Messages in this thread |  | | Date | Wed, 13 Apr 2011 21:39:54 +0200 | Subject | Re: [RFC][PATCH V4] axi: add AXI bus driver | From | Rafał Miłecki <> |
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2011/4/13 Greg KH <greg@kroah.com>: >> diff --git a/drivers/axi/axi_pci_bridge.c b/drivers/axi/axi_pci_bridge.c >> new file mode 100644 >> index 0000000..17e882c >> --- /dev/null >> +++ b/drivers/axi/axi_pci_bridge.c >> @@ -0,0 +1,33 @@ >> +/* >> + * AXI PCI bridge module >> + * >> + * Licensed under the GNU/GPL. See COPYING for details. >> + */ >> + >> +#include "axi_private.h" >> + >> +#include <linux/axi/axi.h> >> +#include <linux/pci.h> >> + >> +static DEFINE_PCI_DEVICE_TABLE(axi_pci_bridge_tbl) = { >> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4331) }, >> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4353) }, >> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4727) }, >> + { 0, }, >> +}; >> +MODULE_DEVICE_TABLE(pci, axi_pci_bridge_tbl); >> + >> +static struct pci_driver axi_pci_bridge_driver = { >> + .name = "axi-pci-bridge", >> + .id_table = axi_pci_bridge_tbl, >> +}; >> + >> +int __init axi_pci_bridge_init(void) >> +{ >> + return axi_host_pci_register(&axi_pci_bridge_driver); >> +} >> + >> +void __exit axi_pci_bridge_exit(void) >> +{ >> + axi_host_pci_unregister(&axi_pci_bridge_driver); >> +} > > You register a pci driver that does nothing? That's not right, you need > to then base your axi bus off of that pci device, so it is hooked up > correctly in the /sys/devices/ tree. Otherwise you are somewhere up in > the virtual location for your axi bus, right?
Please take a look at: driver->probe = axi_host_pci_probe; driver->remove = axi_host_pci_remove; return pci_register_driver(driver);
>> +bool axi_core_is_enabled(struct axi_device *core) >> +{ >> + if ((axi_aread32(core, AXI_IOCTL) & (AXI_IOCTL_CLK | AXI_IOCTL_FGC)) >> + != AXI_IOCTL_CLK) >> + return false; >> + if (axi_aread32(core, AXI_RESET_CTL) & AXI_RESET_CTL_RESET) >> + return false; >> + return true; >> +} >> +EXPORT_SYMBOL(axi_core_is_enabled); > > EXPORT_SYMBOL_GPL()? > > What module uses this? And why would it care? > >> +EXPORT_SYMBOL(axi_core_enable); > > EXPORT_SYMBOL_GPL()? > > Same goes for your other exports, just want you to be sure here.
Hm, I'm not sure. Using EXPORT_SYMBOL_GPL will forbid closed source drivers from using our bus driver, right? I'm don't have preferences on this, if you prefer us to force GPL, I can.
>> +u32 xaxi_chipco_gpio_control(struct axi_drv_cc *cc, u32 mask, u32 value) >> +{ >> + return axi_cc_write32_masked(cc, AXI_CC_GPIOCTL, mask, value); >> +} >> +EXPORT_SYMBOL(xaxi_chipco_gpio_control); > > "xaxi"? Shouldn't that be consistant with the other exports and start > with "axi"?
Left from old tests/rewrites/splitting. Thanks.
>> +static u8 axi_host_pci_read8(struct axi_device *core, u16 offset) >> +{ >> + if (unlikely(core->bus->mapped_core != core)) > > Are you sure about the use of unlikely in this, and other functions? > The compiler almost always does a better job than we do for these types > of calls, just let it do it's job. > >> + axi_host_pci_switch_core(core); >> + return ioread8(core->bus->mmio + offset); > > I think because of that unlikely, you just slowed down all pci devices, > right? That's not very nice :)
Hm, my logic suggests it is alright, but please consider this once more with me ;)
For the most of the time mapped_core (active core) do not change. We perform few hundreds of operations on one core in a row. This way mapped_core points to passed core for most of the time. Condition (mapped_core != core) is unlikely to happen.
Is there anything wrong in my logic?
-- Rafał -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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