*max_irr = -1;
for (i = vec = 0; i <= 7; i++, vec += 32) {
+ u32 *p_irr = (u32 *)(regs + APIC_IRR + i * 0x10);
+
+ irr_val = *p_irr;
pir_val = READ_ONCE(pir[i]);
- irr_val = *((u32 *)(regs + APIC_IRR + i * 0x10));
+
if (pir_val) {
+ pir_val = xchg(&pir[i], 0);
+
prev_irr_val = irr_val;
- irr_val |= xchg(&pir[i], 0);
- *((u32 *)(regs + APIC_IRR + i * 0x10)) = irr_val;
- if (prev_irr_val != irr_val) {
- max_updated_irr =
- __fls(irr_val ^ prev_irr_val) + vec;
- }
+ do {
+ irr_val = prev_irr_val | pir_val;
+ } while (prev_irr_val != irr_val &&
+ !try_cmpxchg(p_irr, &prev_irr_val, irr_val));
+
+ if (prev_irr_val != irr_val)
+ max_updated_irr = __fls(irr_val ^ prev_irr_val) + vec;
}
if (irr_val)
*max_irr = __fls(irr_val) + vec;