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x86/irq: Use cached IOAPIC entry instead of reading from hardware 

Use cached IOAPIC entry instead of reading data from IOAPIC hardware
registers to improve performance.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Cohen <david.a.cohen@linux.intel.com>
Cc: Sander Eikelenboom <linux@eikelenboom.it>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Grant Likely <grant.likely@linaro.org>
Link: http://lkml.kernel.org/r/1428978610-28986-21-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Jiang Liu 2015-04-14 10:29:57 +08:00 committed by Thomas Gleixner
parent 154d9e50e4
commit 0be275e3a5
1 changed files with 21 additions and 57 deletions
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76
arch/x86/kernel/apic/io_apic.c
View File

@ -69,6 +69,11 @@
/*
* 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
* lose 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);