From 746cddd37d48a166f170165a0df4bd50fde1ea60 Mon Sep 17 00:00:00 2001 From: Weidong Han Date: Fri, 10 Apr 2009 17:17:17 +0800 Subject: x86, intr-remap: fix eoi for interrupt remapping without x2apic To simplify level irq migration in the presence of interrupt-remapping, Suresh used a virtual vector (io-apic pin number) to eliminate io-apic RTE modification. Level triggered interrupt will appear as an edge to the local apic cpu but still as level to the IO-APIC. So in addition to do the local apic EOI, it still needs to do IO-APIC directed EOI to clear the remote IRR bit in the IO-APIC RTE. Pls refer to Suresh's patch for more details (commit 0280f7c416c652a2fd95d166f52b199ae61122c0). Now interrupt remapping is decoupled from x2apic, it also needs to do the directed EOI for apic. Otherwise, apic interrupts won't work correctly. Signed-off-by: Weidong Han Cc: iommu@lists.linux-foundation.org Cc: Weidong Han Cc: suresh.b.siddha@intel.com Cc: dwmw2@infradead.org Cc: allen.m.kay@intel.com LKML-Reference: <1239355037-22856-1-git-send-email-weidong.han@intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/io_apic.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel/apic/io_apic.c') diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 767fe7e46d6..a2789e42e16 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -2524,7 +2524,6 @@ static void irq_complete_move(struct irq_desc **descp) static inline void irq_complete_move(struct irq_desc **descp) {} #endif -#ifdef CONFIG_X86_X2APIC static void __eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg) { int apic, pin; @@ -2558,6 +2557,7 @@ eoi_ioapic_irq(struct irq_desc *desc) spin_unlock_irqrestore(&ioapic_lock, flags); } +#ifdef CONFIG_X86_X2APIC static void ack_x2apic_level(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); @@ -2634,6 +2634,9 @@ static void ack_apic_level(unsigned int irq) */ ack_APIC_irq(); + if (irq_remapped(irq)) + eoi_ioapic_irq(desc); + /* Now we can move and renable the irq */ if (unlikely(do_unmask_irq)) { /* Only migrate the irq if the ack has been received. -- cgit v1.2.3-70-g09d2 From 6ec3cfeca04622e3d80c9270191cd7f5f88214af Mon Sep 17 00:00:00 2001 From: "Pallipadi, Venkatesh" Date: Mon, 13 Apr 2009 15:20:58 -0700 Subject: x86, irq: Remove IRQ_DISABLED check in process context IRQ move As discussed in the thread here: http://marc.info/?l=linux-kernel&m=123964468521142&w=2 Eric W. Biederman observed: > It looks like some additional bugs have slipped in since last I looked. > > set_irq_affinity does this: > ifdef CONFIG_GENERIC_PENDING_IRQ > if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { > cpumask_copy(desc->affinity, cpumask); > desc->chip->set_affinity(irq, cpumask); > } else { > desc->status |= IRQ_MOVE_PENDING; > cpumask_copy(desc->pending_mask, cpumask); > } > #else > > That IRQ_DISABLED case is a software state and as such it has nothing to > do with how safe it is to move an irq in process context. [...] > > The only reason we migrate MSIs in interrupt context today is that there > wasn't infrastructure for support migration both in interrupt context > and outside of it. Yes. The idea here was to force the MSI migration to happen in process context. One of the patches in the series did disable_irq(dev->irq); irq_set_affinity(dev->irq, cpumask_of(dev->cpu)); enable_irq(dev->irq); with the above patch adding irq/manage code check for interrupt disabled and moving the interrupt in process context. IIRC, there was no IRQ_MOVE_PCNTXT when we were developing this HPET code and we ended up having this ugly hack. IRQ_MOVE_PCNTXT was there when we eventually submitted the patch upstream. But, looks like I did a blind rebasing instead of using IRQ_MOVE_PCNTXT in hpet MSI code. Below patch fixes this. i.e., revert commit 932775a4ab622e3c99bd59f14cc and add PCNTXT to HPET MSI setup. Also removes copying of desc->affinity in generic code as set_affinity routines are doing it internally. Reported-by: "Eric W. Biederman" Signed-off-by: Venkatesh Pallipadi Acked-by: "Eric W. Biederman" Cc: "Li Shaohua" Cc: Gary Hade Cc: "lcm@us.ibm.com" Cc: suresh.b.siddha@intel.com LKML-Reference: <20090413222058.GB8211@linux-os.sc.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/io_apic.c | 2 ++ kernel/irq/manage.c | 5 ++--- 2 files changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/apic/io_apic.c') diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index a2789e42e16..30da617d18e 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -3670,12 +3670,14 @@ int arch_setup_hpet_msi(unsigned int irq) { int ret; struct msi_msg msg; + struct irq_desc *desc = irq_to_desc(irq); ret = msi_compose_msg(NULL, irq, &msg); if (ret < 0) return ret; hpet_msi_write(irq, &msg); + desc->status |= IRQ_MOVE_PCNTXT; set_irq_chip_and_handler_name(irq, &hpet_msi_type, handle_edge_irq, "edge"); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 7e2e7dd4cd2..2734eca5924 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -109,10 +109,9 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) spin_lock_irqsave(&desc->lock, flags); #ifdef CONFIG_GENERIC_PENDING_IRQ - if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { - cpumask_copy(desc->affinity, cpumask); + if (desc->status & IRQ_MOVE_PCNTXT) desc->chip->set_affinity(irq, cpumask); - } else { + else { desc->status |= IRQ_MOVE_PENDING; cpumask_copy(desc->pending_mask, cpumask); } -- cgit v1.2.3-70-g09d2