sparc32: Kill none_mask, it's bogus.

For some reason, the pte_none() calculation for srmmu sparc32
chips was masking out the top 4 bits.  That doesn't make any
sense, as those are just some of the physical bits of the PTE
encoding.

Furthermore, this mistake breaks things when the offset of of a swap
entry has a large enough offset as reported by Тхай Кирилл.

Sun4c always set it to zero, so it's really completely useless,
kill it.
Reported-by: Тхай Кирилл <tkhai@yandex.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/pgtable_32.h

@@ -142,13 +142,12 @@ BTFIXUPDEF_CALL_CONST(unsigned long, pgd_page_vaddr, pgd_t)
 #define pmd_page(pmd) BTFIXUP_CALL(pmd_page)(pmd)
 #define pgd_page_vaddr(pgd) BTFIXUP_CALL(pgd_page_vaddr)(pgd)
 
-BTFIXUPDEF_SETHI(none_mask)
 BTFIXUPDEF_CALL_CONST(int, pte_present, pte_t)
 BTFIXUPDEF_CALL(void, pte_clear, pte_t *)
 
 static inline int pte_none(pte_t pte)
 {
-	return !(pte_val(pte) & ~BTFIXUP_SETHI(none_mask));
+	return !pte_val(pte);
 }
 
 #define pte_present(pte) BTFIXUP_CALL(pte_present)(pte)
@@ -160,7 +159,7 @@ BTFIXUPDEF_CALL(void, pmd_clear, pmd_t *)
 
 static inline int pmd_none(pmd_t pmd)
 {
-	return !(pmd_val(pmd) & ~BTFIXUP_SETHI(none_mask));
+	return !pmd_val(pmd);
 }
 
 #define pmd_bad(pmd) BTFIXUP_CALL(pmd_bad)(pmd)

arch/sparc/mm/srmmu.c

@@ -2215,8 +2215,6 @@ void __init ld_mmu_srmmu(void)
 	BTFIXUPSET_CALL(pmd_page, srmmu_pmd_page, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(pgd_page_vaddr, srmmu_pgd_page, BTFIXUPCALL_NORM);
 
-	BTFIXUPSET_SETHI(none_mask, 0xF0000000);
-
 	BTFIXUPSET_CALL(pte_present, srmmu_pte_present, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(pte_clear, srmmu_pte_clear, BTFIXUPCALL_SWAPO0G0);
 

arch/sparc/mm/sun4c.c

@@ -2087,9 +2087,6 @@ void __init ld_mmu_sun4c(void)
 
 	BTFIXUPSET_CALL(set_pte, sun4c_set_pte, BTFIXUPCALL_STO1O0);
 
-	/* The 2.4.18 code does not set this on sun4c, how does it work? XXX */
-	/* BTFIXUPSET_SETHI(none_mask, 0x00000000); */	/* Defaults to zero? */
-
 	BTFIXUPSET_CALL(pte_pfn, sun4c_pte_pfn, BTFIXUPCALL_NORM);
 #if 0 /* PAGE_SHIFT <= 12 */ /* Eek. Investigate. XXX */
 	BTFIXUPSET_CALL(pmd_page, sun4c_pmd_page, BTFIXUPCALL_ANDNINT(PAGE_SIZE - 1));