PCI/VGA: Move firmware default device detection to ADD_DEVICE path
Previously we selected the firmware default device, i.e., one that owns the
boot framebuffer, as the default device in vga_arb_select_default_device().
This was only done in the vga_arb_device_init() subsys_initcall, so devices
enumerated later, e.g., by pcibios_init(), were not eligible.
Fix this by moving the firmware default device selection from
vga_arb_select_default_device() to vga_arbiter_add_pci_device(), which is
called after every PCI device is enumerated, either by the
vga_arb_device_init() subsys_initcall or as an ADD_DEVICE notifier.
Note that if vga_arb_select_default_device() previously found a device
owning the boot framebuffer, it unconditionally set it to be the default
VGA device, and no subsequent device could replace it.
[bhelgaas: commit log, restructure slightly]
Link: https://lore.kernel.org/r/20211015061512.2941859-7-chenhuacai@loongson.cn
Link: https://lore.kernel.org/r/20220224224753.297579-6-helgaas@kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Bruno Prémont <bonbons@linux-vserver.org>
diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index 58e0a12..c3323ab 100644
--- a/drivers/pci/vgaarb.c
+++ b/drivers/pci/vgaarb.c
@@ -72,6 +72,7 @@ struct vga_device {
unsigned int io_norm_cnt; /* normal IO count */
unsigned int mem_norm_cnt; /* normal MEM count */
bool bridge_has_one_vga;
+ bool is_firmware_default; /* device selected by firmware */
unsigned int (*set_decode)(struct pci_dev *pdev, bool decode);
};
@@ -565,10 +566,9 @@ void vga_put(struct pci_dev *pdev, unsigned int rsrc)
}
EXPORT_SYMBOL(vga_put);
-static void __init vga_select_framebuffer_device(struct pci_dev *pdev)
+static bool vga_is_firmware_default(struct pci_dev *pdev)
{
#if defined(CONFIG_X86) || defined(CONFIG_IA64)
- struct device *dev = &pdev->dev;
u64 base = screen_info.lfb_base;
u64 size = screen_info.lfb_size;
u64 limit;
@@ -583,15 +583,6 @@ static void __init vga_select_framebuffer_device(struct pci_dev *pdev)
limit = base + size;
- /*
- * Override vga_arbiter_add_pci_device()'s I/O based detection
- * as it may take the wrong device (e.g. on Apple system under
- * EFI).
- *
- * Select the device owning the boot framebuffer if there is
- * one.
- */
-
/* Does firmware framebuffer belong to us? */
for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
flags = pci_resource_flags(pdev, i);
@@ -608,13 +599,10 @@ static void __init vga_select_framebuffer_device(struct pci_dev *pdev)
if (base < start || limit >= end)
continue;
- if (!vga_default_device())
- vgaarb_info(dev, "setting as boot device\n");
- else if (pdev != vga_default_device())
- vgaarb_info(dev, "overriding boot device\n");
- vga_set_default_device(pdev);
+ return true;
}
#endif
+ return false;
}
static bool vga_arb_integrated_gpu(struct device *dev)
@@ -635,6 +623,7 @@ static bool vga_arb_integrated_gpu(struct device *dev)
static bool vga_is_boot_device(struct vga_device *vgadev)
{
struct vga_device *boot_vga = vgadev_find(vga_default_device());
+ struct pci_dev *pdev = vgadev->pdev;
/*
* We select the default VGA device in this order:
@@ -646,6 +635,18 @@ static bool vga_is_boot_device(struct vga_device *vgadev)
*/
/*
+ * We always prefer a firmware default device, so if we've already
+ * found one, there's no need to consider vgadev.
+ */
+ if (boot_vga && boot_vga->is_firmware_default)
+ return false;
+
+ if (vga_is_firmware_default(pdev)) {
+ vgadev->is_firmware_default = true;
+ return true;
+ }
+
+ /*
* A legacy VGA device has MEM and IO enabled and any bridges
* leading to it have PCI_BRIDGE_CTL_VGA enabled so the legacy
* resources ([mem 0xa0000-0xbffff], [io 0x3b0-0x3bb], etc) are
@@ -1531,10 +1532,6 @@ static void __init vga_arb_select_default_device(void)
struct pci_dev *pdev, *found = NULL;
struct vga_device *vgadev;
- list_for_each_entry(vgadev, &vga_list, list) {
- vga_select_framebuffer_device(vgadev->pdev);
- }
-
if (!vga_default_device()) {
list_for_each_entry_reverse(vgadev, &vga_list, list) {
struct device *dev = &vgadev->pdev->dev;
