powerpc/64e: remove mmu_linear_psize

mmu_linear_psize is only set at boot once on 64e, is not necessarily
the correct size of the linear map pages, and is never used anywhere.
Remove it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Retain the extern, so we can use IS_ENABLED() for related code]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-14-npiggin@gmail.com

arch/powerpc/mm/nohash/tlb.c

@@ -150,7 +150,6 @@ static inline int mmu_get_tsize(int psize)
  */
 #ifdef CONFIG_PPC64
 
-int mmu_linear_psize;		/* Page size used for the linear mapping */
 int mmu_pte_psize;		/* Page size used for PTE pages */
 int mmu_vmemmap_psize;		/* Page size used for the virtual mem map */
 int book3e_htw_mode;		/* HW tablewalk?  Value is PPC_HTW_* */
@@ -657,14 +656,6 @@ static void early_init_this_mmu(void)
 
 static void __init early_init_mmu_global(void)
 {
-	/* XXX This will have to be decided at runtime, but right
-	 * now our boot and TLB miss code hard wires it. Ideally
-	 * we should find out a suitable page size and patch the
-	 * TLB miss code (either that or use the PACA to store
-	 * the value we want)
-	 */
-	mmu_linear_psize = MMU_PAGE_1G;
-
 	/* XXX This should be decided at runtime based on supported
 	 * page sizes in the TLB, but for now let's assume 16M is
 	 * always there and a good fit (which it probably is)