lkml.org 
[lkml]   [2004]   [Dec]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] add legacy resources to sysfs
On Tue, Dec 21, 2004 at 12:47:44PM -0800, Jesse Barnes wrote:
> + * Find the base of legacy memory for @dev. This is typically the first
> + * megabyte of bus address space for @dev or is simply 0 on platforms whose
> + * chipsets support legacy I/O and memory routing. Returns 0 on success
> + * or a standard error code on failure.
> +int ia64_pci_get_legacy_mem(struct pci_bus *bus, unsigned long *addr)
> +{
> + *addr = 0;
> + return 0;
> +}

This is a slightly klunky interface. How about:

* Find the base of legacy memory for @dev. This is typically the first
* megabyte of bus address space for @dev or is simply 0 on platforms whose
* chipsets support legacy I/O and memory routing. Returns the base address
* or an error pointer if an error occurred

The generic one is too trivial to demonstrate with, but the sn2 one
makes more sense:

> ===== arch/ia64/sn/pci/pci_dma.c 1.2 vs edited =====
> +int sn_pci_get_legacy_mem(struct pci_bus *bus, unsigned long *addr)
> +{
> + if (!SN_PCIBUS_BUSSOFT(bus))
> + return -ENODEV;
> +
> + *addr = SN_PCIBUS_BUSSOFT(bus)->bs_legacy_mem | __IA64_UNCACHED_OFFSET;
> +
> + return 0;
> +}

int sn_pci_get_legacy_mem(struct pci_bus *bus)
{
if (!SN_PCIBUS_BUSSOFT(bus))
return ERR_PTR(-ENODEV);
return SN_PCIBUS_BUSSOFT(bus)->bs_legacy_mem | __IA64_UNCACHED_OFFSET;
}
> b->class_dev.class = &pcibus_class;
> sprintf(b->class_dev.class_id, "%04x:%02x", pci_domain_nr(b), bus);
> error = class_device_register(&b->class_dev);
> +
> if (error)
> goto class_dev_reg_err;

Actually, I rather dislike having the newline there. It implies a logical
separation between registering and testing for the error, whereas the logical
separation is much more like this:

b->class_dev.class = &pcibus_class;
sprintf(b->class_dev.class_id, "%04x:%02x", pci_domain_nr(b), bus);
error = class_device_register(&b->class_dev);
if (error)
goto class_dev_reg_err;
error = class_device_create_file(...)

--
"Next the statesmen will invent cheap lies, putting the blame upon
the nation that is attacked, and every man will be glad of those
conscience-soothing falsities, and will diligently study them, and refuse
to examine any refutations of them; and thus he will by and by convince
himself that the war is just, and will thank God for the better sleep
he enjoys after this process of grotesque self-deception." -- Mark Twain
-
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/

\
 
 \ /
  Last update: 2005-03-22 14:08    [from the cache]
©2003-2011 Jasper Spaans