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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] arm: fix unaligned memcpy() and memmove()
# HG changeset patch
# User David Vrabel <david.vrabel@xxxxxxxxxx>
# Date 1330362318 0
# Node ID e4fc04c15cd71a4090f06cd1f0df66703824fcb8
# Parent 21c0c086119fea9514949ddbc4b1a17f994f2724
arm: fix unaligned memcpy() and memmove()
If memcpy() and memmove() were used with source and destination of
different alignment then the result would be all jumbled.
When their implementations were imported from Linux some macros for
big-endian platforms were taken instead of the correct little-endian
ones (specifically, the push and pull macros in assembler.h).
Fix this by taking Linux's arch/include/asm/assembler.h as-is and
making only the minimum changes necessary for Xen.
Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Committed-by: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
---
diff -r 21c0c086119f -r e4fc04c15cd7 xen/arch/arm/lib/assembler.h
--- a/xen/arch/arm/lib/assembler.h Mon Feb 27 16:12:24 2012 +0000
+++ b/xen/arch/arm/lib/assembler.h Mon Feb 27 17:05:18 2012 +0000
@@ -1,25 +1,24 @@
-#ifndef __ARCH_ARM_LIB_ASSEMBLER_H__
-#define __ARCH_ARM_LIB_ASSEMBLER_H__
-
/* From Linux arch/arm/include/asm/assembler.h */
/*
- * Data preload for architectures that support it
+ * 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.
*/
-#define PLD(code...) code
+#ifndef __ASM_ASSEMBLER_H__
+#define __ASM_ASSEMBLER_H__
-/*
- * 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 /* Not in Xen... */
-#define CALGN(code...) code
-#else
-#define CALGN(code...)
+#ifndef __ASSEMBLY__
+#error "Only include this from assembly code"
#endif
// No Thumb, hence:
@@ -33,17 +32,294 @@
#define UNWIND(code...)
#endif
+/*
+ * 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_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_0 lsl #24
+#define put_byte_1 lsl #16
+#define put_byte_2 lsl #8
#define put_byte_3 lsl #0
+#endif
-#define smp_dmb dmb
+/*
+ * Data preload for architectures that support it
+ */
+#if __LINUX_ARM_ARCH__ >= 5
+#define PLD(code...) code
+#else
+#define PLD(code...)
+#endif
-#endif /* __ARCH_ARM_LIB_ASSEMBLER_H__ */
+/*
+ * 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
+ mrs \oldcpsr, cpsr
+ disable_irq
+ .endm
+
+/*
+ * Restore interrupt state previously stored in a register. We don't
+ * guarantee that this will preserve the flags.
+ */
+ .macro restore_irqs_notrace, oldcpsr
+ msr cpsr_c, \oldcpsr
+ .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)
+ .else
+ ALT_SMP(W(dmb))
+ .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
+
+#ifdef 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
+
+/*
+ * STRT/LDRT access macros with ARM and Thumb-2 variants
+ */
+#ifdef CONFIG_THUMB2_KERNEL
+
+ .macro usraccoff, instr, reg, ptr, inc, off, cond, abort, t=T()
+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=T()
+ .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
+
+#endif /* __ASM_ASSEMBLER_H__ */
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