From 336e2136e1353db8e9e731c27381ee0735656a8a Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Thu, 5 Mar 2015 17:06:31 +0530 Subject: ARC: mm: preps ahead of HIGHMEM support Before we plug in highmem support, some of code needs to be ready for it - copy_user_highpage() needs to be using the kmap_atomic API - mk_pte() can't assume page_address() - do_page_fault() can't assume VMALLOC_END is end of kernel vaddr space Signed-off-by: Alexey Brodkin Signed-off-by: Vineet Gupta --- arch/arc/mm/fault.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'arch/arc/mm/fault.c') diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c index d948e4e9d89c..af63f4a13e60 100644 --- a/arch/arc/mm/fault.c +++ b/arch/arc/mm/fault.c @@ -18,7 +18,14 @@ #include #include -static int handle_vmalloc_fault(unsigned long address) +/* + * kernel virtual address is required to implement vmalloc/pkmap/fixmap + * Refer to asm/processor.h for System Memory Map + * + * It simply copies the PMD entry (pointer to 2nd level page table or hugepage) + * from swapper pgdir to task pgdir. The 2nd level table/page is thus shared + */ +noinline static int handle_kernel_vaddr_fault(unsigned long address) { /* * Synchronize this task's top level page-table @@ -72,8 +79,8 @@ void do_page_fault(unsigned long address, struct pt_regs *regs) * only copy the information from the master page table, * nothing more. */ - if (address >= VMALLOC_START && address <= VMALLOC_END) { - ret = handle_vmalloc_fault(address); + if (address >= VMALLOC_START) { + ret = handle_kernel_vaddr_fault(address); if (unlikely(ret)) goto bad_area_nosemaphore; else -- cgit v1.2.3