[apple/xnu.git] / pexpert / ppc / pe_clock_speed_asm.s

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 *  clock_speed_asm.s - Uses the Via timer, decrementer, and counter
 *			to determine the clock and bus rates.
 *
 *  (c) Apple Computer, Inc. 1998-9
 *
 *  Writen by:	 Josh de Cesare
 *
 */

#include <ppc/asm.h>

// constants for the via
#define CountLow  0x800
#define CountHigh 0xa00
#define LatchLow  0xc00
#define LatchHigh 0xe00


// void pe_run_clock_test(clock_test_data *data)
//
// data points to the base address of the via and two longs
// for storing the via and dec results.
//
// The basic idea is this...
// Use the counter register to execute a loop that will take
// 10,000,000 processor clocks.  Time it using both the via counter
// and the time base.  Return the number of ticks for both so the
// raw values for processor and bus speed can be calculated.
ENTRY(pe_run_clock_test, TAG_NO_FRAME_USED)

	li	r4,	1		; flag for cache load
	li	r5,	1		; Only once through this time
	lwz	r9,	0(r3)		; r9 is the via addr

L_again:
	mtctr	r5			; set the count
	li	r5,	0xff		; Start the counter at 0xffff
	stb	r5,	CountLow(r9)	; clear the via counter
	eieio
	stb	r5,	CountHigh(r9)
	eieio
	mftb	r10			; save starting value of the time base
	isync

L_loop:
	addi	r5,	r5,	1	; 8 adds for 8 cycles
	addi	r5,	r5,	2	; the bdnz should be 0 cycles
	addi	r5,	r5,	3
	addi	r5,	r5,	4
	addi	r5,	r5,	5
	addi	r5,	r5,	6
	addi	r5,	r5,	7
	addi	r5,	r5,	8
	bdnz	L_loop

	sync
	mftb	r5			; save the raw time base value
	lbz	r6,	CountHigh(r9)	; get the via counter values
	eieio
	lbz	r7,	CountLow(r9)
	eieio
	lbz	r8,	CountHigh(r9)
	eieio

	cmpi	cr0,	r4,	1	; see if the was the cache run
	bne	L_finish_up		; nope, we are done.

	li	r4,	0		; set flag for the real test
	li	r5,	0x12d0		; set the initial count to 1.25e+6
	oris	r5,	r5,	0x13
	b	L_again

L_finish_up:
	cmpi    cr0,    r7,     0	; if L1 is zero then H1 is good. 
	beq     L_use_H1		; else H2 will be good.

	mr      r6,     r8		; use H2 instead.

L_use_H1:
	rlwimi	r7,	r6,	8, 16, 23
	not	r6,	r7	        ; neg - 1 is not
	andi.	r6,	r6,	0xffff
	stw	r6,	4(r3)		; save via ticks

	sub	r5,	r5,	r10	; r5 is the number of time base ticks
	stw	r5,	8(r3)		; save time base ticks

        blr
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
de355530 A	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
1c79356b	11	*
de355530 A	12	* This Original Code and all software distributed under the License are
de355530 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
de355530 A	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
1c79356b A	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* clock_speed_asm.s - Uses the Via timer, decrementer, and counter
	24	* to determine the clock and bus rates.
	25	*
	26	* (c) Apple Computer, Inc. 1998-9
	27	*
	28	* Writen by: Josh de Cesare
	29	*
	30	*/
	31
	32	#include <ppc/asm.h>
	33
	34	// constants for the via
	35	#define CountLow 0x800
	36	#define CountHigh 0xa00
	37	#define LatchLow 0xc00
	38	#define LatchHigh 0xe00
	39
	40
	41	// void pe_run_clock_test(clock_test_data *data)
	42	//
	43	// data points to the base address of the via and two longs
	44	// for storing the via and dec results.
	45	//
	46	// The basic idea is this...
	47	// Use the counter register to execute a loop that will take
	48	// 10,000,000 processor clocks. Time it using both the via counter
	49	// and the time base. Return the number of ticks for both so the
	50	// raw values for processor and bus speed can be calculated.
	51	ENTRY(pe_run_clock_test, TAG_NO_FRAME_USED)
	52
	53	li r4, 1 ; flag for cache load
	54	li r5, 1 ; Only once through this time
	55	lwz r9, 0(r3) ; r9 is the via addr
	56
	57	L_again:
	58	mtctr r5 ; set the count
	59	li r5, 0xff ; Start the counter at 0xffff
	60	stb r5, CountLow(r9) ; clear the via counter
	61	eieio
	62	stb r5, CountHigh(r9)
	63	eieio
	64	mftb r10 ; save starting value of the time base
	65	isync
	66
	67	L_loop:
	68	addi r5, r5, 1 ; 8 adds for 8 cycles
	69	addi r5, r5, 2 ; the bdnz should be 0 cycles
	70	addi r5, r5, 3
	71	addi r5, r5, 4
	72	addi r5, r5, 5
	73	addi r5, r5, 6
	74	addi r5, r5, 7
	75	addi r5, r5, 8
	76	bdnz L_loop
	77
	78	sync
	79	mftb r5 ; save the raw time base value
	80	lbz r6, CountHigh(r9) ; get the via counter values
	81	eieio
	82	lbz r7, CountLow(r9)
83	eieio
84	lbz r8, CountHigh(r9)
85	eieio
86
87	cmpi cr0, r4, 1 ; see if the was the cache run
88	bne L_finish_up ; nope, we are done.
89
90	li r4, 0 ; set flag for the real test
91	li r5, 0x12d0 ; set the initial count to 1.25e+6
92	oris r5, r5, 0x13
93	b L_again
94
95	L_finish_up:
96	cmpi cr0, r7, 0 ; if L1 is zero then H1 is good.
97	beq L_use_H1 ; else H2 will be good.
98
99	mr r6, r8 ; use H2 instead.
100
101	L_use_H1:
102	rlwimi r7, r6, 8, 16, 23
103	not r6, r7 ; neg - 1 is not
104	andi. r6, r6, 0xffff
105	stw r6, 4(r3) ; save via ticks
106
107	sub r5, r5, r10 ; r5 is the number of time base ticks
108	stw r5, 8(r3) ; save time base ticks
109
110	blr