Blackfin: SIC: cut down on IAR MMR reads a bit
Tweak the for loops that operate on the SIC IAR system MMRs to avoid
re-reading them multiple times in a row. System MMRs are a little
slower to access, so avoid the penalty when possible.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/mach-common/ints-priority.c b/arch/blackfin/mach-common/ints-priority.c
index ce98871..1c8c4c7 100644
--- a/arch/blackfin/mach-common/ints-priority.c
+++ b/arch/blackfin/mach-common/ints-priority.c
@@ -92,26 +92,29 @@
{
unsigned ivg, irq_pos = 0;
for (ivg = 0; ivg <= IVG13 - IVG7; ivg++) {
- int irqn;
+ int irqN;
ivg7_13[ivg].istop = ivg7_13[ivg].ifirst = &ivg_table[irq_pos];
- for (irqn = 0; irqn < NR_PERI_INTS; irqn++) {
- int iar_shift = (irqn & 7) * 4;
- if (ivg == (0xf &
-#if defined(CONFIG_BF52x) || defined(CONFIG_BF538) \
- || defined(CONFIG_BF539) || defined(CONFIG_BF51x)
- bfin_read32((unsigned long *)SIC_IAR0 +
- ((irqn % 32) >> 3) + ((irqn / 32) *
- ((SIC_IAR4 - SIC_IAR0) / 4))) >> iar_shift)) {
+ for (irqN = 0; irqN < NR_PERI_INTS; irqN += 4) {
+ int irqn;
+ u32 iar = bfin_read32((unsigned long *)SIC_IAR0 +
+#if defined(CONFIG_BF51x) || defined(CONFIG_BF52x) || \
+ defined(CONFIG_BF538) || defined(CONFIG_BF539)
+ ((irqN % 32) >> 3) + ((irqN / 32) * ((SIC_IAR4 - SIC_IAR0) / 4))
#else
- bfin_read32((unsigned long *)SIC_IAR0 +
- (irqn >> 3)) >> iar_shift)) {
+ (irqN >> 3)
#endif
- ivg_table[irq_pos].irqno = IVG7 + irqn;
- ivg_table[irq_pos].isrflag = 1 << (irqn % 32);
- ivg7_13[ivg].istop++;
- irq_pos++;
+ );
+
+ for (irqn = irqN; irqn < irqN + 4; ++irqn) {
+ int iar_shift = (irqn & 7) * 4;
+ if (ivg == (0xf & (iar >> iar_shift))) {
+ ivg_table[irq_pos].irqno = IVG7 + irqn;
+ ivg_table[irq_pos].isrflag = 1 << (irqn % 32);
+ ivg7_13[ivg].istop++;
+ irq_pos++;
+ }
}
}
}