MIPS: csrc-sb1250: Extract hpt cycle acquisition from sb1250_hpt_read

This is to prepare for the upcoming read_sched_clock implementation, which
will also need to get cycles from the high precision timer.
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: macro@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9486/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/csrc-sb1250.c

@@ -33,15 +33,22 @@
  * The HPT is free running from SB1250_HPT_VALUE down to 0 then starts over
  * again.
  */
-static cycle_t sb1250_hpt_read(struct clocksource *cs)
+static inline cycle_t sb1250_hpt_get_cycles(void)
 {
 	unsigned int count;
+	void __iomem *addr;
 
-	count = G_SCD_TIMER_CNT(__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT))));
+	addr = IOADDR(A_SCD_TIMER_REGISTER(SB1250_HPT_NUM, R_SCD_TIMER_CNT));
+	count = G_SCD_TIMER_CNT(__raw_readq(addr));
 
 	return SB1250_HPT_VALUE - count;
 }
 
+static cycle_t sb1250_hpt_read(struct clocksource *cs)
+{
+	return sb1250_hpt_get_cycles();
+}
+
 struct clocksource bcm1250_clocksource = {
 	.name	= "bcm1250-counter-3",
 	.rating = 200,