diff options
Diffstat (limited to 'arch/s390/include/asm/pgtable.h')
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 75b91bb..dd647c9 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -119,13 +119,12 @@ static inline int is_zero_pfn(unsigned long pfn) #ifndef __ASSEMBLY__ /* - * The vmalloc area will always be on the topmost area of the kernel - * mapping. We reserve 96MB (31bit) / 128GB (64bit) for vmalloc, - * which should be enough for any sane case. - * By putting vmalloc at the top, we maximise the gap between physical - * memory and vmalloc to catch misplaced memory accesses. As a side - * effect, this also makes sure that 64 bit module code cannot be used - * as system call address. + * The vmalloc and module area will always be on the topmost area of the kernel + * mapping. We reserve 96MB (31bit) / 128GB (64bit) for vmalloc and modules. + * On 64 bit kernels we have a 2GB area at the top of the vmalloc area where + * modules will reside. That makes sure that inter module branches always + * happen without trampolines and in addition the placement within a 2GB frame + * is branch prediction unit friendly. */ extern unsigned long VMALLOC_START; extern unsigned long VMALLOC_END; @@ -133,6 +132,14 @@ extern struct page *vmemmap; #define VMEM_MAX_PHYS ((unsigned long) vmemmap) +#ifdef CONFIG_64BIT +extern unsigned long MODULES_VADDR; +extern unsigned long MODULES_END; +#define MODULES_VADDR MODULES_VADDR +#define MODULES_END MODULES_END +#define MODULES_LEN (1UL << 31) +#endif + /* * A 31 bit pagetable entry of S390 has following format: * | PFRA | | OS | |