Messages in this thread | | | Subject | PCI bridge devices questions | Date | Sat, 02 Apr 2005 13:04:33 -0500 | From | "Marty Leisner" <> |
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I have to write some code to insert a non-standard bridge (it identifies itself as bridge-other, but it functions as a pci-pci bridge).
I'm going to be using 2.4.2x and eventually 2.6.x for intel and ppc...
In the pci_dev structure (for 2.4.29) there's (in include/linux/pci.h)
00355 #define DEVICE_COUNT_RESOURCE 12 00410 struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */
We also have: 00431 /* 00432 * For PCI devices, the region numbers are assigned this way: 00433 * 00434 * 0-5 standard PCI regions 00435 * 6 expansion ROM 00436 * 7-10 bridges: address space assigned to buses behind the bridge 00437 */ 00438 00439 #define PCI_ROM_RESOURCE 6 00440 #define PCI_BRIDGE_RESOURCES 7 00441 #define PCI_NUM_RESOURCES 11
Now where my confusion sets in: 1) PCI_NUM_RESOURCES + 1 == DEVICE_COUNT_RESOURCE Why? 2) I understand the first 6 regions (standard) and the expansion rom) -- why 5 more? 3) I've only seen instances of 3 bus regions used -- IO, MEM prefetch, MEM nonprefetch -- are they order dependent? 4) would it make more sense to have seperate arrays? One of for the device resources, one for the bridge resources?
Thanks...
Marty Leisner leisner@rochester.rr.com - 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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