From 2f9bf9beddb1649485b47302a5aba9761cbc9084 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Fri, 1 Feb 2013 16:23:08 +0100 Subject: ARM: fixup_pv_table bug when CPU_ENDIAN_BE8 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. Signed-off-by: Ben Dooks Reviewed-by: Dave Martin Tested-by: Thomas Petazzoni --- arch/arm/kernel/head.S | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/arm/kernel/head.S') diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 2c7cc1e03473..9e5906cf7d32 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -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 -- cgit v1.2.3 From 97bcb0fea590d3d704f985bec08f342d28992634 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Fri, 1 Feb 2013 09:40:42 +0000 Subject: ARM: set BE8 if LE in head code 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. Signed-off-by: Ben Dooks Reviewed-by: Dave Martin Tested-by: Thomas Petazzoni --- arch/arm/boot/compressed/head.S | 1 + arch/arm/kernel/head.S | 4 ++++ arch/arm/kernel/sleep.S | 1 + 3 files changed, 6 insertions(+) (limited to 'arch/arm/kernel/head.S') diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index c912c2a95de8..066b03480b63 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -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 diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 9e5906cf7d32..a047acfa6b6d 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -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 diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index db1536b8b30b..716343caa960 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -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) -- cgit v1.2.3