[PATCH v2 1/2] powerpc/mm/hash/4k: Don't use 64K page size for vmemmap with 4K pagesize

[PATCH v2 1/2] powerpc/mm/hash/4k: Don't use 64K page size for vmemmap with 4K pagesize

[Aneesh Kumar K.V]

With hash translation and 4K PAGE_SIZE config, we need to make sure we don't
use 64K page size for vmemmap.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/book3s64/hash_utils.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 28ced26f2a00..a8cc40d2a9ed 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -684,10 +684,8 @@ static void __init htab_init_page_sizes(void)
 	if (mmu_psize_defs[MMU_PAGE_16M].shift &&
 	    memblock_phys_mem_size() >= 0x40000000)
 		mmu_vmemmap_psize = MMU_PAGE_16M;
-	else if (mmu_psize_defs[MMU_PAGE_64K].shift)
-		mmu_vmemmap_psize = MMU_PAGE_64K;
 	else
-		mmu_vmemmap_psize = MMU_PAGE_4K;
+		mmu_vmemmap_psize = mmu_virtual_psize;
 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 
 	printk(KERN_DEBUG "Page orders: linear mapping = %d, "
-- 
2.21.0

[PATCH v2 2/2] powerpc/mm/radix: Use the right page size for vmemmap mapping

[Aneesh Kumar K.V]

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

diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 273ae66a9a45..8deb432c2975 100644
--- 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(void)
 	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
-- 
2.21.0

Re: [PATCH v2 1/2] powerpc/mm/hash/4k: Don't use 64K page size for vmemmap with 4K pagesize

[Michael Ellerman]

On Mon, 2019-07-01 at 14:34:41 UTC, "Aneesh Kumar K.V" wrote:
> With hash translation and 4K PAGE_SIZE config, we need to make sure we don't
> use 64K page size for vmemmap.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/78c949888549a6318ae420802703408caae999f5

cheers