56 lines
1.3 KiB
ArmAsm
56 lines
1.3 KiB
ArmAsm
/*
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* Coherency fabric: low level functions
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*
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* Copyright (C) 2012 Marvell
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*
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* Gregory CLEMENT <gregory.clement@free-electrons.com>
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*
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* This file implements the assembly function to add a CPU to the
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* coherency fabric. This function is called by each of the secondary
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* CPUs during their early boot in an SMP kernel, this why this
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* function have to callable from assembly. It can also be called by a
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* primary CPU from C code during its boot.
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*/
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#include <linux/linkage.h>
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#define ARMADA_XP_CFB_CTL_REG_OFFSET 0x0
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#define ARMADA_XP_CFB_CFG_REG_OFFSET 0x4
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.text
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/*
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* r0: Coherency fabric base register address
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* r1: HW CPU id
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*/
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ENTRY(ll_set_cpu_coherent)
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/* Create bit by cpu index */
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mov r3, #(1 << 24)
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lsl r1, r3, r1
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/* Add CPU to SMP group - Atomic */
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add r3, r0, #ARMADA_XP_CFB_CTL_REG_OFFSET
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1:
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ldrex r2, [r3]
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orr r2, r2, r1
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strex r0, r2, [r3]
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cmp r0, #0
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bne 1b
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/* Enable coherency on CPU - Atomic */
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add r3, r3, #ARMADA_XP_CFB_CFG_REG_OFFSET
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1:
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ldrex r2, [r3]
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orr r2, r2, r1
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strex r0, r2, [r3]
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cmp r0, #0
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bne 1b
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dsb
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mov r0, #0
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mov pc, lr
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ENDPROC(ll_set_cpu_coherent)
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