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linux-hardened/arch/arm/mm/proc-arm920.S
Russell King 22b1908610 [ARM] nommu: provide a way for correct control register value selection 
Most MMU-based CPUs have a restriction on the setting of the data cache
enable and mmu enable bits in the control register, whereby if the data
cache is enabled, the MMU must also be enabled.  Enabling the data
cache without the MMU is an invalid combination.

However, there are CPUs where the data cache can be enabled without the
MMU.

In order to allow these CPUs to take advantage of that, provide a
method whereby each proc-*.S file defines the control regsiter value
for use with nommu (with the MMU disabled.)  Later on, when we add
support for enabling the MMU on these devices, we can adjust the
"crval" macro to also enable the data cache for nommu.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-29 15:09:57 +01:00

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/*
* linux/arch/arm/mm/proc-arm920.S: MMU functions for ARM920
*
* Copyright (C) 1999,2000 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd.
* hacked for non-paged-MM by Hyok S. Choi, 2003.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* These are the low level assembler for performing cache and TLB
* functions on the arm920.
*
* CONFIG_CPU_ARM920_CPU_IDLE -> nohlt
*/
#include <linux/linkage.h>
#include <linux/config.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include <asm/procinfo.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include "proc-macros.S"
/*
* The size of one data cache line.
*/
#define CACHE_DLINESIZE 32
/*
* The number of data cache segments.
*/
#define CACHE_DSEGMENTS 8
/*
* The number of lines in a cache segment.
*/
#define CACHE_DENTRIES 64
/*
* This is the size at which it becomes more efficient to
* clean the whole cache, rather than using the individual
* cache line maintainence instructions.
*/
#define CACHE_DLIMIT 65536
.text
/*
* cpu_arm920_proc_init()
*/
ENTRY(cpu_arm920_proc_init)
mov pc, lr
/*
* cpu_arm920_proc_fin()
*/
ENTRY(cpu_arm920_proc_fin)
stmfd sp!, {lr}
mov ip, #PSR_F_BIT | PSR_I_BIT | SVC_MODE
msr cpsr_c, ip
#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
bl arm920_flush_kern_cache_all
#else
bl v4wt_flush_kern_cache_all
#endif
mrc p15, 0, r0, c1, c0, 0 @ ctrl register
bic r0, r0, #0x1000 @ ...i............
bic r0, r0, #0x000e @ ............wca.
mcr p15, 0, r0, c1, c0, 0 @ disable caches
ldmfd sp!, {pc}
/*
* cpu_arm920_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
ENTRY(cpu_arm920_reset)
mov ip, #0
mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches
mcr p15, 0, ip, c7, c10, 4 @ drain WB
#ifdef CONFIG_MMU
mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
#endif
mrc p15, 0, ip, c1, c0, 0 @ ctrl register
bic ip, ip, #0x000f @ ............wcam
bic ip, ip, #0x1100 @ ...i...s........
mcr p15, 0, ip, c1, c0, 0 @ ctrl register
mov pc, r0
/*
* cpu_arm920_do_idle()
*/
.align 5
ENTRY(cpu_arm920_do_idle)
mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt
mov pc, lr
#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
/*
* flush_user_cache_all()
*
* Invalidate all cache entries in a particular address
* space.
*/
ENTRY(arm920_flush_user_cache_all)
/* FALLTHROUGH */
/*
* flush_kern_cache_all()
*
* Clean and invalidate the entire cache.
*/
ENTRY(arm920_flush_kern_cache_all)
mov r2, #VM_EXEC
mov ip, #0
__flush_whole_cache:
mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 8 segments
1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2: mcr p15, 0, r3, c7, c14, 2 @ clean+invalidate D index
subs r3, r3, #1 << 26
bcs 2b @ entries 63 to 0
subs r1, r1, #1 << 5
bcs 1b @ segments 7 to 0
tst r2, #VM_EXEC
mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcrne p15, 0, ip, c7, c10, 4 @ drain WB
mov pc, lr
/*
* flush_user_cache_range(start, end, flags)
*
* Invalidate a range of cache entries in the specified
* address space.
*
* - start - start address (inclusive)
* - end - end address (exclusive)
* - flags - vm_flags for address space
*/
ENTRY(arm920_flush_user_cache_range)
mov ip, #0
sub r3, r1, r0 @ calculate total size
cmp r3, #CACHE_DLIMIT
bhs __flush_whole_cache
1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
tst r2, #VM_EXEC
mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
tst r2, #VM_EXEC
mcrne p15, 0, ip, c7, c10, 4 @ drain WB
mov pc, lr
/*
* coherent_kern_range(start, end)
*
* Ensure coherency between the Icache and the Dcache in the
* region described by start, end. If you have non-snooping
* Harvard caches, you need to implement this function.
*
* - start - virtual start address
* - end - virtual end address
*/
ENTRY(arm920_coherent_kern_range)
/* FALLTHROUGH */
/*
* coherent_user_range(start, end)
*
* Ensure coherency between the Icache and the Dcache in the
* region described by start, end. If you have non-snooping
* Harvard caches, you need to implement this function.
*
* - start - virtual start address
* - end - virtual end address
*/
ENTRY(arm920_coherent_user_range)
bic r0, r0, #CACHE_DLINESIZE - 1
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
mov pc, lr
/*
* flush_kern_dcache_page(void *page)
*
* Ensure no D cache aliasing occurs, either with itself or
* the I cache
*
* - addr - page aligned address
*/
ENTRY(arm920_flush_kern_dcache_page)
add r1, r0, #PAGE_SZ
1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
mcr p15, 0, r0, c7, c10, 4 @ drain WB
mov pc, lr
/*
* dma_inv_range(start, end)
*
* Invalidate (discard) the specified virtual address range.
* May not write back any entries. If 'start' or 'end'
* are not cache line aligned, those lines must be written
* back.
*
* - start - virtual start address
* - end - virtual end address
*
* (same as v4wb)
*/
ENTRY(arm920_dma_inv_range)
tst r0, #CACHE_DLINESIZE - 1
bic r0, r0, #CACHE_DLINESIZE - 1
mcrne p15, 0, r0, c7, c10, 1 @ clean D entry
tst r1, #CACHE_DLINESIZE - 1
mcrne p15, 0, r1, c7, c10, 1 @ clean D entry
1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
mov pc, lr
/*
* dma_clean_range(start, end)
*
* Clean the specified virtual address range.
*
* - start - virtual start address
* - end - virtual end address
*
* (same as v4wb)
*/
ENTRY(arm920_dma_clean_range)
bic r0, r0, #CACHE_DLINESIZE - 1
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
mov pc, lr
/*
* dma_flush_range(start, end)
*
* Clean and invalidate the specified virtual address range.
*
* - start - virtual start address
* - end - virtual end address
*/
ENTRY(arm920_dma_flush_range)
bic r0, r0, #CACHE_DLINESIZE - 1
1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ drain WB
mov pc, lr
ENTRY(arm920_cache_fns)
.long arm920_flush_kern_cache_all
.long arm920_flush_user_cache_all
.long arm920_flush_user_cache_range
.long arm920_coherent_kern_range
.long arm920_coherent_user_range
.long arm920_flush_kern_dcache_page
.long arm920_dma_inv_range
.long arm920_dma_clean_range
.long arm920_dma_flush_range
#endif
ENTRY(cpu_arm920_dcache_clean_area)
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #CACHE_DLINESIZE
subs r1, r1, #CACHE_DLINESIZE
bhi 1b
mov pc, lr
/* =============================== PageTable ============================== */
/*
* cpu_arm920_switch_mm(pgd)
*
* Set the translation base pointer to be as described by pgd.
*
* pgd: new page tables
*/
.align 5
ENTRY(cpu_arm920_switch_mm)
#ifdef CONFIG_MMU
mov ip, #0
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
#else
@ && 'Clean & Invalidate whole DCache'
@ && Re-written to use Index Ops.
@ && Uses registers r1, r3 and ip
mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 8 segments
1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index
subs r3, r3, #1 << 26
bcs 2b @ entries 63 to 0
subs r1, r1, #1 << 5
bcs 1b @ segments 7 to 0
#endif
mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcr p15, 0, ip, c7, c10, 4 @ drain WB
mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
#endif
mov pc, lr
/*
* cpu_arm920_set_pte(ptep, pte)
*
* Set a PTE and flush it out
*/
.align 5
ENTRY(cpu_arm920_set_pte)
#ifdef CONFIG_MMU
str r1, [r0], #-2048 @ linux version
eor r1, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY
bic r2, r1, #PTE_SMALL_AP_MASK
bic r2, r2, #PTE_TYPE_MASK
orr r2, r2, #PTE_TYPE_SMALL
tst r1, #L_PTE_USER @ User?
orrne r2, r2, #PTE_SMALL_AP_URO_SRW
tst r1, #L_PTE_WRITE | L_PTE_DIRTY @ Write and Dirty?
orreq r2, r2, #PTE_SMALL_AP_UNO_SRW
tst r1, #L_PTE_PRESENT | L_PTE_YOUNG @ Present and Young?
movne r2, #0
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
eor r3, r2, #0x0a @ C & small page?
tst r3, #0x0b
biceq r2, r2, #4
#endif
str r2, [r0] @ hardware version
mov r0, r0
mcr p15, 0, r0, c7, c10, 1 @ clean D entry
mcr p15, 0, r0, c7, c10, 4 @ drain WB
#endif /* CONFIG_MMU */
mov pc, lr
__INIT
.type __arm920_setup, #function
__arm920_setup:
mov r0, #0
mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4
#ifdef CONFIG_MMU
mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4
#endif
adr r5, arm920_crval
ldmia r5, {r5, r6}
mrc p15, 0, r0, c1, c0 @ get control register v4
bic r0, r0, r5
orr r0, r0, r6
mov pc, lr
.size __arm920_setup, . - __arm920_setup
/*
* R
* .RVI ZFRS BLDP WCAM
* ..11 0001 ..11 0101
*
*/
.type arm920_crval, #object
arm920_crval:
crval clear=0x00003f3f, mmuset=0x00003135, ucset=0x00001130
__INITDATA
/*
* Purpose : Function pointers used to access above functions - all calls
* come through these
*/
.type arm920_processor_functions, #object
arm920_processor_functions:
.word v4t_early_abort
.word cpu_arm920_proc_init
.word cpu_arm920_proc_fin
.word cpu_arm920_reset
.word cpu_arm920_do_idle
.word cpu_arm920_dcache_clean_area
.word cpu_arm920_switch_mm
.word cpu_arm920_set_pte
.size arm920_processor_functions, . - arm920_processor_functions
.section ".rodata"
.type cpu_arch_name, #object
cpu_arch_name:
.asciz "armv4t"
.size cpu_arch_name, . - cpu_arch_name
.type cpu_elf_name, #object
cpu_elf_name:
.asciz "v4"
.size cpu_elf_name, . - cpu_elf_name
.type cpu_arm920_name, #object
cpu_arm920_name:
.asciz "ARM920T"
.size cpu_arm920_name, . - cpu_arm920_name
.align
.section ".proc.info.init", #alloc, #execinstr
.type __arm920_proc_info,#object
__arm920_proc_info:
.long 0x41009200
.long 0xff00fff0
.long PMD_TYPE_SECT | \
PMD_SECT_BUFFERABLE | \
PMD_SECT_CACHEABLE | \
PMD_BIT4 | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
b __arm920_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB
.long cpu_arm920_name
.long arm920_processor_functions
.long v4wbi_tlb_fns
.long v4wb_user_fns
#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
.long arm920_cache_fns
#else
.long v4wt_cache_fns
#endif
.size __arm920_proc_info, . - __arm920_proc_info
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