On 07/10/2013 01:20 PM, Bhushan Bharat-R65777 wrote:
-----Original Message-----
From: Linuxppc-dev [mailto:linuxppc-dev-
bounces+bharat.bhushan=freescale....@lists.ozlabs.org] On Behalf Of Tiejun Chen
Sent: Tuesday, July 09, 2013 1:33 PM
To: b...@kernel.crashing.org
Cc: linuxppc-...@lists.ozlabs.org; linux-kernel@vger.kernel.org
Subject: [v3][PATCH 7/8] book3e/kexec/kdump: redefine VIRT_PHYS_OFFSET
Book3e is always aligned 1GB to create TLB so we should
use (KERNELBASE - MEMORY_START) as VIRT_PHYS_OFFSET to
get __pa/__va properly while boot kdump.
Signed-off-by: Tiejun Chen <tiejun.c...@windriver.com>
---
arch/powerpc/include/asm/page.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 988c812..5b00081 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -112,6 +112,8 @@ extern long long virt_phys_offset;
/* See Description below for VIRT_PHYS_OFFSET */
#ifdef CONFIG_RELOCATABLE_PPC32
#define VIRT_PHYS_OFFSET virt_phys_offset
+#elif defined(CONFIG_PPC_BOOK3E_64)
+#define VIRT_PHYS_OFFSET (KERNELBASE - MEMORY_START)
Can you please explain this code a bit more. I am not understanding this part:)
Nothing is special, we only need to redefine this to make sure __va()/__pa() can
work well for BOOk3E-64 in BOOKE case:
#ifdef CONFIG_BOOKE
#define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
#define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
And the arch/powerpc/include/asm/page.h file has more descriptions inline :)
Tiejun
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