PCI/VGA: Select VGA devices earlier

Select VGA devices in vga_arb_device_init() and pci_notify() instead of in
vga_arbiter_add_pci_device().

This is a trivial optimization for adding devices.  It's a bigger
optimization for the removal case because pci_notify() won't call
vga_arbiter_del_pci_device() for non-VGA devices, so it won't have to
search the vga_list for them.

https://lore.kernel.org/r/20230830111532.444535-3-sui.jingfeng@linux.dev
Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
[bhelgaas: commit log, split from functional change]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index 2ef3c88e9c33cfe343adb0d6d56a812ce74ffcbf..feca96fc4255b4227802a97577de2dde50cc756e 100644 (file)
--- a/drivers/pci/vgaarb.c
+++ b/drivers/pci/vgaarb.c
@@ -764,10 +764,6 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
        struct pci_dev *bridge;
        u16 cmd;
 
-       /* Only deal with VGA class devices */
-       if (!pci_is_vga(pdev))
-               return false;
-
        /* Allocate structure */
        vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL);
        if (vgadev == NULL) {
@@ -1503,6 +1499,10 @@ static int pci_notify(struct notifier_block *nb, unsigned long action,
 
        vgaarb_dbg(dev, "%s\n", __func__);
 
+       /* Only deal with VGA class devices */
+       if (!pci_is_vga(pdev))
+               return 0;
+
        /*
         * For now, we're only interested in devices added and removed.
         * I didn't test this thing here, so someone needs to double check
@@ -1550,8 +1550,10 @@ static int __init vga_arb_device_init(void)
        pdev = NULL;
        while ((pdev =
                pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
-                              PCI_ANY_ID, pdev)) != NULL)
-               vga_arbiter_add_pci_device(pdev);
+                              PCI_ANY_ID, pdev)) != NULL) {
+               if (pci_is_vga(pdev))
+                       vga_arbiter_add_pci_device(pdev);
+       }
 
        pr_info("loaded\n");
        return rc;