x86: change_page_attr bandaids
- Disable CLFLUSH again; it is still broken. Always do WBINVD.
- Always flush in the i386 case, not only when there are deferred pages.
These are both brute-force inefficient fixes, to be improved
next release cycle.
The changes to i386 are a little more extensive than strictly
needed (some dead code added), but it is more similar to the x86-64 version
now and the dead code will be used soon.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index 47bd477..2eb14a7 100644
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -68,14 +68,23 @@
return base;
}
-static void flush_kernel_map(void *arg)
+static void cache_flush_page(struct page *p)
{
- unsigned long adr = (unsigned long)arg;
+ unsigned long adr = (unsigned long)page_address(p);
+ int i;
+ for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
+ asm volatile("clflush (%0)" :: "r" (adr + i));
+}
- if (adr && cpu_has_clflush) {
- int i;
- for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
- asm volatile("clflush (%0)" :: "r" (adr + i));
+static void flush_kernel_map(void *arg)
+{
+ struct list_head *lh = (struct list_head *)arg;
+ struct page *p;
+
+ /* High level code is not ready for clflush yet */
+ if (0 && cpu_has_clflush) {
+ list_for_each_entry (p, lh, lru)
+ cache_flush_page(p);
} else if (boot_cpu_data.x86_model >= 4)
wbinvd();
@@ -181,9 +190,9 @@
return 0;
}
-static inline void flush_map(void *adr)
+static inline void flush_map(struct list_head *l)
{
- on_each_cpu(flush_kernel_map, adr, 1, 1);
+ on_each_cpu(flush_kernel_map, l, 1, 1);
}
/*
@@ -225,11 +234,8 @@
spin_lock_irq(&cpa_lock);
list_replace_init(&df_list, &l);
spin_unlock_irq(&cpa_lock);
- if (!cpu_has_clflush)
- flush_map(NULL);
+ flush_map(&l);
list_for_each_entry_safe(pg, next, &l, lru) {
- if (cpu_has_clflush)
- flush_map(page_address(pg));
__free_page(pg);
}
}