On Sat, Jul 14, 2012 at 10:10:15AM -0700, Greg KH wrote:
> On Fri, Jul 13, 2012 at 02:44:59PM -0700, Jon Mason wrote:
> > +static int max_num_cbs = 2;
> > +module_param(max_num_cbs, uint, 0644);
> > +MODULE_PARM_DESC(max_num_cbs, "Maximum number of NTB transport connections");
> > +
> > +static bool no_msix;
> > +module_param(no_msix, bool, 0644);
> > +MODULE_PARM_DESC(no_msix, "Do not allow MSI-X interrupts to be selected");
>
> How would a user, or a distro, know to set these options? Why are they
> even options at all?
Good question. There is actually a potential benefit to disabling MSI-X. The NTB device on one of our platforms only has 3 MSI-X vectors. In the current driver design, that would limit them to 3 client/virtual devices. However, there are 15bits in the ISR that can be used for the same purpose. So, if you disable MSI-X, you can have 15 instead of 3.
>
>
> > +struct ntb_device {
> > + struct pci_dev *pdev;
> > + struct msix_entry *msix_entries;
> > + void __iomem *reg_base;
> > + struct ntb_mw mw[NTB_NUM_MW];
> > + struct {
> > + unsigned int max_spads;
> > + unsigned int max_db_bits;
> > + unsigned int msix_cnt;
> > + } limits;
> > + struct {
> > + void __iomem *pdb;
> > + void __iomem *pdb_mask;
> > + void __iomem *sdb;
> > + void __iomem *sbar2_xlat;
> > + void __iomem *sbar4_xlat;
> > + void __iomem *spad_write;
> > + void __iomem *spad_read;
> > + void __iomem *lnk_cntl;
> > + void __iomem *lnk_stat;
> > + void __iomem *spci_cmd;
> > + } reg_ofs;
> > + void *ntb_transport;
> > + void (*event_cb)(void *handle, unsigned int event);
>
> Shouldn't the event be an enum?
No, that would be too smart.
>
> > + struct ntb_db_cb *db_cb;
> > + unsigned char hw_type;
> > + unsigned char conn_type;
> > + unsigned char dev_type;
> > + unsigned char num_msix;
> > + unsigned char bits_per_vector;
> > + unsigned char max_cbs;
> > + unsigned char link_status;
> > + struct delayed_work hb_timer;
> > + unsigned long last_ts;
> > +};
>
> Why isn't this either a 'struct device' itself, or why isn't the 'struct
> pci_device' embedded within it? What controls the lifetime of this
> device? Why doesn't it show up in sysfs? Don't you want it to show up
> in the global device tree?
>
> > +static DEFINE_PCI_DEVICE_TABLE(ntb_pci_tbl) = {
> > + {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_BWD)},
> > + {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_JSF)},
> > + {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_CLASSIC_JSF)},
> > + {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_RP_JSF)},
> > + {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_RP_SNB)},
> > + {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_SNB)},
> > + {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_CLASSIC_SNB)},
> > + {0}
> > +};
> > +MODULE_DEVICE_TABLE(pci, ntb_pci_tbl);
> > +
> > +static struct ntb_device *ntbdev;
>
> You can really only have just one of these in the whole system? Is that
> wise? Why isn't it dynamic and tied to the pci device itself as a
> child?
Good point, I will fix that up.
Thanks for the review!
>
> thanks,
>
> greg k-h
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