arm64: mm: Introduce a C wrapper for by-range TLB invalidation

As part of efforts to reduce our reliance on complex preprocessor macros
for TLB invalidation routines, introduce a new C wrapper for by-range
TLB invalidation which can be used instead of the __tlbi() macro and can
additionally be called from C code.

Each specific tlbi range op is implemented as a C function and the
appropriate function pointer is passed to __tlbi_range(). Since
everything is declared inline and is statically resolvable, the compiler
will convert the indirect function call to a direct inline execution.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: ryanhrob

arch/arm64/include/asm/tlbflush.h

@@ -468,6 +468,36 @@ static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
  *    operations can only span an even number of pages. We save this for last to
  *    ensure 64KB start alignment is maintained for the LPA2 case.
  */
+static __always_inline void rvae1is(u64 arg)
+{
+	__tlbi(rvae1is, arg);
+}
+
+static __always_inline void rvale1(u64 arg)
+{
+	__tlbi(rvale1, arg);
+}
+
+static __always_inline void rvale1is(u64 arg)
+{
+	__tlbi(rvale1is, arg);
+}
+
+static __always_inline void rvaale1is(u64 arg)
+{
+	__tlbi(rvaale1is, arg);
+}
+
+static __always_inline void ripas2e1is(u64 arg)
+{
+	__tlbi(ripas2e1is, arg);
+}
+
+static __always_inline void __tlbi_range(tlbi_op op, u64 arg)
+{
+	op(arg);
+}
+
 #define __flush_tlb_range_op(op, start, pages, stride,			\
 				asid, tlb_level, tlbi_user, lpa2)	\
 do {									\
@@ -495,7 +525,7 @@ do {									\
 		if (num >= 0) {						\
 			addr = __TLBI_VADDR_RANGE(__flush_start >> shift, asid, \
 						scale, num, tlb_level);	\
-			__tlbi(r##op, addr);				\
+			__tlbi_range(r##op, addr);			\
 			if (tlbi_user)					\
 				__tlbi_user(r##op, addr);		\
 			__flush_start += __TLBI_RANGE_PAGES(num, scale) << PAGE_SHIFT; \