X configuration failed\n");
> > > + return ret;
> > > + }
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int pci_epf_test_notifier(struct notifier_block *nb, unsigned long val,
> > > + void *data)
> > > +{
> > > + struct pci_epf *epf = container_of(nb, struct pci_epf, nb);
> > > + struct pci_epf_test *epf_test = epf_get_drvdata(epf);
> > > + int ret;
> > > +
> > > + switch (val) {
> > > + case CORE_INIT:
> > > + ret = pci_epf_test_core_init(epf);
> > > + if (ret)
> > > + return NOTIFY_BAD;
> > > + break;
> > > +
> > > + case LINK_UP:
> > > + queue_delayed_work(kpcitest_workqueue, &epf_test->cmd_handler,
> > > + msecs_to_jiffies(1));
> > > + break;
> > > +
> > > + default:
> > > + dev_err(&epf->dev, "Invalid EPF test notifier event\n");
> > > + return NOTIFY_BAD;
> > > + }
> > > +
> > > + return NOTIFY_OK;
> > > +}
> > > +
> > > static int pci_epf_test_alloc_space(struct pci_epf *epf)
> > > {
> > > struct pci_epf_test *epf_test = epf_get_drvdata(epf);
> > > @@ -496,14 +556,11 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> > > {
> > > int ret;
> > > struct pci_epf_test *epf_test = epf_get_drvdata(epf);
> > > - struct pci_epf_header *header = epf->header;
> > > const struct pci_epc_features *epc_features;
> > > enum pci_barno test_reg_bar = BAR_0;
> > > struct pci_epc *epc = epf->epc;
> > > - struct device *dev = &epf->dev;
> > > bool linkup_notifier = false;
> > > - bool msix_capable = false;
> > > - bool msi_capable = true;
> > > + bool core_init_notifier = false;
> > >
> > > if (WARN_ON_ONCE(!epc))
> > > return -EINVAL;
> > > @@ -511,8 +568,7 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> > > epc_features = pci_epc_get_features(epc, epf->func_no);
> > > if (epc_features) {
> > > linkup_notifier = epc_features->linkup_notifier;
> > > - msix_capable = epc_features->msix_capable;
> > > - msi_capable = epc_features->msi_capable;
> > > + core_init_notifier = epc_features->core_init_notifier;
> > > test_reg_bar = pci_epc_get_first_free_bar(epc_features);
> > > pci_epf_configure_bar(epf, epc_features);
> > > }
> > > @@ -520,34 +576,14 @@ static int pci_epf_test_bind(struct pci_epf *epf)
> > > epf_test->test_reg_bar = test_reg_bar;
> > > epf_test->epc_features = epc_features;
> > >
> > > - ret = pci_epc_write_header(epc, epf->func_no, header);
> > > - if (ret) {
> > > - dev_err(dev, "Configuration header write failed\n");
> > > - return ret;
> > > - }
> > > -
> > > ret = pci_epf_test_alloc_space(epf);
> > > if (ret)
> > > return ret;
> > >
> > > - ret = pci_epf_test_set_bar(epf);
> > > - if (ret)
> > > - return ret;
> > > -
> > > - if (msi_capable) {
> > > - ret = pci_epc_set_msi(epc, epf->func_no, epf->msi_interrupts);
> > > - if (ret) {
> > > - dev_err(dev, "MSI configuration failed\n");
> > > - return ret;
> > > - }
> > > - }
> > > -
> > > - if (msix_capable) {
> > > - ret = pci_epc_set_msix(epc, epf->func_no, epf->msix_interrupts);
> > > - if (ret) {
> > > - dev_err(dev, "MSI-X configuration failed\n");
> > > + if (!core_init_notifier) {
> > > + ret = pci_epf_test_core_init(epf);
> > > + if (ret)
> > > return ret;
> > > - }
> > > }
> > >
> > > if (linkup_notifier) {
> > > --
> > > 2.17.1
> > >