diff options
| author | Jeremy Fitzhardinge <jeremy@xensource.com> | 2006-09-25 23:32:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 08:48:55 -0700 |
| commit | 052e79941a042e5be4feffa03b1fd60d93fb9e9a (patch) | |
| tree | fd3ac24a05029b50a6c6ddfa486ea441b4091806 /arch/i386/mm | |
| parent | 9f093394d75cd9c5df82c7a99c5eb5d7ce7ba199 (diff) | |
[PATCH] x86: make __FIXADDR_TOP variable to allow it to make space for a hypervisor
Make __FIXADDR_TOP a variable, so that it can be set to not get in the way of
address space a hypervisor may want to reserve.
Original patch by Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/mm')
| -rw-r--r-- | arch/i386/mm/init.c | 42 | ||||
| -rw-r--r-- | arch/i386/mm/pgtable.c | 26 |
2 files changed, 68 insertions, 0 deletions
diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c index 353453d550a..efd0bcdac65 100644 --- a/arch/i386/mm/init.c +++ b/arch/i386/mm/init.c @@ -629,6 +629,48 @@ void __init mem_init(void) (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)) ); +#if 1 /* double-sanity-check paranoia */ + printk("virtual kernel memory layout:\n" + " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" +#ifdef CONFIG_HIGHMEM + " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" +#endif + " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" + " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" + " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" + " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" + " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", + FIXADDR_START, FIXADDR_TOP, + (FIXADDR_TOP - FIXADDR_START) >> 10, + +#ifdef CONFIG_HIGHMEM + PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, + (LAST_PKMAP*PAGE_SIZE) >> 10, +#endif + + VMALLOC_START, VMALLOC_END, + (VMALLOC_END - VMALLOC_START) >> 20, + + (unsigned long)__va(0), (unsigned long)high_memory, + ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, + + (unsigned long)&__init_begin, (unsigned long)&__init_end, + ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10, + + (unsigned long)&_etext, (unsigned long)&_edata, + ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, + + (unsigned long)&_text, (unsigned long)&_etext, + ((unsigned long)&_etext - (unsigned long)&_text) >> 10); + +#ifdef CONFIG_HIGHMEM + BUG_ON(PKMAP_BASE+LAST_PKMAP*PAGE_SIZE > FIXADDR_START); + BUG_ON(VMALLOC_END > PKMAP_BASE); +#endif + BUG_ON(VMALLOC_START > VMALLOC_END); + BUG_ON((unsigned long)high_memory > VMALLOC_START); +#endif /* double-sanity-check paranoia */ + #ifdef CONFIG_X86_PAE if (!cpu_has_pae) panic("cannot execute a PAE-enabled kernel on a PAE-less CPU!"); diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c index a9f4910a22f..10126e3f817 100644 --- a/arch/i386/mm/pgtable.c +++ b/arch/i386/mm/pgtable.c @@ -12,6 +12,7 @@ #include <linux/slab.h> #include <linux/pagemap.h> #include <linux/spinlock.h> +#include <linux/module.h> #include <asm/system.h> #include <asm/pgtable.h> @@ -139,6 +140,12 @@ void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags) __flush_tlb_one(vaddr); } +static int fixmaps; +#ifndef CONFIG_COMPAT_VDSO +unsigned long __FIXADDR_TOP = 0xfffff000; +EXPORT_SYMBOL(__FIXADDR_TOP); +#endif + void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags) { unsigned long address = __fix_to_virt(idx); @@ -148,6 +155,25 @@ void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags) return; } set_pte_pfn(address, phys >> PAGE_SHIFT, flags); + fixmaps++; +} + +/** + * reserve_top_address - reserves a hole in the top of kernel address space + * @reserve - size of hole to reserve + * + * Can be used to relocate the fixmap area and poke a hole in the top + * of kernel address space to make room for a hypervisor. + */ +void reserve_top_address(unsigned long reserve) +{ + BUG_ON(fixmaps > 0); +#ifdef CONFIG_COMPAT_VDSO + BUG_ON(reserve != 0); +#else + __FIXADDR_TOP = -reserve - PAGE_SIZE; + __VMALLOC_RESERVE += reserve; +#endif } pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) |