Initial import

1 files changed, 244 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
new file mode 100644
index 000000000..a76b4af37
--- /dev/null
+++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
@@ -0,0 +1,244 @@
+/*
+ * Userland implementation of gettimeofday() for 64 bits processes in a
+ * ppc64 kernel for use in the vDSO
+ *
+ * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org),
+ *                    IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/vdso.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+
+	.text
+/*
+ * Exact prototype of gettimeofday
+ *
+ * int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz);
+ *
+ */
+V_FUNCTION_BEGIN(__kernel_gettimeofday)
+  .cfi_startproc
+	mflr	r12
+  .cfi_register lr,r12
+
+	mr	r11,r3			/* r11 holds tv */
+	mr	r10,r4			/* r10 holds tz */
+	bl	V_LOCAL_FUNC(__get_datapage)	/* get data page */
+	cmpldi	r11,0			/* check if tv is NULL */
+	beq	2f
+	lis	r7,1000000@ha		/* load up USEC_PER_SEC */
+	addi	r7,r7,1000000@l
+	bl	V_LOCAL_FUNC(__do_get_tspec) /* get sec/us from tb & kernel */
+	std	r4,TVAL64_TV_SEC(r11)	/* store sec in tv */
+	std	r5,TVAL64_TV_USEC(r11)	/* store usec in tv */
+2:	cmpldi	r10,0			/* check if tz is NULL */
+	beq	1f
+	lwz	r4,CFG_TZ_MINUTEWEST(r3)/* fill tz */
+	lwz	r5,CFG_TZ_DSTTIME(r3)
+	stw	r4,TZONE_TZ_MINWEST(r10)
+	stw	r5,TZONE_TZ_DSTTIME(r10)
+1:	mtlr	r12
+	crclr	cr0*4+so
+	li	r3,0			/* always success */
+	blr
+  .cfi_endproc
+V_FUNCTION_END(__kernel_gettimeofday)
+
+
+/*
+ * Exact prototype of clock_gettime()
+ *
+ * int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp);
+ *
+ */
+V_FUNCTION_BEGIN(__kernel_clock_gettime)
+  .cfi_startproc
+	/* Check for supported clock IDs */
+	cmpwi	cr0,r3,CLOCK_REALTIME
+	cmpwi	cr1,r3,CLOCK_MONOTONIC
+	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
+	bne	cr0,99f
+
+	mflr	r12			/* r12 saves lr */
+  .cfi_register lr,r12
+	mr	r11,r4			/* r11 saves tp */
+	bl	V_LOCAL_FUNC(__get_datapage)	/* get data page */
+	lis	r7,NSEC_PER_SEC@h	/* want nanoseconds */
+	ori	r7,r7,NSEC_PER_SEC@l
+50:	bl	V_LOCAL_FUNC(__do_get_tspec)	/* get time from tb & kernel */
+	bne	cr1,80f			/* if not monotonic, all done */
+
+	/*
+	 * CLOCK_MONOTONIC
+	 */
+
+	/* now we must fixup using wall to monotonic. We need to snapshot
+	 * that value and do the counter trick again. Fortunately, we still
+	 * have the counter value in r8 that was returned by __do_get_tspec.
+	 * At this point, r4,r5 contain our sec/nsec values.
+	 */
+
+	lwa	r6,WTOM_CLOCK_SEC(r3)
+	lwa	r9,WTOM_CLOCK_NSEC(r3)
+
+	/* We now have our result in r6,r9. We create a fake dependency
+	 * on that result and re-check the counter
+	 */
+	or	r0,r6,r9
+	xor	r0,r0,r0
+	add	r3,r3,r0
+	ld	r0,CFG_TB_UPDATE_COUNT(r3)
+        cmpld   cr0,r0,r8		/* check if updated */
+	bne-	50b
+
+	/* Add wall->monotonic offset and check for overflow or underflow.
+	 */
+	add	r4,r4,r6
+	add	r5,r5,r9
+	cmpd	cr0,r5,r7
+	cmpdi	cr1,r5,0
+	blt	1f
+	subf	r5,r7,r5
+	addi	r4,r4,1
+1:	bge	cr1,80f
+	addi	r4,r4,-1
+	add	r5,r5,r7
+
+80:	std	r4,TSPC64_TV_SEC(r11)
+	std	r5,TSPC64_TV_NSEC(r11)
+
+	mtlr	r12
+	crclr	cr0*4+so
+	li	r3,0
+	blr
+
+	/*
+	 * syscall fallback
+	 */
+99:
+	li	r0,__NR_clock_gettime
+	sc
+	blr
+  .cfi_endproc
+V_FUNCTION_END(__kernel_clock_gettime)
+
+
+/*
+ * Exact prototype of clock_getres()
+ *
+ * int __kernel_clock_getres(clockid_t clock_id, struct timespec *res);
+ *
+ */
+V_FUNCTION_BEGIN(__kernel_clock_getres)
+  .cfi_startproc
+	/* Check for supported clock IDs */
+	cmpwi	cr0,r3,CLOCK_REALTIME
+	cmpwi	cr1,r3,CLOCK_MONOTONIC
+	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
+	bne	cr0,99f
+
+	li	r3,0
+	cmpli	cr0,r4,0
+	crclr	cr0*4+so
+	beqlr
+	lis	r5,CLOCK_REALTIME_RES@h
+	ori	r5,r5,CLOCK_REALTIME_RES@l
+	std	r3,TSPC64_TV_SEC(r4)
+	std	r5,TSPC64_TV_NSEC(r4)
+	blr
+
+	/*
+	 * syscall fallback
+	 */
+99:
+	li	r0,__NR_clock_getres
+	sc
+	blr
+  .cfi_endproc
+V_FUNCTION_END(__kernel_clock_getres)
+
+/*
+ * Exact prototype of time()
+ *
+ * time_t time(time *t);
+ *
+ */
+V_FUNCTION_BEGIN(__kernel_time)
+  .cfi_startproc
+	mflr	r12
+  .cfi_register lr,r12
+
+	mr	r11,r3			/* r11 holds t */
+	bl	V_LOCAL_FUNC(__get_datapage)
+
+	ld	r4,STAMP_XTIME+TSPC64_TV_SEC(r3)
+
+	cmpldi	r11,0			/* check if t is NULL */
+	beq	2f
+	std	r4,0(r11)		/* store result at *t */
+2:	mtlr	r12
+	crclr	cr0*4+so
+	mr	r3,r4
+	blr
+  .cfi_endproc
+V_FUNCTION_END(__kernel_time)
+
+
+/*
+ * This is the core of clock_gettime() and gettimeofday(),
+ * it returns the current time in r4 (seconds) and r5.
+ * On entry, r7 gives the resolution of r5, either USEC_PER_SEC
+ * or NSEC_PER_SEC, giving r5 in microseconds or nanoseconds.
+ * It expects the datapage ptr in r3 and doesn't clobber it.
+ * It clobbers r0, r6 and r9.
+ * On return, r8 contains the counter value that can be reused.
+ * This clobbers cr0 but not any other cr field.
+ */
+V_FUNCTION_BEGIN(__do_get_tspec)
+  .cfi_startproc
+	/* check for update count & load values */
+1:	ld	r8,CFG_TB_UPDATE_COUNT(r3)
+	andi.	r0,r8,1			/* pending update ? loop */
+	bne-	1b
+	xor	r0,r8,r8		/* create dependency */
+	add	r3,r3,r0
+
+	/* Get TB & offset it. We use the MFTB macro which will generate
+	 * workaround code for Cell.
+	 */
+	MFTB(r6)
+	ld	r9,CFG_TB_ORIG_STAMP(r3)
+	subf	r6,r9,r6
+
+	/* Scale result */
+	ld	r5,CFG_TB_TO_XS(r3)
+	sldi	r6,r6,12		/* compute time since stamp_xtime */
+	mulhdu	r6,r6,r5		/* in units of 2^-32 seconds */
+
+	/* Add stamp since epoch */
+	ld	r4,STAMP_XTIME+TSPC64_TV_SEC(r3)
+	lwz	r5,STAMP_SEC_FRAC(r3)
+	or	r0,r4,r5
+	or	r0,r0,r6
+	xor	r0,r0,r0
+	add	r3,r3,r0
+	ld	r0,CFG_TB_UPDATE_COUNT(r3)
+	cmpld   r0,r8			/* check if updated */
+	bne-	1b			/* reload if so */
+
+	/* convert to seconds & nanoseconds and add to stamp */
+	add	r6,r6,r5		/* add on fractional seconds of xtime */
+	mulhwu	r5,r6,r7		/* compute micro or nanoseconds and */
+	srdi	r6,r6,32		/* seconds since stamp_xtime */
+	clrldi	r5,r5,32
+	add	r4,r4,r6
+	blr
+  .cfi_endproc
+V_FUNCTION_END(__do_get_tspec)