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authorJeremy Fitzhardinge <jeremy@goop.org>2008-07-01 16:46:37 -0700
committerIngo Molnar <mingo@elte.hu>2008-07-08 13:16:30 +0200
commit5a654ba7a88d90483d0f0586297ea9075d755fc8 (patch)
treed3832d3d7ba02dd7f39f125536d754fcb2ea0b83 /arch/x86/mm
parentef5e94af16c0c82452e1ea5d387e1203dd2198d6 (diff)
x86/cpa: use an undefined PTE bit for testing CPA
Rather than using _PAGE_GLOBAL - which not all CPUs support - to test CPA, use one of the reserved-for-software-use PTE flags instead. This allows CPA testing to work on CPUs which don't support PGD. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm')
-rw-r--r--arch/x86/mm/pageattr-test.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c
index 75f1b109aae..0dcd42eb94e 100644
--- a/arch/x86/mm/pageattr-test.c
+++ b/arch/x86/mm/pageattr-test.c
@@ -1,8 +1,8 @@
/*
* self test for change_page_attr.
*
- * Clears the global bit on random pages in the direct mapping, then reverts
- * and compares page tables forwards and afterwards.
+ * Clears the a test pte bit on random pages in the direct mapping,
+ * then reverts and compares page tables forwards and afterwards.
*/
#include <linux/bootmem.h>
#include <linux/kthread.h>
@@ -32,6 +32,13 @@ enum {
GPS = (1<<30)
};
+#define PAGE_TESTBIT __pgprot(_PAGE_UNUSED1)
+
+static int pte_testbit(pte_t pte)
+{
+ return pte_flags(pte) & _PAGE_UNUSED1;
+}
+
struct split_state {
long lpg, gpg, spg, exec;
long min_exec, max_exec;
@@ -165,15 +172,14 @@ static int pageattr_test(void)
continue;
}
- err = change_page_attr_clear(addr[i], len[i],
- __pgprot(_PAGE_GLOBAL));
+ err = change_page_attr_set(addr[i], len[i], PAGE_TESTBIT);
if (err < 0) {
printk(KERN_ERR "CPA %d failed %d\n", i, err);
failed++;
}
pte = lookup_address(addr[i], &level);
- if (!pte || pte_global(*pte) || pte_huge(*pte)) {
+ if (!pte || !pte_testbit(*pte) || pte_huge(*pte)) {
printk(KERN_ERR "CPA %lx: bad pte %Lx\n", addr[i],
pte ? (u64)pte_val(*pte) : 0ULL);
failed++;
@@ -198,14 +204,13 @@ static int pageattr_test(void)
failed++;
continue;
}
- err = change_page_attr_set(addr[i], len[i],
- __pgprot(_PAGE_GLOBAL));
+ err = change_page_attr_clear(addr[i], len[i], PAGE_TESTBIT);
if (err < 0) {
printk(KERN_ERR "CPA reverting failed: %d\n", err);
failed++;
}
pte = lookup_address(addr[i], &level);
- if (!pte || !pte_global(*pte)) {
+ if (!pte || pte_testbit(*pte)) {
printk(KERN_ERR "CPA %lx: bad pte after revert %Lx\n",
addr[i], pte ? (u64)pte_val(*pte) : 0ULL);
failed++;