powerpc/mm: pte_frag abstraction
In this patch we make the number of pte fragments per level 4 page table
page a variable. Radix level 4 table size is 256 bytes and hence we can
have 256 fragments per level 4 page. We don't update the fragment count
in this patch. We need to do performance measurements to find the right
value for fragment count.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 68aee43..262082e 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -873,6 +873,9 @@
/*
* initialize page table size
*/
+ __pte_frag_nr = H_PTE_FRAG_NR;
+ __pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
+
__pte_index_size = H_PTE_INDEX_SIZE;
__pmd_index_size = H_PMD_INDEX_SIZE;
__pud_index_size = H_PUD_INDEX_SIZE;
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 13afacd..a5a5253 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -334,6 +334,11 @@
__vmalloc_end = RADIX_VMALLOC_END;
vmemmap = (struct page *)RADIX_VMEMMAP_BASE;
ioremap_bot = IOREMAP_BASE;
+ /*
+ * For now radix also use the same frag size
+ */
+ __pte_frag_nr = H_PTE_FRAG_NR;
+ __pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT;
radix_init_page_sizes();
if (!firmware_has_feature(FW_FEATURE_LPAR))
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 216e2bd..95df08e 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -107,6 +107,10 @@
EXPORT_SYMBOL(__vmalloc_end);
struct page *vmemmap;
EXPORT_SYMBOL(vmemmap);
+unsigned long __pte_frag_nr;
+EXPORT_SYMBOL(__pte_frag_nr);
+unsigned long __pte_frag_size_shift;
+EXPORT_SYMBOL(__pte_frag_size_shift);
unsigned long ioremap_bot;
#else /* !CONFIG_PPC_BOOK3S_64 */
unsigned long ioremap_bot = IOREMAP_BASE;