MIPS: import CPU and cache detection code from Linux 3.4

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 97 insertions, 0 deletions

diff --git a/arch/mips/lib/c-r4k.c b/arch/mips/lib/c-r4k.c
new file mode 100644
index 0000000000..01b8665193
--- /dev/null
+++ b/arch/mips/lib/c-r4k.c
@@ -0,0 +1,97 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Ralf Baechle (ralf@gnu.org)
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#include <common.h>
+#include <asm/io.h>
+#include <asm/mipsregs.h>
+#include <asm/cpu.h>
+#include <asm/cpu-info.h>
+#include <asm/bitops.h>
+
+void r4k_cache_init(void);
+
+static void probe_pcache(void)
+{
+	struct cpuinfo_mips *c = &current_cpu_data;
+	unsigned int icache_size, dcache_size;
+	unsigned int config = read_c0_config();
+	unsigned long config1;
+	unsigned int lsize;
+
+	switch (c->cputype) {
+
+	default:
+		/*
+		 * So we seem to be a MIPS32 or MIPS64 CPU
+		 * So let's probe the I-cache ...
+		 */
+		config1 = read_c0_config1();
+
+		if ((lsize = ((config1 >> 19) & 7)))
+			c->icache.linesz = 2 << lsize;
+		else
+			c->icache.linesz = lsize;
+		c->icache.sets = 64 << ((config1 >> 22) & 7);
+		c->icache.ways = 1 + ((config1 >> 16) & 7);
+
+		icache_size = c->icache.sets *
+		              c->icache.ways *
+		              c->icache.linesz;
+		c->icache.waybit = __ffs(icache_size/c->icache.ways);
+
+		if (config & 0x8)		/* VI bit */
+			c->icache.flags |= MIPS_CACHE_VTAG;
+
+		/*
+		 * Now probe the MIPS32 / MIPS64 data cache.
+		 */
+		c->dcache.flags = 0;
+
+		if ((lsize = ((config1 >> 10) & 7)))
+			c->dcache.linesz = 2 << lsize;
+		else
+			c->dcache.linesz= lsize;
+		c->dcache.sets = 64 << ((config1 >> 13) & 7);
+		c->dcache.ways = 1 + ((config1 >> 7) & 7);
+
+		dcache_size = c->dcache.sets *
+		              c->dcache.ways *
+		              c->dcache.linesz;
+		c->dcache.waybit = __ffs(dcache_size/c->dcache.ways);
+
+		c->options |= MIPS_CPU_PREFETCH;
+		break;
+	}
+
+	/* compute a couple of other cache variables */
+	c->icache.waysize = icache_size / c->icache.ways;
+	c->dcache.waysize = dcache_size / c->dcache.ways;
+
+	c->icache.sets = c->icache.linesz ?
+		icache_size / (c->icache.linesz * c->icache.ways) : 0;
+	c->dcache.sets = c->dcache.linesz ?
+		dcache_size / (c->dcache.linesz * c->dcache.ways) : 0;
+
+	/*
+	 * R10000 and R12000 P-caches are odd in a positive way.  They're 32kB
+	 * 2-way virtually indexed so normally would suffer from aliases.  So
+	 * normally they'd suffer from aliases but magic in the hardware deals
+	 * with that for us so we don't need to take care ourselves.
+	 */
+	switch (c->cputype) {
+	default:
+		if (c->dcache.waysize > PAGE_SIZE)
+			c->dcache.flags |= MIPS_CACHE_ALIASES;
+	}
+}
+
+void r4k_cache_init(void)
+{
+	probe_pcache();
+}