diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2013-05-09 21:54:51 +0530 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2013-05-09 21:59:46 +0530 |
| commit | 4102b53392d6397d80b6e09b516517efacf7ea77 (patch) | |
| tree | b79aa87af1b3a1ff39b4a00b889cb806dfe32ae7 /arch/arc/include/asm/page.h | |
| parent | 6ec18a81b22ab2b40df8424f2b5fc6be20ccad87 (diff) | |
ARC: [mm] Aliasing VIPT dcache support 2/4
This is the meat of the series which prevents any dcache alias creation
by always keeping the U and K mapping of a page congruent.
If a mapping already exists, and other tries to access the page, prev
one is flushed to physical page (wback+inv)
Essentially flush_dcache_page()/copy_user_highpage() create K-mapping
of a page, but try to defer flushing, unless U-mapping exist.
When page is actually mapped to userspace, update_mmu_cache() flushes
the K-mapping (in certain cases this can be optimised out)
Additonally flush_cache_mm(), flush_cache_range(), flush_cache_page()
handle the puring of stale userspace mappings on exit/munmap...
flush_anon_page() handles the existing U-mapping for anon page before
kernel reads it via the GUP path.
Note that while not complete, this is enough to boot a simple
dynamically linked Busybox based rootfs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/include/asm/page.h')
| -rw-r--r-- | arch/arc/include/asm/page.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/arc/include/asm/page.h b/arch/arc/include/asm/page.h index bdf546104551..374a35514116 100644 --- a/arch/arc/include/asm/page.h +++ b/arch/arc/include/asm/page.h @@ -16,13 +16,27 @@ #define get_user_page(vaddr) __get_free_page(GFP_KERNEL) #define free_user_page(page, addr) free_page(addr) -/* TBD: for now don't worry about VIPT D$ aliasing */ #define clear_page(paddr) memset((paddr), 0, PAGE_SIZE) #define copy_page(to, from) memcpy((to), (from), PAGE_SIZE) +#ifndef CONFIG_ARC_CACHE_VIPT_ALIASING + #define clear_user_page(addr, vaddr, pg) clear_page(addr) #define copy_user_page(vto, vfrom, vaddr, pg) copy_page(vto, vfrom) +#else /* VIPT aliasing dcache */ + +struct vm_area_struct; +struct page; + +#define __HAVE_ARCH_COPY_USER_HIGHPAGE + +void copy_user_highpage(struct page *to, struct page *from, + unsigned long u_vaddr, struct vm_area_struct *vma); +void clear_user_page(void *to, unsigned long u_vaddr, struct page *page); + +#endif /* CONFIG_ARC_CACHE_VIPT_ALIASING */ + #undef STRICT_MM_TYPECHECKS #ifdef STRICT_MM_TYPECHECKS |