[PATCH] powerpc/highmem: change BUG_ON() to WARN_ON()

[Christophe Leroy]

In arch/powerpc/mm/highmem.c, BUG_ON() is called only when
CONFIG_DEBUG_HIGHMEM is selected, this means the BUG_ON() is
not vital and can be replaced by a a WARN_ON

At the sametime, use IS_ENABLED() instead of #ifdef to clean a bit.

Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
 arch/powerpc/mm/highmem.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
index 82a0e37557a5..b68c9f20fbdf 100644
--- a/arch/powerpc/mm/highmem.c
+++ b/arch/powerpc/mm/highmem.c
@@ -43,9 +43,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
        type = kmap_atomic_idx_push();
        idx = type + KM_TYPE_NR*smp_processor_id();
        vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
-       BUG_ON(!pte_none(*(kmap_pte-idx)));
-#endif
+       WARN_ON(IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !pte_none(*(kmap_pte - 
idx)));
        __set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
        local_flush_tlb_page(NULL, vaddr);
 
@@ -56,7 +54,7 @@ EXPORT_SYMBOL(kmap_atomic_prot);
 void __kunmap_atomic(void *kvaddr)
 {
        unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
-       int type __maybe_unused;
+       int type;
 
        if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
                pagefault_enable();
@@ -66,12 +64,11 @@ void __kunmap_atomic(void *kvaddr)
 
        type = kmap_atomic_idx();
 
-#ifdef CONFIG_DEBUG_HIGHMEM
-       {
+       if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM)) {
                unsigned int idx;
 
                idx = type + KM_TYPE_NR * smp_processor_id();
-               BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+               WARN_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
 
                /*
                 * force other mappings to Oops if they'll try to access
@@ -80,7 +77,6 @@ void __kunmap_atomic(void *kvaddr)
                pte_clear(&init_mm, vaddr, kmap_pte-idx);
                local_flush_tlb_page(NULL, vaddr);
        }
-#endif
 
        kmap_atomic_idx_pop();
        pagefault_enable();
-- 
2.13.3