PCI/VGA: Fix typos

Fix typos, rewrap to fill 78 columns, convert to conventional multi-line
style.

[bhelgaas: squash and add more fixes]
Link: https://lore.kernel.org/r/20230808223412.1743176-7-sui

PCI/VGA: Fix typos

Fix typos, rewrap to fill 78 columns, convert to conventional multi-line
style.

[bhelgaas: squash and add more fixes]
Link: https://lore.kernel.org/r/20230808223412.1743176-7-sui.jingfeng@linux.dev
Link: https://lore.kernel.org/r/20230808223412.1743176-9-sui.jingfeng@linux.dev
Link: https://lore.kernel.org/r/20230808223412.1743176-10-sui.jingfeng@linux.dev
Link: https://lore.kernel.org/r/20230808223412.1743176-11-sui.jingfeng@linux.dev
Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Simplify vga_client_register()

Reorganize vga_client_register() to avoid the goto and the need to save the
return value. Update the kernel-doc to reflect -ENODEV on failure. No
functional

PCI/VGA: Simplify vga_client_register()

Reorganize vga_client_register() to avoid the goto and the need to save the
return value. Update the kernel-doc to reflect -ENODEV on failure. No
functional change intended.

[bhelgaas: drop "ret" variable, commit log]
Link: https://lore.kernel.org/r/20230808223412.1743176-8-sui.jingfeng@linux.dev
Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Simplify vga_arbiter_notify_clients()

In vga_arbiter_notify_clients(), "new_state" was computed during every loop
iteration even though it doesn't depend on anything that changes during the

PCI/VGA: Simplify vga_arbiter_notify_clients()

In vga_arbiter_notify_clients(), "new_state" was computed during every loop
iteration even though it doesn't depend on anything that changes during the
loop. Move the computation outside the loop.

[bhelgaas: drop renames that obscure the purpose, commit log]
Link: https://lore.kernel.org/r/20230808223412.1743176-6-sui.jingfeng@linux.dev
Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Correct vga_update_device_decodes() parameter type

Previously vga_update_device_decodes() took "int new_decodes", but the
callers pass "unsigned int new_decodes". Correct the
vga_update_de

PCI/VGA: Correct vga_update_device_decodes() parameter type

Previously vga_update_device_decodes() took "int new_decodes", but the
callers pass "unsigned int new_decodes". Correct the
vga_update_device_decodes() parameter type to "unsigned int" to match.

In vga_arbiter_notify_clients(), the return from vgadev->set_decode() is
"unsigned int" but was stored as "uint32_t new_decodes". Correct the
new_decodes type to "unsigned int".

[bhelgaas: use correct type for ->set_decode() return, commit log]
Link: https://lore.kernel.org/r/20230808223412.1743176-5-sui.jingfeng@linux.dev
Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Correct vga_str_to_iostate() io_state parameter type

Previously vga_str_to_iostate() took "int *io_state", but vga_arb_write()
is the only caller and it passes "unsigned int *". Make the
v

PCI/VGA: Correct vga_str_to_iostate() io_state parameter type

Previously vga_str_to_iostate() took "int *io_state", but vga_arb_write()
is the only caller and it passes "unsigned int *". Make the
vga_str_to_iostate() parameter type "unsigned int *" to match.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20230808223412.1743176-2-sui.jingfeng@linux.dev
Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

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PCI: Introduce pci_dev_for_each_resource()

Instead of open-coding it everywhere introduce a tiny helper that can be
used to iterate over each resource of a PCI device, and convert the most
obvious u

PCI: Introduce pci_dev_for_each_resource()

Instead of open-coding it everywhere introduce a tiny helper that can be
used to iterate over each resource of a PCI device, and convert the most
obvious users into it.

While at it drop doubled empty line before pdev_sort_resources().

No functional changes intended.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230330162434.35055-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>

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PCI/VGA: Replace full MIT license text with SPDX identifier

Per Documentation/process/license-rules.rst, the SPDX MIT identifier is
equivalent to including the entire MIT license text from
LICENSES/

PCI/VGA: Replace full MIT license text with SPDX identifier

Per Documentation/process/license-rules.rst, the SPDX MIT identifier is
equivalent to including the entire MIT license text from
LICENSES/preferred/MIT.

Replace the MIT license text with the equivalent SPDX identifier.

Link: https://lore.kernel.org/r/20220224224753.297579-12-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Use unsigned format string to print lock counts

In struct vga_device, io_lock_cnt and mem_lock_cnt are unsigned, but we
previously printed them with "%d", the signed decimal format. Print

PCI/VGA: Use unsigned format string to print lock counts

In struct vga_device, io_lock_cnt and mem_lock_cnt are unsigned, but we
previously printed them with "%d", the signed decimal format. Print them
with the unsigned format "%u" instead.

Link: https://lore.kernel.org/r/20220224224753.297579-11-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Log bridge control messages when adding devices

Previously vga_arb_device_init() iterated through all VGA devices and
indicated whether legacy VGA routing to each could be controlled by an

PCI/VGA: Log bridge control messages when adding devices

Previously vga_arb_device_init() iterated through all VGA devices and
indicated whether legacy VGA routing to each could be controlled by an
upstream bridge.

But we determine that information in vga_arbiter_add_pci_device(), which we
call for every device, so we can log it there without iterating through the
VGA devices again.

Note that we call vga_arbiter_check_bridge_sharing() before adding the
device to vga_list, so we have to handle the very first device separately.

Link: https://lore.kernel.org/r/20220224224753.297579-10-helgaas@kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Remove empty vga_arb_device_card_gone()

vga_arb_device_card_gone() has always been empty. Remove it.

Link: https://lore.kernel.org/r/20220224224753.297579-9-helgaas@kernel.org
Signed-off-

PCI/VGA: Remove empty vga_arb_device_card_gone()

vga_arb_device_card_gone() has always been empty. Remove it.

Link: https://lore.kernel.org/r/20220224224753.297579-9-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Move disabled VGA device detection to ADD_DEVICE path

a37c0f48950b ("vgaarb: Select a default VGA device even if there's no
legacy VGA") extended the vga_arb_device_init() subsys_initcall s

PCI/VGA: Move disabled VGA device detection to ADD_DEVICE path

a37c0f48950b ("vgaarb: Select a default VGA device even if there's no
legacy VGA") extended the vga_arb_device_init() subsys_initcall so that if
there are no other eligible devices, it could select a disabled VGA device
as the default.

Move this detection from vga_arb_select_default_device() to
vga_arbiter_add_pci_device() so every device, even those hot-added or
enumerated after vga_arb_device_init() is eligible for selection as the
default VGA device.

[bhelgaas: commit log, restructure]
Link: https://lore.kernel.org/r/20211015061512.2941859-5-chenhuacai@loongson.cn
Link: https://lore.kernel.org/r/20220224224753.297579-8-helgaas@kernel.org
Signed-off-by: Huacai Chen <chenhuacai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Zhou Wang <wangzhou1@hisilicon.com>

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PCI/VGA: Move non-legacy VGA detection to ADD_DEVICE path

a37c0f48950b ("vgaarb: Select a default VGA device even if there's no
legacy VGA") extended the vga_arb_device_init() subsys_initcall so it

PCI/VGA: Move non-legacy VGA detection to ADD_DEVICE path

a37c0f48950b ("vgaarb: Select a default VGA device even if there's no
legacy VGA") extended the vga_arb_device_init() subsys_initcall so it could
select a non-legacy VGA device as the default.

That failed to consider that PCI devices may be enumerated after
vga_arb_device_init(), e.g., hot-added devices or non-ACPI systems that do
PCI enumeration in pcibios_init(). Devices found then could never be
selected as the default.

One system where this is a problem is the MIPS-based Loongson where an
ASpeed AST2500 VGA device is behind a bridge that doesn't implement the VGA
Enable bit, so legacy resources are not routed to the VGA device. [1]

Fix this by moving the non-legacy VGA 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.

[1] https://lore.kernel.org/r/20210514080025.1828197-6-chenhuacai@loongson.cn

[bhelgaas: commit log, restructure]
Link: https://lore.kernel.org/r/20211015061512.2941859-5-chenhuacai@loongson.cn
Link: https://lore.kernel.org/r/20211015061512.2941859-7-chenhuacai@loongson.cn
Link: https://lore.kernel.org/r/20220224224753.297579-7-helgaas@kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Zhou Wang <wangzhou1@hisilicon.com>

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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_sele

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>

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PCI/VGA: Factor out default VGA device selection

Default VGA device selection fails when PCI devices are enumerated after
the vga_arb_device_init() subsys_initcall.

vga_arbiter_add_pci_device() sel

PCI/VGA: Factor out default VGA device selection

Default VGA device selection fails when PCI devices are enumerated after
the vga_arb_device_init() subsys_initcall.

vga_arbiter_add_pci_device() selects the first fully enabled device to
which legacy VGA resources are routed as the default VGA device. This is
an ADD_DEVICE notifier, so it runs after every PCI device is enumerated.

vga_arb_select_default_device() may select framebuffer devices, partially
enabled GPUs, or non-legacy devices that don't have legacy VGA resources
routed to them as the default VGA device. But this only happens once, from
the vga_arb_device_init() subsys_initcall, so it doesn't consider devices
enumerated after that:

acpi_init
acpi_scan_init
acpi_pci_root_init # PCI device enumeration (ACPI systems)

vga_arb_device_init
for_each_pci_device
vga_arbiter_add_pci_device # ADD_DEVICE notifier
if (VGA-owner)
vga_set_default_device <-- set default VGA
vga_arb_select_default_device # only called ONCE
for_each_vga_device
if (framebuffer)
vga_set_default_device <-- set default VGA to framebuffer
if (!vga_default_device())
if (non-legacy, integrated GPU, etc)
vga_set_default_device <-- set default VGA
if (!vga_default_device())
vga_set_default_device <-- set default VGA

pcibios_init
pcibios_scanbus # PCI device enumeration (non-ACPI systems)
...
vga_arbiter_add_pci_device # ADD_DEVICE notification
if (VGA-owner)
vga_set_default_device <-- set default VGA

Note that on non-ACPI systems, vga_arb_select_default_device() runs before
pcibios_init(), so it sees no VGA devices and can never set a framebuffer
device, a non-legacy integrated GPU, etc., as the default device.

Factor out the default VGA device selection to vga_is_boot_device(), called
from vga_arbiter_add_pci_device().

Then we can migrate the default device selection from
vga_arb_select_default_device() to the vga_arbiter_add_pci_device() path.

[bhelgaas: commit log, split to separate patch]
Link: https://lore.kernel.org/r/20211015061512.2941859-4-chenhuacai@loongson.cn
Link: https://lore.kernel.org/r/20220224224753.297579-5-helgaas@kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Factor out vga_select_framebuffer_device()

On x86 and ia64, if a VGA device BARs include a framebuffer reported by
platform firmware, we select the device as the default VGA device. Factor

PCI/VGA: Factor out vga_select_framebuffer_device()

On x86 and ia64, if a VGA device BARs include a framebuffer reported by
platform firmware, we select the device as the default VGA device. Factor
this code to a separate function. No functional change intended.

Link: https://lore.kernel.org/r/20220224224753.297579-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Bruno Prémont <bonbons@linux-vserver.org>

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PCI/VGA: Move vga_arb_integrated_gpu() earlier in file

Move vga_arb_integrated_gpu() earlier in file to prepare for future patch.
No functional change intended.

[bhelgaas: pull #ifdefs inside funct

PCI/VGA: Move vga_arb_integrated_gpu() earlier in file

Move vga_arb_integrated_gpu() earlier in file to prepare for future patch.
No functional change intended.

[bhelgaas: pull #ifdefs inside function]
Link: https://lore.kernel.org/r/20211015061512.2941859-3-chenhuacai@loongson.cn
Link: https://lore.kernel.org/r/20220224224753.297579-3-helgaas@kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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PCI/VGA: Move vgaarb to drivers/pci

The VGA arbiter is really PCI-specific and doesn't depend on any GPU
things. Move it to the PCI subsystem.

Note that misc_init() must be called before vga_arb_d

PCI/VGA: Move vgaarb to drivers/pci

The VGA arbiter is really PCI-specific and doesn't depend on any GPU
things. Move it to the PCI subsystem.

Note that misc_init() must be called before vga_arb_device_init(). These
are both subsys_initcalls, so this ordering depends on the link order,
which is determined by drivers/Makefile:

obj-y += pci/
obj-y += char/ <-- misc_init()
obj-y += gpu/ <-- vga_arb_device_init() (before this commit)

The drivers/pci/ subsys_initcalls are called *before* misc_init(), so
convert vga_arb_device_init() to subsys_initcall_sync(), which is called
after *all* subsys_initcalls.

Link: https://lore.kernel.org/r/20220224224753.297579-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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