From f637a49e507c88354ab32b5d914e06acfb7ee00d Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 27 May 2009 13:44:50 +1000 Subject: powerpc: Minor cleanups of kernel virt address space definitions Make FIXADDR_TOP a compile time constant and cleanup a couple of definitions relative to the layout of the kernel address space on ppc32. We also print out that layout at boot time for debugging purposes. This is a pre-requisite for properly fixing non-coherent DMA allocactions. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/pgtable-ppc32.h | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/include/asm/pgtable-ppc32.h') diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h index ba45c997830..28fe9d4bae3 100644 --- a/arch/powerpc/include/asm/pgtable-ppc32.h +++ b/arch/powerpc/include/asm/pgtable-ppc32.h @@ -10,7 +10,7 @@ extern unsigned long va_to_phys(unsigned long address); extern pte_t *va_to_pte(unsigned long address); -extern unsigned long ioremap_bot, ioremap_base; +extern unsigned long ioremap_bot; #ifdef CONFIG_44x extern int icache_44x_need_flush; @@ -55,9 +55,27 @@ extern int icache_44x_need_flush; #define pgd_ERROR(e) \ printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e)) +/* + * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary + * value (for now) on others, from where we can start layout kernel + * virtual space that goes below PKMAP and FIXMAP + */ +#ifdef CONFIG_HIGHMEM +#define KVIRT_TOP PKMAP_BASE +#else +#define KVIRT_TOP (0xfe000000UL) /* for now, could be FIXMAP_BASE ? */ +#endif + +/* + * ioremap_bot starts at that address. Early ioremaps move down from there, + * until mem_init() at which point this becomes the top of the vmalloc + * and ioremap space + */ +#define IOREMAP_TOP KVIRT_TOP + /* * Just any arbitrary offset to the start of the vmalloc VM area: the - * current 64MB value just means that there will be a 64MB "hole" after the + * current 16MB value just means that there will be a 64MB "hole" after the * physical memory until the kernel virtual memory starts. That means that * any out-of-bounds memory accesses will hopefully be caught. * The vmalloc() routines leaves a hole of 4kB between each vmalloced -- cgit v1.2.3-70-g09d2