linux/arch/arm/mm/cache-v6.S
Russell King 6ebbf2ce43 ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+
ARMv6 and greater introduced a new instruction ("bx") which can be used
to return from function calls.  Recent CPUs perform better when the
"bx lr" instruction is used rather than the "mov pc, lr" instruction,
and this sequence is strongly recommended to be used by the ARM
architecture manual (section A.4.1.1).

We provide a new macro "ret" with all its variants for the condition
code which will resolve to the appropriate instruction.

Rather than doing this piecemeal, and miss some instances, change all
the "mov pc" instances to use the new macro, with the exception of
the "movs" instruction and the kprobes code.  This allows us to detect
the "mov pc, lr" case and fix it up - and also gives us the possibility
of deploying this for other registers depending on the CPU selection.

Reported-by: Will Deacon <will.deacon@arm.com>
Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S
Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood
Tested-by: Shawn Guo <shawn.guo@freescale.com>
Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385
Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci
Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M
Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-07-18 12:29:04 +01:00

336 lines
7.8 KiB
ArmAsm

/*
* linux/arch/arm/mm/cache-v6.S
*
* Copyright (C) 2001 Deep Blue Solutions 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 ARMv6 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"
#define HARVARD_CACHE
#define CACHE_LINE_SIZE 32
#define D_CACHE_LINE_SIZE 32
#define BTB_FLUSH_SIZE 8
/*
* v6_flush_icache_all()
*
* Flush the whole I-cache.
*
* ARM1136 erratum 411920 - Invalidate Instruction Cache operation can fail.
* This erratum is present in 1136, 1156 and 1176. It does not affect the
* MPCore.
*
* Registers:
* r0 - set to 0
* r1 - corrupted
*/
ENTRY(v6_flush_icache_all)
mov r0, #0
#ifdef CONFIG_ARM_ERRATA_411920
mrs r1, cpsr
cpsid ifa @ disable interrupts
mcr p15, 0, r0, c7, c5, 0 @ invalidate entire I-cache
mcr p15, 0, r0, c7, c5, 0 @ invalidate entire I-cache
mcr p15, 0, r0, c7, c5, 0 @ invalidate entire I-cache
mcr p15, 0, r0, c7, c5, 0 @ invalidate entire I-cache
msr cpsr_cx, r1 @ restore interrupts
.rept 11 @ ARM Ltd recommends at least
nop @ 11 NOPs
.endr
#else
mcr p15, 0, r0, c7, c5, 0 @ invalidate I-cache
#endif
ret lr
ENDPROC(v6_flush_icache_all)
/*
* v6_flush_cache_all()
*
* Flush the entire cache.
*
* It is assumed that:
*/
ENTRY(v6_flush_kern_cache_all)
mov r0, #0
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c14, 0 @ D cache clean+invalidate
#ifndef CONFIG_ARM_ERRATA_411920
mcr p15, 0, r0, c7, c5, 0 @ I+BTB cache invalidate
#else
b v6_flush_icache_all
#endif
#else
mcr p15, 0, r0, c7, c15, 0 @ Cache clean+invalidate
#endif
ret lr
/*
* v6_flush_cache_all()
*
* Flush all TLB entries in a particular address space
*
* - mm - mm_struct describing address space
*/
ENTRY(v6_flush_user_cache_all)
/*FALLTHROUGH*/
/*
* v6_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(v6_flush_user_cache_range)
ret lr
/*
* v6_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(v6_coherent_kern_range)
/* FALLTHROUGH */
/*
* v6_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(v6_coherent_user_range)
UNWIND(.fnstart )
#ifdef HARVARD_CACHE
bic r0, r0, #CACHE_LINE_SIZE - 1
1:
USER( mcr p15, 0, r0, c7, c10, 1 ) @ clean D line
add r0, r0, #CACHE_LINE_SIZE
cmp r0, r1
blo 1b
#endif
mov r0, #0
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
#ifndef CONFIG_ARM_ERRATA_411920
mcr p15, 0, r0, c7, c5, 0 @ I+BTB cache invalidate
#else
b v6_flush_icache_all
#endif
#else
mcr p15, 0, r0, c7, c5, 6 @ invalidate BTB
#endif
ret lr
/*
* Fault handling for the cache operation above. If the virtual address in r0
* isn't mapped, fail with -EFAULT.
*/
9001:
mov r0, #-EFAULT
ret lr
UNWIND(.fnend )
ENDPROC(v6_coherent_user_range)
ENDPROC(v6_coherent_kern_range)
/*
* v6_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(v6_flush_kern_dcache_area)
add r1, r0, r1
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line
#else
mcr p15, 0, r0, c7, c15, 1 @ clean & invalidate unified line
#endif
add r0, r0, #D_CACHE_LINE_SIZE
cmp r0, r1
blo 1b
#ifdef HARVARD_CACHE
mov r0, #0
mcr p15, 0, r0, c7, c10, 4
#endif
ret lr
/*
* v6_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
*/
v6_dma_inv_range:
#ifdef CONFIG_DMA_CACHE_RWFO
ldrb r2, [r0] @ read for ownership
strb r2, [r0] @ write for ownership
#endif
tst r0, #D_CACHE_LINE_SIZE - 1
bic r0, r0, #D_CACHE_LINE_SIZE - 1
#ifdef HARVARD_CACHE
mcrne p15, 0, r0, c7, c10, 1 @ clean D line
#else
mcrne p15, 0, r0, c7, c11, 1 @ clean unified line
#endif
tst r1, #D_CACHE_LINE_SIZE - 1
#ifdef CONFIG_DMA_CACHE_RWFO
ldrneb r2, [r1, #-1] @ read for ownership
strneb r2, [r1, #-1] @ write for ownership
#endif
bic r1, r1, #D_CACHE_LINE_SIZE - 1
#ifdef HARVARD_CACHE
mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D line
#else
mcrne p15, 0, r1, c7, c15, 1 @ clean & invalidate unified line
#endif
1:
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c6, 1 @ invalidate D line
#else
mcr p15, 0, r0, c7, c7, 1 @ invalidate unified line
#endif
add r0, r0, #D_CACHE_LINE_SIZE
cmp r0, r1
#ifdef CONFIG_DMA_CACHE_RWFO
ldrlo r2, [r0] @ read for ownership
strlo r2, [r0] @ write for ownership
#endif
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
ret lr
/*
* v6_dma_clean_range(start,end)
* - start - virtual start address of region
* - end - virtual end address of region
*/
v6_dma_clean_range:
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
#ifdef CONFIG_DMA_CACHE_RWFO
ldr r2, [r0] @ read for ownership
#endif
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c10, 1 @ clean D line
#else
mcr p15, 0, r0, c7, c11, 1 @ clean unified line
#endif
add r0, r0, #D_CACHE_LINE_SIZE
cmp r0, r1
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
ret lr
/*
* v6_dma_flush_range(start,end)
* - start - virtual start address of region
* - end - virtual end address of region
*/
ENTRY(v6_dma_flush_range)
#ifdef CONFIG_DMA_CACHE_RWFO
ldrb r2, [r0] @ read for ownership
strb r2, [r0] @ write for ownership
#endif
bic r0, r0, #D_CACHE_LINE_SIZE - 1
1:
#ifdef HARVARD_CACHE
mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line
#else
mcr p15, 0, r0, c7, c15, 1 @ clean & invalidate line
#endif
add r0, r0, #D_CACHE_LINE_SIZE
cmp r0, r1
#ifdef CONFIG_DMA_CACHE_RWFO
ldrlob r2, [r0] @ read for ownership
strlob r2, [r0] @ write for ownership
#endif
blo 1b
mov r0, #0
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
ret lr
/*
* dma_map_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
ENTRY(v6_dma_map_area)
add r1, r1, r0
teq r2, #DMA_FROM_DEVICE
beq v6_dma_inv_range
#ifndef CONFIG_DMA_CACHE_RWFO
b v6_dma_clean_range
#else
teq r2, #DMA_TO_DEVICE
beq v6_dma_clean_range
b v6_dma_flush_range
#endif
ENDPROC(v6_dma_map_area)
/*
* dma_unmap_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
ENTRY(v6_dma_unmap_area)
#ifndef CONFIG_DMA_CACHE_RWFO
add r1, r1, r0
teq r2, #DMA_TO_DEVICE
bne v6_dma_inv_range
#endif
ret lr
ENDPROC(v6_dma_unmap_area)
.globl v6_flush_kern_cache_louis
.equ v6_flush_kern_cache_louis, v6_flush_kern_cache_all
__INITDATA
@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
define_cache_functions v6