linux/arch/arm/mm/proc-sa110.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

226 lines
5.2 KiB
ArmAsm

/*
* linux/arch/arm/mm/proc-sa110.S
*
* Copyright (C) 1997-2002 Russell King
* 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 version 2 as
* published by the Free Software Foundation.
*
* MMU functions for SA110
*
* These are the low level assembler for performing cache and TLB
* functions on the StrongARM-110.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
#include <asm/hwcap.h>
#include <mach/hardware.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include "proc-macros.S"
/*
* the cache line size of the I and D cache
*/
#define DCACHELINESIZE 32
.text
/*
* cpu_sa110_proc_init()
*/
ENTRY(cpu_sa110_proc_init)
mov r0, #0
mcr p15, 0, r0, c15, c1, 2 @ Enable clock switching
ret lr
/*
* cpu_sa110_proc_fin()
*/
ENTRY(cpu_sa110_proc_fin)
mov r0, #0
mcr p15, 0, r0, c15, c2, 2 @ Disable clock switching
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
ret lr
/*
* cpu_sa110_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_sa110_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
ret r0
ENDPROC(cpu_sa110_reset)
.popsection
/*
* cpu_sa110_do_idle(type)
*
* Cause the processor to idle
*
* type: call type:
* 0 = slow idle
* 1 = fast idle
* 2 = switch to slow processor clock
* 3 = switch to fast processor clock
*/
.align 5
ENTRY(cpu_sa110_do_idle)
mcr p15, 0, ip, c15, c2, 2 @ disable clock switching
ldr r1, =UNCACHEABLE_ADDR @ load from uncacheable loc
ldr r1, [r1, #0] @ force switch to MCLK
mov r0, r0 @ safety
mov r0, r0 @ safety
mov r0, r0 @ safety
mcr p15, 0, r0, c15, c8, 2 @ Wait for interrupt, cache aligned
mov r0, r0 @ safety
mov r0, r0 @ safety
mov r0, r0 @ safety
mcr p15, 0, r0, c15, c1, 2 @ enable clock switching
ret lr
/* ================================= CACHE ================================ */
/*
* cpu_sa110_dcache_clean_area(addr,sz)
*
* Clean the specified entry of any caches such that the MMU
* translation fetches will obtain correct data.
*
* addr: cache-unaligned virtual address
*/
.align 5
ENTRY(cpu_sa110_dcache_clean_area)
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #DCACHELINESIZE
subs r1, r1, #DCACHELINESIZE
bhi 1b
ret lr
/* =============================== PageTable ============================== */
/*
* cpu_sa110_switch_mm(pgd)
*
* Set the translation base pointer to be as described by pgd.
*
* pgd: new page tables
*/
.align 5
ENTRY(cpu_sa110_switch_mm)
#ifdef CONFIG_MMU
str lr, [sp, #-4]!
bl v4wb_flush_kern_cache_all @ clears IP
mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
ldr pc, [sp], #4
#else
ret lr
#endif
/*
* cpu_sa110_set_pte_ext(ptep, pte, ext)
*
* Set a PTE and flush it out
*/
.align 5
ENTRY(cpu_sa110_set_pte_ext)
#ifdef CONFIG_MMU
armv3_set_pte_ext wc_disable=0
mov r0, r0
mcr p15, 0, r0, c7, c10, 1 @ clean D entry
mcr p15, 0, r0, c7, c10, 4 @ drain WB
#endif
ret lr
.type __sa110_setup, #function
__sa110_setup:
mov r10, #0
mcr p15, 0, r10, c7, c7 @ invalidate I,D caches on v4
mcr p15, 0, r10, c7, c10, 4 @ drain write buffer on v4
#ifdef CONFIG_MMU
mcr p15, 0, r10, c8, c7 @ invalidate I,D TLBs on v4
#endif
adr r5, sa110_crval
ldmia r5, {r5, r6}
mrc p15, 0, r0, c1, c0 @ get control register v4
bic r0, r0, r5
orr r0, r0, r6
ret lr
.size __sa110_setup, . - __sa110_setup
/*
* R
* .RVI ZFRS BLDP WCAM
* ..01 0001 ..11 1101
*
*/
.type sa110_crval, #object
sa110_crval:
crval clear=0x00003f3f, mmuset=0x0000113d, ucset=0x00001130
__INITDATA
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
define_processor_functions sa110, dabort=v4_early_abort, pabort=legacy_pabort
.section ".rodata"
string cpu_arch_name, "armv4"
string cpu_elf_name, "v4"
string cpu_sa110_name, "StrongARM-110"
.align
.section ".proc.info.init", #alloc, #execinstr
.type __sa110_proc_info,#object
__sa110_proc_info:
.long 0x4401a100
.long 0xfffffff0
.long PMD_TYPE_SECT | \
PMD_SECT_BUFFERABLE | \
PMD_SECT_CACHEABLE | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
.long PMD_TYPE_SECT | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
b __sa110_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP | HWCAP_HALF | HWCAP_26BIT | HWCAP_FAST_MULT
.long cpu_sa110_name
.long sa110_processor_functions
.long v4wb_tlb_fns
.long v4wb_user_fns
.long v4wb_cache_fns
.size __sa110_proc_info, . - __sa110_proc_info