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2874c5fd28
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
83 lines
1.9 KiB
ArmAsm
83 lines
1.9 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* Copied from <file:arch/powerpc/kernel/misc_32.S>
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*
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* This file contains miscellaneous low-level functions.
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
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* and Paul Mackerras.
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*
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* kexec bits:
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* Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
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* GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
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*/
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#include "ppc_asm.h"
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#define SPRN_PVR 0x11F /* Processor Version Register */
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.text
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/* udelay (on non-601 processors) needs to know the period of the
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* timebase in nanoseconds. This used to be hardcoded to be 60ns
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* (period of 66MHz/4). Now a variable is used that is initialized to
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* 60 for backward compatibility, but it can be overridden as necessary
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* with code something like this:
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* extern unsigned long timebase_period_ns;
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* timebase_period_ns = 1000000000 / bd->bi_tbfreq;
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*/
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.data
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.globl timebase_period_ns
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timebase_period_ns:
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.long 60
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.text
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/*
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* Delay for a number of microseconds
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*/
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.globl udelay
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udelay:
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mfspr r4,SPRN_PVR
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srwi r4,r4,16
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cmpwi 0,r4,1 /* 601 ? */
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bne .Ludelay_not_601
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00: li r0,86 /* Instructions / microsecond? */
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mtctr r0
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10: addi r0,r0,0 /* NOP */
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bdnz 10b
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subic. r3,r3,1
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bne 00b
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blr
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.Ludelay_not_601:
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mulli r4,r3,1000 /* nanoseconds */
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/* Change r4 to be the number of ticks using:
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* (nanoseconds + (timebase_period_ns - 1 )) / timebase_period_ns
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* timebase_period_ns defaults to 60 (16.6MHz) */
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mflr r5
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bl 0f
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0: mflr r6
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mtlr r5
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lis r5,0b@ha
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addi r5,r5,0b@l
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subf r5,r5,r6 /* In case we're relocated */
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addis r5,r5,timebase_period_ns@ha
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lwz r5,timebase_period_ns@l(r5)
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add r4,r4,r5
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addi r4,r4,-1
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divw r4,r4,r5 /* BUS ticks */
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1: MFTBU(r5)
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MFTBL(r6)
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MFTBU(r7)
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cmpw 0,r5,r7
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bne 1b /* Get [synced] base time */
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addc r9,r6,r4 /* Compute end time */
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addze r8,r5
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2: MFTBU(r5)
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cmpw 0,r5,r8
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blt 2b
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bgt 3f
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MFTBL(r6)
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cmpw 0,r6,r9
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blt 2b
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3: blr
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