+ movl S_ARG0, %ecx
+
+ rdtsc
+
+ movl %edx, 0(%ecx)
+ movl %eax, 4(%ecx)
+
+ ret
+
+
+/*
+ * Convert between various timer units
+ *
+ * uint64_t tmrCvt(uint64_t time, uint64_t *conversion)
+ *
+ * This code converts 64-bit time units to other units.
+ * For example, the TSC is converted to HPET units.
+ *
+ * Time is a 64-bit integer that is some number of ticks.
+ * Conversion is 64-bit fixed point number which is composed
+ * of a 32 bit integer and a 32 bit fraction.
+ *
+ * The time ticks are multiplied by the conversion factor. The
+ * calculations are done as a 128-bit value but both the high
+ * and low words are dropped. The high word is overflow and the
+ * low word is the fraction part of the result.
+ *
+ * We return a 64-bit value.
+ *
+ * Note that we can use this function to multiply 2 conversion factors.
+ * We do this in order to calculate the multiplier used to convert
+ * directly between any two units.
+ *
+ */
+
+ .globl EXT(tmrCvt)
+ .align FALIGN
+
+LEXT(tmrCvt)
+
+ pushl %ebp // Save a volatile
+ movl %esp,%ebp // Get the parameters - 8
+ pushl %ebx // Save a volatile
+ pushl %esi // Save a volatile
+ pushl %edi // Save a volatile
+
+// %ebp + 8 - low-order ts
+// %ebp + 12 - high-order ts
+// %ebp + 16 - low-order cvt
+// %ebp + 20 - high-order cvt
+
+ movl 8(%ebp),%eax // Get low-order ts
+ mull 16(%ebp) // Multiply by low-order conversion
+ movl %edx,%edi // Need to save only the high order part
+
+ movl 12(%ebp),%eax // Get the high-order ts
+ mull 16(%ebp) // Multiply by low-order conversion
+ addl %eax,%edi // Add in the overflow from the low x low calculation
+ adcl $0,%edx // Add in any overflow to high high part
+ movl %edx,%esi // Save high high part
+
+// We now have the upper 64 bits of the 96 bit multiply of ts and the low half of cvt
+// in %esi:%edi
+
+ movl 8(%ebp),%eax // Get low-order ts
+ mull 20(%ebp) // Multiply by high-order conversion
+ movl %eax,%ebx // Need to save the low order part
+ movl %edx,%ecx // Need to save the high order part
+
+ movl 12(%ebp),%eax // Get the high-order ts
+ mull 20(%ebp) // Multiply by high-order conversion
+
+// Now have %ecx:%ebx as low part of high low and %edx:%eax as high part of high high
+// We don't care about the highest word since it is overflow
+
+ addl %edi,%ebx // Add the low words
+ adcl %ecx,%esi // Add in the high plus carry from low
+ addl %eax,%esi // Add in the rest of the high
+
+ movl %ebx,%eax // Pass back low word
+ movl %esi,%edx // and the high word
+
+ popl %edi // Restore a volatile
+ popl %esi // Restore a volatile
+ popl %ebx // Restore a volatile
+ popl %ebp // Restore a volatile
+
+ ret // Leave...
+
+ .globl EXT(rtc_nanotime_store)
+ .align FALIGN
+
+LEXT(rtc_nanotime_store)
+ push %ebp
+ mov %esp,%ebp
+
+ mov 32(%ebp),%edx
+
+ mov 8(%ebp),%eax
+ mov %eax,RNT_TSC_BASE(%edx)
+ mov 12(%ebp),%eax
+ mov %eax,RNT_TSC_BASE+4(%edx)
+
+ mov 24(%ebp),%eax
+ mov %eax,RNT_SCALE(%edx)
+
+ mov 28(%ebp),%eax
+ mov %eax,RNT_SHIFT(%edx)
+
+ mov 16(%ebp),%eax
+ mov %eax,RNT_NS_BASE(%edx)
+ mov 20(%ebp),%eax
+ mov %eax,RNT_NS_BASE+4(%edx)
+
+ pop %ebp
+ ret
+
+ .globl EXT(rtc_nanotime_load)
+ .align FALIGN
+
+LEXT(rtc_nanotime_load)
+ push %ebp
+ mov %esp,%ebp
+
+ mov 8(%ebp),%ecx
+ mov 12(%ebp),%edx
+
+ mov RNT_TSC_BASE(%ecx),%eax
+ mov %eax,RNT_TSC_BASE(%edx)
+ mov RNT_TSC_BASE+4(%ecx),%eax
+ mov %eax,RNT_TSC_BASE+4(%edx)
+
+ mov RNT_SCALE(%ecx),%eax
+ mov %eax,RNT_SCALE(%edx)
projects / apple / xnu.git / blobdiff