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powerpc: Minor cleanups of kernel virt address space definitions

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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 <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt 2009-05-27 13:44:50 +10:00
parent b16e7766d6
commit f637a49e50
5 changed files with 37 additions and 12 deletions
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4
arch/powerpc/include/asm/fixmap.h
View File

@ -14,8 +14,6 @@
#ifndef _ASM_FIXMAP_H
#define _ASM_FIXMAP_H
extern unsigned long FIXADDR_TOP;
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <asm/page.h>
@ -24,6 +22,8 @@ extern unsigned long FIXADDR_TOP;
#include <asm/kmap_types.h>
#endif
#define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
/*
* Here we define all the compile-time 'special' virtual
* addresses. The point is to have a constant address at

22
arch/powerpc/include/asm/pgtable-ppc32.h
View File

@ -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

8
arch/powerpc/mm/init_32.c
View File

@ -168,12 +168,8 @@ void __init MMU_init(void)
ppc_md.progress("MMU:mapin", 0x301);
mapin_ram();
#ifdef CONFIG_HIGHMEM
ioremap_base = PKMAP_BASE;
#else
ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
#endif /* CONFIG_HIGHMEM */
ioremap_bot = ioremap_base;
/* Initialize early top-down ioremap allocator */
ioremap_bot = IOREMAP_TOP;
/* Map in I/O resources */
if (ppc_md.progress)

13
arch/powerpc/mm/mem.c
View File

@ -380,6 +380,19 @@ void __init mem_init(void)
bsssize >> 10,
initsize >> 10);
#ifdef CONFIG_PPC32
pr_info("Kernel virtual memory layout:\n");
pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
#ifdef CONFIG_HIGHMEM
pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
#endif /* CONFIG_HIGHMEM */
pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
ioremap_bot, IOREMAP_TOP);
pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
VMALLOC_START, VMALLOC_END);
#endif /* CONFIG_PPC32 */
mem_init_done = 1;
}

2
arch/powerpc/mm/pgtable_32.c
View File

@ -399,8 +399,6 @@ void kernel_map_pages(struct page *page, int numpages, int enable)
#endif /* CONFIG_DEBUG_PAGEALLOC */
static int fixmaps;
unsigned long FIXADDR_TOP = (-PAGE_SIZE);
EXPORT_SYMBOL(FIXADDR_TOP);
void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
{