From: Bjorn Helgaas bhelgaas@google.com

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

Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/gpu/vga/Kconfig | 19 ------------------- drivers/gpu/vga/Makefile | 1 - drivers/pci/Kconfig | 19 +++++++++++++++++++ drivers/pci/Makefile | 1 + drivers/{gpu/vga => pci}/vgaarb.c | 0 5 files changed, 20 insertions(+), 20 deletions(-) rename drivers/{gpu/vga => pci}/vgaarb.c (100%)

diff --git a/drivers/gpu/vga/Kconfig b/drivers/gpu/vga/Kconfig index 1ad4c4ef0b5e..eb8b14ab22c3 100644 --- a/drivers/gpu/vga/Kconfig +++ b/drivers/gpu/vga/Kconfig @@ -1,23 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only -config VGA_ARB - bool "VGA Arbitration" if EXPERT - default y - depends on (PCI && !S390) - help - Some "legacy" VGA devices implemented on PCI typically have the same - hard-decoded addresses as they did on ISA. When multiple PCI devices - are accessed at same time they need some kind of coordination. Please - see Documentation/gpu/vgaarbiter.rst for more details. Select this to - enable VGA arbiter. - -config VGA_ARB_MAX_GPUS - int "Maximum number of GPUs" - default 16 - depends on VGA_ARB - help - Reserves space in the kernel to maintain resource locking for - multiple GPUS. The overhead for each GPU is very small. - config VGA_SWITCHEROO bool "Laptop Hybrid Graphics - GPU switching support" depends on X86 diff --git a/drivers/gpu/vga/Makefile b/drivers/gpu/vga/Makefile index e92064442d60..9800620deda3 100644 --- a/drivers/gpu/vga/Makefile +++ b/drivers/gpu/vga/Makefile @@ -1,3 +1,2 @@ # SPDX-License-Identifier: GPL-2.0-only -obj-$(CONFIG_VGA_ARB) += vgaarb.o obj-$(CONFIG_VGA_SWITCHEROO) += vga_switcheroo.o diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 0c473d75e625..7c9e56d7b857 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -252,6 +252,25 @@ config PCIE_BUS_PEER2PEER

endchoice

+config VGA_ARB + bool "VGA Arbitration" if EXPERT + default y + depends on (PCI && !S390) + help + Some "legacy" VGA devices implemented on PCI typically have the same + hard-decoded addresses as they did on ISA. When multiple PCI devices + are accessed at same time they need some kind of coordination. Please + see Documentation/gpu/vgaarbiter.rst for more details. Select this to + enable VGA arbiter. + +config VGA_ARB_MAX_GPUS + int "Maximum number of GPUs" + default 16 + depends on VGA_ARB + help + Reserves space in the kernel to maintain resource locking for + multiple GPUS. The overhead for each GPU is very small. + source "drivers/pci/hotplug/Kconfig" source "drivers/pci/controller/Kconfig" source "drivers/pci/endpoint/Kconfig" diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index d62c4ac4ae1b..ebe720f69b15 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_PCI_PF_STUB) += pci-pf-stub.o obj-$(CONFIG_PCI_ECAM) += ecam.o obj-$(CONFIG_PCI_P2PDMA) += p2pdma.o obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o +obj-$(CONFIG_VGA_ARB) += vgaarb.o

# Endpoint library must be initialized before its users obj-$(CONFIG_PCI_ENDPOINT) += endpoint/ diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/pci/vgaarb.c similarity index 100% rename from drivers/gpu/vga/vgaarb.c rename to drivers/pci/vgaarb.c

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

Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/pci/vgaarb.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index 6a5169d8578f..29e725ebaa43 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -565,6 +565,20 @@ void vga_put(struct pci_dev *pdev, unsigned int rsrc) } EXPORT_SYMBOL(vga_put);

+#if defined(CONFIG_ACPI) +static bool vga_arb_integrated_gpu(struct device *dev) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + + return adev && !strcmp(acpi_device_hid(adev), ACPI_VIDEO_HID); +} +#else +static bool vga_arb_integrated_gpu(struct device *dev) +{ + return false; +} +#endif + /* * Rules for using a bridge to control a VGA descendant decoding: if a bridge * has only one VGA descendant then it can be used to control the VGA routing @@ -1430,20 +1444,6 @@ static struct miscdevice vga_arb_device = { MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops };

-#if defined(CONFIG_ACPI) -static bool vga_arb_integrated_gpu(struct device *dev) -{ - struct acpi_device *adev = ACPI_COMPANION(dev); - - return adev && !strcmp(acpi_device_hid(adev), ACPI_VIDEO_HID); -} -#else -static bool vga_arb_integrated_gpu(struct device *dev) -{ - return false; -} -#endif - static void __init vga_arb_select_default_device(void) { struct pci_dev *pdev, *found = NULL;

This patch is the second step of the rework: Update default VGA device if a better one is found. What is a better one? A device with legacy I/O resources enabled is better those not enabled. And the integrated GPU is better than others.

Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/pci/vgaarb.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index f8f95244d499..02b68810273a 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -582,14 +582,32 @@ static bool vga_arb_integrated_gpu(struct device *dev) static void vga_arb_update_default_device(struct vga_device *vgadev) { struct pci_dev *pdev = vgadev->pdev; + struct device *dev = &pdev->dev; + struct vga_device *vgadev_default;

/* * If we don't have a default VGA device yet, and this device owns * the legacy VGA resources, make it the default. */ - if (!vga_default_device() && - ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { - vgaarb_info(&pdev->dev, "setting as boot VGA device\n"); + if (!vga_default_device()) { + if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK) + vgaarb_info(dev, "setting as boot VGA device\n"); + else + vgaarb_info(dev, "setting as boot device (VGA legacy resources not available)\n"); + vga_set_default_device(pdev); + } + + vgadev_default = vgadev_find(vga_default); + + /* Overridden by a better device */ + if (vgadev_default && ((vgadev_default->owns & VGA_RSRC_LEGACY_MASK) == 0) + && ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { + vgaarb_info(dev, "overriding boot VGA device\n"); + vga_set_default_device(pdev); + } + + if (vga_arb_integrated_gpu(dev)) { + vgaarb_info(dev, "overriding boot VGA device\n"); vga_set_default_device(pdev); } }

This patch is the last step of the rework: Since vga_arb_update_default_ device() is complete, we can remove vga_arb_select_default_device() and its call-site.

Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/pci/vgaarb.c | 89 -------------------------------------------- 1 file changed, 89 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index c768365138b6..5a008d190ed8 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -1514,92 +1514,6 @@ static struct miscdevice vga_arb_device = { MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops };

-static void __init vga_arb_select_default_device(void) -{ - struct pci_dev *pdev, *found = NULL; - struct vga_device *vgadev; - -#if defined(CONFIG_X86) || defined(CONFIG_IA64) - u64 base = screen_info.lfb_base; - u64 size = screen_info.lfb_size; - u64 limit; - resource_size_t start, end; - unsigned long flags; - int i; - - if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) - base |= (u64)screen_info.ext_lfb_base << 32; - - limit = base + size; - - list_for_each_entry(vgadev, &vga_list, list) { - struct device *dev = &vgadev->pdev->dev; - /* - * 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(vgadev->pdev, i); - - if ((flags & IORESOURCE_MEM) == 0) - continue; - - start = pci_resource_start(vgadev->pdev, i); - end = pci_resource_end(vgadev->pdev, i); - - if (!start || !end) - continue; - - if (base < start || limit >= end) - continue; - - if (!vga_default_device()) - vgaarb_info(dev, "setting as boot device\n"); - else if (vgadev->pdev != vga_default_device()) - vgaarb_info(dev, "overriding boot device\n"); - vga_set_default_device(vgadev->pdev); - } - } -#endif - - if (!vga_default_device()) { - list_for_each_entry_reverse(vgadev, &vga_list, list) { - struct device *dev = &vgadev->pdev->dev; - u16 cmd; - - pdev = vgadev->pdev; - pci_read_config_word(pdev, PCI_COMMAND, &cmd); - if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { - found = pdev; - if (vga_arb_integrated_gpu(dev)) - break; - } - } - } - - if (found) { - vgaarb_info(&found->dev, "setting as boot device (VGA legacy resources not available)\n"); - vga_set_default_device(found); - return; - } - - if (!vga_default_device()) { - vgadev = list_first_entry_or_null(&vga_list, - struct vga_device, list); - if (vgadev) { - struct device *dev = &vgadev->pdev->dev; - vgaarb_info(dev, "setting as boot device (VGA legacy resources not available)\n"); - vga_set_default_device(vgadev->pdev); - } - } -} - static int __init vga_arb_device_init(void) { int rc; @@ -1629,9 +1543,6 @@ static int __init vga_arb_device_init(void) vgaarb_info(dev, "no bridge control possible\n"); }

- vga_arb_select_default_device(); - - pr_info("loaded\n"); return rc; } subsys_initcall(vga_arb_device_init);

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.

Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/pci/vgaarb.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index 1a829cbacbc8..5a042f9ac82c 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -672,8 +672,10 @@ static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev)

vgadev->bridge_has_one_vga = true;

- if (list_empty(&vga_list)) + if (list_empty(&vga_list)) { + vgaarb_info(&vgadev->pdev->dev, "bridge control possible\n"); return; + }

/* okay iterate the new devices bridge hierarachy */ new_bus = vgadev->pdev->bus; @@ -712,6 +714,11 @@ static void vga_arbiter_check_bridge_sharing(struct vga_device *vgadev) } new_bus = new_bus->parent; } + + if (vgadev->bridge_has_one_vga) + vgaarb_info(&vgadev->pdev->dev, "bridge control possible\n"); + else + vgaarb_info(&vgadev->pdev->dev, "no bridge control possible\n"); }

/* @@ -1504,7 +1511,6 @@ static int __init vga_arb_device_init(void) { int rc; struct pci_dev *pdev; - struct vga_device *vgadev;

rc = misc_register(&vga_arb_device); if (rc < 0) @@ -1520,15 +1526,6 @@ static int __init vga_arb_device_init(void) PCI_ANY_ID, pdev)) != NULL) vga_arbiter_add_pci_device(pdev);

- list_for_each_entry(vgadev, &vga_list, list) { - struct device *dev = &vgadev->pdev->dev; - - if (vgadev->bridge_has_one_vga) - vgaarb_info(dev, "bridge control possible\n"); - else - vgaarb_info(dev, "no bridge control possible\n"); - } - return rc; } subsys_initcall(vga_arb_device_init);

From: Bjorn Helgaas bhelgaas@google.com

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.

Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/pci/vgaarb.c | 23 +---------------------- 1 file changed, 1 insertion(+), 22 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index f9581775939b..54d0b451b335 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -1,32 +1,11 @@ +// SPDX-License-Identifier: MIT /* * vgaarb.c: Implements the VGA arbitration. For details refer to * Documentation/gpu/vgaarbiter.rst * - * * (C) Copyright 2005 Benjamin Herrenschmidt benh@kernel.crashing.org * (C) Copyright 2007 Paulo R. Zanoni przanoni@gmail.com * (C) Copyright 2007, 2009 Tiago Vignatti vignatti@freedesktop.org - * - * Permission is hereby granted, free of charge, to any person obtaining a - * copy of this software and associated documentation files (the "Software"), - * to deal in the Software without restriction, including without limitation - * the rights to use, copy, modify, merge, publish, distribute, sublicense, - * and/or sell copies of the Software, and to permit persons to whom the - * Software is furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice (including the next - * paragraph) shall be included in all copies or substantial portions of the - * Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER - * DEALINGS - * IN THE SOFTWARE. - * */

#define pr_fmt(fmt) "vgaarb: " fmt