From b5416ca9f824d3deb1e25a32683100360e104b72 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Mon, 7 Jun 2010 15:34:38 +0000 Subject: [PATCH] powerpc: Move kdump default base address to 64MB on 64bit We are seeing boot fails on some System p machines when using the kdump crashkernel= boot option. The default kdump base address is 32MB, so if we reserve 256MB for kdump then we reserve all of the RMO except the first 32MB. We really want kdump to reserve some memory in the RMO and most of it elsewhere but that will require more significant changes. For now we can shift the default base address to 64MB when CONFIG_PPC64 and CONFIG_RELOCATABLE are set. This isn't quite correct since what we really care about is the kdump kernel is relocatable, but we already make the assumption that base kernel and kdump kernel have the same CONFIG_RELOCATABLE setting, eg: #ifndef CONFIG_RELOCATABLE if (crashk_res.start != KDUMP_KERNELBASE) printk("Crash kernel location must be 0x%x\n", KDUMP_KERNELBASE); ... RTAS is instantiated towards the top of our RMO, so if we were to go any higher we risk not having enough RMO memory for the kdump kernel on boxes with a 128MB RMO. Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/kdump.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/kdump.h b/arch/powerpc/include/asm/kdump.h index 5ebfe5d3c61f..6857af58b02e 100644 --- a/arch/powerpc/include/asm/kdump.h +++ b/arch/powerpc/include/asm/kdump.h @@ -3,8 +3,17 @@ #include -/* Kdump kernel runs at 32 MB, change at your peril. */ +/* + * If CONFIG_RELOCATABLE is enabled we can place the kdump kernel anywhere. + * To keep enough space in the RMO for the first stage kernel on 64bit, we + * place it at 64MB. If CONFIG_RELOCATABLE is not enabled we must place + * the second stage at 32MB. + */ +#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC64) +#define KDUMP_KERNELBASE 0x4000000 +#else #define KDUMP_KERNELBASE 0x2000000 +#endif /* How many bytes to reserve at zero for kdump. The reserve limit should * be greater or equal to the trampoline's end address.