Use cached IOAPIC entry instead of reading data from IOAPIC hardware registers to improve performance. Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Cc: Joerg Roedel <joro@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Yinghai Lu <yinghai@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Grant Likely <grant.likely@xxxxxxxxxx> Link: http://lkml.kernel.org/r/1416901802-24211-30-git-send-email-jiang.liu@xxxxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Tested-by: Joerg Roedel <jroedel@xxxxxxx> --- arch/x86/kernel/apic/io_apic.c | 78 +++++++++++----------------------------- 1 file changed, 21 insertions(+), 57 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 32a8d51975b3..c06f4b531392 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -67,8 +67,13 @@ list_for_each_entry(entry, &head, list) /* - * Is the SiS APIC rmw bug present ? + * Is the SiS APIC rmw bug present ? * -1 = don't know, 0 = no, 1 = yes + * When doing a read-modify-write operation on IOAPIC registers, older SiS APIC + * requires we rewrite the index register again where the read already set up + * the index register. + * The code to make use of sis_apic_bug has been removed, but we don't want to + * loss this knowledge. */ int sis_apic_bug = -1; @@ -293,22 +298,6 @@ static void io_apic_write(unsigned int apic, unsigned int reg, writel(value, &io_apic->data); } -/* - * Re-write a value: to be used for read-modify-write - * cycles where the read already set up the index register. - * - * Older SiS APIC requires we rewrite the index register - */ -static void io_apic_modify(unsigned int apic, unsigned int reg, - unsigned int value) -{ - struct io_apic __iomem *io_apic = io_apic_base(apic); - - if (sis_apic_bug) - writel(reg, &io_apic->index); - writel(value, &io_apic->data); -} - union entry_union { struct { u32 w1, w2; }; struct IO_APIC_route_entry entry; @@ -445,29 +434,23 @@ static void __init replace_pin_at_irq_node(struct mp_chip_data *data, int node, add_pin_to_irq_node(data, 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 mp_chip_data *data, int mask_and, int mask_or, void (*final)(struct irq_pin_list *entry)) { + union entry_union eu; struct irq_pin_list *entry; - for_each_irq_pin(entry, data->irq_2_pin) - __io_apic_modify_irq(entry, mask_and, mask_or, final); + eu.entry = data->entry; + eu.w1 &= mask_and; + eu.w1 |= mask_or; + data->entry = eu.entry; + + for_each_irq_pin(entry, data->irq_2_pin) { + io_apic_write(entry->apic, 0x10 + 2 * entry->pin, eu.w1); + if (final) + final(entry); + } } static void io_apic_sync(struct irq_pin_list *entry) @@ -1739,28 +1722,6 @@ static unsigned int startup_ioapic_irq(struct irq_data *data) return was_pending; } -static void __target_IO_APIC_irq(unsigned int irq, struct irq_cfg *cfg, - struct mp_chip_data *data) -{ - int apic, pin; - struct irq_pin_list *entry; - u8 vector = cfg->vector; - unsigned int dest = SET_APIC_LOGICAL_ID(cfg->dest_apicid); - - for_each_irq_pin(entry, data->irq_2_pin) { - unsigned int reg; - - apic = entry->apic; - pin = entry->pin; - - io_apic_write(apic, 0x11 + pin*2, dest); - reg = io_apic_read(apic, 0x10 + pin*2); - reg &= ~IO_APIC_REDIR_VECTOR_MASK; - reg |= vector; - io_apic_modify(apic, 0x10 + pin*2, reg); - } -} - atomic_t irq_mis_count; #ifdef CONFIG_GENERIC_PENDING_IRQ @@ -1926,6 +1887,7 @@ static int ioapic_set_affinity(struct irq_data *irq_data, { struct irq_data *parent = irq_data->parent_data; struct mp_chip_data *data = irq_data->chip_data; + struct irq_pin_list *entry; struct irq_cfg *cfg; unsigned long flags; int ret; @@ -1936,7 +1898,9 @@ static int ioapic_set_affinity(struct irq_data *irq_data, cfg = irqd_cfg(irq_data); data->entry.dest = cfg->dest_apicid; data->entry.vector = cfg->vector; - __target_IO_APIC_irq(irq_data->irq, cfg, irq_data->chip_data); + for_each_irq_pin(entry, data->irq_2_pin) + __ioapic_write_entry(entry->apic, entry->pin, + data->entry); } raw_spin_unlock_irqrestore(&ioapic_lock, flags); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
