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kernel-ark/arch/arm/mm/proc-arm1020.S
Lorenzo Pieralisi 031bd879f7 ARM: mm: implement LoUIS API for cache maintenance ops 
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>
2012-09-25 11:20:25 +01:00

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/*
* linux/arch/arm/mm/proc-arm1020.S: MMU functions for ARM1020
*
* Copyright (C) 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 arm1020.
*
* CONFIG_CPU_ARM1020_CPU_IDLE -> nohlt
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
#include <asm/hwcap.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include "proc-macros.S"
/*
* This is the maximum size of an area which will be invalidated
* using the single invalidate entry instructions. Anything larger
* than this, and we go for the whole cache.
*
* This value should be chosen such that we choose the cheapest
* alternative.
*/
#define MAX_AREA_SIZE 32768
/*
* The size of one data cache line.
*/
#define CACHE_DLINESIZE 32
/*
* The number of data cache segments.
*/
#define CACHE_DSEGMENTS 16
/*
* 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 maintenance instructions.
*/
#define CACHE_DLIMIT 32768
.text
/*
* cpu_arm1020_proc_init()
*/
ENTRY(cpu_arm1020_proc_init)
mov pc, lr
/*
* cpu_arm1020_proc_fin()
*/
ENTRY(cpu_arm1020_proc_fin)
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
mov pc, lr
/*
* cpu_arm1020_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_arm1020_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
ENDPROC(cpu_arm1020_reset)
.popsection
/*
* cpu_arm1020_do_idle()
*/
.align 5
ENTRY(cpu_arm1020_do_idle)
mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt
mov pc, lr
/* ================================= CACHE ================================ */
.align 5
/*
* flush_icache_all()
*
* Unconditionally clean and invalidate the entire icache.
*/
ENTRY(arm1020_flush_icache_all)
#ifndef CONFIG_CPU_ICACHE_DISABLE
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
#endif
mov pc, lr
ENDPROC(arm1020_flush_icache_all)
/*
* flush_user_cache_all()
*
* Invalidate all cache entries in a particular address
* space.
*/
ENTRY(arm1020_flush_user_cache_all)
/* FALLTHROUGH */
/*
* flush_kern_cache_all()
*
* Clean and invalidate the entire cache.
*/
ENTRY(arm1020_flush_kern_cache_all)
mov r2, #VM_EXEC
mov ip, #0
__flush_whole_cache:
#ifndef CONFIG_CPU_DCACHE_DISABLE
mcr p15, 0, ip, c7, c10, 4 @ drain WB
mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 16 segments
1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2: mcr p15, 0, r3, c7, c14, 2 @ clean+invalidate D index
mcr p15, 0, ip, c7, c10, 4 @ drain WB
subs r3, r3, #1 << 26
bcs 2b @ entries 63 to 0
subs r1, r1, #1 << 5
bcs 1b @ segments 15 to 0
#endif
tst r2, #VM_EXEC
#ifndef CONFIG_CPU_ICACHE_DISABLE
mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
#endif
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 this space
*/
ENTRY(arm1020_flush_user_cache_range)
mov ip, #0
sub r3, r1, r0 @ calculate total size
cmp r3, #CACHE_DLIMIT
bhs __flush_whole_cache
#ifndef CONFIG_CPU_DCACHE_DISABLE
mcr p15, 0, ip, c7, c10, 4
1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
mcr p15, 0, ip, c7, c10, 4 @ drain WB
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
#endif
tst r2, #VM_EXEC
#ifndef CONFIG_CPU_ICACHE_DISABLE
mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
#endif
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. If you have non-snooping
* Harvard caches, you need to implement this function.
*
* - start - virtual start address
* - end - virtual end address
*/
ENTRY(arm1020_coherent_kern_range)
/* FALLTRHOUGH */
/*
* coherent_user_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
*/
ENTRY(arm1020_coherent_user_range)
mov ip, #0
bic r0, r0, #CACHE_DLINESIZE - 1
mcr p15, 0, ip, c7, c10, 4
1:
#ifndef CONFIG_CPU_DCACHE_DISABLE
mcr p15, 0, r0, c7, c10, 1 @ clean D entry
mcr p15, 0, ip, c7, c10, 4 @ drain WB
#endif
#ifndef CONFIG_CPU_ICACHE_DISABLE
mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry
#endif
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
mcr p15, 0, ip, c7, c10, 4 @ drain WB
mov r0, #0
mov pc, 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(arm1020_flush_kern_dcache_area)
mov ip, #0
#ifndef CONFIG_CPU_DCACHE_DISABLE
add r1, r0, r1
1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
mcr p15, 0, ip, c7, c10, 4 @ drain WB
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
#endif
mcr p15, 0, ip, 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)
*/
arm1020_dma_inv_range:
mov ip, #0
#ifndef CONFIG_CPU_DCACHE_DISABLE
tst r0, #CACHE_DLINESIZE - 1
bic r0, r0, #CACHE_DLINESIZE - 1
mcrne p15, 0, ip, c7, c10, 4
mcrne p15, 0, r0, c7, c10, 1 @ clean D entry
mcrne p15, 0, ip, c7, c10, 4 @ drain WB
tst r1, #CACHE_DLINESIZE - 1
mcrne p15, 0, ip, c7, c10, 4
mcrne p15, 0, r1, c7, c10, 1 @ clean D entry
mcrne p15, 0, ip, c7, c10, 4 @ drain WB
1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
#endif
mcr p15, 0, ip, 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)
*/
arm1020_dma_clean_range:
mov ip, #0
#ifndef CONFIG_CPU_DCACHE_DISABLE
bic r0, r0, #CACHE_DLINESIZE - 1
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
mcr p15, 0, ip, c7, c10, 4 @ drain WB
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
#endif
mcr p15, 0, ip, 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(arm1020_dma_flush_range)
mov ip, #0
#ifndef CONFIG_CPU_DCACHE_DISABLE
bic r0, r0, #CACHE_DLINESIZE - 1
mcr p15, 0, ip, c7, c10, 4
1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
mcr p15, 0, ip, c7, c10, 4 @ drain WB
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
#endif
mcr p15, 0, ip, c7, c10, 4 @ drain WB
mov pc, lr
/*
* dma_map_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
ENTRY(arm1020_dma_map_area)
add r1, r1, r0
cmp r2, #DMA_TO_DEVICE
beq arm1020_dma_clean_range
bcs arm1020_dma_inv_range
b arm1020_dma_flush_range
ENDPROC(arm1020_dma_map_area)
/*
* dma_unmap_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
ENTRY(arm1020_dma_unmap_area)
mov pc, lr
ENDPROC(arm1020_dma_unmap_area)
.globl arm1020_flush_kern_cache_louis
.equ arm1020_flush_kern_cache_louis, arm1020_flush_kern_cache_all
@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
define_cache_functions arm1020
.align 5
ENTRY(cpu_arm1020_dcache_clean_area)
#ifndef CONFIG_CPU_DCACHE_DISABLE
mov ip, #0
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
mcr p15, 0, ip, c7, c10, 4 @ drain WB
add r0, r0, #CACHE_DLINESIZE
subs r1, r1, #CACHE_DLINESIZE
bhi 1b
#endif
mov pc, lr
/* =============================== PageTable ============================== */
/*
* cpu_arm1020_switch_mm(pgd)
*
* Set the translation base pointer to be as described by pgd.
*
* pgd: new page tables
*/
.align 5
ENTRY(cpu_arm1020_switch_mm)
#ifdef CONFIG_MMU
#ifndef CONFIG_CPU_DCACHE_DISABLE
mcr p15, 0, r3, c7, c10, 4
mov r1, #0xF @ 16 segments
1: mov r3, #0x3F @ 64 entries
2: mov ip, r3, LSL #26 @ shift up entry
orr ip, ip, r1, LSL #5 @ shift in/up index
mcr p15, 0, ip, c7, c14, 2 @ Clean & Inval DCache entry
mov ip, #0
mcr p15, 0, ip, c7, c10, 4
subs r3, r3, #1
cmp r3, #0
bge 2b @ entries 3F to 0
subs r1, r1, #1
cmp r1, #0
bge 1b @ segments 15 to 0
#endif
mov r1, #0
#ifndef CONFIG_CPU_ICACHE_DISABLE
mcr p15, 0, r1, c7, c5, 0 @ invalidate I cache
#endif
mcr p15, 0, r1, c7, c10, 4 @ drain WB
mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
mcr p15, 0, r1, c8, c7, 0 @ invalidate I & D TLBs
#endif /* CONFIG_MMU */
mov pc, lr
/*
* cpu_arm1020_set_pte(ptep, pte)
*
* Set a PTE and flush it out
*/
.align 5
ENTRY(cpu_arm1020_set_pte_ext)
#ifdef CONFIG_MMU
armv3_set_pte_ext
mov r0, r0
#ifndef CONFIG_CPU_DCACHE_DISABLE
mcr p15, 0, r0, c7, c10, 4
mcr p15, 0, r0, c7, c10, 1 @ clean D entry
#endif
mcr p15, 0, r0, c7, c10, 4 @ drain WB
#endif /* CONFIG_MMU */
mov pc, lr
__CPUINIT
.type __arm1020_setup, #function
__arm1020_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, arm1020_crval
ldmia r5, {r5, r6}
mrc p15, 0, r0, c1, c0 @ get control register v4
bic r0, r0, r5
orr r0, r0, r6
#ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
orr r0, r0, #0x4000 @ .R.. .... .... ....
#endif
mov pc, lr
.size __arm1020_setup, . - __arm1020_setup
/*
* R
* .RVI ZFRS BLDP WCAM
* .011 1001 ..11 0101
*/
.type arm1020_crval, #object
arm1020_crval:
crval clear=0x0000593f, mmuset=0x00003935, ucset=0x00001930
__INITDATA
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
define_processor_functions arm1020, dabort=v4t_early_abort, pabort=legacy_pabort
.section ".rodata"
string cpu_arch_name, "armv5t"
string cpu_elf_name, "v5"
.type cpu_arm1020_name, #object
cpu_arm1020_name:
.ascii "ARM1020"
#ifndef CONFIG_CPU_ICACHE_DISABLE
.ascii "i"
#endif
#ifndef CONFIG_CPU_DCACHE_DISABLE
.ascii "d"
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
.ascii "(wt)"
#else
.ascii "(wb)"
#endif
#endif
#ifndef CONFIG_CPU_BPREDICT_DISABLE
.ascii "B"
#endif
#ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
.ascii "RR"
#endif
.ascii "\0"
.size cpu_arm1020_name, . - cpu_arm1020_name
.align
.section ".proc.info.init", #alloc, #execinstr
.type __arm1020_proc_info,#object
__arm1020_proc_info:
.long 0x4104a200 @ ARM 1020T (Architecture v5T)
.long 0xff0ffff0
.long PMD_TYPE_SECT | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
.long PMD_TYPE_SECT | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
b __arm1020_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB
.long cpu_arm1020_name
.long arm1020_processor_functions
.long v4wbi_tlb_fns
.long v4wb_user_fns
.long arm1020_cache_fns
.size __arm1020_proc_info, . - __arm1020_proc_info
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