33e1402435
bl;mflr is used at several places to get code position.
Use bcl 20,31,+4 instead of bl in order to preserve link stack.
See commit c974809a26 ("powerpc/vdso: Avoid link stack corruption
in __get_datapage()") for details.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c6eabb4fb6c156f75d56dcbcc6f243e5ac0fba42.1629791763.git.christophe.leroy@csgroup.eu
391 lines
7.3 KiB
ArmAsm
391 lines
7.3 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
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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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*/
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#include <linux/sys.h>
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#include <asm/unistd.h>
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#include <asm/errno.h>
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#include <asm/reg.h>
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#include <asm/page.h>
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#include <asm/cache.h>
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#include <asm/cputable.h>
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#include <asm/mmu.h>
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#include <asm/ppc_asm.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/processor.h>
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#include <asm/bug.h>
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#include <asm/ptrace.h>
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#include <asm/export.h>
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#include <asm/feature-fixups.h>
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.text
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/*
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* This returns the high 64 bits of the product of two 64-bit numbers.
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*/
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_GLOBAL(mulhdu)
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cmpwi r6,0
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cmpwi cr1,r3,0
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mr r10,r4
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mulhwu r4,r4,r5
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beq 1f
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mulhwu r0,r10,r6
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mullw r7,r10,r5
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addc r7,r0,r7
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addze r4,r4
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1: beqlr cr1 /* all done if high part of A is 0 */
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mullw r9,r3,r5
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mulhwu r10,r3,r5
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beq 2f
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mullw r0,r3,r6
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mulhwu r8,r3,r6
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addc r7,r0,r7
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adde r4,r4,r8
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addze r10,r10
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2: addc r4,r4,r9
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addze r3,r10
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blr
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/*
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* reloc_got2 runs through the .got2 section adding an offset
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* to each entry.
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*/
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_GLOBAL(reloc_got2)
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mflr r11
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lis r7,__got2_start@ha
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addi r7,r7,__got2_start@l
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lis r8,__got2_end@ha
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addi r8,r8,__got2_end@l
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subf r8,r7,r8
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srwi. r8,r8,2
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beqlr
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mtctr r8
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bcl 20,31,$+4
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1: mflr r0
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lis r4,1b@ha
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addi r4,r4,1b@l
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subf r0,r4,r0
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add r7,r0,r7
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2: lwz r0,0(r7)
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add r0,r0,r3
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stw r0,0(r7)
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addi r7,r7,4
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bdnz 2b
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mtlr r11
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blr
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/*
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* call_setup_cpu - call the setup_cpu function for this cpu
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* r3 = data offset, r24 = cpu number
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*
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* Setup function is called with:
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* r3 = data offset
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* r4 = ptr to CPU spec (relocated)
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*/
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_GLOBAL(call_setup_cpu)
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addis r4,r3,cur_cpu_spec@ha
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addi r4,r4,cur_cpu_spec@l
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lwz r4,0(r4)
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add r4,r4,r3
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lwz r5,CPU_SPEC_SETUP(r4)
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cmpwi 0,r5,0
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add r5,r5,r3
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beqlr
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mtctr r5
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bctr
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#if defined(CONFIG_CPU_FREQ_PMAC) && defined(CONFIG_PPC_BOOK3S_32)
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/* This gets called by via-pmu.c to switch the PLL selection
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* on 750fx CPU. This function should really be moved to some
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* other place (as most of the cpufreq code in via-pmu
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*/
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_GLOBAL(low_choose_750fx_pll)
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/* Clear MSR:EE */
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mfmsr r7
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rlwinm r0,r7,0,17,15
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mtmsr r0
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/* If switching to PLL1, disable HID0:BTIC */
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cmplwi cr0,r3,0
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beq 1f
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mfspr r5,SPRN_HID0
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rlwinm r5,r5,0,27,25
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sync
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mtspr SPRN_HID0,r5
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isync
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sync
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1:
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/* Calc new HID1 value */
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mfspr r4,SPRN_HID1 /* Build a HID1:PS bit from parameter */
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rlwinm r5,r3,16,15,15 /* Clear out HID1:PS from value read */
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rlwinm r4,r4,0,16,14 /* Could have I used rlwimi here ? */
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or r4,r4,r5
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mtspr SPRN_HID1,r4
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#ifdef CONFIG_SMP
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/* Store new HID1 image */
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lwz r6,TASK_CPU(r2)
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slwi r6,r6,2
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#else
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li r6, 0
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#endif
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addis r6,r6,nap_save_hid1@ha
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stw r4,nap_save_hid1@l(r6)
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/* If switching to PLL0, enable HID0:BTIC */
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cmplwi cr0,r3,0
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bne 1f
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mfspr r5,SPRN_HID0
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ori r5,r5,HID0_BTIC
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sync
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mtspr SPRN_HID0,r5
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isync
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sync
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1:
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/* Return */
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mtmsr r7
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blr
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_GLOBAL(low_choose_7447a_dfs)
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/* Clear MSR:EE */
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mfmsr r7
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rlwinm r0,r7,0,17,15
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mtmsr r0
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/* Calc new HID1 value */
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mfspr r4,SPRN_HID1
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insrwi r4,r3,1,9 /* insert parameter into bit 9 */
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sync
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mtspr SPRN_HID1,r4
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sync
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isync
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/* Return */
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mtmsr r7
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blr
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#endif /* CONFIG_CPU_FREQ_PMAC && CONFIG_PPC_BOOK3S_32 */
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#ifdef CONFIG_40x
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/*
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* Do an IO access in real mode
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*/
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_GLOBAL(real_readb)
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mfmsr r7
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rlwinm r0,r7,0,~MSR_DR
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sync
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mtmsr r0
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sync
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isync
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lbz r3,0(r3)
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sync
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mtmsr r7
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sync
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isync
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blr
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_ASM_NOKPROBE_SYMBOL(real_readb)
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/*
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* Do an IO access in real mode
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*/
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_GLOBAL(real_writeb)
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mfmsr r7
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rlwinm r0,r7,0,~MSR_DR
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sync
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mtmsr r0
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sync
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isync
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stb r3,0(r4)
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sync
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mtmsr r7
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sync
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isync
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blr
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_ASM_NOKPROBE_SYMBOL(real_writeb)
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#endif /* CONFIG_40x */
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/*
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* Copy a whole page. We use the dcbz instruction on the destination
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* to reduce memory traffic (it eliminates the unnecessary reads of
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* the destination into cache). This requires that the destination
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* is cacheable.
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*/
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#define COPY_16_BYTES \
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lwz r6,4(r4); \
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lwz r7,8(r4); \
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lwz r8,12(r4); \
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lwzu r9,16(r4); \
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stw r6,4(r3); \
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stw r7,8(r3); \
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stw r8,12(r3); \
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stwu r9,16(r3)
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_GLOBAL(copy_page)
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rlwinm r5, r3, 0, L1_CACHE_BYTES - 1
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addi r3,r3,-4
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0: twnei r5, 0 /* WARN if r3 is not cache aligned */
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EMIT_WARN_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
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addi r4,r4,-4
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li r5,4
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#if MAX_COPY_PREFETCH > 1
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li r0,MAX_COPY_PREFETCH
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li r11,4
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mtctr r0
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11: dcbt r11,r4
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addi r11,r11,L1_CACHE_BYTES
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bdnz 11b
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#else /* MAX_COPY_PREFETCH == 1 */
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dcbt r5,r4
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li r11,L1_CACHE_BYTES+4
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#endif /* MAX_COPY_PREFETCH */
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li r0,PAGE_SIZE/L1_CACHE_BYTES - MAX_COPY_PREFETCH
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crclr 4*cr0+eq
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2:
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mtctr r0
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1:
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dcbt r11,r4
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dcbz r5,r3
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COPY_16_BYTES
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#if L1_CACHE_BYTES >= 32
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COPY_16_BYTES
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#if L1_CACHE_BYTES >= 64
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COPY_16_BYTES
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COPY_16_BYTES
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#if L1_CACHE_BYTES >= 128
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COPY_16_BYTES
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COPY_16_BYTES
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COPY_16_BYTES
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COPY_16_BYTES
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#endif
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#endif
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#endif
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bdnz 1b
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beqlr
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crnot 4*cr0+eq,4*cr0+eq
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li r0,MAX_COPY_PREFETCH
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li r11,4
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b 2b
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EXPORT_SYMBOL(copy_page)
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/*
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* Extended precision shifts.
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*
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* Updated to be valid for shift counts from 0 to 63 inclusive.
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* -- Gabriel
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*
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* R3/R4 has 64 bit value
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* R5 has shift count
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* result in R3/R4
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*
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* ashrdi3: arithmetic right shift (sign propagation)
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* lshrdi3: logical right shift
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* ashldi3: left shift
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*/
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_GLOBAL(__ashrdi3)
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subfic r6,r5,32
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srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count
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addi r7,r5,32 # could be xori, or addi with -32
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slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count)
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rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0
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sraw r7,r3,r7 # t2 = MSW >> (count-32)
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or r4,r4,r6 # LSW |= t1
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slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2
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sraw r3,r3,r5 # MSW = MSW >> count
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or r4,r4,r7 # LSW |= t2
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blr
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EXPORT_SYMBOL(__ashrdi3)
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_GLOBAL(__ashldi3)
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subfic r6,r5,32
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slw r3,r3,r5 # MSW = count > 31 ? 0 : MSW << count
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addi r7,r5,32 # could be xori, or addi with -32
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srw r6,r4,r6 # t1 = count > 31 ? 0 : LSW >> (32-count)
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slw r7,r4,r7 # t2 = count < 32 ? 0 : LSW << (count-32)
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or r3,r3,r6 # MSW |= t1
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slw r4,r4,r5 # LSW = LSW << count
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or r3,r3,r7 # MSW |= t2
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blr
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EXPORT_SYMBOL(__ashldi3)
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_GLOBAL(__lshrdi3)
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subfic r6,r5,32
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srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count
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addi r7,r5,32 # could be xori, or addi with -32
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slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count)
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srw r7,r3,r7 # t2 = count < 32 ? 0 : MSW >> (count-32)
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or r4,r4,r6 # LSW |= t1
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srw r3,r3,r5 # MSW = MSW >> count
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or r4,r4,r7 # LSW |= t2
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blr
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EXPORT_SYMBOL(__lshrdi3)
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/*
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* 64-bit comparison: __cmpdi2(s64 a, s64 b)
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* Returns 0 if a < b, 1 if a == b, 2 if a > b.
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*/
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_GLOBAL(__cmpdi2)
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cmpw r3,r5
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li r3,1
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bne 1f
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cmplw r4,r6
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beqlr
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1: li r3,0
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bltlr
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li r3,2
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blr
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EXPORT_SYMBOL(__cmpdi2)
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/*
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* 64-bit comparison: __ucmpdi2(u64 a, u64 b)
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* Returns 0 if a < b, 1 if a == b, 2 if a > b.
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*/
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_GLOBAL(__ucmpdi2)
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cmplw r3,r5
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li r3,1
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bne 1f
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cmplw r4,r6
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beqlr
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1: li r3,0
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bltlr
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li r3,2
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blr
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EXPORT_SYMBOL(__ucmpdi2)
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_GLOBAL(__bswapdi2)
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rotlwi r9,r4,8
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rotlwi r10,r3,8
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rlwimi r9,r4,24,0,7
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rlwimi r10,r3,24,0,7
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rlwimi r9,r4,24,16,23
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rlwimi r10,r3,24,16,23
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mr r3,r9
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mr r4,r10
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blr
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EXPORT_SYMBOL(__bswapdi2)
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#ifdef CONFIG_SMP
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_GLOBAL(start_secondary_resume)
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/* Reset stack */
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rlwinm r1, r1, 0, 0, 31 - THREAD_SHIFT
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addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
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li r3,0
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stw r3,0(r1) /* Zero the stack frame pointer */
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bl start_secondary
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b .
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#endif /* CONFIG_SMP */
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