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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/include/asm/assembler.h
Initial import
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diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
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+/*
+ * 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>
+#include <asm/asm-offsets.h>
+#include <asm/page.h>
+#include <asm/thread_info.h>
+
+#define IOMEM(x) (x)
+
+/*
+ * Endian independent macros for shifting bytes within registers.
+ */
+#ifndef __ARMEB__
+#define lspull lsr
+#define lspush 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 lspull lsl
+#define lspush 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
+
+/* Select code for any configuration running in BE8 mode */
+#ifdef CONFIG_CPU_ENDIAN_BE8
+#define ARM_BE8(code...) code
+#else
+#define ARM_BE8(code...)
+#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
+
+/*
+ * Get current thread_info.
+ */
+ .macro get_thread_info, rd
+ ARM( mov \rd, sp, lsr #THREAD_SIZE_ORDER + PAGE_SHIFT )
+ THUMB( mov \rd, sp )
+ THUMB( lsr \rd, \rd, #THREAD_SIZE_ORDER + PAGE_SHIFT )
+ mov \rd, \rd, lsl #THREAD_SIZE_ORDER + PAGE_SHIFT
+ .endm
+
+/*
+ * Increment/decrement the preempt count.
+ */
+#ifdef CONFIG_PREEMPT_COUNT
+ .macro inc_preempt_count, ti, tmp
+ ldr \tmp, [\ti, #TI_PREEMPT] @ get preempt count
+ add \tmp, \tmp, #1 @ increment it
+ str \tmp, [\ti, #TI_PREEMPT]
+ .endm
+
+ .macro dec_preempt_count, ti, tmp
+ ldr \tmp, [\ti, #TI_PREEMPT] @ get preempt count
+ sub \tmp, \tmp, #1 @ decrement it
+ str \tmp, [\ti, #TI_PREEMPT]
+ .endm
+
+ .macro dec_preempt_count_ti, ti, tmp
+ get_thread_info \ti
+ dec_preempt_count \ti, \tmp
+ .endm
+#else
+ .macro inc_preempt_count, ti, tmp
+ .endm
+
+ .macro dec_preempt_count, ti, tmp
+ .endm
+
+ .macro dec_preempt_count_ti, ti, tmp
+ .endm
+#endif
+
+#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 == 2 ;\
+ nop ;\
+ .endif ;\
+ .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 && !defined(CONFIG_CPU_V7M)
+ 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
+
+ .irp c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo
+ .macro ret\c, reg
+#if __LINUX_ARM_ARCH__ < 6
+ mov\c pc, \reg
+#else
+ .ifeqs "\reg", "lr"
+ bx\c \reg
+ .else
+ mov\c pc, \reg
+ .endif
+#endif
+ .endm
+ .endr
+
+ .macro ret.w, reg
+ ret \reg
+#ifdef CONFIG_THUMB2_KERNEL
+ nop
+#endif
+ .endm
+
+#endif /* __ASM_ASSEMBLER_H__ */