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@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <Ian.Campbell@citrix.com>

1 files changed, 300 insertions, 24 deletions

diff --git a/xen/arch/arm/lib/assembler.h b/xen/arch/arm/lib/assembler.h
index f8f0961a00..f8d4b3aa04 100644
--- a/xen/arch/arm/lib/assembler.h
+++ b/xen/arch/arm/lib/assembler.h
@@ -1,11 +1,72 @@
-#ifndef __ARCH_ARM_LIB_ASSEMBLER_H__
-#define __ARCH_ARM_LIB_ASSEMBLER_H__
-
 /* From Linux arch/arm/include/asm/assembler.h */
 /*
+ *  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
+
+// No Thumb, hence:
+#define W(instr)        instr
+#define ARM(instr...)   instr
+#define THUMB(instr...)
+
+#ifdef CONFIG_ARM_UNWIND
+#define UNWIND(code...)         code
+#else
+#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_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
  */
-#define PLD(code...)    code
+#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
@@ -16,34 +77,249 @@
  *
  * On Feroceon there is much to gain however, regardless of cache mode.
  */
-#ifdef CONFIG_CPU_FEROCEON /* Not in Xen... */
+#ifdef CONFIG_CPU_FEROCEON
 #define CALGN(code...) code
 #else
 #define CALGN(code...)
 #endif
 
-// No Thumb, hence:
-#define W(instr)        instr
-#define ARM(instr...)   instr
-#define THUMB(instr...)
+/*
+ * Enable and disable interrupts
+ */
+#if __LINUX_ARM_ARCH__ >= 6
+	.macro	disable_irq_notrace
+	cpsid	i
+	.endm
 
-#ifdef CONFIG_ARM_UNWIND
-#define UNWIND(code...)         code
+	.macro	enable_irq_notrace
+	cpsie	i
+	.endm
 #else
-#define UNWIND(code...)
+	.macro	disable_irq_notrace
+	msr	cpsr_c, #PSR_I_BIT | SVC_MODE
+	.endm
+
+	.macro	enable_irq_notrace
+	msr	cpsr_c, #SVC_MODE
+	.endm
 #endif
 
-#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
+	.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
 
-#define smp_dmb dmb
+/* Utility macro for declaring string literals */
+	.macro	string name:req, string
+	.type \name , #object
+\name:
+	.asciz "\string"
+	.size \name , . - \name
+	.endm
 
-#endif /*  __ARCH_ARM_LIB_ASSEMBLER_H__ */
+#endif /* __ASM_ASSEMBLER_H__ */