[RFC PATCH V1 03/10] powerpc/mm/radix: Add radix_set_pte to use in early init

[Aneesh Kumar K.V]

We want to use the static key based feature check in set_pte_at. Since
we call radix__map_kernel_page early in boot before jump label is
initialized we can't call set_pte_at there. Add radix__set_pte for the
same.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
 arch/powerpc/mm/pgtable-radix.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index d6598cd1c3e6..85da0212b276 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -36,6 +36,27 @@ static __ref void *early_alloc_pgtable(unsigned long size)
 
 	return pt;
 }
+/*
+ * set_pte stores a linux PTE into the linux page table.
+ */
+static void radix__set_pte(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+			   pte_t pte)
+{
+	/*
+	 * When handling numa faults, we already have the pte marked
+	 * _PAGE_PRESENT, but we can be sure that it is not in hpte.
+	 * Hence we can use set_pte_at for them.
+	 */
+	VM_WARN_ON(pte_present(*ptep) && !pte_protnone(*ptep));
+
+	/*
+	 * Add the pte bit when tryint set a pte
+	 */
+	pte = __pte(pte_val(pte) | _PAGE_PTE);
+
+	/* Perform the setting of the PTE */
+	radix__set_pte_at(mm, addr, ptep, pte, 0);
+}
 
 int radix__map_kernel_page(unsigned long ea, unsigned long pa,
 			  pgprot_t flags,
@@ -99,7 +120,7 @@ int radix__map_kernel_page(unsigned long ea, unsigned long pa,
 	}
 
 set_the_pte:
-	set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, flags));
+	radix__set_pte(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, flags));
 	smp_wmb();
 	return 0;
 }
-- 
2.7.4