/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* linux/arch/arm/mm/arm940.S: utility functions for ARM940T
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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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#include <linux/linkage.h>
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#include <linux/init.h>
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#include <linux/pgtable.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/ptrace.h>
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#include "proc-macros.S"
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/* ARM940T has a 4KB DCache comprising 256 lines of 4 words */
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#define CACHE_DLINESIZE 16
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#define CACHE_DSEGMENTS 4
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#define CACHE_DENTRIES 64
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.text
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/*
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* cpu_arm940_proc_init()
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* cpu_arm940_switch_mm()
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*
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* These are not required.
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*/
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ENTRY(cpu_arm940_proc_init)
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ENTRY(cpu_arm940_switch_mm)
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ret lr
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/*
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* cpu_arm940_proc_fin()
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*/
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ENTRY(cpu_arm940_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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ret lr
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/*
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* cpu_arm940_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_arm940_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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ret r0
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ENDPROC(cpu_arm940_reset)
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.popsection
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/*
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* cpu_arm940_do_idle()
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*/
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.align 5
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ENTRY(cpu_arm940_do_idle)
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mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt
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ret 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(arm940_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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ret lr
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ENDPROC(arm940_flush_icache_all)
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/*
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* flush_user_cache_all()
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*/
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ENTRY(arm940_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(arm940_flush_kern_cache_all)
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mov r2, #VM_EXEC
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/* FALLTHROUGH */
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/*
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* flush_user_cache_range(start, end, flags)
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*
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* There is no efficient way to flush a range of cache entries
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* in the specified address range. Thus, flushes all.
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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(arm940_flush_user_cache_range)
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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 @ flush D cache
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#else
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mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
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1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 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 << 26
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bcs 2b @ entries 63 to 0
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subs r1, r1, #1 << 4
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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 @ invalidate I cache
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mcrne p15, 0, ip, c7, c10, 4 @ drain WB
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ret 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(arm940_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(arm940_coherent_user_range)
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/* FALLTHROUGH */
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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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*/
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ENTRY(arm940_flush_kern_dcache_area)
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mov r0, #0
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mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
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1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 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 << 26
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bcs 2b @ entries 63 to 0
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subs r1, r1, #1 << 4
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bcs 1b @ segments 7 to 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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ret lr
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/*
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* dma_inv_range(start, end)
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*
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* There is no efficient way to invalidate a specifid virtual
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* address range. Thus, invalidates all.
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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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arm940_dma_inv_range:
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mov ip, #0
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mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
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1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
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2: mcr p15, 0, r3, c7, c6, 2 @ flush D entry
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subs r3, r3, #1 << 26
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bcs 2b @ entries 63 to 0
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subs r1, r1, #1 << 4
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bcs 1b @ segments 7 to 0
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mcr p15, 0, ip, c7, c10, 4 @ drain WB
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ret lr
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/*
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* dma_clean_range(start, end)
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*
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* There is no efficient way to clean a specifid virtual
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* address range. Thus, cleans all.
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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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arm940_dma_clean_range:
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ENTRY(cpu_arm940_dcache_clean_area)
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mov ip, #0
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#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
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mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
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1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
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2: mcr p15, 0, r3, c7, c10, 2 @ clean D entry
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subs r3, r3, #1 << 26
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bcs 2b @ entries 63 to 0
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subs r1, r1, #1 << 4
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bcs 1b @ segments 7 to 0
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#endif
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mcr p15, 0, ip, c7, c10, 4 @ drain WB
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ret lr
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/*
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* dma_flush_range(start, end)
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*
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* There is no efficient way to clean and invalidate a specifid
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* 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(arm940_dma_flush_range)
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mov ip, #0
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mov r1, #(CACHE_DSEGMENTS - 1) << 4 @ 4 segments
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1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
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2:
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#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
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mcr p15, 0, r3, c7, c14, 2 @ clean/flush D entry
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#else
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mcr p15, 0, r3, c7, c6, 2 @ invalidate D entry
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#endif
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subs r3, r3, #1 << 26
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bcs 2b @ entries 63 to 0
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subs r1, r1, #1 << 4
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bcs 1b @ segments 7 to 0
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mcr p15, 0, ip, c7, c10, 4 @ drain WB
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ret 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(arm940_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 arm940_dma_clean_range
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bcs arm940_dma_inv_range
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b arm940_dma_flush_range
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ENDPROC(arm940_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(arm940_dma_unmap_area)
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ret lr
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ENDPROC(arm940_dma_unmap_area)
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.globl arm940_flush_kern_cache_louis
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.equ arm940_flush_kern_cache_louis, arm940_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 arm940
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.type __arm940_setup, #function
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__arm940_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 data area 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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mcr p15, 0, r0, c6, c3, 1 @ disable instruction area 3~7
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mcr p15, 0, r0, c6, c4, 1
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mcr p15, 0, r0, c6, c5, 1
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mcr p15, 0, r0, c6, c6, 1
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mcr p15, 0, r0, c6, c7, 1
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mov r0, #0x0000003F @ base = 0, size = 4GB
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mcr p15, 0, r0, c6, c0, 0 @ set area 0, default
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mcr p15, 0, r0, c6, c0, 1
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ldr r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM
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ldr r7, =CONFIG_DRAM_SIZE >> 12 @ size of RAM (must be >= 4KB)
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pr_val r3, r0, r7, #1
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mcr p15, 0, r3, c6, c1, 0 @ set area 1, RAM
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mcr p15, 0, r3, c6, c1, 1
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ldr r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH
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ldr r7, =CONFIG_FLASH_SIZE @ size of FLASH (must be >= 4KB)
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pr_val r3, r0, r6, #1
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mcr p15, 0, r3, c6, c2, 0 @ set area 2, ROM/FLASH
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mcr p15, 0, r3, c6, c2, 1
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mov r0, #0x06
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mcr p15, 0, r0, c2, c0, 0 @ Region 1&2 cacheable
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mcr p15, 0, r0, c2, c0, 1
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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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mov r0, #0x10000
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sub r0, r0, #1 @ r0 = 0xffff
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mcr p15, 0, r0, c5, c0, 0 @ all read/write access
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mcr p15, 0, r0, c5, c0, 1
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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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ret lr
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.size __arm940_setup, . - __arm940_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 arm940, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
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.section ".rodata"
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string cpu_arch_name, "armv4t"
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string cpu_elf_name, "v4"
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string cpu_arm940_name, "ARM940T"
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.align
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.section ".proc.info.init", "a"
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.type __arm940_proc_info,#object
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__arm940_proc_info:
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.long 0x41009400
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.long 0xff00fff0
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.long 0
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initfn __arm940_setup, __arm940_proc_info
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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_arm940_name
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.long arm940_processor_functions
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.long 0
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.long 0
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.long arm940_cache_fns
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.size __arm940_proc_info, . - __arm940_proc_info
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