[-next 2/5] PCI/VGA: Deal with VGA devices

Sui Jingfeng
2023-08-30T19:03:36Z

From: Sui Jingfeng <suijingfeng@loongson.cn>

VGAARB only cares about PCI(e) VGA devices, thus filtering out unqualified
devices as early as possible. This also means that deleting a non-VGA
device snooped won't unnecessarily call into vga_arbiter_del_pci_device()
function. By using the newly implemented pci_is_vga(),
PCI(e) with PCI_CLASS_NOT_DEFINED_VGA class code will also be handled.

Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
---
drivers/pci/vgaarb.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index 5e6b1eb54c64..ef8fe685de67 100644
--- 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 ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
- return false;
-
/* Allocate structure */
vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL);
if (vgadev == NULL) {
@@ -1503,6 +1499,9 @@ static int pci_notify(struct notifier_block *nb, unsigned long action,

vgaarb_dbg(dev, "%s\n", __func__);

+ 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
@@ -1537,8 +1536,8 @@ static struct miscdevice vga_arb_device = {

static int __init vga_arb_device_init(void)
{
+ struct pci_dev *pdev = NULL;
int rc;
- struct pci_dev *pdev;

rc = misc_register(&vga_arb_device);
if (rc < 0)
@@ -1547,11 +1546,11 @@ static int __init vga_arb_device_init(void)
bus_register_notifier(&pci_bus_type, &pci_notifier);

/* Add all VGA class PCI devices by default */
- 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);
+ do {
+ pdev = pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, pdev);
+ if (pci_is_vga(pdev))
+ vga_arbiter_add_pci_device(pdev);
+ } while (pdev);

pr_info("loaded\n");
return rc;
--
2.34.1