My original work is at [1].
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).
Bjorn do some rework and extension in V2. It moves the VGA arbiter to the PCI subsystem, fixes a few nits, and breaks a few pieces to make the main patch a little smaller.
V3 rewrite the commit log of the last patch (which is also summarized by Bjorn).
V4 split the last patch to two steps.
V5 split Patch-9 again and sort the patches.
V5 split Patch-5 again and sort the patches again.
All comments welcome!
[1] https://lore.kernel.org/dri-devel/20210705100503.1120643-1-chenhuacai@loongs...
Huacai Chen (8): PCI/VGA: Prefer vga_default_device() PCI/VGA: Move vga_arb_integrated_gpu() earlier in file PCI/VGA: Split out vga_arb_update_default_device() PCI/VGA: Prefer VGA device with legacy I/O enabled PCI/VGA: Prefer VGA device belongs to integrated GPU PCI/VGA: Prefer VGA device owns the firmware framebuffer PCI/VGA: Remove vga_arb_select_default_device() PCI/VGA: Log bridge control messages when adding devices
Bjorn Helgaas (4): PCI/VGA: Remove empty vga_arb_device_card_gone() PCI/VGA: Use unsigned format string to print lock counts PCI/VGA: Replace full MIT license text with SPDX identifier PCI/VGA: Move vgaarb to drivers/pci
Signed-off-by: Huacai Chen chenhuacai@loongson.cn 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 | 269 ++++++++++++------------------ 5 files changed, 126 insertions(+), 183 deletions(-) rename drivers/{gpu/vga => pci}/vgaarb.c (90%) -- 2.27.0
Use the vga_default_device() interface consistently instead of directly testing vga_default. No functional change intended.
Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/gpu/vga/vgaarb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 569930552957..6a5169d8578f 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -193,7 +193,7 @@ 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");
@@ -695,7 +695,7 @@ 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); @@ -732,7 +732,7 @@ 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))
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/gpu/vga/vgaarb.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 6a5169d8578f..29e725ebaa43 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/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 first step of the rework: If there's no default VGA device, and we find a VGA device that owns the legacy VGA resources, we make that device the default. Split this logic out from vga_arbiter_add_ pci_device() into a new function, vga_arb_update_default_device().
Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/gpu/vga/vgaarb.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 29e725ebaa43..f8f95244d499 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -579,6 +579,21 @@ static bool vga_arb_integrated_gpu(struct device *dev) } #endif
+static void vga_arb_update_default_device(struct vga_device *vgadev) +{ + struct pci_dev *pdev = vgadev->pdev; + + /* + * 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"); + vga_set_default_device(pdev); + } +} + /* * 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 @@ -706,15 +721,7 @@ 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_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); - } - + vga_arb_update_default_device(vgadev); vga_arbiter_check_bridge_sharing(vgadev);
/* Add to the list */
This patch is the second step of the rework: A VGA device with legacy I/O resources enabled is more preferred than those not enabled.
Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/gpu/vga/vgaarb.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index f8f95244d499..1ffc3decc9cb 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -582,14 +582,27 @@ 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); } }
This patch is the third step of the rework: A VGA device belongs to integrated GPU is more preferred than those not belong to.
Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/gpu/vga/vgaarb.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 1ffc3decc9cb..1daf2a011f83 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -605,6 +605,11 @@ static void vga_arb_update_default_device(struct vga_device *vgadev) vgaarb_info(dev, "overriding boot VGA device\n"); vga_set_default_device(pdev); } + + if (vga_arb_integrated_gpu(dev) && vgadev->pdev != vga_default_device()) { + vgaarb_info(dev, "overriding boot VGA device\n"); + vga_set_default_device(pdev); + } }
/*
This patch is the fourth step of the rework: On X86 and IA64 platform, update default VGA device if the new found device owns the firmware framebuffer because it is the most preferred.
Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Bjorn Helgaas bhelgaas@google.com --- drivers/gpu/vga/vgaarb.c | 45 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 1daf2a011f83..042e1f1371fc 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -584,6 +584,14 @@ 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 defined(CONFIG_X86) || defined(CONFIG_IA64) + int i; + unsigned long flags; + u64 base = screen_info.lfb_base; + u64 size = screen_info.lfb_size; + u64 limit; + resource_size_t start, end; +#endif
/* * If we don't have a default VGA device yet, and this device owns @@ -610,6 +618,43 @@ static void vga_arb_update_default_device(struct vga_device *vgadev) vgaarb_info(dev, "overriding boot VGA device\n"); vga_set_default_device(pdev); } + +#if defined(CONFIG_X86) || defined(CONFIG_IA64) + if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) + base |= (u64)screen_info.ext_lfb_base << 32; + + 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(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 (vgadev->pdev != vga_default_device()) + vgaarb_info(dev, "overriding boot device\n"); + vga_set_default_device(vgadev->pdev); + } +#endif }
/*
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/gpu/vga/vgaarb.c | 89 ---------------------------------------- 1 file changed, 89 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 042e1f1371fc..05174fd7e7ef 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/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);
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 Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- drivers/gpu/vga/vgaarb.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 05174fd7e7ef..7cd989c5d03b 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -122,8 +122,6 @@ 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) { @@ -825,10 +823,6 @@ 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); @@ -1078,9 +1072,7 @@ 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 */ @@ -1097,8 +1089,6 @@ 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; @@ -1442,10 +1432,6 @@ 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
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/gpu/vga/vgaarb.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 7cd989c5d03b..7f52db439c11 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/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
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.
Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- drivers/gpu/vga/vgaarb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 7f52db439c11..8d07279cb49d 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -1103,7 +1103,7 @@ 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),
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 Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- drivers/gpu/vga/vgaarb.c | 23 +---------------------- 1 file changed, 1 insertion(+), 22 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 8d07279cb49d..ee9e4dab6b35 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/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
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 Signed-off-by: Huacai Chen chenhuacai@loongson.cn --- 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
Hi, Bjorn,
On Thu, Sep 16, 2021 at 4:39 PM Huacai Chen chenhuacai@loongson.cn wrote:
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.
I found a new problem, after moving vgaarb.c to drivers/pci, misc_register() in vga_arb_device_init() fails with -ENODEV, the root cause is still initcall order. Both vga_arb_device_init() and misc_init() are subsys_initcall(), and drivers/Makefile looks like this: obj-y += pci/ ...... obj-y += char/ ...... obj-y += gpu/
So vga_arb_device_init() in the pci directory runs before misc_init() in the char directory, and misc_register() fails.
There are two methods to resolve: 1, keep vgaarb.c in drivers/gpu; 2, make vga_arb_device_init() to be subsys_initcall_sync(). I prefer the first one, but it seems you don't like both of them.
Huacai
Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Huacai Chen chenhuacai@loongson.cn
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 EXPERTdefault ydepends on (PCI && !S390)helpSome "legacy" VGA devices implemented on PCI typically have the samehard-decoded addresses as they did on ISA. When multiple PCI devicesare accessed at same time they need some kind of coordination. Pleasesee Documentation/gpu/vgaarbiter.rst for more details. Select this toenable VGA arbiter.-config VGA_ARB_MAX_GPUS
int "Maximum number of GPUs"default 16depends on VGA_ARBhelpReserves space in the kernel to maintain resource locking formultiple 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 EXPERTdefault ydepends on (PCI && !S390)helpSome "legacy" VGA devices implemented on PCI typically have the samehard-decoded addresses as they did on ISA. When multiple PCI devicesare accessed at same time they need some kind of coordination. Pleasesee Documentation/gpu/vgaarbiter.rst for more details. Select this toenable VGA arbiter.+config VGA_ARB_MAX_GPUS
int "Maximum number of GPUs"default 16depends on VGA_ARBhelpReserves space in the kernel to maintain resource locking formultiple 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 -- 2.27.0
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