+/* Function codes for the ptff instruction. */
+#define PTFF_QAF 0x00 /* query available functions */
+#define PTFF_QTO 0x01 /* query tod offset */
+#define PTFF_QSI 0x02 /* query steering information */
+#define PTFF_ATO 0x40 /* adjust tod offset */
+#define PTFF_STO 0x41 /* set tod offset */
+#define PTFF_SFS 0x42 /* set fine steering rate */
+#define PTFF_SGS 0x43 /* set gross steering rate */
+
+/* Query TOD offset result */
+struct ptff_qto {
+ unsigned long long physical_clock;
+ unsigned long long tod_offset;
+ unsigned long long logical_tod_offset;
+ unsigned long long tod_epoch_difference;
+} __packed;
+
+static inline int ptff(void *ptff_block, size_t len, unsigned int func)
+{
+ typedef struct { char _[len]; } addrtype;
+ register unsigned int reg0 asm("0") = func;
+ register unsigned long reg1 asm("1") = (unsigned long) ptff_block;
+ int rc;
+
+ asm volatile(
+ " .word 0x0104\n"
+ " ipm %0\n"
+ " srl %0,28\n"
+ : "=d" (rc), "+m" (*(addrtype *) ptff_block)
+ : "d" (reg0), "d" (reg1) : "cc");
+ return rc;
+}
+