[mirror_ubuntu-bionic-kernel.git] / arch / powerpc / kernel / vdso64 / gettimeofday.S


	/*
 * 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 <linux/config.h>
#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 */
	bl	V_LOCAL_FUNC(__do_get_xsec)	/* get xsec from tb & kernel */
	lis     r7,15			/* r7 = 1000000 = USEC_PER_SEC */
	ori     r7,r7,16960
	rldicl  r5,r4,44,20		/* r5 = sec = xsec / XSEC_PER_SEC */
	rldicr  r6,r5,20,43		/* r6 = sec * XSEC_PER_SEC */
	std	r5,TVAL64_TV_SEC(r11)	/* store sec in tv */
	subf	r0,r6,r4		/* r0 = xsec = (xsec - r6) */
	mulld   r0,r0,r7		/* usec = (xsec * USEC_PER_SEC) /
					 * XSEC_PER_SEC
					 */
	rldicl  r0,r0,44,20
	cmpldi	cr0,r10,0		/* check if tz is NULL */
	std	r0,TVAL64_TV_USEC(r11)	/* store usec in tv */
	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
	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	r10,r3			/* r10 saves id */
	mr	r11,r4			/* r11 saves tp */
	bl	V_LOCAL_FUNC(__get_datapage)	/* get data page */
	beq	cr1,50f			/* if monotonic -> jump there */

	/*
	 * CLOCK_REALTIME
	 */

	bl	V_LOCAL_FUNC(__do_get_xsec)	/* get xsec from tb & kernel */

	lis     r7,15			/* r7 = 1000000 = USEC_PER_SEC */
	ori     r7,r7,16960
	rldicl  r5,r4,44,20		/* r5 = sec = xsec / XSEC_PER_SEC */
	rldicr  r6,r5,20,43		/* r6 = sec * XSEC_PER_SEC */
	std	r5,TSPC64_TV_SEC(r11)	/* store sec in tv */
	subf	r0,r6,r4		/* r0 = xsec = (xsec - r6) */
	mulld   r0,r0,r7		/* usec = (xsec * USEC_PER_SEC) /
					 * XSEC_PER_SEC
					 */
	rldicl  r0,r0,44,20
	mulli	r0,r0,1000		/* nsec = usec * 1000 */
	std	r0,TSPC64_TV_NSEC(r11)	/* store nsec in tp */

	mtlr	r12
	li	r3,0
	blr

	/*
	 * CLOCK_MONOTONIC
	 */

50:	bl	V_LOCAL_FUNC(__do_get_xsec)	/* get xsec from tb & kernel */

	lis     r7,15			/* r7 = 1000000 = USEC_PER_SEC */
	ori     r7,r7,16960
	rldicl  r5,r4,44,20		/* r5 = sec = xsec / XSEC_PER_SEC */
	rldicr  r6,r5,20,43		/* r6 = sec * XSEC_PER_SEC */
	subf	r0,r6,r4		/* r0 = xsec = (xsec - r6) */
	mulld   r0,r0,r7		/* usec = (xsec * USEC_PER_SEC) /
					 * XSEC_PER_SEC
					 */
	rldicl  r6,r0,44,20
	mulli	r6,r6,1000		/* nsec = usec * 1000 */

	/* 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_xsec.
	 * At this point, r5,r6 contain our sec/nsec values.
	 * can be used
	 */

	lwa	r4,WTOM_CLOCK_SEC(r3)
	lwa	r7,WTOM_CLOCK_NSEC(r3)

	/* We now have our result in r4,r7. We create a fake dependency
	 * on that result and re-check the counter
	 */
	or	r9,r4,r7
	xor	r0,r9,r9
	add	r3,r3,r0
	ld	r0,CFG_TB_UPDATE_COUNT(r3)
        cmpld   cr0,r0,r8		/* check if updated */
	bne-	50b

	/* Calculate and store result. Note that this mimmics the C code,
	 * which may cause funny results if nsec goes negative... is that
	 * possible at all ?
	 */
	add	r4,r4,r5
	add	r7,r7,r6
	lis	r9,NSEC_PER_SEC@h
	ori	r9,r9,NSEC_PER_SEC@l
	cmpl	cr0,r7,r9
	cmpli	cr1,r7,0
	blt	1f
	subf	r7,r9,r7
	addi	r4,r4,1
1:	bge	cr1,1f
	addi	r4,r4,-1
	add	r7,r7,r9
1:	std	r4,TSPC64_TV_SEC(r11)
	std	r7,TSPC64_TV_NSEC(r11)

	mtlr	r12
	li	r3,0
	blr

	/*
	 * syscall fallback
	 */
98:
	mtlr	r12
	mr	r3,r10
	mr	r4,r11
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
	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)


/*
 * This is the core of gettimeofday(), it returns the xsec
 * value in r4 and expects the datapage ptr (non clobbered)
 * in r3. clobbers r0,r4,r5,r6,r7,r8
 * When returning, r8 contains the counter value that can be reused
 */
V_FUNCTION_BEGIN(__do_get_xsec)
  .cfi_startproc
	/* check for update count & load values */
1:	ld	r8,CFG_TB_UPDATE_COUNT(r3)
	andi.	r0,r4,1			/* pending update ? loop */
	bne-	1b
	xor	r0,r4,r4		/* create dependency */
	add	r3,r3,r0

	/* Get TB & offset it */
	mftb	r7
	ld	r9,CFG_TB_ORIG_STAMP(r3)
	subf	r7,r9,r7

	/* Scale result */
	ld	r5,CFG_TB_TO_XS(r3)
	mulhdu	r7,r7,r5

	/* Add stamp since epoch */
	ld	r6,CFG_STAMP_XSEC(r3)
	add	r4,r6,r7

	xor	r0,r4,r4
	add	r3,r3,r0
	ld	r0,CFG_TB_UPDATE_COUNT(r3)
        cmpld   cr0,r0,r8		/* check if updated */
	bne-	1b
	blr
  .cfi_endproc
V_FUNCTION_END(__do_get_xsec)
Commit	Line	Data
0c37ec2a BH	1
0c37ec2a BH	2	/*
a7f290da BH	3	* Userland implementation of gettimeofday() for 64 bits processes in a
	4	* ppc64 kernel for use in the vDSO
	5	*
	6	* Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org),
	7	* IBM Corp.
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
	14	#include <linux/config.h>
	15	#include <asm/processor.h>
	16	#include <asm/ppc_asm.h>
	17	#include <asm/vdso.h>
	18	#include <asm/asm-offsets.h>
	19	#include <asm/unistd.h>
	20
	21	.text
	22	/*
	23	* Exact prototype of gettimeofday
	24	*
	25	* int __kernel_gettimeofday(struct timeval tv, struct timezone tz);
	26	*
	27	*/
	28	V_FUNCTION_BEGIN(__kernel_gettimeofday)
	29	.cfi_startproc
	30	mflr r12
	31	.cfi_register lr,r12
	32
	33	mr r11,r3 /* r11 holds tv */
	34	mr r10,r4 /* r10 holds tz */
	35	bl V_LOCAL_FUNC(__get_datapage) /* get data page */
	36	bl V_LOCAL_FUNC(__do_get_xsec) /* get xsec from tb & kernel */
	37	lis r7,15 /* r7 = 1000000 = USEC_PER_SEC */
	38	ori r7,r7,16960
	39	rldicl r5,r4,44,20 /* r5 = sec = xsec / XSEC_PER_SEC */
	40	rldicr r6,r5,20,43 /* r6 = sec * XSEC_PER_SEC */
	41	std r5,TVAL64_TV_SEC(r11) /* store sec in tv */
	42	subf r0,r6,r4 /* r0 = xsec = (xsec - r6) */
	43	mulld r0,r0,r7 /* usec = (xsec * USEC_PER_SEC) /
	44	* XSEC_PER_SEC
	45	*/
	46	rldicl r0,r0,44,20
	47	cmpldi cr0,r10,0 /* check if tz is NULL */
	48	std r0,TVAL64_TV_USEC(r11) /* store usec in tv */
	49	beq 1f
	50	lwz r4,CFG_TZ_MINUTEWEST(r3)/* fill tz */
	51	lwz r5,CFG_TZ_DSTTIME(r3)
	52	stw r4,TZONE_TZ_MINWEST(r10)
	53	stw r5,TZONE_TZ_DSTTIME(r10)
	54	1: mtlr r12
	55	li r3,0 /* always success */
	56	blr
	57	.cfi_endproc
	58	V_FUNCTION_END(__kernel_gettimeofday)
	59
	60
	61	/*
	62	* Exact prototype of clock_gettime()
	63	*
	64	* int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp);
	65	*
	66	*/
67	V_FUNCTION_BEGIN(__kernel_clock_gettime)
68	.cfi_startproc
69	/* Check for supported clock IDs */
70	cmpwi cr0,r3,CLOCK_REALTIME
71	cmpwi cr1,r3,CLOCK_MONOTONIC
0c37ec2a	72	cror cr04+eq,cr04+eq,cr1*4+eq
a7f290da BH	73	bne cr0,99f
	74
	75	mflr r12 /* r12 saves lr */
	76	.cfi_register lr,r12
	77	mr r10,r3 /* r10 saves id */
	78	mr r11,r4 /* r11 saves tp */
	79	bl V_LOCAL_FUNC(__get_datapage) /* get data page */
	80	beq cr1,50f /* if monotonic -> jump there */
	81
	82	/*
	83	* CLOCK_REALTIME
	84	*/
	85
	86	bl V_LOCAL_FUNC(__do_get_xsec) /* get xsec from tb & kernel */
	87
0c37ec2a BH	88	lis r7,15 /* r7 = 1000000 = USEC_PER_SEC */
0c37ec2a BH	89	ori r7,r7,16960
a7f290da BH	90	rldicl r5,r4,44,20 /* r5 = sec = xsec / XSEC_PER_SEC */
	91	rldicr r6,r5,20,43 /* r6 = sec * XSEC_PER_SEC */
	92	std r5,TSPC64_TV_SEC(r11) /* store sec in tv */
	93	subf r0,r6,r4 /* r0 = xsec = (xsec - r6) */
0c37ec2a	94	mulld r0,r0,r7 /* usec = (xsec * USEC_PER_SEC) /
a7f290da BH	95	* XSEC_PER_SEC
	96	*/
	97	rldicl r0,r0,44,20
0c37ec2a	98	mulli r0,r0,1000 /* nsec = usec * 1000 */
a7f290da BH	99	std r0,TSPC64_TV_NSEC(r11) /* store nsec in tp */
	100
	101	mtlr r12
	102	li r3,0
	103	blr
	104
	105	/*
	106	* CLOCK_MONOTONIC
	107	*/
	108
	109	50: bl V_LOCAL_FUNC(__do_get_xsec) /* get xsec from tb & kernel */
	110
0c37ec2a BH	111	lis r7,15 /* r7 = 1000000 = USEC_PER_SEC */
0c37ec2a BH	112	ori r7,r7,16960
a7f290da BH	113	rldicl r5,r4,44,20 /* r5 = sec = xsec / XSEC_PER_SEC */
	114	rldicr r6,r5,20,43 /* r6 = sec * XSEC_PER_SEC */
	115	subf r0,r6,r4 /* r0 = xsec = (xsec - r6) */
0c37ec2a	116	mulld r0,r0,r7 /* usec = (xsec * USEC_PER_SEC) /
a7f290da BH	117	* XSEC_PER_SEC
	118	*/
	119	rldicl r6,r0,44,20
0c37ec2a	120	mulli r6,r6,1000 /* nsec = usec * 1000 */
a7f290da BH	121
	122	/* now we must fixup using wall to monotonic. We need to snapshot
	123	* that value and do the counter trick again. Fortunately, we still
	124	* have the counter value in r8 that was returned by __do_get_xsec.
	125	* At this point, r5,r6 contain our sec/nsec values.
	126	* can be used
	127	*/
	128
0c37ec2a BH	129	lwa r4,WTOM_CLOCK_SEC(r3)
0c37ec2a BH	130	lwa r7,WTOM_CLOCK_NSEC(r3)
a7f290da BH	131
	132	/* We now have our result in r4,r7. We create a fake dependency
	133	* on that result and re-check the counter
	134	*/
	135	or r9,r4,r7
	136	xor r0,r9,r9
	137	add r3,r3,r0
	138	ld r0,CFG_TB_UPDATE_COUNT(r3)
	139	cmpld cr0,r0,r8 /* check if updated */
	140	bne- 50b
	141
	142	/* Calculate and store result. Note that this mimmics the C code,
	143	* which may cause funny results if nsec goes negative... is that
	144	* possible at all ?
	145	*/
	146	add r4,r4,r5
	147	add r7,r7,r6
	148	lis r9,NSEC_PER_SEC@h
	149	ori r9,r9,NSEC_PER_SEC@l
0c37ec2a BH	150	cmpl cr0,r7,r9
0c37ec2a BH	151	cmpli cr1,r7,0
a7f290da BH	152	blt 1f
	153	subf r7,r9,r7
	154	addi r4,r4,1
0c37ec2a BH	155	1: bge cr1,1f
	156	addi r4,r4,-1
	157	add r7,r7,r9
a7f290da BH	158	1: std r4,TSPC64_TV_SEC(r11)
	159	std r7,TSPC64_TV_NSEC(r11)
	160
	161	mtlr r12
	162	li r3,0
	163	blr
	164
	165	/*
	166	* syscall fallback
	167	*/
	168	98:
	169	mtlr r12
	170	mr r3,r10
	171	mr r4,r11
	172	99:
	173	li r0,__NR_clock_gettime
	174	sc
	175	blr
	176	.cfi_endproc
	177	V_FUNCTION_END(__kernel_clock_gettime)
	178
	179
	180	/*
	181	* Exact prototype of clock_getres()
	182	*
	183	* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res);
	184	*
	185	*/
	186	V_FUNCTION_BEGIN(__kernel_clock_getres)
	187	.cfi_startproc
	188	/* Check for supported clock IDs */
	189	cmpwi cr0,r3,CLOCK_REALTIME
	190	cmpwi cr1,r3,CLOCK_MONOTONIC
0c37ec2a	191	cror cr04+eq,cr04+eq,cr1*4+eq
a7f290da BH	192	bne cr0,99f
	193
	194	li r3,0
	195	cmpli cr0,r4,0
	196	beqlr
	197	lis r5,CLOCK_REALTIME_RES@h
	198	ori r5,r5,CLOCK_REALTIME_RES@l
	199	std r3,TSPC64_TV_SEC(r4)
	200	std r5,TSPC64_TV_NSEC(r4)
	201	blr
	202
	203	/*
	204	* syscall fallback
	205	*/
	206	99:
	207	li r0,__NR_clock_getres
	208	sc
	209	blr
	210	.cfi_endproc
	211	V_FUNCTION_END(__kernel_clock_getres)
	212
	213
	214	/*
	215	* This is the core of gettimeofday(), it returns the xsec
	216	* value in r4 and expects the datapage ptr (non clobbered)
	217	* in r3. clobbers r0,r4,r5,r6,r7,r8
	218	* When returning, r8 contains the counter value that can be reused
	219	*/
	220	V_FUNCTION_BEGIN(__do_get_xsec)
	221	.cfi_startproc
	222	/* check for update count & load values */
	223	1: ld r8,CFG_TB_UPDATE_COUNT(r3)
	224	andi. r0,r4,1 /* pending update ? loop */
	225	bne- 1b
	226	xor r0,r4,r4 /* create dependency */
	227	add r3,r3,r0
	228
	229	/* Get TB & offset it */
	230	mftb r7
	231	ld r9,CFG_TB_ORIG_STAMP(r3)
	232	subf r7,r9,r7
	233
	234	/* Scale result */
	235	ld r5,CFG_TB_TO_XS(r3)
	236	mulhdu r7,r7,r5
	237
	238	/* Add stamp since epoch */
	239	ld r6,CFG_STAMP_XSEC(r3)
	240	add r4,r6,r7
	241
	242	xor r0,r4,r4
	243	add r3,r3,r0
	244	ld r0,CFG_TB_UPDATE_COUNT(r3)
	245	cmpld cr0,r0,r8 /* check if updated */
	246	bne- 1b
	247	blr
	248	.cfi_endproc
	249	V_FUNCTION_END(__do_get_xsec)