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PCI/VGA: Move firmware default device detection to ADD_DEVICE path

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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>
This commit is contained in:
Huacai Chen 2022-02-24 16:47:47 -06:00 committed by Bjorn Helgaas
parent dfe3da812d
commit f8d81df285
1 changed files with 17 additions and 20 deletions
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37
drivers/pci/vgaarb.c
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@ -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 @@ bail:
}
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:
@ -645,6 +634,18 @@ static bool vga_is_boot_device(struct vga_device *vgadev)
* Other device (see vga_arb_select_default_device())
*/
/*
* 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
@ -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;