MIPS: Loongson: Add Loongson-3A R2 basic support

Loongson-3 CPU family:

Code-name       Brand-name       PRId
Loongson-3A R1  Loongson-3A1000  0x6305
Loongson-3A R2  Loongson-3A2000  0x6308
Loongson-3B R1  Loongson-3B1000  0x6306
Loongson-3B R2  Loongson-3B1500  0x6307

Features of R2 revision of Loongson-3A:

  - Primary cache includes I-Cache, D-Cache and V-Cache (Victim Cache).
  - I-Cache, D-Cache and V-Cache are 16-way set-associative, linesize is
     64 bytes.
  - 64 entries of VTLB (classic TLB), 1024 entries of FTLB (8-way
     set-associative).
  - Supports DSP/DSPv2 instructions, UserLocal register and Read-Inhibit/
     Execute-Inhibit.

[ralf@linux-mips.org: Resolved merge conflicts.]

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12751/
Patchwork: https://patchwork.linux-mips.org/patch/13136/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 6f43bdf9a679..77fbaf1cdfd6 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -77,6 +77,7 @@ static inline void r4k_on_each_cpu(void (*func) (void *info), void *info)
  */
 static unsigned long icache_size __read_mostly;
 static unsigned long dcache_size __read_mostly;
+static unsigned long vcache_size __read_mostly;
 static unsigned long scache_size __read_mostly;
 
 /*
@@ -1349,6 +1350,31 @@ static void probe_pcache(void)
 	       c->dcache.linesz);
 }
 
+static void probe_vcache(void)
+{
+	struct cpuinfo_mips *c = &current_cpu_data;
+	unsigned int config2, lsize;
+
+	if (current_cpu_type() != CPU_LOONGSON3)
+		return;
+
+	config2 = read_c0_config2();
+	if ((lsize = ((config2 >> 20) & 15)))
+		c->vcache.linesz = 2 << lsize;
+	else
+		c->vcache.linesz = lsize;
+
+	c->vcache.sets = 64 << ((config2 >> 24) & 15);
+	c->vcache.ways = 1 + ((config2 >> 16) & 15);
+
+	vcache_size = c->vcache.sets * c->vcache.ways * c->vcache.linesz;
+
+	c->vcache.waybit = 0;
+
+	pr_info("Unified victim cache %ldkB %s, linesize %d bytes.\n",
+		vcache_size >> 10, way_string[c->vcache.ways], c->vcache.linesz);
+}
+
 /*
  * If you even _breathe_ on this function, look at the gcc output and make sure
  * it does not pop things on and off the stack for the cache sizing loop that
@@ -1671,6 +1697,7 @@ void r4k_cache_init(void)
 	struct cpuinfo_mips *c = &current_cpu_data;
 
 	probe_pcache();
+	probe_vcache();
 	setup_scache();
 
 	r4k_blast_dcache_page_setup();