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authorVineet Gupta <vgupta@synopsys.com>2015-03-05 17:06:31 +0530
committerVineet Gupta <vgupta@synopsys.com>2015-10-28 19:31:05 +0530
commit336e2136e1353db8e9e731c27381ee0735656a8a (patch)
treee386405627b5e1f68f04a1d4f854f3121b913d45 /arch/arc/mm
parentd40846457fc23cd841a60fdc2786e08a8bedb35b (diff)
downloadlinux-336e2136e1353db8e9e731c27381ee0735656a8a.tar.bz2
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 <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/mm')
-rw-r--r--arch/arc/mm/cache.c16
-rw-r--r--arch/arc/mm/fault.c13
2 files changed, 21 insertions, 8 deletions
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index ae3b772ecc4d..521fb2bf90bd 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -806,8 +806,8 @@ void flush_anon_page(struct vm_area_struct *vma, struct page *page,
void copy_user_highpage(struct page *to, struct page *from,
unsigned long u_vaddr, struct vm_area_struct *vma)
{
- unsigned long kfrom = (unsigned long)page_address(from);
- unsigned long kto = (unsigned long)page_address(to);
+ void *kfrom = kmap_atomic(from);
+ void *kto = kmap_atomic(to);
int clean_src_k_mappings = 0;
/*
@@ -817,13 +817,16 @@ void copy_user_highpage(struct page *to, struct page *from,
*
* Note that while @u_vaddr refers to DST page's userspace vaddr, it is
* equally valid for SRC page as well
+ *
+ * For !VIPT cache, all of this gets compiled out as
+ * addr_not_cache_congruent() is 0
*/
if (page_mapped(from) && addr_not_cache_congruent(kfrom, u_vaddr)) {
- __flush_dcache_page(kfrom, u_vaddr);
+ __flush_dcache_page((unsigned long)kfrom, u_vaddr);
clean_src_k_mappings = 1;
}
- copy_page((void *)kto, (void *)kfrom);
+ copy_page(kto, kfrom);
/*
* Mark DST page K-mapping as dirty for a later finalization by
@@ -840,11 +843,14 @@ void copy_user_highpage(struct page *to, struct page *from,
* sync the kernel mapping back to physical page
*/
if (clean_src_k_mappings) {
- __flush_dcache_page(kfrom, kfrom);
+ __flush_dcache_page((unsigned long)kfrom, (unsigned long)kfrom);
set_bit(PG_dc_clean, &from->flags);
} else {
clear_bit(PG_dc_clean, &from->flags);
}
+
+ kunmap_atomic(kto);
+ kunmap_atomic(kfrom);
}
void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
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 <asm/pgalloc.h>
#include <asm/mmu.h>
-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