From mboxrd@z Thu Jan 1 00:00:00 1970 From: junxiao.bi@windriver.com (Junxiao Bi) Date: Thu, 8 Dec 2011 18:07:47 +0800 Subject: [PATCH 1/6] ARM: fix be8 support for phys/virt address conversion In-Reply-To: <1323338872-24716-1-git-send-email-junxiao.bi@windriver.com> References: <1323338872-24716-1-git-send-email-junxiao.bi@windriver.com> Message-ID: <1323338872-24716-2-git-send-email-junxiao.bi@windriver.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org phys_to_virt() and virt_to_phys() is implemented by one assembler instruction, add/sub an offset between the physical and virtual address. For some arm machines with CONFIG_ARM_PATCH_PHYS_VIRT defined, this offset is unknown at compile time, it is calculated dynamically at run time and then patched to the add/sub instruction. To support BE8 mode, firstly we need to convert the instruntion to big-endian after loading it from the memory, and then modify its offset field, at last convert it to little-endian and write it back to the memory. Reviewed-by: Nicolas Pitre Signed-off-by: Junxiao Bi --- arch/arm/kernel/head.S | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 54fa641..a52aec7 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -565,8 +565,14 @@ __fixup_a_pv_table: b 2f 1: add r7, r3 ldrh ip, [r7, #2] +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev16 ip, ip +#endif and ip, 0x8f00 orr ip, r6 @ mask in offset bits 31-24 +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev16 ip, ip +#endif strh ip, [r7, #2] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot @@ -575,8 +581,14 @@ __fixup_a_pv_table: #else b 2f 1: ldr ip, [r7, r3] +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev ip, ip +#endif bic ip, ip, #0x000000ff orr ip, ip, r6 @ mask in offset bits 31-24 +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev ip, ip +#endif str ip, [r7, r3] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot -- 1.7.0.4