[PATCH 5.2 011/124] powerpc/mm/radix: Use the right page size for vmemmap mapping

From: Greg Kroah-Hartman
Date: Thu Sep 19 2019 - 18:07:39 EST


From: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>

commit 89a3496e0664577043666791ec07fb731d57c950 upstream.

We use mmu_vmemmap_psize to find the page size for mapping the vmmemap area.
With radix translation, we are suboptimally setting this value to PAGE_SIZE.

We do check for 2M page size support and update mmu_vmemap_psize to use
hugepage size but we suboptimally reset the value to PAGE_SIZE in
radix__early_init_mmu(). This resulted in always mapping vmemmap area with
64K page size.

Fixes: 2bfd65e45e87 ("powerpc/mm/radix: Add radix callbacks for early init routines")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/mm/book3s64/radix_pgtable.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -515,14 +515,6 @@ void __init radix__early_init_devtree(vo
mmu_psize_defs[MMU_PAGE_64K].shift = 16;
mmu_psize_defs[MMU_PAGE_64K].ap = 0x5;
found:
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
- if (mmu_psize_defs[MMU_PAGE_2M].shift) {
- /*
- * map vmemmap using 2M if available
- */
- mmu_vmemmap_psize = MMU_PAGE_2M;
- }
-#endif /* CONFIG_SPARSEMEM_VMEMMAP */
return;
}

@@ -587,7 +579,13 @@ void __init radix__early_init_mmu(void)

#ifdef CONFIG_SPARSEMEM_VMEMMAP
/* vmemmap mapping */
- mmu_vmemmap_psize = mmu_virtual_psize;
+ if (mmu_psize_defs[MMU_PAGE_2M].shift) {
+ /*
+ * map vmemmap using 2M if available
+ */
+ mmu_vmemmap_psize = MMU_PAGE_2M;
+ } else
+ mmu_vmemmap_psize = mmu_virtual_psize;
#endif
/*
* initialize page table size