On Mon, May 11, 2020 at 09:13:01PM -0700, Moritz Fischer wrote:
> On Mon, Apr 20, 2020 at 04:11:38PM +0800, Xu Yilun wrote:
> > Some DFL FPGA PCIe cards (e.g. Intel FPGA Programmable Acceleration
> > Card) support MSI-X based interrupts. This patch allows PCIe driver
> > to prepare and pass interrupt resources to DFL via enumeration API.
> > These interrupt resources could then be assigned to actual features
> > which use them.
> > 
> > Signed-off-by: Luwei Kang <[email protected]>
> > Signed-off-by: Wu Hao <[email protected]>
> > Signed-off-by: Xu Yilun <[email protected]>
> > Acked-by: Wu Hao <[email protected]>
> > ----
> > v2: put irq resources init code inside cce_enumerate_feature_dev()
> >     Some minor changes for Hao's comments.
> > v3: Some minor fix for Hao's comments for v2.
> > v4: Some minor fix for Hao's comments for v3.
> > v5: No change.
> > ---
> >  drivers/fpga/dfl-pci.c | 80 
> > ++++++++++++++++++++++++++++++++++++++++++++------
> >  1 file changed, 71 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
> > index a78c409..2ff1274 100644
> > --- a/drivers/fpga/dfl-pci.c
> > +++ b/drivers/fpga/dfl-pci.c
> > @@ -39,6 +39,27 @@ static void __iomem *cci_pci_ioremap_bar(struct pci_dev 
> > *pcidev, int bar)
> >     return pcim_iomap_table(pcidev)[bar];
> >  }
> >  
> > +static int cci_pci_alloc_irq(struct pci_dev *pcidev)
> > +{
> > +   int ret, nvec = pci_msix_vec_count(pcidev);
> > +
> > +   if (nvec <= 0) {
> > +           dev_dbg(&pcidev->dev, "fpga interrupt not supported\n");
> > +           return 0;
> > +   }
> > +
> > +   ret = pci_alloc_irq_vectors(pcidev, nvec, nvec, PCI_IRQ_MSIX);
> > +   if (ret < 0)
> > +           return ret;
> > +
> > +   return nvec;
> > +}
> > +
> > +static void cci_pci_free_irq(struct pci_dev *pcidev)
> > +{
> > +   pci_free_irq_vectors(pcidev);
> > +}
> > +
> >  /* PCI Device ID */
> >  #define PCIE_DEVICE_ID_PF_INT_5_X  0xBCBD
> >  #define PCIE_DEVICE_ID_PF_INT_6_X  0xBCC0
> > @@ -78,17 +99,38 @@ static void cci_remove_feature_devs(struct pci_dev 
> > *pcidev)
> >  
> >     /* remove all children feature devices */
> >     dfl_fpga_feature_devs_remove(drvdata->cdev);
> > +   cci_pci_free_irq(pcidev);
> > +}
> > +
> > +static int *cci_pci_create_irq_table(struct pci_dev *pcidev, unsigned int 
> > nvec)
> > +{
> > +   unsigned int i;
> > +   int *table;
> > +
> > +   table = kcalloc(nvec, sizeof(int), GFP_KERNEL);
> > +   if (table) {
> > +           for (i = 0; i < nvec; i++)
> > +                   table[i] = pci_irq_vector(pcidev, i);
> > +   }
> 
> Have you considered:
>       if (!table)
>               return table;
> 
>       for (i = 0; i < nvec; i++)
>               table[i] = pci_irq_vector(pcidev, i);
> 
>       return table;

I'm fine with this. I'll change it.

> > +
> > +   return table;
> > +}
> > +
> > +static void cci_pci_free_irq_table(int *table)
> > +{
> > +   kfree(table);
> >  }
> 
> Have you considered just using kfree()?

I thought there is a cci_pci_create_irq_table(), and a symmetric
xx_free_xx() function would make the code easier to understand.

How about we keep this?

Thanks,
Yilun.

> >  
> >  /* enumerate feature devices under pci device */
> >  static int cci_enumerate_feature_devs(struct pci_dev *pcidev)
> >  {
> >     struct cci_drvdata *drvdata = pci_get_drvdata(pcidev);
> > +   int port_num, bar, i, nvec, ret = 0;
> >     struct dfl_fpga_enum_info *info;
> >     struct dfl_fpga_cdev *cdev;
> >     resource_size_t start, len;
> > -   int port_num, bar, i, ret = 0;
> >     void __iomem *base;
> > +   int *irq_table;
> >     u32 offset;
> >     u64 v;
> >  
> > @@ -97,11 +139,30 @@ static int cci_enumerate_feature_devs(struct pci_dev 
> > *pcidev)
> >     if (!info)
> >             return -ENOMEM;
> >  
> > +   /* add irq info for enumeration if the device support irq */
> > +   nvec = cci_pci_alloc_irq(pcidev);
> > +   if (nvec < 0) {
> > +           dev_err(&pcidev->dev, "Fail to alloc irq %d.\n", nvec);
> > +           ret = nvec;
> > +           goto enum_info_free_exit;
> > +   } else if (nvec) {
> > +           irq_table = cci_pci_create_irq_table(pcidev, nvec);
> > +           if (!irq_table) {
> > +                   ret = -ENOMEM;
> > +                   goto irq_free_exit;
> > +           }
> > +
> > +           ret = dfl_fpga_enum_info_add_irq(info, nvec, irq_table);
> > +           cci_pci_free_irq_table(irq_table);
> > +           if (ret)
> > +                   goto irq_free_exit;
> > +   }
> > +
> >     /* start to find Device Feature List from Bar 0 */
> >     base = cci_pci_ioremap_bar(pcidev, 0);
> >     if (!base) {
> >             ret = -ENOMEM;
> > -           goto enum_info_free_exit;
> > +           goto irq_free_exit;
> >     }
> >  
> >     /*
> > @@ -154,7 +215,7 @@ static int cci_enumerate_feature_devs(struct pci_dev 
> > *pcidev)
> >             dfl_fpga_enum_info_add_dfl(info, start, len, base);
> >     } else {
> >             ret = -ENODEV;
> > -           goto enum_info_free_exit;
> > +           goto irq_free_exit;
> >     }
> >  
> >     /* start enumeration with prepared enumeration information */
> > @@ -162,11 +223,14 @@ static int cci_enumerate_feature_devs(struct pci_dev 
> > *pcidev)
> >     if (IS_ERR(cdev)) {
> >             dev_err(&pcidev->dev, "Enumeration failure\n");
> >             ret = PTR_ERR(cdev);
> > -           goto enum_info_free_exit;
> > +           goto irq_free_exit;
> >     }
> >  
> >     drvdata->cdev = cdev;
> >  
> > +irq_free_exit:
> > +   if (ret)
> > +           cci_pci_free_irq(pcidev);
> >  enum_info_free_exit:
> >     dfl_fpga_enum_info_free(info);
> >  
> > @@ -211,12 +275,10 @@ int cci_pci_probe(struct pci_dev *pcidev, const 
> > struct pci_device_id *pcidevid)
> >     }
> >  
> >     ret = cci_enumerate_feature_devs(pcidev);
> > -   if (ret) {
> > -           dev_err(&pcidev->dev, "enumeration failure %d.\n", ret);
> > -           goto disable_error_report_exit;
> > -   }
> > +   if (!ret)
> > +           return ret;
> >  
> > -   return ret;
> > +   dev_err(&pcidev->dev, "enumeration failure %d.\n", ret);
> >  
> >  disable_error_report_exit:
> >     pci_disable_pcie_error_reporting(pcidev);
> > -- 
> > 2.7.4
> > 
> 
> Thanks,
> Moritz

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