/*
* linux/arch/arm/mm/proc-xsc3.S
*
* Original Author: Matthew Gilbert
* Current Maintainer: Deepak Saxena <dsaxena@plexity.net>
*
* 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 orignal XScale code by Nicolas Pitre
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/procinfo.h>
#include <asm/hardware.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 I and D cache.
*/
#define CACHELINESIZE 32
/*
* The size of the data cache.
*/
#define CACHESIZE 32768
/*
* Run with L2 enabled.
*/
#define L2_CACHE_ENABLE 1
/*
* Enable the Branch Target Buffer (can cause crashes, see erratum #42.)
*/
#define BTB_ENABLE 0
/*
* This macro is used to wait for a CP15 write and is needed
* when we have to ensure that the last operation to the co-pro
* 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 & invalidates the entire xsc3 dcache by set & way.
*/
.macro clean_d_cache rd, rs
mov \rd, #0x1f00
orr \rd, \rd, #0x00e0
1: mcr p15, 0, \rd, c7, c14, 2 @ clean/inv set/way
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)
mov pc, lr
/*
* cpu_xsc3_proc_fin()
*/
ENTRY(cpu_xsc3_proc_fin)
str lr, [sp, #-4]!
mov r0, #PSR_F_BIT|PSR_I_BIT|SVC_MODE
msr cpsr_c, r0
bl xsc3_flush_kern_cache_all @ clean caches
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
ldr pc, [sp], #4
/*
* 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
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, #0x0086 @ ........B....CA.
bic r1, r1, #0x3900 @ ..VIZ..S........
mcr p15, 0, r1, c1, c0, 0 @ ctrl register
mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches & 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 & D TLBs
mov pc, r0
/*
* 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.
MMG: Come back to this one.
*/
.align 5
ENTRY(cpu_xsc3_do_idle)
mov r0, #1
mcr p14, 0, r0, c7, c0, 0 @ Go to IDLE
mov pc, lr
/* ================================= CACHE ================================ */
/*
* 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 I cache & BTB
mcrne p15, 0, ip, c7, c10, 4 @ Drain Write Buffer
mcrne p15, 0, ip, c7, c5, 4 @ Prefetch Flush
mov pc, 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 I cache line
mcr p15, 0, r0, c7, c14, 1 @ Clean/invalidate D cache 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 @ Drain Write Buffer
mcrne p15, 0, ip, c7, c5, 4 @ Prefetch Flush
mov pc, lr
/*
* coherent_kern_range(start, end)
*
* Ensure coherency between the Icache and the Dcache 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 D entry
add r0, r0, #CACHELINESIZE
cmp r0, r1
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ Invalidate I cache & BTB
mcr p15, 0, r0, c7, c10, 4 @ Drain Write Buffer
mcr p15, 0, r0, c7, c5, 4 @ Prefetch Flush
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(xsc3_flush_kern_dcache_page)
add r1, r0, #PAGE_SZ
1: mcr p15, 0, r0, c7, c14, 1 @ Clean/Invalidate D Cache line
add r0, r0, #CACHELINESIZE
cmp r0, r1
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ Invalidate I cache & BTB
mcr p15, 0, r0, c7, c10, 4 @ Drain Write Buffer
mcr p15, 0, r0, c7, c5, 4 @ Prefetch Flush
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
*/
ENTRY(xsc3_dma_inv_range)
tst r0, #CACHELINESIZE - 1
bic r0, r0, #CACHELINESIZE - 1
mcrne p15, 0, r0, c7, c10, 1 @ clean L1 D entry
mcrne p15, 1, r0, c7, c11, 1 @ clean L2 D entry
tst r1, #CACHELINESIZE - 1
mcrne p15, 0, r1, c7, c10, 1 @ clean L1 D entry
mcrne p15, 1, r1, c7, c11, 1 @ clean L2 D entry
1: mcr p15, 0, r0, c7, c6, 1 @ invalidate L1 D entry
mcr p15, 1, r0, c7, c7, 1 @ Invalidate L2 D cache line
add r0, r0, #CACHELINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ Drain Write Buffer
mov pc, lr
/*
* dma_clean_range(start, end)
*
* Clean the specified virtual address range.
*
* - start - virtual start address
* - end - virtual end address
*/
ENTRY(xsc3_dma_clean_range)
bic r0, r0, #CACHELINESIZE - 1
1: mcr p15, 0, r0, c7, c10, 1 @ clean L1 D entry
mcr p15, 1, r0, c7, c11, 1 @ clean L2 D entry
add r0, r0, #CACHELINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ Drain Write Buffer
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(xsc3_dma_flush_range)
bic r0, r0, #CACHELINESIZE - 1
1: mcr p15, 0, r0, c7, c14, 1 @ Clean/invalidate L1 D cache line
mcr p15, 1, r0, c7, c11, 1 @ Clean L2 D cache line
mcr p15, 1, r0, c7, c7, 1 @ Invalidate L2 D cache line
add r0, r0, #CACHELINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, r0, c7, c10, 4 @ Drain Write Buffer
mov pc, lr
ENTRY(xsc3_cache_fns)
.long xsc3_flush_kern_cache_all
.long xsc3_flush_user_cache_all
.long xsc3_flush_user_cache_range
.long xsc3_coherent_kern_range
.long xsc3_coherent_user_range
.long xsc3_flush_kern_dcache_page
.long xsc3_dma_inv_range
.long xsc3_dma_clean_range
.long xsc3_dma_flush_range
ENTRY(cpu_xsc3_dcache_clean_area)
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #CACHELINESIZE
subs r1, r1, #CACHELINESIZE
bhi 1b
mov pc, lr
/* =============================== PageTable ============================== */
/*
* cpu_xsc3_switch_mm(pgd)
*
* Set the translation base pointer to be as described by pgd.
*
* pgd: new page tables
*/
.align 5
ENTRY(cpu_xsc3_switch_mm)
clean_d_cache r1, r2
mcr p15, 0, ip, c7, c5, 0 @ Invalidate I cache & BTB
mcr p15, 0, ip, c7, c10, 4 @ Drain Write Buffer
mcr p15, 0, ip, c7, c5, 4 @ Prefetch Flush
#ifdef L2_CACHE_ENABLE
orr r0, r0, #0x18 @ cache the page table in L2
#endif
mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
cpwait_ret lr, ip
/*
* cpu_xsc3_set_pte(ptep, pte)
*
* Set a PTE and flush it out
*
*/
.align 5
ENTRY(cpu_xsc3_set_pte)
str r1, [r0], #-2048 @ linux version
bic r2, r1, #0xdf0 @ Keep C, B, coherency bits
orr r2, r2, #PTE_TYPE_EXT @ extended page
eor r3, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY
tst r3, #L_PTE_USER @ User?
orrne r2, r2, #PTE_EXT_AP_URO_SRW @ yes -> user r/o, system r/w
tst r3, #L_PTE_WRITE | L_PTE_DIRTY @ Write and Dirty?
orreq r2, r2, #PTE_EXT_AP_UNO_SRW @ yes -> user n/a, system r/w
@ combined with user -> user r/w
#if L2_CACHE_ENABLE
@ If its cacheable it needs to be in L2 also.
eor ip, r1, #L_PTE_CACHEABLE
tst ip, #L_PTE_CACHEABLE
orreq r2, r2, #PTE_EXT_TEX(0x5)
#endif
tst r3, #L_PTE_PRESENT | L_PTE_YOUNG @ Present and Young?
movne r2, #0 @ no -> fault
str r2, [r0] @ hardware version
mov ip, #0
mcr p15, 0, r0, c7, c10, 1 @ Clean D cache line mcr
mcr p15, 0, ip, c7, c10, 4 @ Drain Write Buffer
mov pc, lr
.ltorg
.align
__INIT
.type __xsc3_setup, #function
__xsc3_setup:
mov r0, #PSR_F_BIT|PSR_I_BIT|SVC_MODE
msr cpsr_c, r0
mcr p15, 0, ip, c7, c7, 0 @ invalidate I, D caches & BTB
mcr p15, 0, ip, c7, c10, 4 @ Drain Write Buffer
mcr p15, 0, ip, c7, c5, 4 @ Prefetch Flush
mcr p15, 0, ip, c8, c7, 0 @ invalidate I, D TLBs
#if L2_CACHE_ENABLE
orr r4, r4, #0x18 @ cache the page table in L2
#endif
mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
mov r0, #1 @ Allow access to CP0 and CP13
orr r0, r0, #1 << 13 @ Its undefined whether this
mcr p15, 0, r0, c15, c1, 0 @ affects USR or SVC modes
mrc p15, 0, r0, c1, c0, 1 @ get auxiliary control reg
and r0, r0, #2 @ preserve bit P bit setting
#if L2_CACHE_ENABLE
orr r0, r0, #(1 << 10) @ enable L2 for LLR cache
#endif
mcr p15, 0, r0, c1, c0, 1 @ set auxiliary control reg
mrc p15, 0, r0, c1, c0, 0 @ get control register
bic r0, r0, #0x0002 @ .... .... .... ..A.
orr r0, r0, #0x0005 @ .... .... .... .C.M
#if BTB_ENABLE
bic r0, r0, #0x0200 @ .... ..R. .... ....
orr r0, r0, #0x3900 @ ..VI Z..S .... ....
#else
bic r0, r0, #0x0a00 @ .... Z.R. .... ....
orr r0, r0, #0x3100 @ ..VI ...S .... ....
#endif
#if L2_CACHE_ENABLE
orr r0, r0, #0x4000000 @ L2 enable
#endif
mov pc, lr
.size __xsc3_setup, . - __xsc3_setup
__INITDATA
/*
* Purpose : Function pointers used to access above functions - all calls
* come through these
*/
.type xsc3_processor_functions, #object
ENTRY(xsc3_processor_functions)
.word v5t_early_abort
.word cpu_xsc3_proc_init
.word cpu_xsc3_proc_fin
.word cpu_xsc3_reset
.word cpu_xsc3_do_idle
.word cpu_xsc3_dcache_clean_area
.word cpu_xsc3_switch_mm
.word cpu_xsc3_set_pte
.size xsc3_processor_functions, . - xsc3_processor_functions
.section ".rodata"
.type cpu_arch_name, #object
cpu_arch_name:
.asciz "armv5te"
.size cpu_arch_name, . - cpu_arch_name
.type cpu_elf_name, #object
cpu_elf_name:
.asciz "v5"
.size cpu_elf_name, . - cpu_elf_name
.type cpu_xsc3_name, #object
cpu_xsc3_name:
.asciz "XScale-Core3"
.size cpu_xsc3_name, . - cpu_xsc3_name
.align
.section ".proc.info.init", #alloc, #execinstr
.type __xsc3_proc_info,#object
__xsc3_proc_info:
.long 0x69056000
.long 0xffffe000
.long 0x00000c0e
b __xsc3_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP
.long cpu_xsc3_name
.long xsc3_processor_functions
.long v4wbi_tlb_fns
.long xsc3_mc_user_fns
.long xsc3_cache_fns
.size __xsc3_proc_info, . - __xsc3_proc_info
