[PATCH 4.19 05/79] powerpc/mm/radix: Use the right page size for vmemmap mapping

Greg Kroah-Hartman
2019-09-19T22:13:36Z

From: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

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@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -521,14 +521,6 @@ 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;
}

@@ -567,7 +559,13 @@ 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