device/pci_device.c: Improve pci_bridge_route() readability

Both the secondary and subordinate bus numbers are configured in this
function but it's not easy to search for in the tree as the PCI writes
are hidden inside a bigger write to 'PCI_PRIMARY_BUS'. Use separate
variables and PCI config writes to improve the readability.

Change-Id: I3bafd6a2e1d3a0b8d1d43997868a787ce3940ca9
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59131
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
This commit is contained in:
Arthur Heymans 2021-11-10 22:09:58 +01:00 committed by Felix Held
parent c89f252608
commit f879d36551
1 changed files with 13 additions and 13 deletions

View File

@ -1499,7 +1499,7 @@ static void pci_bridge_route(struct bus *link, scan_state state)
{
struct device *dev = link->dev;
struct bus *parent = dev->bus;
u32 reg, buses = 0;
uint8_t primary, secondary, subordinate;
if (state == PCI_ROUTE_SCAN) {
link->secondary = parent->subordinate + 1;
@ -1507,15 +1507,17 @@ static void pci_bridge_route(struct bus *link, scan_state state)
}
if (state == PCI_ROUTE_CLOSE) {
buses |= 0xfeff << 8;
primary = 0;
secondary = 0xff;
subordinate = 0xfe;
} else if (state == PCI_ROUTE_SCAN) {
buses |= parent->secondary & 0xff;
buses |= ((u32) link->secondary & 0xff) << 8;
buses |= 0xff << 16; /* MAX PCI_BUS number here */
primary = parent->secondary;
secondary = link->secondary;
subordinate = 0xff; /* MAX PCI_BUS number here */
} else if (state == PCI_ROUTE_FINAL) {
buses |= parent->secondary & 0xff;
buses |= ((u32) link->secondary & 0xff) << 8;
buses |= ((u32) link->subordinate & 0xff) << 16;
primary = parent->secondary;
secondary = link->secondary;
subordinate = link->subordinate;
}
if (state == PCI_ROUTE_SCAN) {
@ -1530,11 +1532,9 @@ static void pci_bridge_route(struct bus *link, scan_state state)
* transactions will not be propagated by the bridge if it is not
* correctly configured.
*/
reg = pci_read_config32(dev, PCI_PRIMARY_BUS);
reg &= 0xff000000;
reg |= buses;
pci_write_config32(dev, PCI_PRIMARY_BUS, reg);
pci_write_config8(dev, PCI_PRIMARY_BUS, primary);
pci_write_config8(dev, PCI_SECONDARY_BUS, secondary);
pci_write_config8(dev, PCI_SUBORDINATE_BUS, subordinate);
if (state == PCI_ROUTE_FINAL) {
pci_write_config16(dev, PCI_COMMAND, link->bridge_cmd);