From 4e4e7dc55af5aa62497ac060e3cfd143bd4b4db3 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 3 Jul 2014 09:59:51 -0600 Subject: vgaarb: We can own non-decoded resources MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The VGA arbiter does not allow devices to "own" resources that it doesn't "decode". However, it does allow devices to "lock" resources that it doesn't decode. This gets us into trouble because locking the resource goes through the same bridge routing updates regardless of whether we decode the resource. This means that when a non-decoded resource is released, the bridge is left with VGA routing enabled and locking a different device won't clear it. This happens in the following scenario: VGA device 01:00.0 (VGA1) is owned by the radeon driver, which registers a set_vga_decode function which releases legacy VGA decodes. VGA device 02:00.0 (VGA2) is any VGA device. VGA1 user locks VGA resources triggering first_use callback of set_vga_decoded, clearing "decode" and "owns" of legacy resources on VGA1. VGA1 user unlocks VGA resources. VGA2 user locks VGA resources, which skips VGA1 as conflicting as it does not "own" legacy resources, although VGA routing is still enabled for the VGA1 bridge. VGA routing is enabled on VGA2 bridge. VGA2 may or may not receive VGA transactions depending on the bus priority of VGA1 vs VGA2 bridge. To resolve this, we need to allow devices to "own" resources that they do not "decode". This way we can track bus ownership of VGA. When a device decodes VGA, it only means that we must update the command bits in cases where the conflicting device is on the same bus. Signed-off-by: Alex Williamson Cc: Ville Syrjälä Cc: Daniel Vetter Cc: Dave Airlie Signed-off-by: Dave Airlie --- drivers/gpu/vga/vgaarb.c | 40 ++++++++++++++++++++++------------------ 1 file changed, 22 insertions(+), 18 deletions(-) (limited to 'drivers/gpu/vga/vgaarb.c') diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index af0259708358..d2077f040f3e 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -237,12 +237,10 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev, if (conflict->locks & lwants) return conflict; - /* Ok, now check if he owns the resource we want. We don't need - * to check "decodes" since it should be impossible to own - * own legacy resources you don't decode unless I have a bug - * in this code... + /* Ok, now check if it owns the resource we want. We can + * lock resources that are not decoded, therefore a device + * can own resources it doesn't decode. */ - WARN_ON(conflict->owns & ~conflict->decodes); match = lwants & conflict->owns; if (!match) continue; @@ -254,13 +252,19 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev, flags = 0; pci_bits = 0; + /* If we can't control legacy resources via the bridge, we + * also need to disable normal decoding. + */ if (!conflict->bridge_has_one_vga) { - vga_irq_set_state(conflict, false); - flags |= PCI_VGA_STATE_CHANGE_DECODES; - if (match & (VGA_RSRC_LEGACY_MEM|VGA_RSRC_NORMAL_MEM)) + if ((match & conflict->decodes) & VGA_RSRC_LEGACY_MEM) pci_bits |= PCI_COMMAND_MEMORY; - if (match & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO)) + if ((match & conflict->decodes) & VGA_RSRC_LEGACY_IO) pci_bits |= PCI_COMMAND_IO; + + if (pci_bits) { + vga_irq_set_state(conflict, false); + flags |= PCI_VGA_STATE_CHANGE_DECODES; + } } if (change_bridge) @@ -268,18 +272,19 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev, pci_set_vga_state(conflict->pdev, false, pci_bits, flags); conflict->owns &= ~match; - /* If he also owned non-legacy, that is no longer the case */ - if (match & VGA_RSRC_LEGACY_MEM) + + /* If we disabled normal decoding, reflect it in owns */ + if (pci_bits & PCI_COMMAND_MEMORY) conflict->owns &= ~VGA_RSRC_NORMAL_MEM; - if (match & VGA_RSRC_LEGACY_IO) + if (pci_bits & PCI_COMMAND_IO) conflict->owns &= ~VGA_RSRC_NORMAL_IO; } enable_them: /* ok dude, we got it, everybody conflicting has been disabled, let's - * enable us. Make sure we don't mark a bit in "owns" that we don't - * also have in "decodes". We can lock resources we don't decode but - * not own them. + * enable us. Mark any bits in "owns" regardless of whether we + * decoded them. We can lock resources we don't decode, therefore + * we must track them via "owns". */ flags = 0; pci_bits = 0; @@ -291,7 +296,7 @@ enable_them: if (wants & (VGA_RSRC_LEGACY_IO|VGA_RSRC_NORMAL_IO)) pci_bits |= PCI_COMMAND_IO; } - if (!!(wants & VGA_RSRC_LEGACY_MASK)) + if (wants & VGA_RSRC_LEGACY_MASK) flags |= PCI_VGA_STATE_CHANGE_BRIDGE; pci_set_vga_state(vgadev->pdev, true, pci_bits, flags); @@ -299,7 +304,7 @@ enable_them: if (!vgadev->bridge_has_one_vga) { vga_irq_set_state(vgadev, true); } - vgadev->owns |= (wants & vgadev->decodes); + vgadev->owns |= wants; lock_them: vgadev->locks |= (rsrc & VGA_RSRC_LEGACY_MASK); if (rsrc & VGA_RSRC_LEGACY_IO) @@ -649,7 +654,6 @@ static inline void vga_update_device_decodes(struct vga_device *vgadev, old_decodes = vgadev->decodes; decodes_removed = ~new_decodes & old_decodes; decodes_unlocked = vgadev->locks & decodes_removed; - vgadev->owns &= ~decodes_removed; vgadev->decodes = new_decodes; pr_info("vgaarb: device changed decodes: PCI:%s,olddecodes=%s,decodes=%s:owns=%s\n", -- cgit v1.2.3 From 86fd887b7fe350819dae5b55e7fef05b511c8656 Mon Sep 17 00:00:00 2001 From: Bruno Prémont Date: Sun, 24 Aug 2014 23:09:53 +0200 Subject: vgaarb: Don't default exclusively to first video device with mem+io MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 20cde694027e ("x86, ia64: Move EFI_FB vga_default_device() initialization to pci_vga_fixup()") moved boot video device detection from efifb to x86 and ia64 pci/fixup.c. For dual-GPU Apple computers above change represents a regression as code in efifb did forcefully override vga_default_device while the merge did not (vgaarb happens prior to PCI fixup). To improve on initial device selection by vgaarb (it cannot know if PCI device not behind bridges see/decode legacy VGA I/O or not), move the screen_info based check from pci_video_fixup() to vgaarb's init function and use it to refine/override decision taken while adding the individual PCI VGA devices. This way PCI fixup has no reason to adjust vga_default_device anymore but can depend on its value for flagging shadowed VBIOS. This has the nice benefit of removing duplicated code but does introduce a #if defined() block in vgaarb. Not all architectures have screen_info and would cause compile to fail without it. Link: https://bugzilla.kernel.org/show_bug.cgi?id=84461 Reported-and-Tested-By: Andreas Noever Signed-off-by: Bruno Prémont Signed-off-by: Bjorn Helgaas CC: Matthew Garrett CC: stable@vger.kernel.org # v3.5+ --- arch/ia64/pci/fixup.c | 24 +----------------------- arch/x86/pci/fixup.c | 24 +----------------------- drivers/gpu/vga/vgaarb.c | 38 +++++++++++++++++++++++++++++++++++++- 3 files changed, 39 insertions(+), 47 deletions(-) (limited to 'drivers/gpu/vga/vgaarb.c') diff --git a/arch/ia64/pci/fixup.c b/arch/ia64/pci/fixup.c index ec73b2cf912a..fc505d58f078 100644 --- a/arch/ia64/pci/fixup.c +++ b/arch/ia64/pci/fixup.c @@ -38,27 +38,6 @@ static void pci_fixup_video(struct pci_dev *pdev) return; /* Maybe, this machine supports legacy memory map. */ - if (!vga_default_device()) { - resource_size_t start, end; - int i; - - /* Does firmware framebuffer belong to us? */ - for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { - if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM)) - continue; - - start = pci_resource_start(pdev, i); - end = pci_resource_end(pdev, i); - - if (!start || !end) - continue; - - if (screen_info.lfb_base >= start && - (screen_info.lfb_base + screen_info.lfb_size) < end) - vga_set_default_device(pdev); - } - } - /* Is VGA routed to us? */ bus = pdev->bus; while (bus) { @@ -83,8 +62,7 @@ static void pci_fixup_video(struct pci_dev *pdev) pci_read_config_word(pdev, PCI_COMMAND, &config); if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW; - dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n"); - vga_set_default_device(pdev); + dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n"); } } } diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c index c61ea57d1ba1..9a2b7101ae8a 100644 --- a/arch/x86/pci/fixup.c +++ b/arch/x86/pci/fixup.c @@ -326,27 +326,6 @@ static void pci_fixup_video(struct pci_dev *pdev) struct pci_bus *bus; u16 config; - if (!vga_default_device()) { - resource_size_t start, end; - int i; - - /* Does firmware framebuffer belong to us? */ - for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { - if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM)) - continue; - - start = pci_resource_start(pdev, i); - end = pci_resource_end(pdev, i); - - if (!start || !end) - continue; - - if (screen_info.lfb_base >= start && - (screen_info.lfb_base + screen_info.lfb_size) < end) - vga_set_default_device(pdev); - } - } - /* Is VGA routed to us? */ bus = pdev->bus; while (bus) { @@ -371,8 +350,7 @@ static void pci_fixup_video(struct pci_dev *pdev) pci_read_config_word(pdev, PCI_COMMAND, &config); if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW; - dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n"); - vga_set_default_device(pdev); + dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n"); } } } diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index d2077f040f3e..24ac52e6cd41 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -41,6 +41,7 @@ #include #include #include +#include #include @@ -585,8 +586,11 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) */ #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE if (vga_default == NULL && - ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) + ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { + pr_info("vgaarb: setting as boot device: PCI:%s\n", + pci_name(pdev)); vga_set_default_device(pdev); + } #endif vga_arbiter_check_bridge_sharing(vgadev); @@ -1320,6 +1324,38 @@ static int __init vga_arb_device_init(void) pr_info("vgaarb: loaded\n"); list_for_each_entry(vgadev, &vga_list, list) { +#if defined(CONFIG_X86) || defined(CONFIG_IA64) + /* Override I/O based detection done by vga_arbiter_add_pci_device() + * 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. + */ + resource_size_t start, end; + int i; + + /* Does firmware framebuffer belong to us? */ + for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { + if (!(pci_resource_flags(vgadev->pdev, i) & IORESOURCE_MEM)) + continue; + + start = pci_resource_start(vgadev->pdev, i); + end = pci_resource_end(vgadev->pdev, i); + + if (!start || !end) + continue; + + if (screen_info.lfb_base < start || + (screen_info.lfb_base + screen_info.lfb_size) >= end) + continue; + if (!vga_default_device()) + pr_info("vgaarb: setting as boot device: PCI:%s\n", + pci_name(vgadev->pdev)); + else if (vgadev->pdev != vga_default_device()) + pr_info("vgaarb: overriding boot device: PCI:%s\n", + pci_name(vgadev->pdev)); + vga_set_default_device(vgadev->pdev); + } +#endif if (vgadev->bridge_has_one_vga) pr_info("vgaarb: bridge control possible %s\n", pci_name(vgadev->pdev)); else -- cgit v1.2.3 From ce6eacb07e287c0c3c8b5c316a9a7f9cecf69e95 Mon Sep 17 00:00:00 2001 From: Bruno Prémont Date: Sun, 24 Aug 2014 23:13:15 +0200 Subject: vgaarb: Drop obsolete #ifndef MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 20cde694027e ("x86, ia64: Move EFI_FB vga_default_device() initialization to pci_vga_fixup()") moved boot video device detection from efifb to x86 and ia64 pci/fixup.c. Remove the left-over #ifndef check that will always match since the corresponding arch-specific define is gone with above patch. Signed-off-by: Bruno Prémont Signed-off-by: Bjorn Helgaas CC: Matthew Garrett --- drivers/gpu/vga/vgaarb.c | 8 -------- include/linux/vgaarb.h | 2 -- 2 files changed, 10 deletions(-) (limited to 'drivers/gpu/vga/vgaarb.c') diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 24ac52e6cd41..77711623b973 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -113,10 +113,8 @@ both: return 1; } -#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE /* this is only used a cookie - it should not be dereferenced */ static struct pci_dev *vga_default; -#endif static void vga_arb_device_card_gone(struct pci_dev *pdev); @@ -132,7 +130,6 @@ static struct vga_device *vgadev_find(struct pci_dev *pdev) } /* Returns the default VGA device (vgacon's babe) */ -#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE struct pci_dev *vga_default_device(void) { return vga_default; @@ -148,7 +145,6 @@ void vga_set_default_device(struct pci_dev *pdev) pci_dev_put(vga_default); vga_default = pci_dev_get(pdev); } -#endif static inline void vga_irq_set_state(struct vga_device *vgadev, bool state) { @@ -584,14 +580,12 @@ 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 */ -#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE if (vga_default == NULL && ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { pr_info("vgaarb: setting as boot device: PCI:%s\n", pci_name(pdev)); vga_set_default_device(pdev); } -#endif vga_arbiter_check_bridge_sharing(vgadev); @@ -625,10 +619,8 @@ static bool vga_arbiter_del_pci_device(struct pci_dev *pdev) goto bail; } -#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE if (vga_default == pdev) vga_set_default_device(NULL); -#endif if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM)) vga_decode_count--; diff --git a/include/linux/vgaarb.h b/include/linux/vgaarb.h index 2c02f3a8d2ba..c37bd4d06739 100644 --- a/include/linux/vgaarb.h +++ b/include/linux/vgaarb.h @@ -182,7 +182,6 @@ extern void vga_put(struct pci_dev *pdev, unsigned int rsrc); * vga_get()... */ -#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE #ifdef CONFIG_VGA_ARB extern struct pci_dev *vga_default_device(void); extern void vga_set_default_device(struct pci_dev *pdev); @@ -190,7 +189,6 @@ extern void vga_set_default_device(struct pci_dev *pdev); static inline struct pci_dev *vga_default_device(void) { return NULL; }; static inline void vga_set_default_device(struct pci_dev *pdev) { }; #endif -#endif /** * vga_conflicts -- cgit v1.2.3