MIPS: avoid .set ISA for cache operations

As a step towards unifying the cache maintenance code for mips32 &
mips64 CPUs, stop using ".set <ISA>" directives in the more developed
mips32 version of the code. Instead, when present make use of the GCC
builtin for emitting a cache instruction. When not present, simply don't
bother with the .set directives since U-boot always builds with
-march=mips32 or higher anyway.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

arch/mips/cpu/mips32/cache.S

@@ -22,14 +22,6 @@
 
 #define INDEX_BASE	CKSEG0
 
-	.macro	cache_op op addr
-	.set	push
-	.set	noreorder
-	.set	mips3
-	cache	\op, 0(\addr)
-	.set	pop
-	.endm
-
 	.macro	f_fill64 dst, offset, val
 	LONG_S	\val, (\offset +  0 * LONGSIZE)(\dst)
 	LONG_S	\val, (\offset +  1 * LONGSIZE)(\dst)
@@ -60,17 +52,17 @@ LEAF(mips_init_icache)
 	/* clear tag to invalidate */
 	PTR_LI		t0, INDEX_BASE
 	PTR_ADDU	t1, t0, a1
-1:	cache_op	INDEX_STORE_TAG_I t0
+1:	cache		INDEX_STORE_TAG_I, 0(t0)
 	PTR_ADDU	t0, a2
 	bne		t0, t1, 1b
 	/* fill once, so data field parity is correct */
 	PTR_LI		t0, INDEX_BASE
-2:	cache_op	FILL t0
+2:	cache		FILL, 0(t0)
 	PTR_ADDU	t0, a2
 	bne		t0, t1, 2b
 	/* invalidate again - prudent but not strictly neccessary */
 	PTR_LI		t0, INDEX_BASE
-1:	cache_op	INDEX_STORE_TAG_I t0
+1:	cache		INDEX_STORE_TAG_I, 0(t0)
 	PTR_ADDU	t0, a2
 	bne		t0, t1, 1b
 9:	jr		ra
@@ -85,7 +77,7 @@ LEAF(mips_init_dcache)
 	/* clear all tags */
 	PTR_LI		t0, INDEX_BASE
 	PTR_ADDU	t1, t0, a1
-1:	cache_op	INDEX_STORE_TAG_D t0
+1:	cache		INDEX_STORE_TAG_D, 0(t0)
 	PTR_ADDU	t0, a2
 	bne		t0, t1, 1b
 	/* load from each line (in cached space) */
@@ -95,7 +87,7 @@ LEAF(mips_init_dcache)
 	bne		t0, t1, 2b
 	/* clear all tags */
 	PTR_LI		t0, INDEX_BASE
-1:	cache_op	INDEX_STORE_TAG_D t0
+1:	cache		INDEX_STORE_TAG_D, 0(t0)
 	PTR_ADDU	t0, a2
 	bne		t0, t1, 1b
 9:	jr		ra

arch/mips/cpu/mips32/cpu.c

@@ -12,16 +12,6 @@
 #include <asm/cacheops.h>
 #include <asm/reboot.h>
 
-#define cache_op(op,addr)						\
-	__asm__ __volatile__(						\
-	"	.set	push					\n"	\
-	"	.set	noreorder				\n"	\
-	"	.set	mips3\n\t				\n"	\
-	"	cache	%0, %1					\n"	\
-	"	.set	pop					\n"	\
-	:								\
-	: "i" (op), "R" (*(unsigned char *)(addr)))
-
 void __attribute__((weak)) _machine_restart(void)
 {
 }
@@ -74,20 +64,20 @@ void flush_cache(ulong start_addr, ulong size)
 {
 	unsigned long ilsize = icache_line_size();
 	unsigned long dlsize = dcache_line_size();
-	unsigned long addr, aend;
+	const void *addr, *aend;
 
 	/* aend will be miscalculated when size is zero, so we return here */
 	if (size == 0)
 		return;
 
-	addr = start_addr & ~(dlsize - 1);
-	aend = (start_addr + size - 1) & ~(dlsize - 1);
+	addr = (const void *)(start_addr & ~(dlsize - 1));
+	aend = (const void *)((start_addr + size - 1) & ~(dlsize - 1));
 
 	if (ilsize == dlsize) {
 		/* flush I-cache & D-cache simultaneously */
 		while (1) {
-			cache_op(HIT_WRITEBACK_INV_D, addr);
-			cache_op(HIT_INVALIDATE_I, addr);
+			mips_cache(HIT_WRITEBACK_INV_D, addr);
+			mips_cache(HIT_INVALIDATE_I, addr);
 			if (addr == aend)
 				break;
 			addr += dlsize;
@@ -97,17 +87,17 @@ void flush_cache(ulong start_addr, ulong size)
 
 	/* flush D-cache */
 	while (1) {
-		cache_op(HIT_WRITEBACK_INV_D, addr);
+		mips_cache(HIT_WRITEBACK_INV_D, addr);
 		if (addr == aend)
 			break;
 		addr += dlsize;
 	}
 
 	/* flush I-cache */
-	addr = start_addr & ~(ilsize - 1);
-	aend = (start_addr + size - 1) & ~(ilsize - 1);
+	addr = (const void *)(start_addr & ~(ilsize - 1));
+	aend = (const void *)((start_addr + size - 1) & ~(ilsize - 1));
 	while (1) {
-		cache_op(HIT_INVALIDATE_I, addr);
+		mips_cache(HIT_INVALIDATE_I, addr);
 		if (addr == aend)
 			break;
 		addr += ilsize;
@@ -117,11 +107,11 @@ void flush_cache(ulong start_addr, ulong size)
 void flush_dcache_range(ulong start_addr, ulong stop)
 {
 	unsigned long lsize = dcache_line_size();
-	unsigned long addr = start_addr & ~(lsize - 1);
-	unsigned long aend = (stop - 1) & ~(lsize - 1);
+	const void *addr = (const void *)(start_addr & ~(lsize - 1));
+	const void *aend = (const void *)((stop - 1) & ~(lsize - 1));
 
 	while (1) {
-		cache_op(HIT_WRITEBACK_INV_D, addr);
+		mips_cache(HIT_WRITEBACK_INV_D, addr);
 		if (addr == aend)
 			break;
 		addr += lsize;
@@ -131,11 +121,11 @@ void flush_dcache_range(ulong start_addr, ulong stop)
 void invalidate_dcache_range(ulong start_addr, ulong stop)
 {
 	unsigned long lsize = dcache_line_size();
-	unsigned long addr = start_addr & ~(lsize - 1);
-	unsigned long aend = (stop - 1) & ~(lsize - 1);
+	const void *addr = (const void *)(start_addr & ~(lsize - 1));
+	const void *aend = (const void *)((stop - 1) & ~(lsize - 1));
 
 	while (1) {
-		cache_op(HIT_INVALIDATE_D, addr);
+		mips_cache(HIT_INVALIDATE_D, addr);
 		if (addr == aend)
 			break;
 		addr += lsize;

arch/mips/include/asm/cacheops.h

@@ -11,6 +11,19 @@
 #ifndef	__ASM_CACHEOPS_H
 #define	__ASM_CACHEOPS_H
 
+#ifndef __ASSEMBLY__
+
+static inline void mips_cache(int op, const volatile void *addr)
+{
+#ifdef __GCC_HAVE_BUILTIN_MIPS_CACHE
+	__builtin_mips_cache(op, addr);
+#else
+	__asm__ __volatile__("cache %0, %1" : : "i"(op), "R"(addr))
+#endif
+}
+
+#endif /* !__ASSEMBLY__ */
+
 /*
  * Cache Operations available on all MIPS processors with R4000-style caches
  */