Commit 9be60ca0 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Jesse Barnes
Browse files

PCI: Add support for detection of PCIe and PCI-X bus speeds 



Both PCIe and PCI-X bridges report their secondary bus speed in their
respective capabilities.

Signed-off-by: default avatarMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 3749c51a

drivers/pci/probe.c

+66 −0
Original line number Diff line number Diff line
@@ -393,6 +393,25 @@ static struct pci_bus * pci_alloc_bus(void) 
	return b;

}



static unsigned char pcix_bus_speed[] = {

	PCI_SPEED_UNKNOWN,		/* 0 */

	PCI_SPEED_66MHz_PCIX,		/* 1 */

	PCI_SPEED_100MHz_PCIX,		/* 2 */

	PCI_SPEED_133MHz_PCIX,		/* 3 */

	PCI_SPEED_UNKNOWN,		/* 4 */

	PCI_SPEED_66MHz_PCIX_ECC,	/* 5 */

	PCI_SPEED_100MHz_PCIX_ECC,	/* 6 */

	PCI_SPEED_133MHz_PCIX_ECC,	/* 7 */

	PCI_SPEED_UNKNOWN,		/* 8 */

	PCI_SPEED_66MHz_PCIX_266,	/* 9 */

	PCI_SPEED_100MHz_PCIX_266,	/* A */

	PCI_SPEED_133MHz_PCIX_266,	/* B */

	PCI_SPEED_UNKNOWN,		/* C */

	PCI_SPEED_66MHz_PCIX_533,	/* D */

	PCI_SPEED_100MHz_PCIX_533,	/* E */

	PCI_SPEED_133MHz_PCIX_533	/* F */

};



static unsigned char pcie_link_speed[] = {

	PCI_SPEED_UNKNOWN,		/* 0 */

	PCIE_SPEED_2_5GT,		/* 1 */
@@ -418,6 +437,51 @@ void pcie_update_link_speed(struct pci_bus *bus, u16 linksta) 
}

EXPORT_SYMBOL_GPL(pcie_update_link_speed);



static void pci_set_bus_speed(struct pci_bus *bus)

{

	struct pci_dev *bridge = bus->self;

	int pos;



	pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX);

	if (pos) {

		u16 status;

		enum pci_bus_speed max;

		pci_read_config_word(bridge, pos + 2, &status);



		if (status & 0x8000) {

			max = PCI_SPEED_133MHz_PCIX_533;

		} else if (status & 0x4000) {

			max = PCI_SPEED_133MHz_PCIX_266;

		} else if (status & 0x0002) {

			if (((status >> 12) & 0x3) == 2) {

				max = PCI_SPEED_133MHz_PCIX_ECC;

			} else {

				max = PCI_SPEED_133MHz_PCIX;

			}

		} else {

			max = PCI_SPEED_66MHz_PCIX;

		}



		bus->max_bus_speed = max;

		bus->cur_bus_speed = pcix_bus_speed[(status >> 6) & 0xf];



		return;

	}



	pos = pci_find_capability(bridge, PCI_CAP_ID_EXP);

	if (pos) {

		u32 linkcap;

		u16 linksta;



		pci_read_config_dword(bridge, pos + PCI_EXP_LNKCAP, &linkcap);

		bus->max_bus_speed = pcie_link_speed[linkcap & 0xf];



		pci_read_config_word(bridge, pos + PCI_EXP_LNKSTA, &linksta);

		pcie_update_link_speed(bus, linksta);

	}

}





static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,

					   struct pci_dev *bridge, int busnr)

{
@@ -457,6 +521,8 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent, 
	child->self = bridge;

	child->bridge = get_device(&bridge->dev);



	pci_set_bus_speed(child);



	/* Set up default resource pointers and names.. */

	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) {

		child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i];