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Date:   Wed, 26 Feb 2020 10:07:49 +0000
From:   Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To:     Vidya Sagar <vidyas@nvidia.com>
Cc:     jingoohan1@gmail.com, gustavo.pimentel@synopsys.com,
        andrew.murray@arm.com, bhelgaas@google.com, kishon@ti.com,
        thierry.reding@gmail.com, Jisheng.Zhang@synaptics.com,
        jonathanh@nvidia.com, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org, kthota@nvidia.com,
        mmaddireddy@nvidia.com, sagar.tv@gmail.com
Subject: Re: [PATCH V3 5/5] PCI: pci-epf-test: Add support to defer core
 initialization
Message-ID: <20200226100749.GA13197@e121166-lin.cambridge.arm.com>
References: <20200217121036.3057-1-vidyas@nvidia.com>
 <20200217121036.3057-6-vidyas@nvidia.com>
 <20200225120832.GA7710@e121166-lin.cambridge.arm.com>
 <ac537e94-7ec8-de61-322a-8a8c7ff48ac5@nvidia.com>
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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@nvidia.com>
> > > Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
> > > ---
> > > V3:
> > > * Added Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
> > > 
> > > 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
> > >