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big-endian patch series

PATCH New Ben Dooks 3 participants 23 messages Aug 30, 2013 – Aug 31, 2013

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Ben Dooks

author
#0 lore raw

This is the latest of the big-endian core updates for ARM. It is currently pushed to the following location:

	git://git.baserock.org/delta/linux.git baserock/311-rc7/be/core-v2

It is now well reviewed and has been tested by a number of people including Thomas Petazzoni and Victor Kamensky (who have both contributed to getting this series sorted).

Russell, would this be something that you would accept a pull request for? If so, can I leave the highbank, vexpress and mvebu in the series?

Changes since previous version:

- Updated patches reviewed by Dave Martin
- Fixed message in alignment trap handler (Sergei Shtylov)
- Fixed ordering in highbank (Rob Herring)
- Added Victor Kamensy's signal handling patch

There are a few small outstanding issues to deal with, but those are not directly related to the functionality of this patch series. They are as follows

- KGDB should be disbaled or fixed for THUMB kernels
- The kprobes test suite does not currently work with BE8 properly
- Modules may need 'be8' adding to the vermagic.

author
#1 lore raw

PATCH 1/20 ARM: fix ARCH_IXP4xx usage of ARCH_SUPPORTS_BIG_ENDIAN

The Kconfig for arch/arm/mach-ixp4xx has a local definition of ARCH_SUPPORTS_BIG_ENDIAN which could be used elsewhere. This means that if IXP4xx is selected and this symbol is selected eleswhere then an warning is produced.

Clean the following error up by making the symbol be selected by the main ARCH_IXP4XX definition and have a common definition in arch/arm/mm/Kconfig

warning: (ARCH_xxx) selects ARCH_SUPPORTS_BIG_ENDIAN which has unmet direct dependencies (ARCH_IXP4XX)
warning: (ARCH_xxx) selects ARCH_SUPPORTS_BIG_ENDIAN which has unmet direct dependencies (ARCH_IXP4XX)

---
 arch/arm/Kconfig             |    1 +
 arch/arm/mach-ixp4xx/Kconfig |    4 ----
 arch/arm/mm/Kconfig          |    6 ++++++
 3 files changed, 7 insertions(+), 4 deletions(-)
arch/arm/Kconfig +1 -0
index 43594d5..0628529 100644
@@ -480,6 +480,7 @@ config ARCH_IXP4XX
 	bool "IXP4xx-based"
 	depends on MMU
 	select ARCH_HAS_DMA_SET_COHERENT_MASK
+	select ARCH_SUPPORTS_BIG_ENDIAN
 	select ARCH_REQUIRE_GPIOLIB
 	select CLKSRC_MMIO
 	select CPU_XSCALE
arch/arm/mach-ixp4xx/Kconfig +0 -4
index 30e1ebe..c342dc4 100644
@@ -1,9 +1,5 @@
 if ARCH_IXP4XX
 
-config ARCH_SUPPORTS_BIG_ENDIAN
-	bool
-	default y
-
 menu "Intel IXP4xx Implementation Options"
 
 comment "IXP4xx Platforms"
arch/arm/mm/Kconfig +6 -0
index cd2c88e..1f8fed9 100644
@@ -952,3 +952,9 @@ config ARCH_HAS_BARRIERS
 	help
 	  This option allows the use of custom mandatory barriers
 	  included via the mach/barriers.h file.
+
+config ARCH_SUPPORTS_BIG_ENDIAN
+	bool
+	help
+	  This option specifies the architecture can support big endian
+	  operation.
Signature · 1 line
1.7.10.4
author
#2 lore raw

PATCH 2/20 ARM: asm: Add ARM_BE8() assembly helper

In reply to Ben Dooks

Add ARM_BE8() helper to wrap any code conditional on being compile when CONFIG_ARM_ENDIAN_BE8 is selected and convert existing places where this is to use it.

---
 arch/arm/boot/compressed/head.S  |    8 ++------
 arch/arm/include/asm/assembler.h |    7 +++++++
 arch/arm/kernel/entry-armv.S     |    5 ++---
 arch/arm/kernel/entry-common.S   |    4 +---
 arch/arm/mm/abort-ev6.S          |    5 ++---
 arch/arm/mm/proc-v6.S            |    4 +---
 arch/arm/mm/proc-v7.S            |    4 +---
 7 files changed, 16 insertions(+), 21 deletions(-)
arch/arm/boot/compressed/head.S +2 -6
index 75189f1..c912c2a 100644
@@ -699,9 +699,7 @@ __armv4_mmu_cache_on:
 		mrc	p15, 0, r0, c1, c0, 0	@ read control reg
 		orr	r0, r0, #0x5000		@ I-cache enable, RR cache replacement
 		orr	r0, r0, #0x0030
-#ifdef CONFIG_CPU_ENDIAN_BE8
-		orr	r0, r0, #1 << 25	@ big-endian page tables
-#endif
+ ARM_BE8(	orr	r0, r0, #1 << 25 )	@ big-endian page tables
 		bl	__common_mmu_cache_on
 		mov	r0, #0
 		mcr	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
@@ -728,9 +726,7 @@ __armv7_mmu_cache_on:
 		orr	r0, r0, #1 << 22	@ U (v6 unaligned access model)
 						@ (needed for ARM1176)
 #ifdef CONFIG_MMU
-#ifdef CONFIG_CPU_ENDIAN_BE8
-		orr	r0, r0, #1 << 25	@ big-endian page tables
-#endif
+ ARM_BE8(	orr	r0, r0, #1 << 25 )	@ big-endian page tables
 		mrcne   p15, 0, r6, c2, c0, 2   @ read ttb control reg
 		orrne	r0, r0, #1		@ MMU enabled
 		movne	r1, #0xfffffffd		@ domain 0 = client
arch/arm/include/asm/assembler.h +7 -0
index a5fef71..5350f83 100644
@@ -53,6 +53,13 @@
 #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
  */
arch/arm/kernel/entry-armv.S +2 -3
index 9cbe70c..55090fb 100644
@@ -416,9 +416,8 @@ __und_usr:
 	bne	__und_usr_thumb
 	sub	r4, r2, #4			@ ARM instr@LR - 4
 1:	ldrt	r0, [r4]
-#ifdef CONFIG_CPU_ENDIAN_BE8
-	rev	r0, r0				@ little endian instruction
-#endif
+ ARM_BE8(rev	r0, r0)				@ little endian instruction
+
 	@ r0 = 32-bit ARM instruction which caused the exception
 	@ r2 = PC value for the following instruction (:= regs->ARM_pc)
 	@ r4 = PC value for the faulting instruction
arch/arm/kernel/entry-common.S +1 -3
index 94104bf..cc318cd 100644
@@ -393,9 +393,7 @@ ENTRY(vector_swi)
 #else
  USER(	ldr	r10, [lr, #-4]		)	@ get SWI instruction
 #endif
-#ifdef CONFIG_CPU_ENDIAN_BE8
-	rev	r10, r10			@ little endian instruction
-#endif
+ ARM_BE8(rev	r10, r10)			@ little endian instruction
 
 #elif defined(CONFIG_AEABI)
 
arch/arm/mm/abort-ev6.S +2 -3
index 8074199..3815a82 100644
@@ -38,9 +38,8 @@ ENTRY(v6_early_abort)
 	bne	do_DataAbort
 	bic	r1, r1, #1 << 11		@ clear bit 11 of FSR
 	ldr	r3, [r4]			@ read aborted ARM instruction
-#ifdef CONFIG_CPU_ENDIAN_BE8
-	rev	r3, r3
-#endif
+ ARM_BE8(rev	r3, r3)
+
 	do_ldrd_abort tmp=ip, insn=r3
 	tst	r3, #1 << 20			@ L = 0 -> write
 	orreq	r1, r1, #1 << 11		@ yes.
arch/arm/mm/proc-v6.S +1 -3
index 1128064..45dc29f 100644
@@ -220,9 +220,7 @@ __v6_setup:
 #endif /* CONFIG_MMU */
 	adr	r5, v6_crval
 	ldmia	r5, {r5, r6}
-#ifdef CONFIG_CPU_ENDIAN_BE8
-	orr	r6, r6, #1 << 25		@ big-endian page tables
-#endif
+ ARM_BE8(orr	r6, r6, #1 << 25)		@ big-endian page tables
 	mrc	p15, 0, r0, c1, c0, 0		@ read control register
 	bic	r0, r0, r5			@ clear bits them
 	orr	r0, r0, r6			@ set them
arch/arm/mm/proc-v7.S +1 -3
index 73398bc..03978e3 100644
@@ -355,9 +355,7 @@ __v7_setup:
 #endif
 	adr	r5, v7_crval
 	ldmia	r5, {r5, r6}
-#ifdef CONFIG_CPU_ENDIAN_BE8
-	orr	r6, r6, #1 << 25		@ big-endian page tables
-#endif
+ ARM_BE8(orr	r6, r6, #1 << 25)		@ big-endian page tables
 #ifdef CONFIG_SWP_EMULATE
 	orr     r5, r5, #(1 << 10)              @ set SW bit in "clear"
 	bic     r6, r6, #(1 << 10)              @ clear it in "mmuset"
Signature · 1 line
1.7.10.4
author
#3 lore raw

PATCH 3/20 ARM: fixup_pv_table bug when CPU_ENDIAN_BE8

In reply to Ben Dooks

The fixup_pv_table assumes that the instructions are in the same endian configuration as the data, but when the CPU is running in BE8 the instructions stay in little-endian format.

Make sure if CONFIG_CPU_ENDIAN_BE8 is set that we do all the alterations to the instructions taking in to account the LDR/STR will be swapping the data endian-ness.

Since the code is only modifying a byte, we avoid dual-swapping the data, and just change the bits we clear and ORR in (in the case where the code is not thumb2).

For thumb2, we add the necessary rev16 instructions to ensure that the instructions are processed in the correct format, as it was easier than re-writing the code to contain a mask and shift.

---
 arch/arm/kernel/head.S |    8 ++++++++
 1 file changed, 8 insertions(+)
arch/arm/kernel/head.S +8 -0
index 2c7cc1e..9e5906c 100644
@@ -582,8 +582,10 @@ __fixup_a_pv_table:
 	b	2f
 1:	add     r7, r3
 	ldrh	ip, [r7, #2]
+ARM_BE8(rev16	ip, ip)
 	and	ip, 0x8f00
 	orr	ip, r6	@ mask in offset bits 31-24
+ARM_BE8(rev16	ip, ip)
 	strh	ip, [r7, #2]
 2:	cmp	r4, r5
 	ldrcc	r7, [r4], #4	@ use branch for delay slot
@@ -592,8 +594,14 @@ __fixup_a_pv_table:
 #else
 	b	2f
 1:	ldr	ip, [r7, r3]
+#ifdef CONFIG_CPU_ENDIAN_BE8
+	@ in BE8, we load data in BE, but instructions still in LE
+	bic	ip, ip, #0xff000000
+	orr	ip, ip, r6, lsl#24
+#else
 	bic	ip, ip, #0x000000ff
 	orr	ip, ip, r6	@ mask in offset bits 31-24
+#endif
 	str	ip, [r7, r3]
 2:	cmp	r4, r5
 	ldrcc	r7, [r4], #4	@ use branch for delay slot
Signature · 1 line
1.7.10.4
author
#4 lore raw

PATCH 4/20 ARM: set BE8 if LE in head code

In reply to Ben Dooks

If we are booting in LE and compiled for BE8, then add code to set the state to bE8. Since the instruction stream is always LE, we do not need to do anything special to the instruction.

Also ensure that the secondary processors are started in the same mode.

Note, we do add about 20 bytes to the kernel image, but it seems easier to do this than adding another configuration to change.

---
 arch/arm/boot/compressed/head.S |    1 +
 arch/arm/kernel/head.S          |    4 ++++
 arch/arm/kernel/sleep.S         |    1 +
 3 files changed, 6 insertions(+)
arch/arm/boot/compressed/head.S +1 -0
index c912c2a..066b034 100644
@@ -135,6 +135,7 @@ start:
 		.word	_edata			@ zImage end address
  THUMB(		.thumb			)
 1:
+ ARM_BE8(	setend	be )			@ go BE8 if compiled for BE8
 		mrs	r9, cpsr
 #ifdef CONFIG_ARM_VIRT_EXT
 		bl	__hyp_stub_install	@ get into SVC mode, reversibly
arch/arm/kernel/head.S +4 -0
index 9e5906c..a047acf 100644
@@ -77,6 +77,7 @@
 
 	__HEAD
 ENTRY(stext)
+ ARM_BE8(setend	be )			@ ensure we are in BE8 mode
 
  THUMB(	adr	r9, BSYM(1f)	)	@ Kernel is always entered in ARM.
  THUMB(	bx	r9		)	@ If this is a Thumb-2 kernel,
@@ -352,6 +353,9 @@ ENTRY(secondary_startup)
 	 * the processor type - there is no need to check the machine type
 	 * as it has already been validated by the primary processor.
 	 */
+
+ ARM_BE8(setend	be)				@ ensure we are in BE8 mode
+
 #ifdef CONFIG_ARM_VIRT_EXT
 	bl	__hyp_stub_install_secondary
 #endif
arch/arm/kernel/sleep.S +1 -0
index db1536b..716343c 100644
@@ -130,6 +130,7 @@ ENDPROC(cpu_resume_after_mmu)
 	.data
 	.align
 ENTRY(cpu_resume)
+ARM_BE8(setend be)			@ ensure we are in BE mode
 	mov	r1, #0
 	ALT_SMP(mrc p15, 0, r0, c0, c0, 5)
 	ALT_UP_B(1f)
Signature · 1 line
1.7.10.4
author
#5 lore raw

PATCH 5/20 ARM: pl01x debug code endian fix

In reply to Ben Dooks

The PL01X debug code needs to take into account which endian mode the processor is running in. If it is big-endian, ensure the data is swapped appropriately.

Note, we could do this slightly more efficiently if we have an macro to do the necessary swap for the bits used by test.

---
 arch/arm/include/asm/hardware/debug-pl01x.S |    2 ++
 1 file changed, 2 insertions(+)
arch/arm/include/asm/hardware/debug-pl01x.S +2 -0
index f9fd083..6489d1f 100644
@@ -18,12 +18,14 @@
 
 		.macro	waituart,rd,rx
 1001:		ldr	\rd, [\rx, #UART01x_FR]
+ ARM_BE8(	rev	\rd, \rd )
 		tst	\rd, #UART01x_FR_TXFF
 		bne	1001b
 		.endm
 
 		.macro	busyuart,rd,rx
 1001:		ldr	\rd, [\rx, #UART01x_FR]
+ ARM_BE8(	rev	\rd, \rd )
 		tst	\rd, #UART01x_FR_BUSY
 		bne	1001b
 		.endm
Signature · 1 line
1.7.10.4
author
#6 lore raw

PATCH 6/20 ARM: twd: data endian fix

In reply to Ben Dooks

Ensure the twd driver uses the correct calls to access the hardware to ensure that we do not end up with data in the wrong endian format.

---
 arch/arm/kernel/smp_twd.c |   24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)
arch/arm/kernel/smp_twd.c +12 -12
index 2595620..0804013 100644
@@ -45,7 +45,7 @@ static void twd_set_mode(enum clock_event_mode mode,
 	case CLOCK_EVT_MODE_PERIODIC:
 		ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE
 			| TWD_TIMER_CONTROL_PERIODIC;
-		__raw_writel(DIV_ROUND_CLOSEST(twd_timer_rate, HZ),
+		writel_relaxed(DIV_ROUND_CLOSEST(twd_timer_rate, HZ),
 			twd_base + TWD_TIMER_LOAD);
 		break;
 	case CLOCK_EVT_MODE_ONESHOT:
@@ -58,18 +58,18 @@ static void twd_set_mode(enum clock_event_mode mode,
 		ctrl = 0;
 	}
 
-	__raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL);
+	writel_relaxed(ctrl, twd_base + TWD_TIMER_CONTROL);
 }
 
 static int twd_set_next_event(unsigned long evt,
 			struct clock_event_device *unused)
 {
-	unsigned long ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL);
+	unsigned long ctrl = readl_relaxed(twd_base + TWD_TIMER_CONTROL);
 
 	ctrl |= TWD_TIMER_CONTROL_ENABLE;
 
-	__raw_writel(evt, twd_base + TWD_TIMER_COUNTER);
-	__raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL);
+	writel_relaxed(evt, twd_base + TWD_TIMER_COUNTER);
+	writel_relaxed(ctrl, twd_base + TWD_TIMER_CONTROL);
 
 	return 0;
 }
@@ -82,8 +82,8 @@ static int twd_set_next_event(unsigned long evt,
  */
 static int twd_timer_ack(void)
 {
-	if (__raw_readl(twd_base + TWD_TIMER_INTSTAT)) {
-		__raw_writel(1, twd_base + TWD_TIMER_INTSTAT);
+	if (readl_relaxed(twd_base + TWD_TIMER_INTSTAT)) {
+		writel_relaxed(1, twd_base + TWD_TIMER_INTSTAT);
 		return 1;
 	}
 
@@ -209,15 +209,15 @@ static void twd_calibrate_rate(void)
 		waitjiffies += 5;
 
 				 /* enable, no interrupt or reload */
-		__raw_writel(0x1, twd_base + TWD_TIMER_CONTROL);
+		writel_relaxed(0x1, twd_base + TWD_TIMER_CONTROL);
 
 				 /* maximum value */
-		__raw_writel(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER);
+		writel_relaxed(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER);
 
 		while (get_jiffies_64() < waitjiffies)
 			udelay(10);
 
-		count = __raw_readl(twd_base + TWD_TIMER_COUNTER);
+		count = readl_relaxed(twd_base + TWD_TIMER_COUNTER);
 
 		twd_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5);
 
@@ -275,7 +275,7 @@ static int twd_timer_setup(struct clock_event_device *clk)
 	 * bother with the below.
 	 */
 	if (per_cpu(percpu_setup_called, cpu)) {
-		__raw_writel(0, twd_base + TWD_TIMER_CONTROL);
+		writel_relaxed(0, twd_base + TWD_TIMER_CONTROL);
 		clockevents_register_device(*__this_cpu_ptr(twd_evt));
 		enable_percpu_irq(clk->irq, 0);
 		return 0;
@@ -288,7 +288,7 @@ static int twd_timer_setup(struct clock_event_device *clk)
 	 * The following is done once per CPU the first time .setup() is
 	 * called.
 	 */
-	__raw_writel(0, twd_base + TWD_TIMER_CONTROL);
+	writel_relaxed(0, twd_base + TWD_TIMER_CONTROL);
 
 	clk->name = "local_timer";
 	clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
Signature · 1 line
1.7.10.4
author
#7 lore raw

PATCH 7/20 ARM: smp_scu: data endian fixes

In reply to Ben Dooks

The smp_scu driver needs to use the relaxed readl/write accessors to avoid any issues with the endian mode the processor core is in.

---
 arch/arm/kernel/smp_scu.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)
arch/arm/kernel/smp_scu.c +7 -7
index 5bc1a63..1aafa0d 100644
@@ -28,7 +28,7 @@
  */
 unsigned int __init scu_get_core_count(void __iomem *scu_base)
 {
-	unsigned int ncores = __raw_readl(scu_base + SCU_CONFIG);
+	unsigned int ncores = readl_relaxed(scu_base + SCU_CONFIG);
 	return (ncores & 0x03) + 1;
 }
 
@@ -42,19 +42,19 @@ void scu_enable(void __iomem *scu_base)
 #ifdef CONFIG_ARM_ERRATA_764369
 	/* Cortex-A9 only */
 	if ((read_cpuid_id() & 0xff0ffff0) == 0x410fc090) {
-		scu_ctrl = __raw_readl(scu_base + 0x30);
+		scu_ctrl = readl_relaxed(scu_base + 0x30);
 		if (!(scu_ctrl & 1))
-			__raw_writel(scu_ctrl | 0x1, scu_base + 0x30);
+			writel_relaxed(scu_ctrl | 0x1, scu_base + 0x30);
 	}
 #endif
 
-	scu_ctrl = __raw_readl(scu_base + SCU_CTRL);
+	scu_ctrl = readl_relaxed(scu_base + SCU_CTRL);
 	/* already enabled? */
 	if (scu_ctrl & 1)
 		return;
 
 	scu_ctrl |= 1;
-	__raw_writel(scu_ctrl, scu_base + SCU_CTRL);
+	writel_relaxed(scu_ctrl, scu_base + SCU_CTRL);
 
 	/*
 	 * Ensure that the data accessed by CPU0 before the SCU was
@@ -80,9 +80,9 @@ int scu_power_mode(void __iomem *scu_base, unsigned int mode)
 	if (mode > 3 || mode == 1 || cpu > 3)
 		return -EINVAL;
 
-	val = __raw_readb(scu_base + SCU_CPU_STATUS + cpu) & ~0x03;
+	val = readb_relaxed(scu_base + SCU_CPU_STATUS + cpu) & ~0x03;
 	val |= mode;
-	__raw_writeb(val, scu_base + SCU_CPU_STATUS + cpu);
+	writeb_relaxed(val, scu_base + SCU_CPU_STATUS + cpu);
 
 	return 0;
 }
Signature · 1 line
1.7.10.4
author
#8 lore raw

PATCH 8/20 highbank: enable big-endian

In reply to Ben Dooks

Apart from a xgmac driver issue, the highbank seems to work correctly in big-endian mode. Allow the selection of big-endian in the system.

---
 arch/arm/mach-highbank/Kconfig |    2 ++
 1 file changed, 2 insertions(+)
arch/arm/mach-highbank/Kconfig +2 -0
index cd9fcb1..f82bd88 100644
@@ -2,6 +2,7 @@ config ARCH_HIGHBANK
 	bool "Calxeda ECX-1000/2000 (Highbank/Midway)" if ARCH_MULTI_V7
 	select ARCH_HAS_CPUFREQ
 	select ARCH_HAS_OPP
+	select ARCH_SUPPORTS_BIG_ENDIAN
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARM_AMBA
 	select ARM_GIC
@@ -18,3 +19,4 @@ config ARCH_HIGHBANK
 	select PL320_MBOX
 	select SPARSE_IRQ
 	select USE_OF
+
Signature · 1 line
1.7.10.4
#10 lore raw

PATCH 8/20 highbank: enable big-endian

In reply to Ben Dooks

Hello.

Quoted 12 lines · Ben Dooks

Apart from a xgmac driver issue, the highbank seems to work correctly in big-endian mode. Allow the selection of big-endian in the system.

---
  arch/arm/mach-highbank/Kconfig |    2 ++
  1 file changed, 2 insertions(+)
arch/arm/mach-highbank/Kconfig +0 -0
index cd9fcb1..f82bd88 100644

[...]

arch/arm/mach-highbank/Kconfig config ARCH_HIGHBANK · line 22

Quoted 5 lines
arch/arm/mach-highbank/Kconfig +1 -0
@@ -18,3 +19,4 @@ config ARCH_HIGHBANK
  	select PL320_MBOX
  	select SPARSE_IRQ
  	select USE_OF
+

I don't think you really intended to add this line at end of file.

WBR, Sergei

author
#11 lore raw

PATCH 9/20 mvebu: support running big-endian

In reply to Ben Dooks

Add indication we can run these cores in BE mode, and ensure that the secondary CPU is set to big-endian mode in the initialisation code as the initial code runs little-endian.

---
 arch/arm/mach-mvebu/Kconfig        |    1 +
 arch/arm/mach-mvebu/coherency_ll.S |    3 +++
 arch/arm/mach-mvebu/headsmp.S      |    4 ++++
 3 files changed, 8 insertions(+)
arch/arm/mach-mvebu/Kconfig +1 -0
index 9eb63d7..5e269d7 100644
@@ -1,5 +1,6 @@
 config ARCH_MVEBU
 	bool "Marvell SOCs with Device Tree support" if ARCH_MULTI_V7
+	select ARCH_SUPPORTS_BIG_ENDIAN
 	select CLKSRC_MMIO
 	select COMMON_CLK
 	select GENERIC_CLOCKEVENTS
arch/arm/mach-mvebu/coherency_ll.S +3 -0
index 5476669..ee7598f 100644
@@ -20,6 +20,8 @@
 #define ARMADA_XP_CFB_CTL_REG_OFFSET 0x0
 #define ARMADA_XP_CFB_CFG_REG_OFFSET 0x4
 
+#include <asm/assembler.h>
+
 	.text
 /*
  * r0: Coherency fabric base register address
@@ -29,6 +31,7 @@ ENTRY(ll_set_cpu_coherent)
 	/* Create bit by cpu index */
 	mov	r3, #(1 << 24)
 	lsl	r1, r3, r1
+ARM_BE8(rev	r1, r1)
 
 	/* Add CPU to SMP group - Atomic */
 	add	r3, r0, #ARMADA_XP_CFB_CTL_REG_OFFSET
arch/arm/mach-mvebu/headsmp.S +4 -0
index 8a1b0c9..3dd80df4 100644
@@ -21,12 +21,16 @@
 #include <linux/linkage.h>
 #include <linux/init.h>
 
+#include <asm/assembler.h>
+
 /*
  * Armada XP specific entry point for secondary CPUs.
  * We add the CPU to the coherency fabric and then jump to secondary
  * startup
  */
 ENTRY(armada_xp_secondary_startup)
+ ARM_BE8(setend	be )			@ go BE8 if entered LE
+
 	/* Get coherency fabric base physical address */
 	adr	r0, 1f
 	ldr	r1, [r0]
Signature · 1 line
1.7.10.4
author
#12 lore raw

PATCH 10/20 vexpress: add big endian support

In reply to Ben Dooks

Add support for the versatile express systems to boot big-endian.

---
 arch/arm/mach-vexpress/Kconfig    |    1 +
 arch/arm/plat-versatile/headsmp.S |    2 ++
 2 files changed, 3 insertions(+)
arch/arm/mach-vexpress/Kconfig +1 -0
index b8bbabe..d9dc5d2a 100644
@@ -1,6 +1,7 @@
 config ARCH_VEXPRESS
 	bool "ARM Ltd. Versatile Express family" if ARCH_MULTI_V7
 	select ARCH_REQUIRE_GPIOLIB
+	select ARCH_SUPPORTS_BIG_ENDIAN
 	select ARM_AMBA
 	select ARM_GIC
 	select ARM_TIMER_SP804
arch/arm/plat-versatile/headsmp.S +2 -0
index 2677bc3..40f27e5 100644
@@ -10,6 +10,7 @@
  */
 #include <linux/linkage.h>
 #include <linux/init.h>
+#include <asm/assembler.h>
 
 /*
  * Realview/Versatile Express specific entry point for secondary CPUs.
@@ -17,6 +18,7 @@
  * until we're ready for them to initialise.
  */
 ENTRY(versatile_secondary_startup)
+ ARM_BE8(setend	be)
 	mrc	p15, 0, r0, c0, c0, 5
 	bic	r0, #0xff000000
 	adr	r4, 1f
Signature · 1 line
1.7.10.4
author
#13 lore raw

PATCH 11/20 ARM: alignment: correctly decode instructions in BE8 mode.

In reply to Ben Dooks

If we are in BE8 mode, we must deal with the instruction stream being in LE order when data is being loaded in BE order. Ensure the data is swapped before processing to avoid thre following:

Change to using <asm/opcodes.h> to provide the necessary conversion functions to change the byte ordering.

This stops the following warning messages from the kernel on a fault:

Unhandled fault: alignment exception (0x001) at 0xbfa09567 Alignment trap: not handling instruction 030091e8 at [<80333e8c>]

---
 arch/arm/mm/alignment.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)
arch/arm/mm/alignment.c +7 -2
index 6f4585b..9240364 100644
@@ -25,6 +25,7 @@
 #include <asm/cp15.h>
 #include <asm/system_info.h>
 #include <asm/unaligned.h>
+#include <asm/opcodes.h>
 
 #include "fault.h"
 
@@ -762,21 +763,25 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 	if (thumb_mode(regs)) {
 		u16 *ptr = (u16 *)(instrptr & ~1);
 		fault = probe_kernel_address(ptr, tinstr);
+		tinstr = __mem_to_opcode_thumb16(tinstr);
 		if (!fault) {
 			if (cpu_architecture() >= CPU_ARCH_ARMv7 &&
 			    IS_T32(tinstr)) {
 				/* Thumb-2 32-bit */
 				u16 tinst2 = 0;
 				fault = probe_kernel_address(ptr + 1, tinst2);
-				instr = (tinstr << 16) | tinst2;
+				tinst2 = __mem_to_opcode_thumb16(tinst2);
+				instr = __opcode_thumb32_compose(tinstr, tinst2);
 				thumb2_32b = 1;
 			} else {
 				isize = 2;
 				instr = thumb2arm(tinstr);
 			}
 		}
-	} else
+	} else {
 		fault = probe_kernel_address(instrptr, instr);
+		instr = __mem_to_opcode_arm(instr);
+	}
 
 	if (fault) {
 		type = TYPE_FAULT;
Signature · 1 line
1.7.10.4
author
#14 lore raw

PATCH 12/20 ARM: traps: use <asm/opcodes.h> to get correct instruction order

In reply to Ben Dooks

The trap handler needs to take into account the endian configuration of the system when loading instructions. Use <asm/opcodes.h> to provide the necessary conversion functions.

---
 arch/arm/kernel/traps.c |   16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)
arch/arm/kernel/traps.c +10 -6
index ab517fc..99bcd0e3 100644
@@ -34,6 +34,7 @@
 #include <asm/unwind.h>
 #include <asm/tls.h>
 #include <asm/system_misc.h>
+#include <asm/opcodes.h>
 
 static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" };
 
@@ -402,25 +403,28 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
 	if (processor_mode(regs) == SVC_MODE) {
 #ifdef CONFIG_THUMB2_KERNEL
 		if (thumb_mode(regs)) {
-			instr = ((u16 *)pc)[0];
+			instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]);
 			if (is_wide_instruction(instr)) {
-				instr <<= 16;
-				instr |= ((u16 *)pc)[1];
+				u16 inst2;
+				instr2 = __mem_to_opcode_thumb16(((u16 *)pc)[1]);
+				instr = __opcode_thumb32_compose(instr, instr2);
 			}
 		} else
 #endif
-			instr = *(u32 *) pc;
+			instr = __mem_to_opcode_arm(*(u32 *) pc);
 	} else if (thumb_mode(regs)) {
 		if (get_user(instr, (u16 __user *)pc))
 			goto die_sig;
+		instr = __mem_to_opcode_thumb16(instr);
 		if (is_wide_instruction(instr)) {
 			unsigned int instr2;
 			if (get_user(instr2, (u16 __user *)pc+1))
 				goto die_sig;
-			instr <<= 16;
-			instr |= instr2;
+			instr2 = __mem_to_opcode_thumb16(instr2);
+			instr = __opcode_thumb32_compose(instr, instr2);
 		}
 	} else if (get_user(instr, (u32 __user *)pc)) {
+		instr = __mem_to_opcode_arm(instr);
 		goto die_sig;
 	}
 
Signature · 1 line
1.7.10.4
author
#15 lore raw

PATCH 13/20 ARM: module: correctly relocate instructions in BE8

In reply to Ben Dooks

When in BE8 mode, our instructions are not in the same ordering as the data, so use <asm/opcodes.h> to take this into account.

Note, also requires modules to be built --be8

---
 arch/arm/kernel/module.c |   57 +++++++++++++++++++++++++++-------------------
 1 file changed, 34 insertions(+), 23 deletions(-)
arch/arm/kernel/module.c +34 -23
index 85c3fb6..a1045a7 100644
@@ -24,6 +24,7 @@
 #include <asm/sections.h>
 #include <asm/smp_plat.h>
 #include <asm/unwind.h>
+#include <asm/opcodes.h>
 
 #ifdef CONFIG_XIP_KERNEL
 /*
@@ -60,6 +61,7 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 		Elf32_Sym *sym;
 		const char *symname;
 		s32 offset;
+		u32 tmp;
 #ifdef CONFIG_THUMB2_KERNEL
 		u32 upper, lower, sign, j1, j2;
 #endif
@@ -95,7 +97,8 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 		case R_ARM_PC24:
 		case R_ARM_CALL:
 		case R_ARM_JUMP24:
-			offset = (*(u32 *)loc & 0x00ffffff) << 2;
+			offset = __mem_to_opcode_arm(*(u32 *)loc);
+			offset = (offset & 0x00ffffff) << 2;
 			if (offset & 0x02000000)
 				offset -= 0x04000000;
 
@@ -111,9 +114,10 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 			}
 
 			offset >>= 2;
+			offset &= 0x00ffffff;
 
-			*(u32 *)loc &= 0xff000000;
-			*(u32 *)loc |= offset & 0x00ffffff;
+			*(u32 *)loc &= __opcode_to_mem_arm(0xff000000);
+			*(u32 *)loc |= __opcode_to_mem_arm(offset);
 			break;
 
 	       case R_ARM_V4BX:
@@ -121,8 +125,8 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 			* other bits to re-code instruction as
 			* MOV PC,Rm.
 			*/
-		       *(u32 *)loc &= 0xf000000f;
-		       *(u32 *)loc |= 0x01a0f000;
+		       *(u32 *)loc &= __opcode_to_mem_arm(0xf000000f);
+		       *(u32 *)loc |= __opcode_to_mem_arm(0x01a0f000);
 		       break;
 
 		case R_ARM_PREL31:
@@ -132,7 +136,7 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 
 		case R_ARM_MOVW_ABS_NC:
 		case R_ARM_MOVT_ABS:
-			offset = *(u32 *)loc;
+			offset = tmp = __mem_to_opcode_arm(*(u32 *)loc);
 			offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
 			offset = (offset ^ 0x8000) - 0x8000;
 
@@ -140,16 +144,18 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 			if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
 				offset >>= 16;
 
-			*(u32 *)loc &= 0xfff0f000;
-			*(u32 *)loc |= ((offset & 0xf000) << 4) |
-					(offset & 0x0fff);
+			tmp &= 0xfff0f000;
+			tmp |= ((offset & 0xf000) << 4) |
+				(offset & 0x0fff);
+
+			*(u32 *)loc = __opcode_to_mem_arm(tmp);
 			break;
 
 #ifdef CONFIG_THUMB2_KERNEL
 		case R_ARM_THM_CALL:
 		case R_ARM_THM_JUMP24:
-			upper = *(u16 *)loc;
-			lower = *(u16 *)(loc + 2);
+			upper = __mem_to_opcode_thumb16(*(u16 *)loc);
+			lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));
 
 			/*
 			 * 25 bit signed address range (Thumb-2 BL and B.W
@@ -198,17 +204,20 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 			sign = (offset >> 24) & 1;
 			j1 = sign ^ (~(offset >> 23) & 1);
 			j2 = sign ^ (~(offset >> 22) & 1);
-			*(u16 *)loc = (u16)((upper & 0xf800) | (sign << 10) |
+			upper = (u16)((upper & 0xf800) | (sign << 10) |
 					    ((offset >> 12) & 0x03ff));
-			*(u16 *)(loc + 2) = (u16)((lower & 0xd000) |
-						  (j1 << 13) | (j2 << 11) |
-						  ((offset >> 1) & 0x07ff));
+			lower = (u16)((lower & 0xd000) |
+				      (j1 << 13) | (j2 << 11) |
+				      ((offset >> 1) & 0x07ff));
+
+			*(u16 *)loc = __opcode_to_mem_thumb16(upper);
+			*(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);
 			break;
 
 		case R_ARM_THM_MOVW_ABS_NC:
 		case R_ARM_THM_MOVT_ABS:
-			upper = *(u16 *)loc;
-			lower = *(u16 *)(loc + 2);
+			upper = __mem_to_opcode_thumb16(*(u16 *)loc);
+			lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));
 
 			/*
 			 * MOVT/MOVW instructions encoding in Thumb-2:
@@ -229,12 +238,14 @@ apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
 			if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
 				offset >>= 16;
 
-			*(u16 *)loc = (u16)((upper & 0xfbf0) |
-					    ((offset & 0xf000) >> 12) |
-					    ((offset & 0x0800) >> 1));
-			*(u16 *)(loc + 2) = (u16)((lower & 0x8f00) |
-						  ((offset & 0x0700) << 4) |
-						  (offset & 0x00ff));
+			upper = (u16)((upper & 0xfbf0) |
+				      ((offset & 0xf000) >> 12) |
+				      ((offset & 0x0800) >> 1));
+			lower = (u16)((lower & 0x8f00) |
+				      ((offset & 0x0700) << 4) |
+				      (offset & 0x00ff));
+			*(u16 *)loc = __opcode_to_mem_thumb16(upper);
+			*(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);
 			break;
 #endif
 
Signature · 1 line
1.7.10.4
author
#16 lore raw

PATCH 14/20 ARM: set --be8 when linking modules

In reply to Ben Dooks

To avoid having to make every text section swap the instruction order of all instructions, make sure modules are built also built with --be8 (as is the current kernel final link).

If we do not do this, we would end up having to swap all instructions when loading a module, instead of just the instructions that we are applying ELF relocations to.

---
 arch/arm/Makefile |    1 +
 1 file changed, 1 insertion(+)
arch/arm/Makefile +1 -0
index 6fd2cea..2c659f9 100644
@@ -16,6 +16,7 @@ LDFLAGS		:=
 LDFLAGS_vmlinux	:=-p --no-undefined -X
 ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)
 LDFLAGS_vmlinux	+= --be8
+LDFLAGS_MODULE	+= --be8
 endif
 
 OBJCOPYFLAGS	:=-O binary -R .comment -S
Signature · 1 line
1.7.10.4
author
#17 lore raw

PATCH 15/20 ARM: hardware: fix endian-ness in <hardware/coresight.h>

In reply to Ben Dooks

The <hardware/coresight.h> needs to take into account the endian-ness of the processor when reading and writing data, so change to using the readl/writel relaxed variants from the raw ones.

---
 arch/arm/include/asm/hardware/coresight.h |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
arch/arm/include/asm/hardware/coresight.h +4 -4
index 0cf7a6b..ad774f3 100644
@@ -24,8 +24,8 @@
 #define TRACER_TIMEOUT 10000
 
 #define etm_writel(t, v, x) \
-	(__raw_writel((v), (t)->etm_regs + (x)))
-#define etm_readl(t, x) (__raw_readl((t)->etm_regs + (x)))
+	(writel_relaxed((v), (t)->etm_regs + (x)))
+#define etm_readl(t, x) (readl_relaxed((t)->etm_regs + (x)))
 
 /* CoreSight Management Registers */
 #define CSMR_LOCKACCESS 0xfb0
@@ -142,8 +142,8 @@
 #define ETBFF_TRIGFL		BIT(10)
 
 #define etb_writel(t, v, x) \
-	(__raw_writel((v), (t)->etb_regs + (x)))
-#define etb_readl(t, x) (__raw_readl((t)->etb_regs + (x)))
+	(writel_relaxed((v), (t)->etb_regs + (x)))
+#define etb_readl(t, x) (readl_relaxed((t)->etb_regs + (x)))
 
 #define etm_lock(t) do { etm_writel((t), 0, CSMR_LOCKACCESS); } while (0)
 #define etm_unlock(t) \
Signature · 1 line
1.7.10.4
author
#18 lore raw

PATCH 16/20 ARM: net: fix arm instruction endian-ness in bpf_jit_32.c

In reply to Ben Dooks

Use <asm/opcodes.h> to correctly transform instruction byte ordering into in-memory ordering.

---
 arch/arm/net/bpf_jit_32.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
arch/arm/net/bpf_jit_32.c +5 -1
index f50d223..510d923 100644
@@ -19,6 +19,7 @@
 #include <linux/if_vlan.h>
 #include <asm/cacheflush.h>
 #include <asm/hwcap.h>
+#include <asm/opcodes.h>
 
 #include "bpf_jit_32.h"
 
@@ -113,8 +114,11 @@ static u32 jit_udiv(u32 dividend, u32 divisor)
 
 static inline void _emit(int cond, u32 inst, struct jit_ctx *ctx)
 {
+	inst |= (cond << 28);
+	inst = __opcode_to_mem_arm(inst);
+
 	if (ctx->target != NULL)
-		ctx->target[ctx->idx] = inst | (cond << 28);
+		ctx->target[ctx->idx] = inst;
 
 	ctx->idx++;
 }
Signature · 1 line
1.7.10.4
author
#19 lore raw

PATCH 17/20 ARM: Correct BUG() assembly to ensure it is endian-agnostic

In reply to Ben Dooks

Currently BUG() uses .word or .hword to create the necessary illegal instructions. However if we are building BE8 then these get swapped by the linker into different illegal instructions in the text. This means that the BUG() macro does not get trapped properly.

Change to using <asm/opcodes.h> to provide the necessary ARM instruction building as we cannot rely on gcc/gas having the .inst instructions which where added to try and resolve this issue (reported by Dave Martin <[email protected]>).

---
 arch/arm/include/asm/bug.h |   10 ++++++----
 arch/arm/kernel/traps.c    |    8 +++++---
 2 files changed, 11 insertions(+), 7 deletions(-)
arch/arm/include/asm/bug.h +6 -4
index 7af5c6c..b274bde 100644
@@ -2,6 +2,8 @@
 #define _ASMARM_BUG_H
 
 #include <linux/linkage.h>
+#include <linux/types.h>
+#include <asm/opcodes.h>
 
 #ifdef CONFIG_BUG
 
@@ -12,10 +14,10 @@
  */
 #ifdef CONFIG_THUMB2_KERNEL
 #define BUG_INSTR_VALUE 0xde02
-#define BUG_INSTR_TYPE ".hword "
+#define BUG_INSTR(__value) __inst_thumb16(__value)
 #else
 #define BUG_INSTR_VALUE 0xe7f001f2
-#define BUG_INSTR_TYPE ".word "
+#define BUG_INSTR(__value) __inst_arm(__value)
 #endif
 
 
@@ -33,7 +35,7 @@
 
 #define __BUG(__file, __line, __value)				\
 do {								\
-	asm volatile("1:\t" BUG_INSTR_TYPE #__value "\n"	\
+	asm volatile("1:\t" BUG_INSTR(__value) "\n"  \
 		".pushsection .rodata.str, \"aMS\", %progbits, 1\n" \
 		"2:\t.asciz " #__file "\n" 			\
 		".popsection\n" 				\
@@ -48,7 +50,7 @@ do {								\
 
 #define __BUG(__file, __line, __value)				\
 do {								\
-	asm volatile(BUG_INSTR_TYPE #__value);			\
+	asm volatile(BUG_INSTR(__value) "\n");			\
 	unreachable();						\
 } while (0)
 #endif  /* CONFIG_DEBUG_BUGVERBOSE */
arch/arm/kernel/traps.c +5 -3
index 99bcd0e3..da070db 100644
@@ -342,15 +342,17 @@ void arm_notify_die(const char *str, struct pt_regs *regs,
 int is_valid_bugaddr(unsigned long pc)
 {
 #ifdef CONFIG_THUMB2_KERNEL
-	unsigned short bkpt;
+	u16 bkpt;
+	u16 insn = __opcode_to_mem_thumb16(BUG_INSTR_VALUE);
 #else
-	unsigned long bkpt;
+	u32 bkpt;
+	u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE);
 #endif
 
 	if (probe_kernel_address((unsigned *)pc, bkpt))
 		return 0;
 
-	return bkpt == BUG_INSTR_VALUE;
+	return bkpt == insn;
 }
 
 #endif
Signature · 1 line
1.7.10.4
author
#20 lore raw

PATCH 18/20 ARM: kdgb: use <asm/opcodes.h> for data to be assembled as intruction

In reply to Ben Dooks

The arch_kgdb_breakpoint() function uses an inline assembly directive to assemble a specific instruction using .word. This means the linker will not treat is as an instruction, and therefore incorrectly swap the endian-ness if running BE8.

As noted, this code means that kgdb is really only usable on arm32 kernels, and should be made dependant on not being a thumb2 kernel until fixed. However this is not something to be added to this patch.

---
 arch/arm/include/asm/kgdb.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
arch/arm/include/asm/kgdb.h +2 -1
index 48066ce..0a9d5dd 100644
@@ -11,6 +11,7 @@
 #define __ARM_KGDB_H__
 
 #include <linux/ptrace.h>
+#include <asm/opcodes.h>
 
 /*
  * GDB assumes that we're a user process being debugged, so
@@ -41,7 +42,7 @@
 
 static inline void arch_kgdb_breakpoint(void)
 {
-	asm(".word 0xe7ffdeff");
+	asm(__inst_arm(0xe7ffdeff));
 }
 
 extern void kgdb_handle_bus_error(void);
Signature · 1 line
1.7.10.4
author
#21 lore raw

PATCH 19/20 ARM: atomic64: fix endian-ness in atomic.h

In reply to Ben Dooks

From: Victor Kamensky <[email protected]>

Fix inline asm for atomic64_xxx functions in arm atomic.h. Instead of %H operand specifiers code should use %Q for least significant part of the value, and %R for the most significant part of the value. %H always returns the higher of the two register numbers, and therefore it is not endian neutral. %H should be used with ldrexd and strexd instructions.

---
 arch/arm/include/asm/atomic.h |   26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)
arch/arm/include/asm/atomic.h +13 -13
index da1c77d..6447a0b 100644
@@ -301,8 +301,8 @@ static inline void atomic64_add(u64 i, atomic64_t *v)
 
 	__asm__ __volatile__("@ atomic64_add\n"
 "1:	ldrexd	%0, %H0, [%3]\n"
-"	adds	%0, %0, %4\n"
-"	adc	%H0, %H0, %H4\n"
+"	adds	%Q0, %Q0, %Q4\n"
+"	adc	%R0, %R0, %R4\n"
 "	strexd	%1, %0, %H0, [%3]\n"
 "	teq	%1, #0\n"
 "	bne	1b"
@@ -320,8 +320,8 @@ static inline u64 atomic64_add_return(u64 i, atomic64_t *v)
 
 	__asm__ __volatile__("@ atomic64_add_return\n"
 "1:	ldrexd	%0, %H0, [%3]\n"
-"	adds	%0, %0, %4\n"
-"	adc	%H0, %H0, %H4\n"
+"	adds	%Q0, %Q0, %Q4\n"
+"	adc	%R0, %R0, %R4\n"
 "	strexd	%1, %0, %H0, [%3]\n"
 "	teq	%1, #0\n"
 "	bne	1b"
@@ -341,8 +341,8 @@ static inline void atomic64_sub(u64 i, atomic64_t *v)
 
 	__asm__ __volatile__("@ atomic64_sub\n"
 "1:	ldrexd	%0, %H0, [%3]\n"
-"	subs	%0, %0, %4\n"
-"	sbc	%H0, %H0, %H4\n"
+"	subs	%Q0, %Q0, %Q4\n"
+"	sbc	%R0, %R0, %R4\n"
 "	strexd	%1, %0, %H0, [%3]\n"
 "	teq	%1, #0\n"
 "	bne	1b"
@@ -360,8 +360,8 @@ static inline u64 atomic64_sub_return(u64 i, atomic64_t *v)
 
 	__asm__ __volatile__("@ atomic64_sub_return\n"
 "1:	ldrexd	%0, %H0, [%3]\n"
-"	subs	%0, %0, %4\n"
-"	sbc	%H0, %H0, %H4\n"
+"	subs	%Q0, %Q0, %Q4\n"
+"	sbc	%R0, %R0, %R4\n"
 "	strexd	%1, %0, %H0, [%3]\n"
 "	teq	%1, #0\n"
 "	bne	1b"
@@ -428,9 +428,9 @@ static inline u64 atomic64_dec_if_positive(atomic64_t *v)
 
 	__asm__ __volatile__("@ atomic64_dec_if_positive\n"
 "1:	ldrexd	%0, %H0, [%3]\n"
-"	subs	%0, %0, #1\n"
-"	sbc	%H0, %H0, #0\n"
-"	teq	%H0, #0\n"
+"	subs	%Q0, %Q0, #1\n"
+"	sbc	%R0, %R0, #0\n"
+"	teq	%R0, #0\n"
 "	bmi	2f\n"
 "	strexd	%1, %0, %H0, [%3]\n"
 "	teq	%1, #0\n"
@@ -459,8 +459,8 @@ static inline int atomic64_add_unless(atomic64_t *v, u64 a, u64 u)
 "	teqeq	%H0, %H5\n"
 "	moveq	%1, #0\n"
 "	beq	2f\n"
-"	adds	%0, %0, %6\n"
-"	adc	%H0, %H0, %H6\n"
+"	adds	%Q0, %Q0, %Q6\n"
+"	adc	%R0, %R0, %R6\n"
 "	strexd	%2, %0, %H0, [%4]\n"
 "	teq	%2, #0\n"
 "	bne	1b\n"
Signature · 1 line
1.7.10.4
author
#22 lore raw

PATCH 20/20 ARM: signal: sigreturn_codes should be endian neutral to work in BE8

In reply to Ben Dooks

From: Victor Kamensky <[email protected]>

In case of BE8 kernel data is in BE order whereas code stays in LE order. Move sigreturn_codes to separate .S file and use proper assembler mnemonics for these code snippets. In this case compiler will take care of proper instructions byteswaps for BE8 case. Change assumes that sufficiently Thumb-capable tools are used to build kernel.

Problem was discovered during ltp testing of BE system: all rt_sig* tests failed. Tested against the same tests in both BE and LE modes.

---
 arch/arm/kernel/Makefile          |    3 +-
 arch/arm/kernel/signal.c          |   24 +------------
 arch/arm/kernel/sigreturn_codes.S |   69 +++++++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+), 24 deletions(-)
 create mode 100644 arch/arm/kernel/sigreturn_codes.S
arch/arm/kernel/Makefile +2 -1
index 86d10dd..0722155 100644
@@ -17,7 +17,8 @@ CFLAGS_REMOVE_return_address.o = -pg
 
 obj-y		:= elf.o entry-common.o irq.o opcodes.o \
 		   process.o ptrace.o return_address.o \
-		   setup.o signal.o stacktrace.o sys_arm.o time.o traps.o
+		   setup.o signal.o sigreturn_codes.o \
+		   stacktrace.o sys_arm.o time.o traps.o
 
 obj-$(CONFIG_ATAGS)		+= atags_parse.o
 obj-$(CONFIG_ATAGS_PROC)	+= atags_proc.o
arch/arm/kernel/signal.c +1 -23
index ab33042..64845fc 100644
@@ -21,29 +21,7 @@
 #include <asm/unistd.h>
 #include <asm/vfp.h>
 
-/*
- * For ARM syscalls, we encode the syscall number into the instruction.
- */
-#define SWI_SYS_SIGRETURN	(0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE))
-#define SWI_SYS_RT_SIGRETURN	(0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE))
-
-/*
- * With EABI, the syscall number has to be loaded into r7.
- */
-#define MOV_R7_NR_SIGRETURN	(0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
-#define MOV_R7_NR_RT_SIGRETURN	(0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
-
-/*
- * For Thumb syscalls, we pass the syscall number via r7.  We therefore
- * need two 16-bit instructions.
- */
-#define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
-#define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
-
-static const unsigned long sigreturn_codes[7] = {
-	MOV_R7_NR_SIGRETURN,    SWI_SYS_SIGRETURN,    SWI_THUMB_SIGRETURN,
-	MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
-};
+extern const unsigned long sigreturn_codes[7];
 
 static unsigned long signal_return_offset;
 
arch/arm/kernel/sigreturn_codes.S new file +69 -0

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1.7.10.4