kernel: pci: Optimize PCI bus scanning

From fe1beed19be88e0c43ff2a68994d6abc04a52f54 Mon Sep 17 00:00:00 2001
From: Quinn Stephens <quinn@osmora.org>
Date: Fri, 14 Feb 2025 23:30:03 -0500
Subject: [PATCH] kernel: pci: Optimize PCI bus scanning

Uses recursive bus/bridge scanning, skips nonexistent devices, and only
scans for multiple functions on multifunction devices. This may result
in PCI scanning being up to 100x as fast.

Signed-off-by: Quinn Stephens <quinn@osmora.org>
Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/sys/include/dev/pci/pci.h b/sys/include/dev/pci/pci.h
index b5bb32c..8118cee 100644
--- a/sys/include/dev/pci/pci.h
+++ b/sys/include/dev/pci/pci.h
@@ -60,8 +60,15 @@ struct pci_device {
     uint8_t pci_class;
     uint8_t pci_subclass;
     uint8_t prog_if;
+    uint8_t hdr_type;
+
+    uint8_t pri_bus;
+    uint8_t sec_bus;
+    uint8_t sub_bus;
+
     uintptr_t bar[6];
     uint8_t irq_line;
+
     TAILQ_ENTRY(pci_device) link;
 };