On 8/13/20 11:00 AM, Anshuman Khandual wrote:
On 08/12/2020 12:03 PM, Aneesh Kumar K.V wrote:
The tests do expect _PAGE_PTE bit set by different page table accessors.
This is not true for the kernel. Within the kernel, _PAGE_PTE bits are
usually set by set_pte_at(). To make the below tests work correctly add test
specific pfn_pte/pmd helpers that set _PAGE_PTE bit.
pte_t pte = pfn_pte(pfn, prot);
WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
mm/debug_vm_pgtable.c | 65 +++++++++++++++++++++++++++----------------
1 file changed, 41 insertions(+), 24 deletions(-)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index eea62d5e503b..153c925b5273 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -31,6 +31,23 @@
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
+#ifdef CONFIG_PPC_BOOK3S_64
+static inline pte_t debug_vm_pfn_pte(unsigned long pfn, pgprot_t pgprot)
+{
+ pte_t pte = pfn_pte(pfn, pgprot);
+ return __pte(pte_val(pte) | _PAGE_PTE);
+
+}
+static inline pmd_t debug_vm_pfn_pmd(unsigned long pfn, pgprot_t pgprot)
+{
+ pmd_t pmd = pfn_pmd(pfn, pgprot);
+ return __pmd(pmd_val(pmd) | _PAGE_PTE);
+}
+#else
+#define debug_vm_pfn_pte(pfn, pgprot) pfn_pte(pfn, pgprot)
+#define debug_vm_pfn_pmd(pfn, pgprot) pfn_pmd(pfn, pgprot)
+#endif
Again, no platform specific constructs please. This defeats the whole purpose of
this test. If __PAGE_PTE is required for the helpers, then pfn_pmd/pte() could
be modified to accommodate that. We dont see similar issues on other platforms,
hence could you please explain why ppc64 is different here.
It is not platform specific. set_pte_at is the one that set the
_PAGE_PTE bit. We don't call that in the test. The test seems to make
the assumption that pfn_pte returns a proper pte which is not true.
-aneesh
