372 lines
8.2 KiB
ArmAsm
372 lines
8.2 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* linux/arch/arm/kernel/iwmmxt.S
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*
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* XScale iWMMXt (Concan) context switching and handling
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*
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* Initial code:
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* Copyright (c) 2003, Intel Corporation
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*
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* Full lazy switching support, optimizations and more, by Nicolas Pitre
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* Copyright (c) 2003-2004, MontaVista Software, Inc.
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*/
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#include <linux/linkage.h>
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#include <asm/ptrace.h>
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#include <asm/thread_info.h>
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#include <asm/asm-offsets.h>
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#include <asm/assembler.h>
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#include "iwmmxt.h"
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#if defined(CONFIG_CPU_PJ4) || defined(CONFIG_CPU_PJ4B)
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#define PJ4(code...) code
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#define XSC(code...)
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#elif defined(CONFIG_CPU_MOHAWK) || \
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defined(CONFIG_CPU_XSC3) || \
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defined(CONFIG_CPU_XSCALE)
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#define PJ4(code...)
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#define XSC(code...) code
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#else
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#error "Unsupported iWMMXt architecture"
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#endif
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#define MMX_WR0 (0x00)
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#define MMX_WR1 (0x08)
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#define MMX_WR2 (0x10)
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#define MMX_WR3 (0x18)
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#define MMX_WR4 (0x20)
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#define MMX_WR5 (0x28)
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#define MMX_WR6 (0x30)
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#define MMX_WR7 (0x38)
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#define MMX_WR8 (0x40)
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#define MMX_WR9 (0x48)
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#define MMX_WR10 (0x50)
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#define MMX_WR11 (0x58)
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#define MMX_WR12 (0x60)
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#define MMX_WR13 (0x68)
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#define MMX_WR14 (0x70)
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#define MMX_WR15 (0x78)
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#define MMX_WCSSF (0x80)
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#define MMX_WCASF (0x84)
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#define MMX_WCGR0 (0x88)
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#define MMX_WCGR1 (0x8C)
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#define MMX_WCGR2 (0x90)
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#define MMX_WCGR3 (0x94)
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#define MMX_SIZE (0x98)
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.text
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.arm
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/*
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* Lazy switching of Concan coprocessor context
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*
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* r10 = struct thread_info pointer
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* r9 = ret_from_exception
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* lr = undefined instr exit
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*
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* called from prefetch exception handler with interrupts enabled
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*/
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ENTRY(iwmmxt_task_enable)
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inc_preempt_count r10, r3
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XSC(mrc p15, 0, r2, c15, c1, 0)
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PJ4(mrc p15, 0, r2, c1, c0, 2)
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@ CP0 and CP1 accessible?
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XSC(tst r2, #0x3)
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PJ4(tst r2, #0xf)
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bne 4f @ if so no business here
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@ enable access to CP0 and CP1
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XSC(orr r2, r2, #0x3)
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XSC(mcr p15, 0, r2, c15, c1, 0)
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PJ4(orr r2, r2, #0xf)
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PJ4(mcr p15, 0, r2, c1, c0, 2)
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ldr r3, =concan_owner
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add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
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ldr r2, [sp, #60] @ current task pc value
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ldr r1, [r3] @ get current Concan owner
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str r0, [r3] @ this task now owns Concan regs
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sub r2, r2, #4 @ adjust pc back
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str r2, [sp, #60]
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mrc p15, 0, r2, c2, c0, 0
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mov r2, r2 @ cpwait
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bl concan_save
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#ifdef CONFIG_PREEMPT_COUNT
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get_thread_info r10
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#endif
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4: dec_preempt_count r10, r3
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ret r9 @ normal exit from exception
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concan_save:
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teq r1, #0 @ test for last ownership
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beq concan_load @ no owner, skip save
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tmrc r2, wCon
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@ CUP? wCx
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tst r2, #0x1
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beq 1f
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concan_dump:
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wstrw wCSSF, r1, MMX_WCSSF
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wstrw wCASF, r1, MMX_WCASF
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wstrw wCGR0, r1, MMX_WCGR0
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wstrw wCGR1, r1, MMX_WCGR1
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wstrw wCGR2, r1, MMX_WCGR2
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wstrw wCGR3, r1, MMX_WCGR3
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1: @ MUP? wRn
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tst r2, #0x2
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beq 2f
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wstrd wR0, r1, MMX_WR0
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wstrd wR1, r1, MMX_WR1
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wstrd wR2, r1, MMX_WR2
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wstrd wR3, r1, MMX_WR3
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wstrd wR4, r1, MMX_WR4
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wstrd wR5, r1, MMX_WR5
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wstrd wR6, r1, MMX_WR6
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wstrd wR7, r1, MMX_WR7
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wstrd wR8, r1, MMX_WR8
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wstrd wR9, r1, MMX_WR9
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wstrd wR10, r1, MMX_WR10
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wstrd wR11, r1, MMX_WR11
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wstrd wR12, r1, MMX_WR12
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wstrd wR13, r1, MMX_WR13
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wstrd wR14, r1, MMX_WR14
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wstrd wR15, r1, MMX_WR15
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2: teq r0, #0 @ anything to load?
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reteq lr @ if not, return
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concan_load:
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@ Load wRn
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wldrd wR0, r0, MMX_WR0
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wldrd wR1, r0, MMX_WR1
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wldrd wR2, r0, MMX_WR2
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wldrd wR3, r0, MMX_WR3
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wldrd wR4, r0, MMX_WR4
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wldrd wR5, r0, MMX_WR5
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wldrd wR6, r0, MMX_WR6
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wldrd wR7, r0, MMX_WR7
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wldrd wR8, r0, MMX_WR8
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wldrd wR9, r0, MMX_WR9
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wldrd wR10, r0, MMX_WR10
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wldrd wR11, r0, MMX_WR11
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wldrd wR12, r0, MMX_WR12
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wldrd wR13, r0, MMX_WR13
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wldrd wR14, r0, MMX_WR14
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wldrd wR15, r0, MMX_WR15
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@ Load wCx
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wldrw wCSSF, r0, MMX_WCSSF
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wldrw wCASF, r0, MMX_WCASF
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wldrw wCGR0, r0, MMX_WCGR0
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wldrw wCGR1, r0, MMX_WCGR1
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wldrw wCGR2, r0, MMX_WCGR2
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wldrw wCGR3, r0, MMX_WCGR3
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@ clear CUP/MUP (only if r1 != 0)
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teq r1, #0
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mov r2, #0
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reteq lr
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tmcr wCon, r2
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ret lr
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ENDPROC(iwmmxt_task_enable)
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/*
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* Back up Concan regs to save area and disable access to them
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* (mainly for gdb or sleep mode usage)
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*
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* r0 = struct thread_info pointer of target task or NULL for any
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*/
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ENTRY(iwmmxt_task_disable)
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stmfd sp!, {r4, lr}
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mrs ip, cpsr
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orr r2, ip, #PSR_I_BIT @ disable interrupts
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msr cpsr_c, r2
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ldr r3, =concan_owner
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add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
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ldr r1, [r3] @ get current Concan owner
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teq r1, #0 @ any current owner?
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beq 1f @ no: quit
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teq r0, #0 @ any owner?
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teqne r1, r2 @ or specified one?
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bne 1f @ no: quit
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@ enable access to CP0 and CP1
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XSC(mrc p15, 0, r4, c15, c1, 0)
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XSC(orr r4, r4, #0x3)
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XSC(mcr p15, 0, r4, c15, c1, 0)
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PJ4(mrc p15, 0, r4, c1, c0, 2)
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PJ4(orr r4, r4, #0xf)
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PJ4(mcr p15, 0, r4, c1, c0, 2)
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mov r0, #0 @ nothing to load
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str r0, [r3] @ no more current owner
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mrc p15, 0, r2, c2, c0, 0
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mov r2, r2 @ cpwait
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bl concan_save
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@ disable access to CP0 and CP1
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XSC(bic r4, r4, #0x3)
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XSC(mcr p15, 0, r4, c15, c1, 0)
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PJ4(bic r4, r4, #0xf)
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PJ4(mcr p15, 0, r4, c1, c0, 2)
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mrc p15, 0, r2, c2, c0, 0
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mov r2, r2 @ cpwait
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1: msr cpsr_c, ip @ restore interrupt mode
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ldmfd sp!, {r4, pc}
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ENDPROC(iwmmxt_task_disable)
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/*
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* Copy Concan state to given memory address
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*
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* r0 = struct thread_info pointer of target task
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* r1 = memory address where to store Concan state
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*
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* this is called mainly in the creation of signal stack frames
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*/
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ENTRY(iwmmxt_task_copy)
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mrs ip, cpsr
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orr r2, ip, #PSR_I_BIT @ disable interrupts
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msr cpsr_c, r2
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ldr r3, =concan_owner
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add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
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ldr r3, [r3] @ get current Concan owner
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teq r2, r3 @ does this task own it...
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beq 1f
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@ current Concan values are in the task save area
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msr cpsr_c, ip @ restore interrupt mode
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mov r0, r1
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mov r1, r2
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mov r2, #MMX_SIZE
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b memcpy
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1: @ this task owns Concan regs -- grab a copy from there
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mov r0, #0 @ nothing to load
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mov r2, #3 @ save all regs
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mov r3, lr @ preserve return address
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bl concan_dump
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msr cpsr_c, ip @ restore interrupt mode
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ret r3
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ENDPROC(iwmmxt_task_copy)
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/*
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* Restore Concan state from given memory address
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*
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* r0 = struct thread_info pointer of target task
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* r1 = memory address where to get Concan state from
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*
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* this is used to restore Concan state when unwinding a signal stack frame
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*/
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ENTRY(iwmmxt_task_restore)
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mrs ip, cpsr
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orr r2, ip, #PSR_I_BIT @ disable interrupts
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msr cpsr_c, r2
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ldr r3, =concan_owner
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add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
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ldr r3, [r3] @ get current Concan owner
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bic r2, r2, #0x7 @ 64-bit alignment
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teq r2, r3 @ does this task own it...
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beq 1f
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@ this task doesn't own Concan regs -- use its save area
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msr cpsr_c, ip @ restore interrupt mode
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mov r0, r2
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mov r2, #MMX_SIZE
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b memcpy
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1: @ this task owns Concan regs -- load them directly
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mov r0, r1
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mov r1, #0 @ don't clear CUP/MUP
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mov r3, lr @ preserve return address
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bl concan_load
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msr cpsr_c, ip @ restore interrupt mode
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ret r3
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ENDPROC(iwmmxt_task_restore)
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/*
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* Concan handling on task switch
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*
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* r0 = next thread_info pointer
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*
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* Called only from the iwmmxt notifier with task preemption disabled.
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*/
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ENTRY(iwmmxt_task_switch)
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XSC(mrc p15, 0, r1, c15, c1, 0)
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PJ4(mrc p15, 0, r1, c1, c0, 2)
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@ CP0 and CP1 accessible?
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XSC(tst r1, #0x3)
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PJ4(tst r1, #0xf)
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bne 1f @ yes: block them for next task
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ldr r2, =concan_owner
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add r3, r0, #TI_IWMMXT_STATE @ get next task Concan save area
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ldr r2, [r2] @ get current Concan owner
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teq r2, r3 @ next task owns it?
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retne lr @ no: leave Concan disabled
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1: @ flip Concan access
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XSC(eor r1, r1, #0x3)
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XSC(mcr p15, 0, r1, c15, c1, 0)
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PJ4(eor r1, r1, #0xf)
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PJ4(mcr p15, 0, r1, c1, c0, 2)
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mrc p15, 0, r1, c2, c0, 0
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sub pc, lr, r1, lsr #32 @ cpwait and return
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ENDPROC(iwmmxt_task_switch)
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/*
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* Remove Concan ownership of given task
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*
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* r0 = struct thread_info pointer
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*/
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ENTRY(iwmmxt_task_release)
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mrs r2, cpsr
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orr ip, r2, #PSR_I_BIT @ disable interrupts
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msr cpsr_c, ip
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ldr r3, =concan_owner
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add r0, r0, #TI_IWMMXT_STATE @ get task Concan save area
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ldr r1, [r3] @ get current Concan owner
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eors r0, r0, r1 @ if equal...
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streq r0, [r3] @ then clear ownership
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msr cpsr_c, r2 @ restore interrupts
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ret lr
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ENDPROC(iwmmxt_task_release)
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.data
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.align 2
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concan_owner:
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.word 0
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