[patch 2/4] mm/highmem: Prepare for overriding set_pte_at()

From: Thomas Gleixner
Date: Tue Jan 12 2021 - 12:05:48 EST


The generic kmap_local() map function uses set_pte_at(), but MIPS requires
set_pte() and PowerPC wants __set_pte_at().

Provide arch_kmap_local_set_pte() and default it to set_pte_at().

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
mm/highmem.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -473,6 +473,11 @@ static inline void *arch_kmap_local_high
}
#endif

+#ifndef arch_kmap_local_set_pte
+#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev) \
+ set_pte_at(mm, vaddr, ptep, ptev)
+#endif
+
/* Unmap a local mapping which was obtained by kmap_high_get() */
static inline bool kmap_high_unmap_local(unsigned long vaddr)
{
@@ -515,7 +520,7 @@ void *__kmap_local_pfn_prot(unsigned lon
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
BUG_ON(!pte_none(*(kmap_pte - idx)));
pteval = pfn_pte(pfn, prot);
- set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval);
+ arch_kmap_local_set_pte(&init_mm, vaddr, kmap_pte - idx, pteval);
arch_kmap_local_post_map(vaddr, pteval);
current->kmap_ctrl.pteval[kmap_local_idx()] = pteval;
preempt_enable();