linux/arch/arm/include/asm/assembler.h
Will Deacon 3ea128065e ARM: barrier: allow options to be passed to memory barrier instructions
On ARMv7, the memory barrier instructions take an optional `option'
field which can be used to constrain the effects of a memory barrier
based on shareability and access type.

This patch allows the caller to pass these options if required, and
updates the smp_*() barriers to request inner-shareable barriers,
affecting only stores for the _wmb variant. wmb() is also changed to
use the -st version of dsb.

Reported-by: Albin Tonnerre <albin.tonnerre@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-08-12 12:25:44 +01:00

380 lines
8.1 KiB
C

/*
* arch/arm/include/asm/assembler.h
*
* Copyright (C) 1996-2000 Russell King
*
* 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 file contains arm architecture specific defines
* for the different processors.
*
* Do not include any C declarations in this file - it is included by
* assembler source.
*/
#ifndef __ASM_ASSEMBLER_H__
#define __ASM_ASSEMBLER_H__
#ifndef __ASSEMBLY__
#error "Only include this from assembly code"
#endif
#include <asm/ptrace.h>
#include <asm/domain.h>
#include <asm/opcodes-virt.h>
#define IOMEM(x) (x)
/*
* Endian independent macros for shifting bytes within registers.
*/
#ifndef __ARMEB__
#define pull lsr
#define push lsl
#define get_byte_0 lsl #0
#define get_byte_1 lsr #8
#define get_byte_2 lsr #16
#define get_byte_3 lsr #24
#define put_byte_0 lsl #0
#define put_byte_1 lsl #8
#define put_byte_2 lsl #16
#define put_byte_3 lsl #24
#else
#define pull lsl
#define push lsr
#define get_byte_0 lsr #24
#define get_byte_1 lsr #16
#define get_byte_2 lsr #8
#define get_byte_3 lsl #0
#define put_byte_0 lsl #24
#define put_byte_1 lsl #16
#define put_byte_2 lsl #8
#define put_byte_3 lsl #0
#endif
/*
* Data preload for architectures that support it
*/
#if __LINUX_ARM_ARCH__ >= 5
#define PLD(code...) code
#else
#define PLD(code...)
#endif
/*
* This can be used to enable code to cacheline align the destination
* pointer when bulk writing to memory. Experiments on StrongARM and
* XScale didn't show this a worthwhile thing to do when the cache is not
* set to write-allocate (this would need further testing on XScale when WA
* is used).
*
* On Feroceon there is much to gain however, regardless of cache mode.
*/
#ifdef CONFIG_CPU_FEROCEON
#define CALGN(code...) code
#else
#define CALGN(code...)
#endif
/*
* Enable and disable interrupts
*/
#if __LINUX_ARM_ARCH__ >= 6
.macro disable_irq_notrace
cpsid i
.endm
.macro enable_irq_notrace
cpsie i
.endm
#else
.macro disable_irq_notrace
msr cpsr_c, #PSR_I_BIT | SVC_MODE
.endm
.macro enable_irq_notrace
msr cpsr_c, #SVC_MODE
.endm
#endif
.macro asm_trace_hardirqs_off
#if defined(CONFIG_TRACE_IRQFLAGS)
stmdb sp!, {r0-r3, ip, lr}
bl trace_hardirqs_off
ldmia sp!, {r0-r3, ip, lr}
#endif
.endm
.macro asm_trace_hardirqs_on_cond, cond
#if defined(CONFIG_TRACE_IRQFLAGS)
/*
* actually the registers should be pushed and pop'd conditionally, but
* after bl the flags are certainly clobbered
*/
stmdb sp!, {r0-r3, ip, lr}
bl\cond trace_hardirqs_on
ldmia sp!, {r0-r3, ip, lr}
#endif
.endm
.macro asm_trace_hardirqs_on
asm_trace_hardirqs_on_cond al
.endm
.macro disable_irq
disable_irq_notrace
asm_trace_hardirqs_off
.endm
.macro enable_irq
asm_trace_hardirqs_on
enable_irq_notrace
.endm
/*
* Save the current IRQ state and disable IRQs. Note that this macro
* assumes FIQs are enabled, and that the processor is in SVC mode.
*/
.macro save_and_disable_irqs, oldcpsr
#ifdef CONFIG_CPU_V7M
mrs \oldcpsr, primask
#else
mrs \oldcpsr, cpsr
#endif
disable_irq
.endm
.macro save_and_disable_irqs_notrace, oldcpsr
mrs \oldcpsr, cpsr
disable_irq_notrace
.endm
/*
* Restore interrupt state previously stored in a register. We don't
* guarantee that this will preserve the flags.
*/
.macro restore_irqs_notrace, oldcpsr
#ifdef CONFIG_CPU_V7M
msr primask, \oldcpsr
#else
msr cpsr_c, \oldcpsr
#endif
.endm
.macro restore_irqs, oldcpsr
tst \oldcpsr, #PSR_I_BIT
asm_trace_hardirqs_on_cond eq
restore_irqs_notrace \oldcpsr
.endm
#define USER(x...) \
9999: x; \
.pushsection __ex_table,"a"; \
.align 3; \
.long 9999b,9001f; \
.popsection
#ifdef CONFIG_SMP
#define ALT_SMP(instr...) \
9998: instr
/*
* Note: if you get assembler errors from ALT_UP() when building with
* CONFIG_THUMB2_KERNEL, you almost certainly need to use
* ALT_SMP( W(instr) ... )
*/
#define ALT_UP(instr...) \
.pushsection ".alt.smp.init", "a" ;\
.long 9998b ;\
9997: instr ;\
.if . - 9997b != 4 ;\
.error "ALT_UP() content must assemble to exactly 4 bytes";\
.endif ;\
.popsection
#define ALT_UP_B(label) \
.equ up_b_offset, label - 9998b ;\
.pushsection ".alt.smp.init", "a" ;\
.long 9998b ;\
W(b) . + up_b_offset ;\
.popsection
#else
#define ALT_SMP(instr...)
#define ALT_UP(instr...) instr
#define ALT_UP_B(label) b label
#endif
/*
* Instruction barrier
*/
.macro instr_sync
#if __LINUX_ARM_ARCH__ >= 7
isb
#elif __LINUX_ARM_ARCH__ == 6
mcr p15, 0, r0, c7, c5, 4
#endif
.endm
/*
* SMP data memory barrier
*/
.macro smp_dmb mode
#ifdef CONFIG_SMP
#if __LINUX_ARM_ARCH__ >= 7
.ifeqs "\mode","arm"
ALT_SMP(dmb ish)
.else
ALT_SMP(W(dmb) ish)
.endif
#elif __LINUX_ARM_ARCH__ == 6
ALT_SMP(mcr p15, 0, r0, c7, c10, 5) @ dmb
#else
#error Incompatible SMP platform
#endif
.ifeqs "\mode","arm"
ALT_UP(nop)
.else
ALT_UP(W(nop))
.endif
#endif
.endm
#if defined(CONFIG_CPU_V7M)
/*
* setmode is used to assert to be in svc mode during boot. For v7-M
* this is done in __v7m_setup, so setmode can be empty here.
*/
.macro setmode, mode, reg
.endm
#elif defined(CONFIG_THUMB2_KERNEL)
.macro setmode, mode, reg
mov \reg, #\mode
msr cpsr_c, \reg
.endm
#else
.macro setmode, mode, reg
msr cpsr_c, #\mode
.endm
#endif
/*
* Helper macro to enter SVC mode cleanly and mask interrupts. reg is
* a scratch register for the macro to overwrite.
*
* This macro is intended for forcing the CPU into SVC mode at boot time.
* you cannot return to the original mode.
*/
.macro safe_svcmode_maskall reg:req
#if __LINUX_ARM_ARCH__ >= 6
mrs \reg , cpsr
eor \reg, \reg, #HYP_MODE
tst \reg, #MODE_MASK
bic \reg , \reg , #MODE_MASK
orr \reg , \reg , #PSR_I_BIT | PSR_F_BIT | SVC_MODE
THUMB( orr \reg , \reg , #PSR_T_BIT )
bne 1f
orr \reg, \reg, #PSR_A_BIT
adr lr, BSYM(2f)
msr spsr_cxsf, \reg
__MSR_ELR_HYP(14)
__ERET
1: msr cpsr_c, \reg
2:
#else
/*
* workaround for possibly broken pre-v6 hardware
* (akita, Sharp Zaurus C-1000, PXA270-based)
*/
setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, \reg
#endif
.endm
/*
* STRT/LDRT access macros with ARM and Thumb-2 variants
*/
#ifdef CONFIG_THUMB2_KERNEL
.macro usraccoff, instr, reg, ptr, inc, off, cond, abort, t=TUSER()
9999:
.if \inc == 1
\instr\cond\()b\()\t\().w \reg, [\ptr, #\off]
.elseif \inc == 4
\instr\cond\()\t\().w \reg, [\ptr, #\off]
.else
.error "Unsupported inc macro argument"
.endif
.pushsection __ex_table,"a"
.align 3
.long 9999b, \abort
.popsection
.endm
.macro usracc, instr, reg, ptr, inc, cond, rept, abort
@ explicit IT instruction needed because of the label
@ introduced by the USER macro
.ifnc \cond,al
.if \rept == 1
itt \cond
.elseif \rept == 2
ittt \cond
.else
.error "Unsupported rept macro argument"
.endif
.endif
@ Slightly optimised to avoid incrementing the pointer twice
usraccoff \instr, \reg, \ptr, \inc, 0, \cond, \abort
.if \rept == 2
usraccoff \instr, \reg, \ptr, \inc, \inc, \cond, \abort
.endif
add\cond \ptr, #\rept * \inc
.endm
#else /* !CONFIG_THUMB2_KERNEL */
.macro usracc, instr, reg, ptr, inc, cond, rept, abort, t=TUSER()
.rept \rept
9999:
.if \inc == 1
\instr\cond\()b\()\t \reg, [\ptr], #\inc
.elseif \inc == 4
\instr\cond\()\t \reg, [\ptr], #\inc
.else
.error "Unsupported inc macro argument"
.endif
.pushsection __ex_table,"a"
.align 3
.long 9999b, \abort
.popsection
.endr
.endm
#endif /* CONFIG_THUMB2_KERNEL */
.macro strusr, reg, ptr, inc, cond=al, rept=1, abort=9001f
usracc str, \reg, \ptr, \inc, \cond, \rept, \abort
.endm
.macro ldrusr, reg, ptr, inc, cond=al, rept=1, abort=9001f
usracc ldr, \reg, \ptr, \inc, \cond, \rept, \abort
.endm
/* Utility macro for declaring string literals */
.macro string name:req, string
.type \name , #object
\name:
.asciz "\string"
.size \name , . - \name
.endm
.macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req
#ifndef CONFIG_CPU_USE_DOMAINS
adds \tmp, \addr, #\size - 1
sbcccs \tmp, \tmp, \limit
bcs \bad
#endif
.endm
#endif /* __ASM_ASSEMBLER_H__ */