0214f9221a
Jon Eibertzon writes: > We have noticed that the I-cache is disabled while waiting for > interrupt in cpu_arm926_do_idle in arch/arm/mm/proc-arm926.S > and we are curious to know why, because this causes us a great > performance hit when executing in FIQ-handlers. Is it assumed > here that every individual FIQ-handler re-enables the I-cache? The I-cache disable is an errata workaround, so the solution is to disable FIQs across the section with the I-cache disabled. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
494 lines
12 KiB
ArmAsm
494 lines
12 KiB
ArmAsm
/*
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* linux/arch/arm/mm/proc-arm926.S: MMU functions for ARM926EJ-S
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*
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* Copyright (C) 1999-2001 ARM Limited
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* Copyright (C) 2000 Deep Blue Solutions Ltd.
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* hacked for non-paged-MM by Hyok S. Choi, 2003.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*
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* These are the low level assembler for performing cache and TLB
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* functions on the arm926.
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*
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* CONFIG_CPU_ARM926_CPU_IDLE -> nohlt
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*/
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#include <linux/linkage.h>
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#include <linux/init.h>
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#include <asm/assembler.h>
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#include <asm/elf.h>
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#include <asm/pgtable-hwdef.h>
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#include <asm/pgtable.h>
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#include <asm/page.h>
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#include <asm/ptrace.h>
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#include "proc-macros.S"
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/*
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* This is the maximum size of an area which will be invalidated
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* using the single invalidate entry instructions. Anything larger
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* than this, and we go for the whole cache.
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*
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* This value should be chosen such that we choose the cheapest
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* alternative.
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*/
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#define CACHE_DLIMIT 16384
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/*
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* the cache line size of the I and D cache
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*/
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#define CACHE_DLINESIZE 32
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.text
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/*
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* cpu_arm926_proc_init()
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*/
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ENTRY(cpu_arm926_proc_init)
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mov pc, lr
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/*
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* cpu_arm926_proc_fin()
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*/
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ENTRY(cpu_arm926_proc_fin)
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stmfd sp!, {lr}
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mov ip, #PSR_F_BIT | PSR_I_BIT | SVC_MODE
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msr cpsr_c, ip
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bl arm926_flush_kern_cache_all
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mrc p15, 0, r0, c1, c0, 0 @ ctrl register
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bic r0, r0, #0x1000 @ ...i............
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bic r0, r0, #0x000e @ ............wca.
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mcr p15, 0, r0, c1, c0, 0 @ disable caches
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ldmfd sp!, {pc}
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/*
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* cpu_arm926_reset(loc)
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*
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* Perform a soft reset of the system. Put the CPU into the
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* same state as it would be if it had been reset, and branch
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* to what would be the reset vector.
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*
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* loc: location to jump to for soft reset
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*/
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.align 5
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ENTRY(cpu_arm926_reset)
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mov ip, #0
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mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches
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mcr p15, 0, ip, c7, c10, 4 @ drain WB
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#ifdef CONFIG_MMU
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mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
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#endif
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mrc p15, 0, ip, c1, c0, 0 @ ctrl register
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bic ip, ip, #0x000f @ ............wcam
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bic ip, ip, #0x1100 @ ...i...s........
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mcr p15, 0, ip, c1, c0, 0 @ ctrl register
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mov pc, r0
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/*
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* cpu_arm926_do_idle()
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*
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* Called with IRQs disabled
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*/
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.align 10
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ENTRY(cpu_arm926_do_idle)
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mov r0, #0
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mrc p15, 0, r1, c1, c0, 0 @ Read control register
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mcr p15, 0, r0, c7, c10, 4 @ Drain write buffer
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bic r2, r1, #1 << 12
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mrs r3, cpsr @ Disable FIQs while Icache
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orr ip, r3, #PSR_F_BIT @ is disabled
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msr cpsr_c, ip
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mcr p15, 0, r2, c1, c0, 0 @ Disable I cache
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mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt
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mcr p15, 0, r1, c1, c0, 0 @ Restore ICache enable
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msr cpsr_c, r3 @ Restore FIQ state
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mov pc, lr
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/*
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* flush_user_cache_all()
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*
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* Clean and invalidate all cache entries in a particular
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* address space.
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*/
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ENTRY(arm926_flush_user_cache_all)
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/* FALLTHROUGH */
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/*
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* flush_kern_cache_all()
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*
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* Clean and invalidate the entire cache.
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*/
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ENTRY(arm926_flush_kern_cache_all)
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mov r2, #VM_EXEC
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mov ip, #0
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__flush_whole_cache:
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#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
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mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
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#else
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1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate
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bne 1b
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#endif
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tst r2, #VM_EXEC
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mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
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mcrne p15, 0, ip, c7, c10, 4 @ drain WB
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mov pc, lr
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/*
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* flush_user_cache_range(start, end, flags)
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*
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* Clean and invalidate a range of cache entries in the
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* specified address range.
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*
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* - start - start address (inclusive)
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* - end - end address (exclusive)
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* - flags - vm_flags describing address space
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*/
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ENTRY(arm926_flush_user_cache_range)
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mov ip, #0
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sub r3, r1, r0 @ calculate total size
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cmp r3, #CACHE_DLIMIT
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bgt __flush_whole_cache
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1: tst r2, #VM_EXEC
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#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
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mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
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mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
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add r0, r0, #CACHE_DLINESIZE
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mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
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mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
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add r0, r0, #CACHE_DLINESIZE
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#else
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mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry
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mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
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add r0, r0, #CACHE_DLINESIZE
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mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry
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mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
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add r0, r0, #CACHE_DLINESIZE
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#endif
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cmp r0, r1
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blo 1b
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tst r2, #VM_EXEC
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mcrne p15, 0, ip, c7, c10, 4 @ drain WB
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mov pc, lr
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/*
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* coherent_kern_range(start, end)
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*
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* Ensure coherency between the Icache and the Dcache in the
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* region described by start, end. If you have non-snooping
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* Harvard caches, you need to implement this function.
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*
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* - start - virtual start address
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* - end - virtual end address
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*/
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ENTRY(arm926_coherent_kern_range)
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/* FALLTHROUGH */
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/*
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* coherent_user_range(start, end)
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*
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* Ensure coherency between the Icache and the Dcache in the
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* region described by start, end. If you have non-snooping
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* Harvard caches, you need to implement this function.
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*
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* - start - virtual start address
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* - end - virtual end address
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*/
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ENTRY(arm926_coherent_user_range)
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bic r0, r0, #CACHE_DLINESIZE - 1
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1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
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mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry
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add r0, r0, #CACHE_DLINESIZE
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cmp r0, r1
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blo 1b
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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mov pc, lr
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/*
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* flush_kern_dcache_page(void *page)
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*
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* Ensure no D cache aliasing occurs, either with itself or
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* the I cache
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*
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* - addr - page aligned address
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*/
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ENTRY(arm926_flush_kern_dcache_page)
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add r1, r0, #PAGE_SZ
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1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
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add r0, r0, #CACHE_DLINESIZE
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cmp r0, r1
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blo 1b
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mov r0, #0
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mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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mov pc, lr
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/*
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* dma_inv_range(start, end)
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*
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* Invalidate (discard) the specified virtual address range.
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* May not write back any entries. If 'start' or 'end'
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* are not cache line aligned, those lines must be written
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* back.
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*
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* - start - virtual start address
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* - end - virtual end address
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*
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* (same as v4wb)
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*/
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ENTRY(arm926_dma_inv_range)
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#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
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tst r0, #CACHE_DLINESIZE - 1
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mcrne p15, 0, r0, c7, c10, 1 @ clean D entry
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tst r1, #CACHE_DLINESIZE - 1
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mcrne p15, 0, r1, c7, c10, 1 @ clean D entry
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#endif
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bic r0, r0, #CACHE_DLINESIZE - 1
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1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
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add r0, r0, #CACHE_DLINESIZE
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cmp r0, r1
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blo 1b
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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mov pc, lr
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/*
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* dma_clean_range(start, end)
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*
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* Clean the specified virtual address range.
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*
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* - start - virtual start address
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* - end - virtual end address
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*
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* (same as v4wb)
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*/
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ENTRY(arm926_dma_clean_range)
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#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
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bic r0, r0, #CACHE_DLINESIZE - 1
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1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
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add r0, r0, #CACHE_DLINESIZE
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cmp r0, r1
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blo 1b
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#endif
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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mov pc, lr
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/*
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* dma_flush_range(start, end)
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*
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* Clean and invalidate the specified virtual address range.
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*
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* - start - virtual start address
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* - end - virtual end address
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*/
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ENTRY(arm926_dma_flush_range)
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bic r0, r0, #CACHE_DLINESIZE - 1
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1:
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#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
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mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
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#else
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mcr p15, 0, r0, c7, c10, 1 @ clean D entry
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#endif
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add r0, r0, #CACHE_DLINESIZE
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cmp r0, r1
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blo 1b
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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mov pc, lr
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ENTRY(arm926_cache_fns)
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.long arm926_flush_kern_cache_all
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.long arm926_flush_user_cache_all
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.long arm926_flush_user_cache_range
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.long arm926_coherent_kern_range
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.long arm926_coherent_user_range
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.long arm926_flush_kern_dcache_page
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.long arm926_dma_inv_range
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.long arm926_dma_clean_range
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.long arm926_dma_flush_range
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ENTRY(cpu_arm926_dcache_clean_area)
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#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
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1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
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add r0, r0, #CACHE_DLINESIZE
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subs r1, r1, #CACHE_DLINESIZE
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bhi 1b
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#endif
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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mov pc, lr
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/* =============================== PageTable ============================== */
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/*
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* cpu_arm926_switch_mm(pgd)
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*
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* Set the translation base pointer to be as described by pgd.
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*
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* pgd: new page tables
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*/
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.align 5
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ENTRY(cpu_arm926_switch_mm)
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#ifdef CONFIG_MMU
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mov ip, #0
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#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
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mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
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#else
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@ && 'Clean & Invalidate whole DCache'
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1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate
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bne 1b
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#endif
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mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
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mcr p15, 0, ip, c7, c10, 4 @ drain WB
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mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
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mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
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#endif
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mov pc, lr
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/*
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* cpu_arm926_set_pte_ext(ptep, pte, ext)
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*
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* Set a PTE and flush it out
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*/
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.align 5
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ENTRY(cpu_arm926_set_pte_ext)
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#ifdef CONFIG_MMU
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str r1, [r0], #-2048 @ linux version
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eor r1, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY
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bic r2, r1, #PTE_SMALL_AP_MASK
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bic r2, r2, #PTE_TYPE_MASK
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orr r2, r2, #PTE_TYPE_SMALL
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tst r1, #L_PTE_USER @ User?
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orrne r2, r2, #PTE_SMALL_AP_URO_SRW
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tst r1, #L_PTE_WRITE | L_PTE_DIRTY @ Write and Dirty?
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orreq r2, r2, #PTE_SMALL_AP_UNO_SRW
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tst r1, #L_PTE_PRESENT | L_PTE_YOUNG @ Present and Young?
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movne r2, #0
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#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
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eor r3, r2, #0x0a @ C & small page?
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tst r3, #0x0b
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biceq r2, r2, #4
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#endif
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str r2, [r0] @ hardware version
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mov r0, r0
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#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
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mcr p15, 0, r0, c7, c10, 1 @ clean D entry
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#endif
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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#endif
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mov pc, lr
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__INIT
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.type __arm926_setup, #function
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__arm926_setup:
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mov r0, #0
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mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4
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mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4
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#ifdef CONFIG_MMU
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mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4
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#endif
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#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
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mov r0, #4 @ disable write-back on caches explicitly
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mcr p15, 7, r0, c15, c0, 0
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#endif
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adr r5, arm926_crval
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ldmia r5, {r5, r6}
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mrc p15, 0, r0, c1, c0 @ get control register v4
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bic r0, r0, r5
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orr r0, r0, r6
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#ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
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orr r0, r0, #0x4000 @ .1.. .... .... ....
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#endif
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mov pc, lr
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.size __arm926_setup, . - __arm926_setup
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/*
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* R
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* .RVI ZFRS BLDP WCAM
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* .011 0001 ..11 0101
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*
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*/
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.type arm926_crval, #object
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arm926_crval:
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crval clear=0x00007f3f, mmuset=0x00003135, ucset=0x00001134
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__INITDATA
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/*
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* Purpose : Function pointers used to access above functions - all calls
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* come through these
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*/
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.type arm926_processor_functions, #object
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arm926_processor_functions:
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.word v5tj_early_abort
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.word cpu_arm926_proc_init
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.word cpu_arm926_proc_fin
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.word cpu_arm926_reset
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.word cpu_arm926_do_idle
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.word cpu_arm926_dcache_clean_area
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.word cpu_arm926_switch_mm
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.word cpu_arm926_set_pte_ext
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.size arm926_processor_functions, . - arm926_processor_functions
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.section ".rodata"
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.type cpu_arch_name, #object
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cpu_arch_name:
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.asciz "armv5tej"
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.size cpu_arch_name, . - cpu_arch_name
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.type cpu_elf_name, #object
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cpu_elf_name:
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.asciz "v5"
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.size cpu_elf_name, . - cpu_elf_name
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.type cpu_arm926_name, #object
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cpu_arm926_name:
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.asciz "ARM926EJ-S"
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.size cpu_arm926_name, . - cpu_arm926_name
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.align
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.section ".proc.info.init", #alloc, #execinstr
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.type __arm926_proc_info,#object
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__arm926_proc_info:
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.long 0x41069260 @ ARM926EJ-S (v5TEJ)
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.long 0xff0ffff0
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.long PMD_TYPE_SECT | \
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PMD_SECT_BUFFERABLE | \
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PMD_SECT_CACHEABLE | \
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PMD_BIT4 | \
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PMD_SECT_AP_WRITE | \
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PMD_SECT_AP_READ
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.long PMD_TYPE_SECT | \
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PMD_BIT4 | \
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PMD_SECT_AP_WRITE | \
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PMD_SECT_AP_READ
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b __arm926_setup
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.long cpu_arch_name
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.long cpu_elf_name
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.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA
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.long cpu_arm926_name
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.long arm926_processor_functions
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.long v4wbi_tlb_fns
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.long v4wb_user_fns
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.long arm926_cache_fns
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.size __arm926_proc_info, . - __arm926_proc_info
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