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From: junxiao.bi@windriver.com (Junxiao Bi)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/6] ARM: fix be8 support for phys/virt address conversion
Date: Thu, 8 Dec 2011 18:07:47 +0800	[thread overview]
Message-ID: <1323338872-24716-2-git-send-email-junxiao.bi@windriver.com> (raw)
In-Reply-To: <1323338872-24716-1-git-send-email-junxiao.bi@windriver.com>

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 <nico@linaro.org>
Signed-off-by: Junxiao Bi <junxiao.bi@windriver.com>
---
 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

  reply	other threads:[~2011-12-08 10:07 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-08 10:07 [V2][PATCH 0/6]ARM: fix BE8 mode support Junxiao Bi
2011-12-08 10:07 ` Junxiao Bi [this message]
2011-12-08 10:07 ` [PATCH 2/6] ARM: Atomic64: fix 64bit ops in BE mode Junxiao Bi
2011-12-08 10:07 ` [PATCH 3/6] ARM: early_printk: pl01x: fix big endian support Junxiao Bi
2011-12-08 10:07 ` [PATCH 4/6] ARM: SMP: " Junxiao Bi
2011-12-08 10:07 ` [PATCH 5/6] MTD: map: " Junxiao Bi
2011-12-08 10:07 ` [PATCH 6/6] ARM: support kernel modules in BE8 mode Junxiao Bi
  -- strict thread matches above, loose matches on Subject: below --
2011-11-15  2:06 [PATCH 1/6] ARM: fix be8 support for phys/virt address conversion Junxiao Bi
2011-11-21  5:44 ` Bi Junxiao
2011-11-21 18:32 ` Nicolas Pitre

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