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031bd879f7
linux/arch/arm/mm/cache-v7.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

390 lines
9.9 KiB
ArmAsm
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/*
* linux/arch/arm/mm/cache-v7.S
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
* Copyright (C) 2005 ARM Ltd.
*
* 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.
*
* This is the "shell" of the ARMv7 processor support.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/errno.h>
#include <asm/unwind.h>
#include "proc-macros.S"
/*
* v7_flush_icache_all()
*
* Flush the whole I-cache.
*
* Registers:
* r0 - set to 0
*/
ENTRY(v7_flush_icache_all)
mov r0, #0
ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
mov pc, lr
ENDPROC(v7_flush_icache_all)
/*
* v7_flush_dcache_louis()
*
* Flush the D-cache up to the Level of Unification Inner Shareable
*
* Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
*/
ENTRY(v7_flush_dcache_louis)
dmb @ ensure ordering with previous memory accesses
mrc p15, 1, r0, c0, c0, 1 @ read clidr, r0 = clidr
ands r3, r0, #0xe00000 @ extract LoUIS from clidr
mov r3, r3, lsr #20 @ r3 = LoUIS * 2
moveq pc, lr @ return if level == 0
mov r10, #0 @ r10 (starting level) = 0
b loop1 @ start flushing cache levels
ENDPROC(v7_flush_dcache_louis)
/*
* v7_flush_dcache_all()
*
* Flush the whole D-cache.
*
* Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
*
* - mm - mm_struct describing address space
*/
ENTRY(v7_flush_dcache_all)
dmb @ ensure ordering with previous memory accesses
mrc p15, 1, r0, c0, c0, 1 @ read clidr
ands r3, r0, #0x7000000 @ extract loc from clidr
mov r3, r3, lsr #23 @ left align loc bit field
beq finished @ if loc is 0, then no need to clean
mov r10, #0 @ start clean at cache level 0
loop1:
add r2, r10, r10, lsr #1 @ work out 3x current cache level
mov r1, r0, lsr r2 @ extract cache type bits from clidr
and r1, r1, #7 @ mask of the bits for current cache only
cmp r1, #2 @ see what cache we have at this level
blt skip @ skip if no cache, or just i-cache
#ifdef CONFIG_PREEMPT
save_and_disable_irqs_notrace r9 @ make cssr&csidr read atomic
#endif
mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
isb @ isb to sych the new cssr&csidr
mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
#ifdef CONFIG_PREEMPT
restore_irqs_notrace r9
#endif
and r2, r1, #7 @ extract the length of the cache lines
add r2, r2, #4 @ add 4 (line length offset)
ldr r4, =0x3ff
ands r4, r4, r1, lsr #3 @ find maximum number on the way size
clz r5, r4 @ find bit position of way size increment
ldr r7, =0x7fff
ands r7, r7, r1, lsr #13 @ extract max number of the index size
loop2:
mov r9, r4 @ create working copy of max way size
loop3:
ARM( orr r11, r10, r9, lsl r5 ) @ factor way and cache number into r11
THUMB( lsl r6, r9, r5 )
THUMB( orr r11, r10, r6 ) @ factor way and cache number into r11
ARM( orr r11, r11, r7, lsl r2 ) @ factor index number into r11
THUMB( lsl r6, r7, r2 )
THUMB( orr r11, r11, r6 ) @ factor index number into r11
mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
subs r9, r9, #1 @ decrement the way
bge loop3
subs r7, r7, #1 @ decrement the index
bge loop2
skip:
add r10, r10, #2 @ increment cache number
cmp r3, r10
bgt loop1
finished:
mov r10, #0 @ swith back to cache level 0
mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
dsb
isb
mov pc, lr
ENDPROC(v7_flush_dcache_all)
/*
* v7_flush_cache_all()
*
* Flush the entire cache system.
* The data cache flush is now achieved using atomic clean / invalidates
* working outwards from L1 cache. This is done using Set/Way based cache
* maintenance instructions.
* The instruction cache can still be invalidated back to the point of
* unification in a single instruction.
*
*/
ENTRY(v7_flush_kern_cache_all)
ARM( stmfd sp!, {r4-r5, r7, r9-r11, lr} )
THUMB( stmfd sp!, {r4-r7, r9-r11, lr} )
bl v7_flush_dcache_all
mov r0, #0
ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
ARM( ldmfd sp!, {r4-r5, r7, r9-r11, lr} )
THUMB( ldmfd sp!, {r4-r7, r9-r11, lr} )
mov pc, lr
ENDPROC(v7_flush_kern_cache_all)
/*
* v7_flush_kern_cache_louis(void)
*
* Flush the data cache up to Level of Unification Inner Shareable.
* Invalidate the I-cache to the point of unification.
*/
ENTRY(v7_flush_kern_cache_louis)
ARM( stmfd sp!, {r4-r5, r7, r9-r11, lr} )
THUMB( stmfd sp!, {r4-r7, r9-r11, lr} )
bl v7_flush_dcache_louis
mov r0, #0
ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
ARM( ldmfd sp!, {r4-r5, r7, r9-r11, lr} )
THUMB( ldmfd sp!, {r4-r7, r9-r11, lr} )
mov pc, lr
ENDPROC(v7_flush_kern_cache_louis)
/*
* v7_flush_cache_all()
*
* Flush all TLB entries in a particular address space
*
* - mm - mm_struct describing address space
*/
ENTRY(v7_flush_user_cache_all)
/*FALLTHROUGH*/
/*
* v7_flush_cache_range(start, end, flags)
*
* Flush a range of TLB entries in the specified address space.
*
* - start - start address (may not be aligned)
* - end - end address (exclusive, may not be aligned)
* - flags - vm_area_struct flags describing address space
*
* It is assumed that:
* - we have a VIPT cache.
*/
ENTRY(v7_flush_user_cache_range)
mov pc, lr
ENDPROC(v7_flush_user_cache_all)
ENDPROC(v7_flush_user_cache_range)
/*
* v7_coherent_kern_range(start,end)
*
* Ensure that the I and D caches are coherent within specified
* region. This is typically used when code has been written to
* a memory region, and will be executed.
*
* - start - virtual start address of region
* - end - virtual end address of region
*
* It is assumed that:
* - the Icache does not read data from the write buffer
*/
ENTRY(v7_coherent_kern_range)
/* FALLTHROUGH */
/*
* v7_coherent_user_range(start,end)
*
* Ensure that the I and D caches are coherent within specified
* region. This is typically used when code has been written to
* a memory region, and will be executed.
*
* - start - virtual start address of region
* - end - virtual end address of region
*
* It is assumed that:
* - the Icache does not read data from the write buffer
*/
ENTRY(v7_coherent_user_range)
UNWIND(.fnstart )
dcache_line_size r2, r3
sub r3, r2, #1
bic r12, r0, r3
#ifdef CONFIG_ARM_ERRATA_764369
ALT_SMP(W(dsb))
ALT_UP(W(nop))
#endif
1:
USER( mcr p15, 0, r12, c7, c11, 1 ) @ clean D line to the point of unification
add r12, r12, r2
cmp r12, r1
blo 1b
dsb
icache_line_size r2, r3
sub r3, r2, #1
bic r12, r0, r3
2:
USER( mcr p15, 0, r12, c7, c5, 1 ) @ invalidate I line
add r12, r12, r2
cmp r12, r1
blo 2b
mov r0, #0
ALT_SMP(mcr p15, 0, r0, c7, c1, 6) @ invalidate BTB Inner Shareable
ALT_UP(mcr p15, 0, r0, c7, c5, 6) @ invalidate BTB
dsb
isb
mov pc, lr
/*
* Fault handling for the cache operation above. If the virtual address in r0
* isn't mapped, fail with -EFAULT.
*/
9001:
mov r0, #-EFAULT
mov pc, lr
UNWIND(.fnend )
ENDPROC(v7_coherent_kern_range)
ENDPROC(v7_coherent_user_range)
/*
* v7_flush_kern_dcache_area(void *addr, size_t size)
*
* Ensure that the data held in the page kaddr is written back
* to the page in question.
*
* - addr - kernel address
* - size - region size
*/
ENTRY(v7_flush_kern_dcache_area)
dcache_line_size r2, r3
add r1, r0, r1
sub r3, r2, #1
bic r0, r0, r3
#ifdef CONFIG_ARM_ERRATA_764369
ALT_SMP(W(dsb))
ALT_UP(W(nop))
#endif
1:
mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line / unified line
add r0, r0, r2
cmp r0, r1
blo 1b
dsb
mov pc, lr
ENDPROC(v7_flush_kern_dcache_area)
/*
* v7_dma_inv_range(start,end)
*
* Invalidate the data cache within the specified region; we will
* be performing a DMA operation in this region and we want to
* purge old data in the cache.
*
* - start - virtual start address of region
* - end - virtual end address of region
*/
v7_dma_inv_range:
dcache_line_size r2, r3
sub r3, r2, #1
tst r0, r3
bic r0, r0, r3
#ifdef CONFIG_ARM_ERRATA_764369
ALT_SMP(W(dsb))
ALT_UP(W(nop))
#endif
mcrne p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line
tst r1, r3
bic r1, r1, r3
mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D / U line
1:
mcr p15, 0, r0, c7, c6, 1 @ invalidate D / U line
add r0, r0, r2
cmp r0, r1
blo 1b
dsb
mov pc, lr
ENDPROC(v7_dma_inv_range)
/*
* v7_dma_clean_range(start,end)
* - start - virtual start address of region
* - end - virtual end address of region
*/
v7_dma_clean_range:
dcache_line_size r2, r3
sub r3, r2, #1
bic r0, r0, r3
#ifdef CONFIG_ARM_ERRATA_764369
ALT_SMP(W(dsb))
ALT_UP(W(nop))
#endif
1:
mcr p15, 0, r0, c7, c10, 1 @ clean D / U line
add r0, r0, r2
cmp r0, r1
blo 1b
dsb
mov pc, lr
ENDPROC(v7_dma_clean_range)
/*
* v7_dma_flush_range(start,end)
* - start - virtual start address of region
* - end - virtual end address of region
*/
ENTRY(v7_dma_flush_range)
dcache_line_size r2, r3
sub r3, r2, #1
bic r0, r0, r3
#ifdef CONFIG_ARM_ERRATA_764369
ALT_SMP(W(dsb))
ALT_UP(W(nop))
#endif
1:
mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line
add r0, r0, r2
cmp r0, r1
blo 1b
dsb
mov pc, lr
ENDPROC(v7_dma_flush_range)
/*
* dma_map_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
ENTRY(v7_dma_map_area)
add r1, r1, r0
teq r2, #DMA_FROM_DEVICE
beq v7_dma_inv_range
b v7_dma_clean_range
ENDPROC(v7_dma_map_area)
/*
* dma_unmap_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
ENTRY(v7_dma_unmap_area)
add r1, r1, r0
teq r2, #DMA_TO_DEVICE
bne v7_dma_inv_range
mov pc, lr
ENDPROC(v7_dma_unmap_area)
__INITDATA
@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
define_cache_functions v7
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