From c29d9db338db606c3335a03f337e1d4b7f6bb727 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Tue, 1 Dec 2009 15:31:16 -0800 Subject: [PATCH] x86, ioapic: Fix the EOI register detection mechanism Maciej W. Rozycki reported: > 82093AA I/O APIC has its version set to 0x11 and it > does not support the EOI register. Similarly I/O APICs > integrated into the 82379AB south bridge and the 82374EB/SB > EISA component. IO-APIC versions below 0x20 don't support EOI register. Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic version as 0x2. This is an error with documentation and these ICH chips use io-apic's of version 0x20 and indeed has a working EOI register for the io-apic. Fix the EOI register detection mechanism to check for version 0x20 and beyond. And also, a platform can potentially have io-apic's with different versions. Make the EOI register check per io-apic. Reported-by: Maciej W. Rozycki Signed-off-by: Suresh Siddha Cc: ebiederm@xmission.com Cc: garyhade@us.ibm.com LKML-Reference: <20091201233335.065361533@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/io_apic.c | 115 ++++++++++++++++++++++------------------- 1 file changed, 61 insertions(+), 54 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index b377b97..78960a3 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -539,23 +539,41 @@ static void __init replace_pin_at_irq_node(struct irq_cfg *cfg, int node, add_pin_to_irq_node(cfg, node, newapic, newpin); } +static void __io_apic_modify_irq(struct irq_pin_list *entry, + int mask_and, int mask_or, + void (*final)(struct irq_pin_list *entry)) +{ + unsigned int reg, pin; + + pin = entry->pin; + reg = io_apic_read(entry->apic, 0x10 + pin * 2); + reg &= mask_and; + reg |= mask_or; + io_apic_modify(entry->apic, 0x10 + pin * 2, reg); + if (final) + final(entry); +} + static void io_apic_modify_irq(struct irq_cfg *cfg, int mask_and, int mask_or, void (*final)(struct irq_pin_list *entry)) { - int pin; struct irq_pin_list *entry; - for_each_irq_pin(entry, cfg->irq_2_pin) { - unsigned int reg; - pin = entry->pin; - reg = io_apic_read(entry->apic, 0x10 + pin * 2); - reg &= mask_and; - reg |= mask_or; - io_apic_modify(entry->apic, 0x10 + pin * 2, reg); - if (final) - final(entry); - } + for_each_irq_pin(entry, cfg->irq_2_pin) + __io_apic_modify_irq(entry, mask_and, mask_or, final); +} + +static void __mask_and_edge_IO_APIC_irq(struct irq_pin_list *entry) +{ + __io_apic_modify_irq(entry, ~IO_APIC_REDIR_LEVEL_TRIGGER, + IO_APIC_REDIR_MASKED, NULL); +} + +static void __unmask_and_level_IO_APIC_irq(struct irq_pin_list *entry) +{ + __io_apic_modify_irq(entry, ~IO_APIC_REDIR_MASKED, + IO_APIC_REDIR_LEVEL_TRIGGER, NULL); } static void __unmask_IO_APIC_irq(struct irq_cfg *cfg) @@ -579,18 +597,6 @@ static void __mask_IO_APIC_irq(struct irq_cfg *cfg) io_apic_modify_irq(cfg, ~0, IO_APIC_REDIR_MASKED, &io_apic_sync); } -static void __mask_and_edge_IO_APIC_irq(struct irq_cfg *cfg) -{ - io_apic_modify_irq(cfg, ~IO_APIC_REDIR_LEVEL_TRIGGER, - IO_APIC_REDIR_MASKED, NULL); -} - -static void __unmask_and_level_IO_APIC_irq(struct irq_cfg *cfg) -{ - io_apic_modify_irq(cfg, ~IO_APIC_REDIR_MASKED, - IO_APIC_REDIR_LEVEL_TRIGGER, NULL); -} - static void mask_IO_APIC_irq_desc(struct irq_desc *desc) { struct irq_cfg *cfg = desc->chip_data; @@ -2492,17 +2498,42 @@ static void ack_apic_edge(unsigned int irq) atomic_t irq_mis_count; -static int use_eoi_reg __read_mostly; - +/* + * IO-APIC versions below 0x20 don't support EOI register. + * For the record, here is the information about various versions: + * 0Xh 82489DX + * 1Xh I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant + * 2Xh I/O(x)APIC which is PCI 2.2 Compliant + * 30h-FFh Reserved + * + * Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic + * version as 0x2. This is an error with documentation and these ICH chips + * use io-apic's of version 0x20. + * + * For IO-APIC's with EOI register, we use that to do an explicit EOI. + * Otherwise, we simulate the EOI message manually by changing the trigger + * mode to edge and then back to level, with RTE being masked during this. +*/ static void __eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg) { struct irq_pin_list *entry; for_each_irq_pin(entry, cfg->irq_2_pin) { - if (irq_remapped(irq)) - io_apic_eoi(entry->apic, entry->pin); - else - io_apic_eoi(entry->apic, cfg->vector); + if (mp_ioapics[entry->apic].apicver >= 0x20) { + /* + * Intr-remapping uses pin number as the virtual vector + * in the RTE. Actual vector is programmed in + * intr-remapping table entry. Hence for the io-apic + * EOI we use the pin number. + */ + if (irq_remapped(irq)) + io_apic_eoi(entry->apic, entry->pin); + else + io_apic_eoi(entry->apic, cfg->vector); + } else { + __mask_and_edge_IO_APIC_irq(entry); + __unmask_and_level_IO_APIC_irq(entry); + } } } @@ -2520,23 +2551,6 @@ static void eoi_ioapic_irq(struct irq_desc *desc) spin_unlock_irqrestore(&ioapic_lock, flags); } -static int ioapic_supports_eoi(void) -{ - struct pci_dev *root; - - root = pci_get_bus_and_slot(0, PCI_DEVFN(0, 0)); - if (root && root->vendor == PCI_VENDOR_ID_INTEL && - mp_ioapics[0].apicver >= 0x2) { - use_eoi_reg = 1; - printk(KERN_INFO "IO-APIC supports EOI register\n"); - } else - printk(KERN_INFO "IO-APIC doesn't support EOI\n"); - - return 0; -} - -fs_initcall(ioapic_supports_eoi); - static void ack_apic_level(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); @@ -2587,14 +2601,7 @@ static void ack_apic_level(unsigned int irq) if (!(v & (1 << (i & 0x1f)))) { atomic_inc(&irq_mis_count); - if (use_eoi_reg) - eoi_ioapic_irq(desc); - else { - spin_lock(&ioapic_lock); - __mask_and_edge_IO_APIC_irq(cfg); - __unmask_and_level_IO_APIC_irq(cfg); - spin_unlock(&ioapic_lock); - } + eoi_ioapic_irq(desc); } /* Now we can move and renable the irq */ -- 2.7.4