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/*
* linux/arch/arm/mm/proc-xsc3.S
*
* Original Author: Matthew Gilbert
* Current Maintainer: Lennert Buytenhek <buytenh@wantstofly.org>
*
* Copyright 2004 (C) Intel Corp.
* Copyright 2005 (C) MontaVista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* MMU functions for the Intel XScale3 Core (XSC3). The XSC3 core is
* an extension to Intel's original XScale core that adds the following
* features:
*
* - ARMv6 Supersections
* - Low Locality Reference pages (replaces mini-cache)
* - 36-bit addressing
* - L2 cache
* - Cache coherency if chipset supports it
*
* Based on original XScale code by Nicolas Pitre.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/hwcap.h>
#include <asm/pgtable.h>
#include <asm/pgtable-hwdef.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include "proc-macros.S"
/*
* This is the maximum size of an area which will be flushed. If the
* area is larger than this, then we flush the whole cache.
*/
#define MAX_AREA_SIZE 32768
/*
* The cache line size of the L1 I, L1 D and unified L2 cache.
*/
#define CACHELINESIZE 32
/*
* The size of the L1 D cache.
*/
#define CACHESIZE 32768
/*
* This macro is used to wait for a CP15 write and is needed when we
* have to ensure that the last operation to the coprocessor was
* completed before continuing with operation.
*/
.macro cpwait_ret, lr, rd
mrc p15, 0, \rd, c2, c0, 0 @ arbitrary read of cp15
sub pc, \lr, \rd, LSR #32 @ wait for completion and
@ flush instruction pipeline
.endm
/*
* This macro cleans and invalidates the entire L1 D cache.
*/
.macro clean_d_cache rd, rs
mov \rd, #0x1f00
orr \rd, \rd, #0x00e0
1: mcr p15, 0, \rd, c7, c14, 2 @ clean/invalidate L1 D line
adds \rd, \rd, #0x40000000
bcc 1b
subs \rd, \rd, #0x20
bpl 1b
.endm
.text
/*
* cpu_xsc3_proc_init()
*
* Nothing too exciting at the moment
*/
ENTRY(cpu_xsc3_proc_init)
ret lr
/*
* cpu_xsc3_proc_fin()
*/
ENTRY(cpu_xsc3_proc_fin)
mrc p15, 0, r0, c1, c0, 0 @ ctrl register
bic r0, r0, #0x1800 @ ...IZ...........
bic r0, r0, #0x0006 @ .............CA.
mcr p15, 0, r0, c1, c0, 0 @ disable caches
ret lr
/*
* cpu_xsc3_reset(loc)
*
* Perform a soft reset of the system. Put the CPU into the
* same state as it would be if it had been reset, and branch
* to what would be the reset vector.
*
* loc: location to jump to for soft reset
*/
.align 5
.pushsection .idmap.text, "ax"
ENTRY(cpu_xsc3_reset)
mov r1, #PSR_F_BIT|PSR_I_BIT|SVC_MODE
msr cpsr_c, r1 @ reset CPSR
mrc p15, 0, r1, c1, c0, 0 @ ctrl register
bic r1, r1, #0x3900 @ ..VIZ..S........
bic r1, r1, #0x0086 @ ........B....CA.
mcr p15, 0, r1, c1, c0, 0 @ ctrl register
mcr p15, 0, ip, c7, c7, 0 @ invalidate L1 caches and BTB
bic r1, r1, #0x0001 @ ...............M
mcr p15, 0, r1, c1, c0, 0 @ ctrl register
@ CAUTION: MMU turned off from this point. We count on the pipeline
@ already containing those two last instructions to survive.
mcr p15, 0, ip, c8, c7, 0 @ invalidate I and D TLBs
ret r0
ENDPROC(cpu_xsc3_reset)
.popsection
/*
* cpu_xsc3_do_idle()
*
* Cause the processor to idle
*
* For now we do nothing but go to idle mode for every case
*
* XScale supports clock switching, but using idle mode support
* allows external hardware to react to system state changes.
*/
.align 5
ENTRY(cpu_xsc3_do_idle)
mov r0, #1
mcr p14, 0, r0, c7, c0, 0 @ go to idle
ret lr
/* ================================= CACHE ================================ */
/*
* flush_icache_all()
*
* Unconditionally clean and invalidate the entire icache.
*/
ENTRY(xsc3_flush_icache_all)
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
ret lr
ENDPROC(xsc3_flush_icache_all)
/*
* flush_user_cache_all()
*
* Invalidate all cache entries in a particular address
* space.
*/
ENTRY(xsc3_flush_user_cache_all)
/* FALLTHROUGH */
/*
* flush_kern_cache_all()
*
* Clean and invalidate the entire cache.
*/
ENTRY(xsc3_flush_kern_cache_all)
mov r2, #VM_EXEC
mov ip, #0
__flush_whole_cache:
clean_d_cache r0, r1
tst r2, #VM_EXEC
mcrne p15, 0, ip, c7, c5, 0 @ invalidate L1 I cache and BTB
mcrne p15, 0, ip, c7, c10, 4 @ data write barrier
mcrne p15, 0, ip, c7, c5, 4 @ prefetch flush
ret lr
/*
* flush_user_cache_range(start, end, vm_flags)
*
* Invalidate a range of cache entries in the specified
* address space.
*
* - start - start address (may not be aligned)
* - end - end address (exclusive, may not be aligned)
* - vma - vma_area_struct describing address space
*/
.align 5
ENTRY(xsc3_flush_user_cache_range)
mov ip, #0
sub r3, r1, r0 @ calculate total size
cmp r3, #MAX_AREA_SIZE
bhs __flush_whole_cache
1: tst r2, #VM_EXEC
mcrne p15, 0, r0, c7, c5, 1 @ invalidate L1 I line
mcr p15, 0, r0, c7, c14, 1 @ clean/invalidate L1 D line
add r0, r0, #CACHELINESIZE
cmp r0, r1
blo 1b
tst r2, #VM_EXEC
mcrne p15, 0, ip, c7, c5, 6 @ invalidate BTB
mcrne p15, 0, ip, c7, c10, 4 @ data write barrier
mcrne p15, 0, ip, c7, c5, 4 @ prefetch flush
ret lr
/*
* coherent_kern_range(start, end)
*
* Ensure coherency between the I cache and the D cache in the
* region described by start. If you have non-snooping
* Harvard caches, you need to implement this function.
*
* - start - virtual start address
* - end - virtual end address
*
* Note: single I-cache line invalidation isn't used here since
* it also trashes the mini I-cache used by JTAG debuggers.
*/
ENTRY(xsc3_coherent_kern_range)
/* FALLTHROUGH */
ENTRY(xsc3_coherent_user_range)
bic r0, r0, #CACHELINESIZE - 1
1: mcr p15, 0, r0, c7, c10, 1 @ clean L1 D line
add r0, r0, #CACHELINESIZE
cmp r0, r1
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ invalidate L1 I cache and BTB
mcr p15, 0, r0, c7, c10, 4 @ data write barrier
mcr p15, 0, r0, c7, c5, 4 @ prefetch flush
ret lr
/*
* flush_kern_dcache_area(void *addr, size_t size)
*
* Ensure no D cache aliasing occurs, either with itself or
* the I cache.
*
* - addr - kernel address
* - size - region size
*/
ENTRY(xsc3_flush_kern_dcache_area)
add r1, r0, r1
1: mcr p15, 0, r0, c7, c14, 1 @ clean/invalidate L1 D line
add r0, r0, #CACHELINESIZE
cmp r0, r1
blo 1b
mov r0, #0
mcr p15, 0, r0, c7,
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