Use per-iosapic lock for indirect iosapic register access. It reduces
lock contention.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
---
arch/ia64/kernel/iosapic.c | 57 ++++++++++++++++++++++-----------------------
include/asm-ia64/iosapic.h | 4 +--
2 files changed, 31 insertions(+), 30 deletions(-)
Index: linux-2.6.21/arch/ia64/kernel/iosapic.c
===================================================================
--- linux-2.6.21.orig/arch/ia64/kernel/iosapic.c 2007-05-07 11:40:27.000000000 +0900
+++ linux-2.6.21/arch/ia64/kernel/iosapic.c 2007-05-07 11:41:48.000000000 +0900
@@ -126,6 +126,7 @@
#ifdef CONFIG_NUMA
unsigned short node; /* numa node association via pxm */
#endif
+ spinlock_t lock; /* lock for indirect reg access */
} iosapic_lists[NR_IOSAPICS];
struct iosapic_rte_info {
@@ -154,6 +155,16 @@
static int iosapic_kmalloc_ok;
static LIST_HEAD(free_rte_list);
+static inline void
+iosapic_write(struct iosapic *iosapic, unsigned int reg, u32 val)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&iosapic->lock, flags);
+ __iosapic_write(iosapic->addr, reg, val);
+ spin_unlock_irqrestore(&iosapic->lock, flags);
+}
+
/*
* Find an IOSAPIC associated with a GSI
*/
@@ -227,7 +238,6 @@
{
unsigned long pol, trigger, dmode;
u32 low32, high32;
- char __iomem *addr;
int rte_index;
char redir;
struct iosapic_rte_info *rte;
@@ -239,7 +249,6 @@
return; /* not an IOSAPIC interrupt */
rte_index = rte->rte_index;
- addr = rte->iosapic->addr;
pol = iosapic_intr_info[vector].polarity;
trigger = iosapic_intr_info[vector].trigger;
dmode = iosapic_intr_info[vector].dmode;
@@ -269,8 +278,8 @@
/* dest contains both id and eid */
high32 = (dest << IOSAPIC_DEST_SHIFT);
- iosapic_write(addr, IOSAPIC_RTE_HIGH(rte_index), high32);
- iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
+ iosapic_write(rte->iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
+ iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
iosapic_intr_info[vector].low32 = low32;
iosapic_intr_info[vector].dest = dest;
}
@@ -293,7 +302,7 @@
iosapic_intr_info + IA64_NUM_VECTORS; ++info, ++vec) {
list_for_each_entry(rte, &info->rtes,
rte_list) {
- iosapic_write(rte->iosapic->addr,
+ iosapic_write(rte->iosapic,
IOSAPIC_RTE_LOW(rte->rte_index),
IOSAPIC_MASK|vec);
iosapic_eoi(rte->iosapic->addr, vec);
@@ -305,8 +314,6 @@
static void
mask_irq (unsigned int irq)
{
- unsigned long flags;
- char __iomem *addr;
u32 low32;
int rte_index;
ia64_vector vec = irq_to_vector(irq);
@@ -315,22 +322,17 @@
if (list_empty(&iosapic_intr_info[vec].rtes))
return; /* not an IOSAPIC interrupt! */
- spin_lock_irqsave(&iosapic_lock, flags);
/* set only the mask bit */
low32 = iosapic_intr_info[vec].low32 |= IOSAPIC_MASK;
list_for_each_entry(rte, &iosapic_intr_info[vec].rtes, rte_list) {
- addr = rte->iosapic->addr;
rte_index = rte->rte_index;
- iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
+ iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
}
- spin_unlock_irqrestore(&iosapic_lock, flags);
}
static void
unmask_irq (unsigned int irq)
{
- unsigned long flags;
- char __iomem *addr;
u32 low32;
int rte_index;
ia64_vector vec = irq_to_vector(irq);
@@ -339,14 +341,11 @@
if (list_empty(&iosapic_intr_info[vec].rtes))
return; /* not an IOSAPIC interrupt! */
- spin_lock_irqsave(&iosapic_lock, flags);
low32 = iosapic_intr_info[vec].low32 &= ~IOSAPIC_MASK;
list_for_each_entry(rte, &iosapic_intr_info[vec].rtes, rte_list) {
- addr = rte->iosapic->addr;
rte_index = rte->rte_index;
- iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
+ iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
}
- spin_unlock_irqrestore(&iosapic_lock, flags);
}
@@ -354,13 +353,12 @@
iosapic_set_affinity (unsigned int irq, cpumask_t mask)
{
#ifdef CONFIG_SMP
- unsigned long flags;
u32 high32, low32;
int dest, rte_index;
- char __iomem *addr;
int redir = (irq & IA64_IRQ_REDIRECTED) ? 1 : 0;
ia64_vector vec;
struct iosapic_rte_info *rte;
+ struct iosapic *iosapic;
irq &= (~IA64_IRQ_REDIRECTED);
vec = irq_to_vector(irq);
@@ -378,7 +376,6 @@
/* dest contains both id and eid */
high32 = dest << IOSAPIC_DEST_SHIFT;
- spin_lock_irqsave(&iosapic_lock, flags);
low32 = iosapic_intr_info[vec].low32 & ~(7 << IOSAPIC_DELIVERY_SHIFT);
if (redir)
/* change delivery mode to lowest priority */
@@ -390,12 +387,11 @@
iosapic_intr_info[vec].low32 = low32;
iosapic_intr_info[vec].dest = dest;
list_for_each_entry(rte, &iosapic_intr_info[vec].rtes, rte_list) {
- addr = rte->iosapic->addr;
+ iosapic = rte->iosapic;
rte_index = rte->rte_index;
- iosapic_write(addr, IOSAPIC_RTE_HIGH(rte_index), high32);
- iosapic_write(addr, IOSAPIC_RTE_LOW(rte_index), low32);
+ iosapic_write(iosapic, IOSAPIC_RTE_HIGH(rte_index), high32);
+ iosapic_write(iosapic, IOSAPIC_RTE_LOW(rte_index), low32);
}
- spin_unlock_irqrestore(&iosapic_lock, flags);
#endif
}
@@ -500,7 +496,7 @@
* unsigned int reserved2 : 8;
* }
*/
- return iosapic_read(addr, IOSAPIC_VERSION);
+ return __iosapic_read(addr, IOSAPIC_VERSION);
}
static int iosapic_find_sharable_vector (unsigned long trigger,
@@ -865,8 +861,7 @@
/* Mask the interrupt */
low32 = iosapic_intr_info[vector].low32 | IOSAPIC_MASK;
- iosapic_write(rte->iosapic->addr,
- IOSAPIC_RTE_LOW(rte->rte_index), low32);
+ iosapic_write(rte->iosapic, IOSAPIC_RTE_LOW(rte->rte_index), low32);
/* Remove the rte entry from the list */
list_del(&rte->rte_list);
@@ -1071,9 +1066,14 @@
unsigned long flags;
spin_lock_irqsave(&iosapic_lock, flags);
+ index = find_iosapic(gsi_base);
+ if (index >= 0) {
+ spin_unlock_irqrestore(&iosapic_lock, flags);
+ return -EBUSY;
+ }
+
addr = ioremap(phys_addr, 0);
ver = iosapic_version(addr);
-
if ((err = iosapic_check_gsi_range(gsi_base, ver))) {
iounmap(addr);
spin_unlock_irqrestore(&iosapic_lock, flags);
@@ -1094,6 +1094,7 @@
#ifdef CONFIG_NUMA
iosapic_lists[index].node = MAX_NUMNODES;
#endif
+ spin_lock_init(&iosapic_lists[index].lock);
spin_unlock_irqrestore(&iosapic_lock, flags);
if ((gsi_base == 0) && pcat_compat) {
Index: linux-2.6.21/include/asm-ia64/iosapic.h
===================================================================
--- linux-2.6.21.orig/include/asm-ia64/iosapic.h 2007-04-26 12:08:32.000000000 +0900
+++ linux-2.6.21/include/asm-ia64/iosapic.h 2007-05-07 11:41:48.000000000 +0900
@@ -53,13 +53,13 @@
#define NR_IOSAPICS 256
-static inline unsigned int iosapic_read(char __iomem *iosapic, unsigned int reg)
+static inline unsigned int __iosapic_read(char __iomem *iosapic, unsigned int reg)
{
writel(reg, iosapic + IOSAPIC_REG_SELECT);
return readl(iosapic + IOSAPIC_WINDOW);
}
-static inline void iosapic_write(char __iomem *iosapic, unsigned int reg, u32 val)
+static inline void __iosapic_write(char __iomem *iosapic, unsigned int reg, u32 val)
{
writel(reg, iosapic + IOSAPIC_REG_SELECT);
writel(val, iosapic + IOSAPIC_WINDOW);
-
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