| Message ID | 1445576642-29624-9-git-send-email-matt@masarand.com |
|---|---|
| State | Changes Requested |
| Headers | show |
[+cc Thomas] Hi Matthew, On Fri, Oct 23, 2015 at 06:03:41AM +0100, Matthew Minter wrote: > The x86 architecture boot code currently traverses the PCI buses with > an extra pass in order to initialise the PCI device IRQs at boot, this > patch avoids this pass and defers the IRQ assignment untill device > enable time which also has the benefit that hot-plugged devices are > assigned IRQs without additional code. I think the outline of this patch (doing the IRQ init at device enable-time instead of at boot-time) is good, but I am concerned about two things: 1) pcibios_lookup_irq() contains a for_each_pci_dev() loop that updates dev->irq for all devices with the same pirq value. Previously we ran that loop at boot-time via this path: pci_subsys_init # subsys_initcall x86_init.pci.init_irq # .init_irq = x86_default_pci_init_irq x86_default_pci_init_irq # x86_default_pci_init_irq = pcibios_irq_init pcibios_irq_init x86_init.pci.fixup_irqs # .fixup_irqs = x86_default_pci_fixup_irqs x86_default_pci_fixup_irqs # x86_default_pci_fixup_irqs = pcibios_fixup_irqs pcibios_fixup_irqs for_each_pci_dev pcibios_lookup_irq Now we'll run it later, in this path: pci_enable_device pci_enable_device_flags do_pci_enable_device pci_assign_irq pci_map_irq # bridge->map_irq pcibios_fixup_irq pcibios_lookup_irq for_each_pci_dev(dev2) dev2->irq = irq # <-- potential problem The problem is that dev2 is an unrelated device and may already have a driver bound to it, and we shouldn't change dev->irq after a driver binds to a device. I don't know enough about interrupts and PIRQ to know whether this is really a problem in practice or not. I added Thomas in case he knows. 2) I'm also worried about the fact that we don't do the IRQ init until a driver calls pci_enable_device(). We've been doing some IRQ init in pcibios_alloc_irq() in this path for a long time: pci_subsys_init ... pcibios_fixup_irqs # <-- moved from here ... for_each_pci_dev ... pci_device_probe pcibios_alloc_irq pcibios_enable_irq # pcibios_enable_irq = acpi_pci_irq_enable # (or pirq_enable_irq, x86_of_pci_irq_enable, lguest_enable_irq, etc) acpi_pci_irq_enable __pci_device_probe ... pci_drv->probe # driver .probe routine ... pci_enable_device ... pci_fixup_irq # <-- ... to here I think there are two problems here: 2.1) We changed the order of pcibios_enable_irq() and pci_fixup_irq(). Both update dev->irq, and I doubt it's safe to reverse the order. 2.2) It's conceivable that a driver may use interrupts without ever calling pci_enable_device(). That driver would be broken by this change. I think we could probably fix both of these worries by calling pci_assign_irq() from pci_device_probe() instead of from do_pci_enable_device(). I'm not so sure about the pcibios_lookup_irq() problem. That's a little farther outside my area, so I'll have to look at that some more. I really want to merge this stuff because it's a major cleanup, so I'm going to push on this more myself. I'm just writing this as a heads-up in case anybody else has ideas. Bjorn > Signed-off-by: Matthew Minter <matt@masarand.com> > --- > arch/x86/include/asm/pci_x86.h | 7 +++-- > arch/x86/kernel/x86_init.c | 1 - > arch/x86/pci/irq.c | 70 +++++++++++++++++++++--------------------- > 3 files changed, 39 insertions(+), 39 deletions(-) > > diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h > index fa1195d..16fd8e9 100644 > --- a/arch/x86/include/asm/pci_x86.h > +++ b/arch/x86/include/asm/pci_x86.h > @@ -90,6 +90,7 @@ extern unsigned int pcibios_irq_mask; > > extern raw_spinlock_t pci_config_lock; > > +extern int pci_map_irq(struct pci_dev *dev, u8 slot, u8 pin); > extern int (*pcibios_enable_irq)(struct pci_dev *dev); > extern void (*pcibios_disable_irq)(struct pci_dev *dev); > > @@ -119,7 +120,7 @@ extern int __init pci_acpi_init(void); > extern void __init pcibios_irq_init(void); > extern int __init pcibios_init(void); > extern int pci_legacy_init(void); > -extern void pcibios_fixup_irqs(void); > +extern int pcibios_fixup_irq(struct pci_dev *dev, u8 pin); > > /* pci-mmconfig.c */ > > @@ -200,9 +201,9 @@ static inline void mmio_config_writel(void __iomem *pos, u32 val) > # define x86_default_pci_init pci_legacy_init > # endif > # define x86_default_pci_init_irq pcibios_irq_init > -# define x86_default_pci_fixup_irqs pcibios_fixup_irqs > +# define x86_default_pci_fixup_irq pcibios_fixup_irq > #else > # define x86_default_pci_init NULL > # define x86_default_pci_init_irq NULL > -# define x86_default_pci_fixup_irqs NULL > +# define x86_default_pci_fixup_irq NULL > #endif > diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c > index 3839628..810f1dd 100644 > --- a/arch/x86/kernel/x86_init.c > +++ b/arch/x86/kernel/x86_init.c > @@ -80,7 +80,6 @@ struct x86_init_ops x86_init __initdata = { > .pci = { > .init = x86_default_pci_init, > .init_irq = x86_default_pci_init_irq, > - .fixup_irqs = x86_default_pci_fixup_irqs, > }, > }; > > diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c > index 350e785..15c507b 100644 > --- a/arch/x86/pci/irq.c > +++ b/arch/x86/pci/irq.c > @@ -1021,47 +1021,38 @@ static int pcibios_lookup_irq(struct pci_dev *dev, int assign) > return 1; > } > > -void __init pcibios_fixup_irqs(void) > +int pcibios_fixup_irq(struct pci_dev *dev, u8 pin) > { > - struct pci_dev *dev = NULL; > - u8 pin; > - > + int irq = dev->irq; > DBG(KERN_DEBUG "PCI: IRQ fixup\n"); > - for_each_pci_dev(dev) { > - /* > - * If the BIOS has set an out of range IRQ number, just > - * ignore it. Also keep track of which IRQ's are > - * already in use. > - */ > - if (dev->irq >= 16) { > - dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", dev->irq); > - dev->irq = 0; > - } > - /* > - * If the IRQ is already assigned to a PCI device, > - * ignore its ISA use penalty > - */ > - if (pirq_penalty[dev->irq] >= 100 && > - pirq_penalty[dev->irq] < 100000) > - pirq_penalty[dev->irq] = 0; > - pirq_penalty[dev->irq]++; > + /* > + * If the BIOS has set an out of range IRQ number, just > + * ignore it. Also keep track of which IRQ's are > + * already in use. > + */ > + if (irq >= 16) { > + dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", irq); > + irq = 0; > } > + /* > + * If the IRQ is already assigned to a PCI device, > + * ignore its ISA use penalty > + */ > + if (pirq_penalty[irq] >= 100 && > + pirq_penalty[irq] < 100000) > + pirq_penalty[irq] = 0; > + pirq_penalty[irq]++; > > - if (io_apic_assign_pci_irqs) > - return; > + if (io_apic_assign_pci_irqs || !pin) > + return irq; > > - dev = NULL; > - for_each_pci_dev(dev) { > - pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); > - if (!pin) > - continue; > + /* > + * Still no IRQ? Try to lookup one... > + */ > + if (!irq && pcibios_lookup_irq(dev, 0)) > + irq = dev->irq; > > - /* > - * Still no IRQ? Try to lookup one... > - */ > - if (!dev->irq) > - pcibios_lookup_irq(dev, 0); > - } > + return irq; > } > > /* > @@ -1174,6 +1165,7 @@ int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) > struct pci_sysdata *sd = bridge->bus->sysdata; > ACPI_COMPANION_SET(&bridge->dev, sd->companion); > } > + bridge->map_irq = pci_map_irq; > return 0; > } > > @@ -1201,6 +1193,14 @@ void pcibios_penalize_isa_irq(int irq, int active) > pirq_penalize_isa_irq(irq, active); > } > > +int pci_map_irq(struct pci_dev *dev, u8 slot, u8 pin) > +{ > + dev->irq = pcibios_fixup_irq(dev, pin); > + if (pcibios_enable_irq(dev)) > + return -1; > + return dev->irq; > +} > + > static int pirq_enable_irq(struct pci_dev *dev) > { > u8 pin = 0; > -- > 2.6.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Bjorn, On Wed, Dec 23, 2015 at 05:04:33PM -0600, Bjorn Helgaas wrote: > [+cc Thomas] > > Hi Matthew, > > On Fri, Oct 23, 2015 at 06:03:41AM +0100, Matthew Minter wrote: > > The x86 architecture boot code currently traverses the PCI buses with > > an extra pass in order to initialise the PCI device IRQs at boot, this > > patch avoids this pass and defers the IRQ assignment untill device > > enable time which also has the benefit that hot-plugged devices are > > assigned IRQs without additional code. > > I think the outline of this patch (doing the IRQ init at device > enable-time instead of at boot-time) is good, but I am concerned about > two things: > > 1) pcibios_lookup_irq() contains a for_each_pci_dev() loop that > updates dev->irq for all devices with the same pirq value. Previously > we ran that loop at boot-time via this path: > > pci_subsys_init # subsys_initcall > x86_init.pci.init_irq # .init_irq = x86_default_pci_init_irq > x86_default_pci_init_irq # x86_default_pci_init_irq = pcibios_irq_init > pcibios_irq_init > x86_init.pci.fixup_irqs # .fixup_irqs = x86_default_pci_fixup_irqs > x86_default_pci_fixup_irqs # x86_default_pci_fixup_irqs = pcibios_fixup_irqs > pcibios_fixup_irqs > for_each_pci_dev > pcibios_lookup_irq > > Now we'll run it later, in this path: > > pci_enable_device > pci_enable_device_flags > do_pci_enable_device > pci_assign_irq > pci_map_irq # bridge->map_irq > pcibios_fixup_irq > pcibios_lookup_irq > for_each_pci_dev(dev2) > dev2->irq = irq # <-- potential problem > > The problem is that dev2 is an unrelated device and may already have a > driver bound to it, and we shouldn't change dev->irq after a driver > binds to a device. Yes, this looks wrong. On the other hand, removing pci_fixup_irqs from generic PCI code does not mean that we cannot implement it in x86 using pci_assign_irq() (in arch code) and leave the current behaviour unchanged. True, do_pci_enable_device() (or better pci_device_probe() as you say below) would carry out the fixup unconditionally, but if arch code carries out the fixup before do_pci_enable_device() I *guess* that the one carried out in do_pci_enable_device() would become a nop (the fixup already assigned an IRQ so basically doing it again in do_pci_enable_device() should not change anything. Still, I am not a fan of this solution either). I would avoid holding this patch series back, it is a nice clean-up. > I don't know enough about interrupts and PIRQ to know whether this is > really a problem in practice or not. I added Thomas in case he knows. > > 2) I'm also worried about the fact that we don't do the IRQ init until > a driver calls pci_enable_device(). We've been doing some IRQ init in > pcibios_alloc_irq() in this path for a long time: > > pci_subsys_init > ... > pcibios_fixup_irqs # <-- moved from here ... > for_each_pci_dev > ... > pci_device_probe > pcibios_alloc_irq > pcibios_enable_irq # pcibios_enable_irq = acpi_pci_irq_enable > # (or pirq_enable_irq, x86_of_pci_irq_enable, lguest_enable_irq, etc) > acpi_pci_irq_enable > __pci_device_probe > ... > pci_drv->probe # driver .probe routine > ... > pci_enable_device > ... > pci_fixup_irq # <-- ... to here > > I think there are two problems here: > > 2.1) We changed the order of pcibios_enable_irq() and pci_fixup_irq(). > Both update dev->irq, and I doubt it's safe to reverse the order. > > 2.2) It's conceivable that a driver may use interrupts without ever > calling pci_enable_device(). That driver would be broken by this > change. > > I think we could probably fix both of these worries by calling > pci_assign_irq() from pci_device_probe() instead of from > do_pci_enable_device(). Yes, I think your proposal makes sense (we can even add it to pci_device_add() (?), the pointers in the bridge used to carry out the mapping, set-up in pci_create_root_bus()->pcibios_root_bridge_prepare() are already set-up by the time that function is called). Actually, executing pci_assign_irq() in pci_device_add(), would not it solve the issue above too ? Certainly we would still have an issue with hot-added devices (I have no idea how this works at present on x86). We have to decide if the assignment can be done in generic code or in pcibios_* arches callbacks (to do it on a per-arch basis). > I'm not so sure about the pcibios_lookup_irq() problem. That's a > little farther outside my area, so I'll have to look at that some > more. > > I really want to merge this stuff because it's a major cleanup, so I'm > going to push on this more myself. I'm just writing this as a > heads-up in case anybody else has ideas. +1, I am reviewing the ARM/ARM64 code to check for correctness. Thanks, Lorenzo > > Bjorn > > > Signed-off-by: Matthew Minter <matt@masarand.com> > > --- > > arch/x86/include/asm/pci_x86.h | 7 +++-- > > arch/x86/kernel/x86_init.c | 1 - > > arch/x86/pci/irq.c | 70 +++++++++++++++++++++--------------------- > > 3 files changed, 39 insertions(+), 39 deletions(-) > > > > diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h > > index fa1195d..16fd8e9 100644 > > --- a/arch/x86/include/asm/pci_x86.h > > +++ b/arch/x86/include/asm/pci_x86.h > > @@ -90,6 +90,7 @@ extern unsigned int pcibios_irq_mask; > > > > extern raw_spinlock_t pci_config_lock; > > > > +extern int pci_map_irq(struct pci_dev *dev, u8 slot, u8 pin); > > extern int (*pcibios_enable_irq)(struct pci_dev *dev); > > extern void (*pcibios_disable_irq)(struct pci_dev *dev); > > > > @@ -119,7 +120,7 @@ extern int __init pci_acpi_init(void); > > extern void __init pcibios_irq_init(void); > > extern int __init pcibios_init(void); > > extern int pci_legacy_init(void); > > -extern void pcibios_fixup_irqs(void); > > +extern int pcibios_fixup_irq(struct pci_dev *dev, u8 pin); > > > > /* pci-mmconfig.c */ > > > > @@ -200,9 +201,9 @@ static inline void mmio_config_writel(void __iomem *pos, u32 val) > > # define x86_default_pci_init pci_legacy_init > > # endif > > # define x86_default_pci_init_irq pcibios_irq_init > > -# define x86_default_pci_fixup_irqs pcibios_fixup_irqs > > +# define x86_default_pci_fixup_irq pcibios_fixup_irq > > #else > > # define x86_default_pci_init NULL > > # define x86_default_pci_init_irq NULL > > -# define x86_default_pci_fixup_irqs NULL > > +# define x86_default_pci_fixup_irq NULL > > #endif > > diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c > > index 3839628..810f1dd 100644 > > --- a/arch/x86/kernel/x86_init.c > > +++ b/arch/x86/kernel/x86_init.c > > @@ -80,7 +80,6 @@ struct x86_init_ops x86_init __initdata = { > > .pci = { > > .init = x86_default_pci_init, > > .init_irq = x86_default_pci_init_irq, > > - .fixup_irqs = x86_default_pci_fixup_irqs, > > }, > > }; > > > > diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c > > index 350e785..15c507b 100644 > > --- a/arch/x86/pci/irq.c > > +++ b/arch/x86/pci/irq.c > > @@ -1021,47 +1021,38 @@ static int pcibios_lookup_irq(struct pci_dev *dev, int assign) > > return 1; > > } > > > > -void __init pcibios_fixup_irqs(void) > > +int pcibios_fixup_irq(struct pci_dev *dev, u8 pin) > > { > > - struct pci_dev *dev = NULL; > > - u8 pin; > > - > > + int irq = dev->irq; > > DBG(KERN_DEBUG "PCI: IRQ fixup\n"); > > - for_each_pci_dev(dev) { > > - /* > > - * If the BIOS has set an out of range IRQ number, just > > - * ignore it. Also keep track of which IRQ's are > > - * already in use. > > - */ > > - if (dev->irq >= 16) { > > - dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", dev->irq); > > - dev->irq = 0; > > - } > > - /* > > - * If the IRQ is already assigned to a PCI device, > > - * ignore its ISA use penalty > > - */ > > - if (pirq_penalty[dev->irq] >= 100 && > > - pirq_penalty[dev->irq] < 100000) > > - pirq_penalty[dev->irq] = 0; > > - pirq_penalty[dev->irq]++; > > + /* > > + * If the BIOS has set an out of range IRQ number, just > > + * ignore it. Also keep track of which IRQ's are > > + * already in use. > > + */ > > + if (irq >= 16) { > > + dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", irq); > > + irq = 0; > > } > > + /* > > + * If the IRQ is already assigned to a PCI device, > > + * ignore its ISA use penalty > > + */ > > + if (pirq_penalty[irq] >= 100 && > > + pirq_penalty[irq] < 100000) > > + pirq_penalty[irq] = 0; > > + pirq_penalty[irq]++; > > > > - if (io_apic_assign_pci_irqs) > > - return; > > + if (io_apic_assign_pci_irqs || !pin) > > + return irq; > > > > - dev = NULL; > > - for_each_pci_dev(dev) { > > - pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); > > - if (!pin) > > - continue; > > + /* > > + * Still no IRQ? Try to lookup one... > > + */ > > + if (!irq && pcibios_lookup_irq(dev, 0)) > > + irq = dev->irq; > > > > - /* > > - * Still no IRQ? Try to lookup one... > > - */ > > - if (!dev->irq) > > - pcibios_lookup_irq(dev, 0); > > - } > > + return irq; > > } > > > > /* > > @@ -1174,6 +1165,7 @@ int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) > > struct pci_sysdata *sd = bridge->bus->sysdata; > > ACPI_COMPANION_SET(&bridge->dev, sd->companion); > > } > > + bridge->map_irq = pci_map_irq; > > return 0; > > } > > > > @@ -1201,6 +1193,14 @@ void pcibios_penalize_isa_irq(int irq, int active) > > pirq_penalize_isa_irq(irq, active); > > } > > > > +int pci_map_irq(struct pci_dev *dev, u8 slot, u8 pin) > > +{ > > + dev->irq = pcibios_fixup_irq(dev, pin); > > + if (pcibios_enable_irq(dev)) > > + return -1; > > + return dev->irq; > > +} > > + > > static int pirq_enable_irq(struct pci_dev *dev) > > { > > u8 pin = 0; > > -- > > 2.6.2 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h index fa1195d..16fd8e9 100644 --- a/arch/x86/include/asm/pci_x86.h +++ b/arch/x86/include/asm/pci_x86.h @@ -90,6 +90,7 @@ extern unsigned int pcibios_irq_mask; extern raw_spinlock_t pci_config_lock; +extern int pci_map_irq(struct pci_dev *dev, u8 slot, u8 pin); extern int (*pcibios_enable_irq)(struct pci_dev *dev); extern void (*pcibios_disable_irq)(struct pci_dev *dev); @@ -119,7 +120,7 @@ extern int __init pci_acpi_init(void); extern void __init pcibios_irq_init(void); extern int __init pcibios_init(void); extern int pci_legacy_init(void); -extern void pcibios_fixup_irqs(void); +extern int pcibios_fixup_irq(struct pci_dev *dev, u8 pin); /* pci-mmconfig.c */ @@ -200,9 +201,9 @@ static inline void mmio_config_writel(void __iomem *pos, u32 val) # define x86_default_pci_init pci_legacy_init # endif # define x86_default_pci_init_irq pcibios_irq_init -# define x86_default_pci_fixup_irqs pcibios_fixup_irqs +# define x86_default_pci_fixup_irq pcibios_fixup_irq #else # define x86_default_pci_init NULL # define x86_default_pci_init_irq NULL -# define x86_default_pci_fixup_irqs NULL +# define x86_default_pci_fixup_irq NULL #endif diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c index 3839628..810f1dd 100644 --- a/arch/x86/kernel/x86_init.c +++ b/arch/x86/kernel/x86_init.c @@ -80,7 +80,6 @@ struct x86_init_ops x86_init __initdata = { .pci = { .init = x86_default_pci_init, .init_irq = x86_default_pci_init_irq, - .fixup_irqs = x86_default_pci_fixup_irqs, }, }; diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c index 350e785..15c507b 100644 --- a/arch/x86/pci/irq.c +++ b/arch/x86/pci/irq.c @@ -1021,47 +1021,38 @@ static int pcibios_lookup_irq(struct pci_dev *dev, int assign) return 1; } -void __init pcibios_fixup_irqs(void) +int pcibios_fixup_irq(struct pci_dev *dev, u8 pin) { - struct pci_dev *dev = NULL; - u8 pin; - + int irq = dev->irq; DBG(KERN_DEBUG "PCI: IRQ fixup\n"); - for_each_pci_dev(dev) { - /* - * If the BIOS has set an out of range IRQ number, just - * ignore it. Also keep track of which IRQ's are - * already in use. - */ - if (dev->irq >= 16) { - dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", dev->irq); - dev->irq = 0; - } - /* - * If the IRQ is already assigned to a PCI device, - * ignore its ISA use penalty - */ - if (pirq_penalty[dev->irq] >= 100 && - pirq_penalty[dev->irq] < 100000) - pirq_penalty[dev->irq] = 0; - pirq_penalty[dev->irq]++; + /* + * If the BIOS has set an out of range IRQ number, just + * ignore it. Also keep track of which IRQ's are + * already in use. + */ + if (irq >= 16) { + dev_dbg(&dev->dev, "ignoring bogus IRQ %d\n", irq); + irq = 0; } + /* + * If the IRQ is already assigned to a PCI device, + * ignore its ISA use penalty + */ + if (pirq_penalty[irq] >= 100 && + pirq_penalty[irq] < 100000) + pirq_penalty[irq] = 0; + pirq_penalty[irq]++; - if (io_apic_assign_pci_irqs) - return; + if (io_apic_assign_pci_irqs || !pin) + return irq; - dev = NULL; - for_each_pci_dev(dev) { - pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); - if (!pin) - continue; + /* + * Still no IRQ? Try to lookup one... + */ + if (!irq && pcibios_lookup_irq(dev, 0)) + irq = dev->irq; - /* - * Still no IRQ? Try to lookup one... - */ - if (!dev->irq) - pcibios_lookup_irq(dev, 0); - } + return irq; } /* @@ -1174,6 +1165,7 @@ int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) struct pci_sysdata *sd = bridge->bus->sysdata; ACPI_COMPANION_SET(&bridge->dev, sd->companion); } + bridge->map_irq = pci_map_irq; return 0; } @@ -1201,6 +1193,14 @@ void pcibios_penalize_isa_irq(int irq, int active) pirq_penalize_isa_irq(irq, active); } +int pci_map_irq(struct pci_dev *dev, u8 slot, u8 pin) +{ + dev->irq = pcibios_fixup_irq(dev, pin); + if (pcibios_enable_irq(dev)) + return -1; + return dev->irq; +} + static int pirq_enable_irq(struct pci_dev *dev) { u8 pin = 0;
The x86 architecture boot code currently traverses the PCI buses with an extra pass in order to initialise the PCI device IRQs at boot, this patch avoids this pass and defers the IRQ assignment untill device enable time which also has the benefit that hot-plugged devices are assigned IRQs without additional code. Signed-off-by: Matthew Minter <matt@masarand.com> --- arch/x86/include/asm/pci_x86.h | 7 +++-- arch/x86/kernel/x86_init.c | 1 - arch/x86/pci/irq.c | 70 +++++++++++++++++++++--------------------- 3 files changed, 39 insertions(+), 39 deletions(-)