From e57253a81d9cc7049e9e43bd806ce6cdd297ec1c Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Thu, 25 Aug 2011 12:01:12 -0700 Subject: [PATCH] x86, ioapic: Restore the mask bit correctly in eoi_ioapic_irq() For older IO-APIC's, we were clearing the remote-IRR by changing the RTE trigger mode to edge and then back to level. We wanted to mask the RTE during this process, so we were essentially doing mask+edge and then to unmask+level. As part of the commit ca64c47cecd0321b2e0dcbd7aaff44b68ce20654, we moved this EOI process earlier where the IO-APIC RTE is masked. So we were wrongly unmasking it in the eoi_ioapic_irq(). So change the remote-IRR clear sequence in eoi_ioapic_irq() to mask + edge and then restore the previous RTE entry which will restore the mask status as well as the level trigger. Signed-off-by: Suresh Siddha Cc: Maciej W. Rozycki Cc: Thomas Renninger Cc: Rafael Wysocki Cc: lchiquitto@novell.com Cc: jbeulich@novell.com Cc: yinghai@kernel.org Link: http://lkml.kernel.org/r/20110825190657.210286410@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/io_apic.c | 43 +++++++++++++++++++++------------- 1 file changed, 27 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 913d4bd2913a..85050c9ab755 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -394,13 +394,21 @@ union entry_union { struct IO_APIC_route_entry entry; }; +static struct IO_APIC_route_entry __ioapic_read_entry(int apic, int pin) +{ + union entry_union eu; + + eu.w1 = io_apic_read(apic, 0x10 + 2 * pin); + eu.w2 = io_apic_read(apic, 0x11 + 2 * pin); + return eu.entry; +} + static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin) { union entry_union eu; unsigned long flags; raw_spin_lock_irqsave(&ioapic_lock, flags); - eu.w1 = io_apic_read(apic, 0x10 + 2 * pin); - eu.w2 = io_apic_read(apic, 0x11 + 2 * pin); + eu.entry = __ioapic_read_entry(apic, pin); raw_spin_unlock_irqrestore(&ioapic_lock, flags); return eu.entry; } @@ -529,18 +537,6 @@ static void io_apic_modify_irq(struct irq_cfg *cfg, __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 io_apic_sync(struct irq_pin_list *entry) { /* @@ -2496,8 +2492,23 @@ static void eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg) else io_apic_eoi(entry->apic, cfg->vector); } else { - __mask_and_edge_IO_APIC_irq(entry); - __unmask_and_level_IO_APIC_irq(entry); + struct IO_APIC_route_entry rte, rte1; + + rte = rte1 = + __ioapic_read_entry(entry->apic, entry->pin); + + /* + * Mask the entry and change the trigger mode to edge. + */ + rte1.mask = 1; + rte1.trigger = IOAPIC_EDGE; + + __ioapic_write_entry(apic, pin, rte1); + + /* + * Restore the previous level triggered entry. + */ + __ioapic_write_entry(apic, pin, rte); } } raw_spin_unlock_irqrestore(&ioapic_lock, flags); -- 2.39.5