arch/xtensa: move kmap build bug out of the way

Move the kmap() build bug to kmap_init() to facilitate patches to lift
kmap() to the core.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian König <christian.koenig@amd.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200507150004.1423069-3-ira.weiny@intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/xtensa/include/asm/highmem.h

@@ -68,11 +68,6 @@ void kunmap_high(struct page *page);
 
 static inline void *kmap(struct page *page)
 {
-	/* Check if this memory layout is broken because PKMAP overlaps
-	 * page table.
-	 */
-	BUILD_BUG_ON(PKMAP_BASE <
-		     TLBTEMP_BASE_1 + TLBTEMP_SIZE);
 	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);

arch/xtensa/mm/highmem.c

@@ -88,6 +88,10 @@ void __init kmap_init(void)
 {
 	unsigned long kmap_vstart;
 
+	/* Check if this memory layout is broken because PKMAP overlaps
+	 * page table.
+	 */
+	BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
 	/* cache the first kmap pte */
 	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);