From 6d2439d9558e259822fb487ec274cc9e362e6a81 Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Sun, 3 Feb 2013 23:01:47 +0000 Subject: parisc: fixes and cleanups in page cache flushing (3/4) flush_cache_mm, for the non current case also uses flush_dcache_page_asm and flush_icache_page_asm which are TMPALIAS flushes. For the non current case, the algorithm used by get_ptep is derived from the vmalloc_to_page implementation in vmalloc.c. It is essentially a generic page table lookup. The other alternative was to duplicate the lookup in entry.S. The break point for switching to a full cache flush is somewhat arbitrary. The same approach is used in flush_cache_range for non current case. In a GCC build and check, many small programs are executed and this change provided a significant performance enhancement, e.g. GCC build time was cut almost in half on a rp3440 at j4. Previously, we always flushed the entire cache. Signed-off-by: John David Anglin Signed-off-by: Helge Deller --- arch/parisc/kernel/cache.c | 88 ++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 81 insertions(+), 7 deletions(-) (limited to 'arch/parisc') diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index d9cbb4b..ec63de9 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -469,8 +469,66 @@ void flush_cache_all(void) on_each_cpu(cacheflush_h_tmp_function, NULL, 1); } +static inline unsigned long mm_total_size(struct mm_struct *mm) +{ + struct vm_area_struct *vma; + unsigned long usize = 0; + + for (vma = mm->mmap; vma; vma = vma->vm_next) + usize += vma->vm_end - vma->vm_start; + return usize; +} + +static inline pte_t *get_ptep(pgd_t *pgd, unsigned long addr) +{ + pte_t *ptep = NULL; + + if (!pgd_none(*pgd)) { + pud_t *pud = pud_offset(pgd, addr); + if (!pud_none(*pud)) { + pmd_t *pmd = pmd_offset(pud, addr); + if (!pmd_none(*pmd)) + ptep = pte_offset_map(pmd, addr); + } + } + return ptep; +} + void flush_cache_mm(struct mm_struct *mm) { + /* Flushing the whole cache on each cpu takes forever on + rp3440, etc. So, avoid it if the mm isn't too big. */ + if (mm_total_size(mm) < parisc_cache_flush_threshold) { + struct vm_area_struct *vma; + + if (mm->context == mfsp(3)) { + for (vma = mm->mmap; vma; vma = vma->vm_next) { + flush_user_dcache_range_asm(vma->vm_start, + vma->vm_end); + if (vma->vm_flags & VM_EXEC) + flush_user_icache_range_asm( + vma->vm_start, vma->vm_end); + } + } else { + pgd_t *pgd = mm->pgd; + + for (vma = mm->mmap; vma; vma = vma->vm_next) { + unsigned long addr; + + for (addr = vma->vm_start; addr < vma->vm_end; + addr += PAGE_SIZE) { + pte_t *ptep = get_ptep(pgd, addr); + if (ptep != NULL) { + pte_t pte = *ptep; + __flush_cache_page(vma, addr, + page_to_phys(pte_page(pte))); + } + } + } + } + return; + } + #ifdef CONFIG_SMP flush_cache_all(); #else @@ -496,20 +554,36 @@ flush_user_icache_range(unsigned long start, unsigned long end) flush_instruction_cache(); } - void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { - int sr3; - BUG_ON(!vma->vm_mm->context); - sr3 = mfsp(3); - if (vma->vm_mm->context == sr3) { - flush_user_dcache_range(start,end); - flush_user_icache_range(start,end); + if ((end - start) < parisc_cache_flush_threshold) { + if (vma->vm_mm->context == mfsp(3)) { + flush_user_dcache_range_asm(start, end); + if (vma->vm_flags & VM_EXEC) + flush_user_icache_range_asm(start, end); + } else { + unsigned long addr; + pgd_t *pgd = vma->vm_mm->pgd; + + for (addr = start & PAGE_MASK; addr < end; + addr += PAGE_SIZE) { + pte_t *ptep = get_ptep(pgd, addr); + if (ptep != NULL) { + pte_t pte = *ptep; + flush_cache_page(vma, + addr, pte_pfn(pte)); + } + } + } } else { +#ifdef CONFIG_SMP flush_cache_all(); +#else + flush_cache_all_local(); +#endif } } -- cgit v1.1