![Lorenzo Pieralisi](/assets/img/avatar_default.png)
ARM v7 architecture introduced the concept of cache levels and related control registers. New processors like A7 and A15 embed an L2 unified cache controller that becomes part of the cache level hierarchy. Some operations in the kernel like cpu_suspend and __cpu_disable do not require a flush of the entire cache hierarchy to DRAM but just the cache levels belonging to the Level of Unification Inner Shareable (LoUIS), which in most of ARM v7 systems correspond to L1. The current cache flushing API used in cpu_suspend and __cpu_disable, flush_cache_all(), ends up flushing the whole cache hierarchy since for v7 it cleans and invalidates all cache levels up to Level of Coherency (LoC) which cripples system performance when used in hot paths like hotplug and cpuidle. Therefore a new kernel cache maintenance API must be added to cope with latest ARM system requirements. This patch adds flush_cache_louis() to the ARM kernel cache maintenance API. This function cleans and invalidates all data cache levels up to the Level of Unification Inner Shareable (LoUIS) and invalidates the instruction cache for processors that support it (> v7). This patch also creates an alias of the cache LoUIS function to flush_kern_all for all processor versions prior to v7, so that the current cache flushing behaviour is unchanged for those processors. v7 cache maintenance code implements a cache LoUIS function that cleans and invalidates the D-cache up to LoUIS and invalidates the I-cache, according to the new API. Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Shawn Guo <shawn.guo@linaro.org>
432 lines
11 KiB
ArmAsm
432 lines
11 KiB
ArmAsm
/*
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* linux/arch/arm/mm/arm946.S: utility functions for ARM946E-S
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*
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* Copyright (C) 2004-2006 Hyok S. Choi (hyok.choi@samsung.com)
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*
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* (Many of cache codes are from proc-arm926.S)
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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 version 2 as
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* published by the Free Software Foundation.
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*
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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/hwcap.h>
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#include <asm/pgtable-hwdef.h>
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#include <asm/pgtable.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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* ARM946E-S is synthesizable to have 0KB to 1MB sized D-Cache,
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* comprising 256 lines of 32 bytes (8 words).
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*/
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#define CACHE_DSIZE (CONFIG_CPU_DCACHE_SIZE) /* typically 8KB. */
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#define CACHE_DLINESIZE 32 /* fixed */
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#define CACHE_DSEGMENTS 4 /* fixed */
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#define CACHE_DENTRIES (CACHE_DSIZE / CACHE_DSEGMENTS / CACHE_DLINESIZE)
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#define CACHE_DLIMIT (CACHE_DSIZE * 4) /* benchmark needed */
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.text
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/*
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* cpu_arm946_proc_init()
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* cpu_arm946_switch_mm()
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*
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* These are not required.
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*/
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ENTRY(cpu_arm946_proc_init)
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ENTRY(cpu_arm946_switch_mm)
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mov pc, lr
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/*
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* cpu_arm946_proc_fin()
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*/
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ENTRY(cpu_arm946_proc_fin)
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mrc p15, 0, r0, c1, c0, 0 @ ctrl register
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bic r0, r0, #0x00001000 @ i-cache
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bic r0, r0, #0x00000004 @ d-cache
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mcr p15, 0, r0, c1, c0, 0 @ disable caches
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mov pc, lr
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/*
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* cpu_arm946_reset(loc)
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* Params : r0 = address to jump to
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* Notes : This sets up everything for a reset
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*/
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.pushsection .idmap.text, "ax"
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ENTRY(cpu_arm946_reset)
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mov ip, #0
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mcr p15, 0, ip, c7, c5, 0 @ flush I cache
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mcr p15, 0, ip, c7, c6, 0 @ flush D cache
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mcr p15, 0, ip, c7, c10, 4 @ drain WB
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mrc p15, 0, ip, c1, c0, 0 @ ctrl register
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bic ip, ip, #0x00000005 @ .............c.p
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bic ip, ip, #0x00001000 @ i-cache
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mcr p15, 0, ip, c1, c0, 0 @ ctrl register
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mov pc, r0
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ENDPROC(cpu_arm946_reset)
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.popsection
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/*
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* cpu_arm946_do_idle()
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*/
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.align 5
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ENTRY(cpu_arm946_do_idle)
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mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt
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mov pc, lr
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/*
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* flush_icache_all()
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*
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* Unconditionally clean and invalidate the entire icache.
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*/
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ENTRY(arm946_flush_icache_all)
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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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mov pc, lr
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ENDPROC(arm946_flush_icache_all)
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/*
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* flush_user_cache_all()
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*/
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ENTRY(arm946_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(arm946_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 @ flush D cache
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#else
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mov r1, #(CACHE_DSEGMENTS - 1) << 29 @ 4 segments
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1: orr r3, r1, #(CACHE_DENTRIES - 1) << 4 @ n entries
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2: mcr p15, 0, r3, c7, c14, 2 @ clean/flush D index
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subs r3, r3, #1 << 4
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bcs 2b @ entries n to 0
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subs r1, r1, #1 << 29
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bcs 1b @ segments 3 to 0
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#endif
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tst r2, #VM_EXEC
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mcrne p15, 0, ip, c7, c5, 0 @ flush 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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* (same as arm926)
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*/
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ENTRY(arm946_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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bhs __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(arm946_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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* (same as arm926)
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*/
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ENTRY(arm946_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 r0, #0
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mov pc, lr
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/*
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* flush_kern_dcache_area(void *addr, size_t size)
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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 - kernel address
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* - size - region size
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* (same as arm926)
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*/
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ENTRY(arm946_flush_kern_dcache_area)
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add r1, r0, r1
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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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* (same as arm926)
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*/
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arm946_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 arm926)
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*/
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arm946_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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* (same as arm926)
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*/
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ENTRY(arm946_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, c6, 1 @ invalidate 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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/*
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* dma_map_area(start, size, dir)
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* - start - kernel virtual start address
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* - size - size of region
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* - dir - DMA direction
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*/
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ENTRY(arm946_dma_map_area)
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add r1, r1, r0
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cmp r2, #DMA_TO_DEVICE
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beq arm946_dma_clean_range
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bcs arm946_dma_inv_range
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b arm946_dma_flush_range
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ENDPROC(arm946_dma_map_area)
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/*
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* dma_unmap_area(start, size, dir)
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* - start - kernel virtual start address
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* - size - size of region
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* - dir - DMA direction
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*/
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ENTRY(arm946_dma_unmap_area)
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mov pc, lr
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ENDPROC(arm946_dma_unmap_area)
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.globl arm946_flush_kern_cache_louis
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.equ arm946_flush_kern_cache_louis, arm946_flush_kern_cache_all
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@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
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define_cache_functions arm946
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ENTRY(cpu_arm946_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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__CPUINIT
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.type __arm946_setup, #function
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__arm946_setup:
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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, c6, 0 @ invalidate D cache
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mcr p15, 0, r0, c7, c10, 4 @ drain WB
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mcr p15, 0, r0, c6, c3, 0 @ disable memory region 3~7
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mcr p15, 0, r0, c6, c4, 0
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mcr p15, 0, r0, c6, c5, 0
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mcr p15, 0, r0, c6, c6, 0
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mcr p15, 0, r0, c6, c7, 0
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mov r0, #0x0000003F @ base = 0, size = 4GB
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mcr p15, 0, r0, c6, c0, 0 @ set region 0, default
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ldr r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM
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ldr r1, =(CONFIG_DRAM_SIZE >> 12) @ size of RAM (must be >= 4KB)
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mov r2, #10 @ 11 is the minimum (4KB)
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1: add r2, r2, #1 @ area size *= 2
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mov r1, r1, lsr #1
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bne 1b @ count not zero r-shift
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orr r0, r0, r2, lsl #1 @ the region register value
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orr r0, r0, #1 @ set enable bit
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mcr p15, 0, r0, c6, c1, 0 @ set region 1, RAM
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ldr r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH
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ldr r1, =(CONFIG_FLASH_SIZE >> 12) @ size of FLASH (must be >= 4KB)
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mov r2, #10 @ 11 is the minimum (4KB)
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1: add r2, r2, #1 @ area size *= 2
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mov r1, r1, lsr #1
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bne 1b @ count not zero r-shift
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orr r0, r0, r2, lsl #1 @ the region register value
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orr r0, r0, #1 @ set enable bit
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mcr p15, 0, r0, c6, c2, 0 @ set region 2, ROM/FLASH
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mov r0, #0x06
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mcr p15, 0, r0, c2, c0, 0 @ region 1,2 d-cacheable
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mcr p15, 0, r0, c2, c0, 1 @ region 1,2 i-cacheable
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#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
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mov r0, #0x00 @ disable whole write buffer
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#else
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mov r0, #0x02 @ region 1 write bufferred
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#endif
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mcr p15, 0, r0, c3, c0, 0
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/*
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* Access Permission Settings for future permission control by PU.
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*
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* priv. user
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* region 0 (whole) rw -- : b0001
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* region 1 (RAM) rw rw : b0011
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* region 2 (FLASH) rw r- : b0010
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* region 3~7 (none) -- -- : b0000
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*/
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mov r0, #0x00000031
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orr r0, r0, #0x00000200
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mcr p15, 0, r0, c5, c0, 2 @ set data access permission
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mcr p15, 0, r0, c5, c0, 3 @ set inst. access permission
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mrc p15, 0, r0, c1, c0 @ get control register
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orr r0, r0, #0x00001000 @ I-cache
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orr r0, r0, #0x00000005 @ MPU/D-cache
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#ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
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orr r0, r0, #0x00004000 @ .1.. .... .... ....
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#endif
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mov pc, lr
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.size __arm946_setup, . - __arm946_setup
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__INITDATA
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@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
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define_processor_functions arm946, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
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.section ".rodata"
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string cpu_arch_name, "armv5te"
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string cpu_elf_name, "v5t"
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string cpu_arm946_name, "ARM946E-S"
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.align
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.section ".proc.info.init", #alloc, #execinstr
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.type __arm946_proc_info,#object
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__arm946_proc_info:
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.long 0x41009460
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.long 0xff00fff0
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.long 0
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.long 0
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b __arm946_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
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.long cpu_arm946_name
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.long arm946_processor_functions
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.long 0
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.long 0
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.long arm946_cache_fns
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.size __arm946_proc_info, . - __arm946_proc_info
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