diff options
| -rw-r--r-- | Documentation/gpu/vgaarbiter.rst | 2 | ||||
| -rw-r--r-- | drivers/gpu/vga/Kconfig | 19 | ||||
| -rw-r--r-- | drivers/gpu/vga/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pci/Kconfig | 19 | ||||
| -rw-r--r-- | drivers/pci/Makefile | 1 | ||||
| -rw-r--r-- | drivers/pci/vgaarb.c (renamed from drivers/gpu/vga/vgaarb.c) | 313 |
6 files changed, 176 insertions, 179 deletions
diff --git a/Documentation/gpu/vgaarbiter.rst b/Documentation/gpu/vgaarbiter.rst index 339ed5fecd2e..bde3c0afb059 100644 --- a/Documentation/gpu/vgaarbiter.rst +++ b/Documentation/gpu/vgaarbiter.rst @@ -100,7 +100,7 @@ In-kernel interface .. kernel-doc:: include/linux/vgaarb.h :internal: -.. kernel-doc:: drivers/gpu/vga/vgaarb.c +.. kernel-doc:: drivers/pci/vgaarb.c :export: libpciaccess 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 d98fafdd0f99..133c73207782 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 37be95adf169..0da6b1ebc694 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -30,6 +30,7 @@ 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 index 569930552957..f80b6ec88dc3 100644 --- a/drivers/gpu/vga/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 @@ -72,6 +51,7 @@ 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); }; @@ -122,8 +102,6 @@ both: /* 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) { @@ -565,6 +543,144 @@ bail: } EXPORT_SYMBOL(vga_put); +static bool vga_is_firmware_default(struct pci_dev *pdev) +{ +#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; + + /* Select the device owning the boot framebuffer if there is one */ + + if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) + base |= (u64)screen_info.ext_lfb_base << 32; + + limit = base + size; + + /* Does firmware framebuffer belong to us? */ + for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { + flags = pci_resource_flags(pdev, i); + + if ((flags & IORESOURCE_MEM) == 0) + continue; + + start = pci_resource_start(pdev, i); + end = pci_resource_end(pdev, i); + + if (!start || !end) + continue; + + if (base < start || limit >= end) + continue; + + return true; + } +#endif + return false; +} + +static bool vga_arb_integrated_gpu(struct device *dev) +{ +#if defined(CONFIG_ACPI) + struct acpi_device *adev = ACPI_COMPANION(dev); + + return adev && !strcmp(acpi_device_hid(adev), ACPI_VIDEO_HID); +#else + return false; +#endif +} + +/* + * Return true if vgadev is a better default VGA device than the best one + * we've seen so far. + */ +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; + u16 cmd, boot_cmd; + + /* + * We select the default VGA device in this order: + * Firmware framebuffer (see vga_arb_select_default_device()) + * Legacy VGA device (owns VGA_RSRC_LEGACY_MASK) + * Non-legacy integrated device (see vga_arb_select_default_device()) + * Non-legacy discrete device (see vga_arb_select_default_device()) + * 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 + * resources ([mem 0xa0000-0xbffff], [io 0x3b0-0x3bb], etc) are + * routed to it. + * + * We use the first one we find, so if we've already found one, + * vgadev is no better. + */ + if (boot_vga && + (boot_vga->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK) + return false; + + if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK) + return true; + + /* + * If we haven't found a legacy VGA device, accept a non-legacy + * device. It may have either IO or MEM enabled, and bridges may + * not have PCI_BRIDGE_CTL_VGA enabled, so it may not be able to + * use legacy VGA resources. Prefer an integrated GPU over others. + */ + pci_read_config_word(pdev, PCI_COMMAND, &cmd); + if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { + + /* + * An integrated GPU overrides a previous non-legacy + * device. We expect only a single integrated GPU, but if + * there are more, we use the *last* because that was the + * previous behavior. + */ + if (vga_arb_integrated_gpu(&pdev->dev)) + return true; + + /* + * We prefer the first non-legacy discrete device we find. + * If we already found one, vgadev is no better. + */ + if (boot_vga) { + pci_read_config_word(boot_vga->pdev, PCI_COMMAND, + &boot_cmd); + if (boot_cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) + return false; + } + return true; + } + + /* + * vgadev has neither IO nor MEM enabled. If we haven't found any + * other VGA devices, it is the best candidate so far. + */ + if (!boot_vga) + return true; + + return false; +} + /* * 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 @@ -582,8 +698,10 @@ 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; @@ -622,6 +740,11 @@ 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"); } /* @@ -692,12 +815,10 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) bus = bus->parent; } - /* Deal with VGA default device. Use first enabled one - * by default if arch doesn't have it's own hook - */ - if (vga_default == NULL && - ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { - vgaarb_info(&pdev->dev, "setting as boot VGA device\n"); + if (vga_is_boot_device(vgadev)) { + vgaarb_info(&pdev->dev, "setting as boot VGA device%s\n", + vga_default_device() ? + " (overriding previous)" : ""); vga_set_default_device(pdev); } @@ -741,10 +862,6 @@ 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 +1111,7 @@ 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 +1128,6 @@ 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; @@ -1022,7 +1135,7 @@ static ssize_t vga_arb_read(struct file *file, char __user *buf, /* Fill the buffer with infos */ len = snprintf(lbuf, 1024, - "count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%d:%d)\n", + "count:%d,PCI:%s,decodes=%s,owns=%s,locks=%s(%u:%u)\n", vga_decode_count, pci_name(pdev), vga_iostate_to_str(vgadev->decodes), vga_iostate_to_str(vgadev->owns), @@ -1358,10 +1471,6 @@ 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 @@ -1430,111 +1539,10 @@ 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; - 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; struct pci_dev *pdev; - struct vga_device *vgadev; rc = misc_register(&vga_arb_device); if (rc < 0) @@ -1550,18 +1558,7 @@ 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"); return rc; } -subsys_initcall(vga_arb_device_init); +subsys_initcall_sync(vga_arb_device_init); |