Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 129e032..f85bd5b 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -17,8 +17,10 @@
 #include <asm/pgtable-64.h>
 #endif
 
+#include <asm/cmpxchg.h>
 #include <asm/io.h>
 #include <asm/pgtable-bits.h>
+#include <asm/cpu-features.h>
 
 struct mm_struct;
 struct vm_area_struct;
@@ -197,58 +199,18 @@
 static inline void set_pte(pte_t *ptep, pte_t pteval)
 {
 	*ptep = pteval;
-#if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
+#if !defined(CONFIG_CPU_R3K_TLB)
 	if (pte_val(pteval) & _PAGE_GLOBAL) {
 		pte_t *buddy = ptep_buddy(ptep);
 		/*
 		 * Make sure the buddy is global too (if it's !none,
 		 * it better already be global)
 		 */
-#ifdef CONFIG_SMP
-		/*
-		 * For SMP, multiple CPUs can race, so we need to do
-		 * this atomically.
-		 */
-		unsigned long page_global = _PAGE_GLOBAL;
-		unsigned long tmp;
-
-		if (kernel_uses_llsc && R10000_LLSC_WAR) {
-			__asm__ __volatile__ (
-			"	.set	arch=r4000			\n"
-			"	.set	push				\n"
-			"	.set	noreorder			\n"
-			"1:"	__LL	"%[tmp], %[buddy]		\n"
-			"	bnez	%[tmp], 2f			\n"
-			"	 or	%[tmp], %[tmp], %[global]	\n"
-				__SC	"%[tmp], %[buddy]		\n"
-			"	beqzl	%[tmp], 1b			\n"
-			"	nop					\n"
-			"2:						\n"
-			"	.set	pop				\n"
-			"	.set	mips0				\n"
-			: [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp)
-			: [global] "r" (page_global));
-		} else if (kernel_uses_llsc) {
-			__asm__ __volatile__ (
-			"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"
-			"	.set	push				\n"
-			"	.set	noreorder			\n"
-			"1:"	__LL	"%[tmp], %[buddy]		\n"
-			"	bnez	%[tmp], 2f			\n"
-			"	 or	%[tmp], %[tmp], %[global]	\n"
-				__SC	"%[tmp], %[buddy]		\n"
-			"	beqz	%[tmp], 1b			\n"
-			"	nop					\n"
-			"2:						\n"
-			"	.set	pop				\n"
-			"	.set	mips0				\n"
-			: [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp)
-			: [global] "r" (page_global));
-		}
-#else /* !CONFIG_SMP */
-		if (pte_none(*buddy))
-			pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL;
-#endif /* CONFIG_SMP */
+# if defined(CONFIG_PHYS_ADDR_T_64BIT) && !defined(CONFIG_CPU_MIPS32)
+		cmpxchg64(&buddy->pte, 0, _PAGE_GLOBAL);
+# else
+		cmpxchg(&buddy->pte, 0, _PAGE_GLOBAL);
+# endif
 	}
 #endif
 }
@@ -256,7 +218,7 @@
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	htw_stop();
-#if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
+#if !defined(CONFIG_CPU_R3K_TLB)
 	/* Preserve global status for the pair */
 	if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
 		set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
@@ -315,6 +277,7 @@
 static inline int pte_write(pte_t pte)	{ return pte.pte_low & _PAGE_WRITE; }
 static inline int pte_dirty(pte_t pte)	{ return pte.pte_low & _PAGE_MODIFIED; }
 static inline int pte_young(pte_t pte)	{ return pte.pte_low & _PAGE_ACCESSED; }
+static inline int pte_special(pte_t pte) { return pte.pte_low & _PAGE_SPECIAL; }
 
 static inline pte_t pte_wrprotect(pte_t pte)
 {
@@ -375,10 +338,17 @@
 	}
 	return pte;
 }
+
+static inline pte_t pte_mkspecial(pte_t pte)
+{
+	pte.pte_low |= _PAGE_SPECIAL;
+	return pte;
+}
 #else
 static inline int pte_write(pte_t pte)	{ return pte_val(pte) & _PAGE_WRITE; }
 static inline int pte_dirty(pte_t pte)	{ return pte_val(pte) & _PAGE_MODIFIED; }
 static inline int pte_young(pte_t pte)	{ return pte_val(pte) & _PAGE_ACCESSED; }
+static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
 
 static inline pte_t pte_wrprotect(pte_t pte)
 {
@@ -422,6 +392,12 @@
 	return pte;
 }
 
+static inline pte_t pte_mkspecial(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_SPECIAL;
+	return pte;
+}
+
 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 static inline int pte_huge(pte_t pte)	{ return pte_val(pte) & _PAGE_HUGE; }
 
@@ -432,8 +408,6 @@
 }
 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
 #endif
-static inline int pte_special(pte_t pte)	{ return 0; }
-static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
 
 /*
  * Macro to make mark a page protection value as "uncacheable".	 Note
@@ -665,6 +639,8 @@
 
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+#define gup_fast_permitted(start, end)	(!cpu_has_dc_aliases)
+
 #include <asm-generic/pgtable.h>
 
 /*
@@ -685,9 +661,4 @@
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 
-/*
- * No page table caches to initialise
- */
-#define pgtable_cache_init()	do { } while (0)
-
 #endif /* _ASM_PGTABLE_H */