[IA64] avoid broken SAL_CACHE_FLUSH implementations

If SAL_CACHE_FLUSH drops interrupts, complain about it and fall back to
using PAL_CACHE_FLUSH instead.

This is to work around a defect in HP rx5670 firmware: when an interrupt
occurs during SAL_CACHE_FLUSH, SAL drops the interrupt but leaves it marked
"in-service", which leaves the interrupt (and others of equal or lower
priority) masked.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/include/asm-ia64/processor.h b/include/asm-ia64/processor.h
index 09b9902..23c8e1b 100644
--- a/include/asm-ia64/processor.h
+++ b/include/asm-ia64/processor.h
@@ -559,6 +559,23 @@
 
 #define cpu_relax()	ia64_hint(ia64_hint_pause)
 
+static inline int
+ia64_get_irr(unsigned int vector)
+{
+	unsigned int reg = vector / 64;
+	unsigned int bit = vector % 64;
+	u64 irr;
+
+	switch (reg) {
+	case 0: irr = ia64_getreg(_IA64_REG_CR_IRR0); break;
+	case 1: irr = ia64_getreg(_IA64_REG_CR_IRR1); break;
+	case 2: irr = ia64_getreg(_IA64_REG_CR_IRR2); break;
+	case 3: irr = ia64_getreg(_IA64_REG_CR_IRR3); break;
+	}
+
+	return test_bit(bit, &irr);
+}
+
 static inline void
 ia64_set_lrr0 (unsigned long val)
 {