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 949fde433ea2..61b57abcb014 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

From: Bjorn Helgaas bhelgaas@google.com

vga_arb_device_card_gone() has always been empty. Remove it.

Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/pci/vgaarb.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index e4153ab70481..c984c76b3fd7 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -104,8 +104,6 @@ static int vga_str_to_iostate(char *buf, int str_size, int *io_state) /* this is only used a cookie - it should not be dereferenced */ static struct pci_dev *vga_default;

-static void vga_arb_device_card_gone(struct pci_dev *pdev); - /* Find somebody in our list */ static struct vga_device *vgadev_find(struct pci_dev *pdev) { @@ -741,10 +739,6 @@ static bool vga_arbiter_del_pci_device(struct pci_dev *pdev) /* Remove entry from list */ list_del(&vgadev->list); vga_count--; - /* Notify userland driver that the device is gone so it discards - * it's copies of the pci_dev pointer - */ - vga_arb_device_card_gone(pdev);

/* Wake up all possible waiters */ wake_up_all(&vga_wait_queue); @@ -994,9 +988,7 @@ static ssize_t vga_arb_read(struct file *file, char __user *buf, if (lbuf == NULL) return -ENOMEM;

- /* Shields against vga_arb_device_card_gone (pci_dev going - * away), and allows access to vga list - */ + /* Protects vga_list */ spin_lock_irqsave(&vga_lock, flags);

/* If we are targeting the default, use it */ @@ -1013,8 +1005,6 @@ static ssize_t vga_arb_read(struct file *file, char __user *buf, /* Wow, it's not in the list, that shouldn't happen, * let's fix us up and return invalid card */ - if (pdev == priv->target) - vga_arb_device_card_gone(pdev); spin_unlock_irqrestore(&vga_lock, flags); len = sprintf(lbuf, "invalid"); goto done; @@ -1358,10 +1348,6 @@ static int vga_arb_release(struct inode *inode, struct file *file) return 0; }

-static void vga_arb_device_card_gone(struct pci_dev *pdev) -{ -} - /* * callback any registered clients to let them know we have a * change in VGA cards

Use the vga_default_device() interface consistently instead of directly testing vga_default. No functional change intended.

[bhelgaas: split to separate patch and extended] Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/pci/vgaarb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index 1f8fb37be5fa..a6a5864ff538 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -173,7 +173,7 @@ int vga_remove_vgacon(struct pci_dev *pdev) { int ret = 0;

- if (pdev != vga_default) + if (pdev != vga_default_device()) return 0; vgaarb_info(&pdev->dev, "deactivate vga console\n");

@@ -707,7 +707,7 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) /* Deal with VGA default device. Use first enabled one * by default if arch doesn't have it's own hook */ - if (vga_default == NULL && + if (!vga_default_device() && ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { vgaarb_info(&pdev->dev, "setting as boot VGA device\n"); vga_set_default_device(pdev); @@ -744,7 +744,7 @@ static bool vga_arbiter_del_pci_device(struct pci_dev *pdev) goto bail; }

- if (vga_default == pdev) + if (vga_default_device() == pdev) vga_set_default_device(NULL);

if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM))

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.

[bhelgaas: commit log, split another piece to separate patch, fix list_empty() issue] Link: https://lore.kernel.org/r/20210705100503.1120643-1-chenhuacai@loongson.cn 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 4cecb599f5ed..dd07b1c3205f 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -609,8 +609,10 @@ 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; @@ -649,6 +651,11 @@ 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"); }

/* @@ -1527,7 +1534,6 @@ 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) @@ -1543,15 +1549,6 @@ 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"); - } - vga_arb_select_default_device();

pr_info("loaded\n");

Current default VGA device selection fails in some cases:

- On BMC system, the AST2500 bridge [1a03:1150] does not implement PCI_BRIDGE_CTL_VGA [1]. This is perfectly legal but means the legacy VGA resources won't reach downstream devices unless they're included in the usual bridge windows.

- vga_arb_select_default_device() will set a device below such a bridge as the default VGA device as long as it has PCI_COMMAND_IO and PCI_COMMAND_MEMORY enabled.

- vga_arbiter_add_pci_device() is called for every VGA device, either at boot-time or at hot-add time, and it will also set the device as the default VGA device, but ONLY if all bridges leading to it implement PCI_BRIDGE_CTL_VGA.

- This difference between vga_arb_select_default_device() and vga_arbiter_add_pci_device() means that a device below an AST2500 or similar bridge can only be set as the default if it is enumerated before vga_arb_device_init().

- On ACPI-based systems, PCI devices are enumerated by acpi_init(), which runs before vga_arb_device_init().

- On non-ACPI systems, like on MIPS system, they are enumerated by pcibios_init(), which typically runs *after* vga_arb_device_init().

So I made vga_arb_update_default_device() to replace the current vga_ arb_select_default_device(), which will be call from vga_arbiter_add_ pci_device(), set the default device even if it does not own the VGA resources because an upstream bridge doesn't implement PCI_BRIDGE_CTL_ VGA. And the default VGA device is updated if a better one is found (device with legacy resources enabled is better, device owns the firmware framebuffer is even better).

This patch is the second step: 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 ee7caee08b1b..0b059a2fc749 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -1507,92 +1507,6 @@ 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; @@ -1612,9 +1526,6 @@ static int __init vga_arb_device_init(void) PCI_ANY_ID, pdev)) != NULL) vga_arbiter_add_pci_device(pdev);

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