> The usual case would be just one address to flush. Would it be too
> much overhead to do a prescan to determine if there are inequivalent
> aliases before doing any flushes? I think I'll try this.
Testing the following. Dropped debug message.
Dave
--
J. David Anglin dave.anglin@xxxxxxxxxxxxxx
National Research Council of Canada (613) 990-0752 (FAX: 952-6602)
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 3f11331..e57c3e8 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -75,14 +75,16 @@ EXPORT_SYMBOL(flush_cache_all_local);
void
update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
{
- struct page *page = pte_page(*ptep);
+ unsigned long pfn = pte_pfn(*ptep);
+ struct page *page;
- if (pfn_valid(page_to_pfn(page)) && page_mapping(page) &&
- test_bit(PG_dcache_dirty, &page->flags)) {
+ if (!pfn_valid(pfn))
+ return;
- flush_kernel_dcache_page(page);
- clear_bit(PG_dcache_dirty, &page->flags);
- } else if (parisc_requires_coherency())
+ page = pfn_to_page(pfn);
+
+ if (test_and_clear_bit(PG_dcache_dirty, &page->flags)
+ || parisc_requires_coherency())
flush_kernel_dcache_page(page);
}
@@ -276,10 +278,10 @@ __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
void flush_dcache_page(struct page *page)
{
struct address_space *mapping = page_mapping(page);
- struct vm_area_struct *mpnt;
+ struct vm_area_struct *mpnt, *old_mpnt;
struct prio_tree_iter iter;
unsigned long offset;
- unsigned long addr, old_addr = 0;
+ unsigned long addr, old_addr;
pgoff_t pgoff;
if (mapping && !mapping_mapped(mapping)) {
@@ -292,26 +294,51 @@ void flush_dcache_page(struct page *page)
if (!mapping)
return;
+ old_addr = 0;
+ old_mpnt = NULL;
pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
/* We have carefully arranged in arch_get_unmapped_area() that
- * *any* mappings of a file are always congruently mapped (whether
- * declared as MAP_PRIVATE or MAP_SHARED), so we only need
- * to flush one address here for them all to become coherent */
+ * all shared mappings of a file are congruently mapped, so we
+ * only need to flush one address here for them all to become
+ * coherent. However, non-shared fixed mappings of executables
+ * are not congruently mapped on the boundary page between text
+ * and data. Further, the data segment sometimes occurs before
+ * the text segment. While it is unlikely that a dirty cache
+ * line would result from accesses through the text mapping,
+ * it is possible that this could occur since binutils doesn't
+ * ensure that the data segment starts on a page boundary. */
flush_dcache_mmap_lock(mapping);
+
+ /* Scan for inequivalent aliases. */
vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
addr = mpnt->vm_start + offset;
- if (old_addr == 0 || (old_addr & (SHMLBA - 1)) != (addr & (SHMLBA - 1))) {
- __flush_cache_page(mpnt, addr, page_to_phys(page));
- if (old_addr)
- printk(KERN_ERR "INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %s\n", old_addr, addr, mpnt->vm_file ? mpnt->vm_file->f_path.dentry->d_name.name : "(null)");
+ if (old_addr == 0) {
old_addr = addr;
+ old_mpnt = mpnt;
}
+ else if ((old_addr & (SHMLBA - 1)) != (addr & (SHMLBA - 1)))
+ goto flush_inequivalent;
+ }
+ flush_dcache_mmap_unlock(mapping);
+
+ /* Handle common case where all aliases are equivalent. */
+ if (old_addr)
+ __flush_cache_page(old_mpnt, old_addr, page_to_phys(page));
+ return;
+
+flush_inequivalent:
+ vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
+ addr = mpnt->vm_start + offset;
+
+ __flush_cache_page(mpnt, addr, page_to_phys(page));
}
flush_dcache_mmap_unlock(mapping);
+ return;
}
EXPORT_SYMBOL(flush_dcache_page);
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index c9b9322..f0cb56e 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -92,11 +92,12 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
{
if (len > TASK_SIZE)
return -ENOMEM;
- /* Might want to check for cache aliasing issues for MAP_FIXED case
- * like ARM or MIPS ??? --BenH.
- */
- if (flags & MAP_FIXED)
+ if (flags & MAP_FIXED) {
+ if ((flags & MAP_SHARED) &&
+ (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
+ return -EINVAL;
return addr;
+ }
if (!addr)
addr = TASK_UNMAPPED_BASE;
--
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