Re: [dpdk-dev] [EXT] Re: [PATCH 1/6] net/qede: define PCI config space specific osals

[Manish Chopra <manishc@marvell.com>]

> -----Original Message-----
> From: Jerin Jacob <jerinjacobk@gmail.com>
> Sent: Friday, June 26, 2020 10:24 AM
> To: Manish Chopra <manishc@marvell.com>; Gaetan Rivet
> <grive@u256.net>
> Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; Ferruh Yigit
> <ferruh.yigit@intel.com>; dpdk-dev <dev@dpdk.org>; Igor Russkikh
> <irusskikh@marvell.com>; Rasesh Mody <rmody@marvell.com>; GR-Everest-
> DPDK-Dev <GR-Everest-DPDK-Dev@marvell.com>
> Subject: [EXT] Re: [PATCH 1/6] net/qede: define PCI config space specific
> osals
> 
> External Email
> 
> ----------------------------------------------------------------------
> On Wed, Jun 10, 2020 at 1:13 AM Manish Chopra <manishc@marvell.com>
> wrote:
> >
> > This patch defines various PCI config space access APIs in order to
> > read and find IOV specific PCI capabilities.
> >
> > With these definitions implemented, it enables the base driver to do
> > SR-IOV specific initialization and HW specific configuration required
> > from PF-PMD driver instance.
> >
> > Signed-off-by: Manish Chopra <manishc@marvell.com>
> > Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
> > Signed-off-by: Rasesh Mody <rmody@marvell.com>
> > ---
> > +
> > +int osal_pci_find_next_ext_capability(struct rte_pci_device *dev,
> > +                                     int cap)
> 
> 
> + Gaetan (PCI maintainer)
> 
> Manish,
> It must be a candidate for a generic PCI API as it is nothing to do with qede.
> Please move to common PCI code if such API is not already present.
> 
> 
> > +{
> > +       int pos = PCI_CFG_SPACE_SIZE;
> > +       uint32_t header;
> > +       int ttl;
> > +
> > +       /* minimum 8 bytes per capability */
> > +       ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
> > +
> > +       if (rte_pci_read_config(dev, &header, 4, pos) < 0)
> > +               return -1;
> > +
> > +       /*
> > +        * If we have no capabilities, this is indicated by cap ID,
> > +        * cap version and next pointer all being 0.
> > +        */
> > +       if (header == 0)
> > +               return 0;
> > +
> > +       while (ttl-- > 0) {
> > +               if (PCI_EXT_CAP_ID(header) == cap)
> > +                       return pos;
> > +
> > +               pos = PCI_EXT_CAP_NEXT(header);
> > +
> > +               if (pos < PCI_CFG_SPACE_SIZE)
> > +                       break;
> > +
> > +               if (rte_pci_read_config(dev, &header, 4, pos) < 0)
> > +                       return -1;
> > +       }
> > +
> > +       return 0;
> > +}
> >
> 
> >
> > +#define PCICFG_VENDOR_ID_OFFSET 0x00
> > +#define PCICFG_DEVICE_ID_OFFSET 0x02
> > +#define PCI_CFG_SPACE_SIZE 256
> > +#define PCI_EXP_DEVCTL 0x0008
> > +#define PCI_EXT_CAP_ID(header) (int)((header) & 0x0000ffff) #define
> > +PCI_EXT_CAP_NEXT(header) (((header) >> 20) & 0xffc) #define
> > +PCI_CFG_SPACE_EXP_SIZE 4096
> > +
> > +#define PCI_SRIOV_CTRL 0x08 /* SR-IOV Control */ #define
> > +PCI_SRIOV_TOTAL_VF 0x0e /* Total VFs */ #define PCI_SRIOV_INITIAL_VF
> > +0x0c /* Initial VFs */ #define PCI_SRIOV_NUM_VF 0x10 /* Number of VFs
> > +*/ #define PCI_SRIOV_VF_OFFSET 0x14 /* First VF Offset */ #define
> > +PCI_SRIOV_VF_STRIDE 0x16 /* Following VF Stride */ #define
> > +PCI_SRIOV_VF_DID 0x1a #define PCI_SRIOV_SUP_PGSIZE 0x1c #define
> > +PCI_SRIOV_CAP 0x04 #define PCI_SRIOV_FUNC_LINK 0x12 #define
> > +PCI_EXT_CAP_ID_SRIOV 0x10
> 
> Dont DEFINE PCI_ symbols in drivers, It may conflict with other PCI
> definitions in the future.
> Please move GENERIC PCI_ symbols to the generic PCI layer.
> 
> 
> 

Hi Jerin/Gaetan,

Which generic PCI code/files these defines/API should be added to ? (lib/librte_pci/rte_pci.[c|h]) ?
Just FYI, note that it can't be done without cleaning up other vendors, as I can see that various other vendors have also
defined this function to find pci extended cap and some of these PCI_* macro defines as well in their respective drivers.

Thanks,
Manish