1 files changed, 150 insertions, 0 deletions

diff --git a/kernel/arch/mips/mm/sc-mips.c b/kernel/arch/mips/mm/sc-mips.c
new file mode 100644
index 000000000..4ceafd138
--- /dev/null
+++ b/kernel/arch/mips/mm/sc-mips.c
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2006 Chris Dearman (chris@mips.com),
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+
+#include <asm/cpu-type.h>
+#include <asm/mipsregs.h>
+#include <asm/bcache.h>
+#include <asm/cacheops.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/mmu_context.h>
+#include <asm/r4kcache.h>
+
+/*
+ * MIPS32/MIPS64 L2 cache handling
+ */
+
+/*
+ * Writeback and invalidate the secondary cache before DMA.
+ */
+static void mips_sc_wback_inv(unsigned long addr, unsigned long size)
+{
+	blast_scache_range(addr, addr + size);
+}
+
+/*
+ * Invalidate the secondary cache before DMA.
+ */
+static void mips_sc_inv(unsigned long addr, unsigned long size)
+{
+	unsigned long lsize = cpu_scache_line_size();
+	unsigned long almask = ~(lsize - 1);
+
+	cache_op(Hit_Writeback_Inv_SD, addr & almask);
+	cache_op(Hit_Writeback_Inv_SD, (addr + size - 1) & almask);
+	blast_inv_scache_range(addr, addr + size);
+}
+
+static void mips_sc_enable(void)
+{
+	/* L2 cache is permanently enabled */
+}
+
+static void mips_sc_disable(void)
+{
+	/* L2 cache is permanently enabled */
+}
+
+static struct bcache_ops mips_sc_ops = {
+	.bc_enable = mips_sc_enable,
+	.bc_disable = mips_sc_disable,
+	.bc_wback_inv = mips_sc_wback_inv,
+	.bc_inv = mips_sc_inv
+};
+
+/*
+ * Check if the L2 cache controller is activated on a particular platform.
+ * MTI's L2 controller and the L2 cache controller of Broadcom's BMIPS
+ * cores both use c0_config2's bit 12 as "L2 Bypass" bit, that is the
+ * cache being disabled.  However there is no guarantee for this to be
+ * true on all platforms.  In an act of stupidity the spec defined bits
+ * 12..15 as implementation defined so below function will eventually have
+ * to be replaced by a platform specific probe.
+ */
+static inline int mips_sc_is_activated(struct cpuinfo_mips *c)
+{
+	unsigned int config2 = read_c0_config2();
+	unsigned int tmp;
+
+	/* Check the bypass bit (L2B) */
+	switch (current_cpu_type()) {
+	case CPU_34K:
+	case CPU_74K:
+	case CPU_1004K:
+	case CPU_1074K:
+	case CPU_INTERAPTIV:
+	case CPU_PROAPTIV:
+	case CPU_P5600:
+	case CPU_BMIPS5000:
+	case CPU_QEMU_GENERIC:
+		if (config2 & (1 << 12))
+			return 0;
+	}
+
+	tmp = (config2 >> 4) & 0x0f;
+	if (0 < tmp && tmp <= 7)
+		c->scache.linesz = 2 << tmp;
+	else
+		return 0;
+	return 1;
+}
+
+static inline int __init mips_sc_probe(void)
+{
+	struct cpuinfo_mips *c = &current_cpu_data;
+	unsigned int config1, config2;
+	unsigned int tmp;
+
+	/* Mark as not present until probe completed */
+	c->scache.flags |= MIPS_CACHE_NOT_PRESENT;
+
+	/* Ignore anything but MIPSxx processors */
+	if (!(c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M32R2 |
+			      MIPS_CPU_ISA_M32R6 | MIPS_CPU_ISA_M64R1 |
+			      MIPS_CPU_ISA_M64R2 | MIPS_CPU_ISA_M64R6)))
+		return 0;
+
+	/* Does this MIPS32/MIPS64 CPU have a config2 register? */
+	config1 = read_c0_config1();
+	if (!(config1 & MIPS_CONF_M))
+		return 0;
+
+	config2 = read_c0_config2();
+
+	if (!mips_sc_is_activated(c))
+		return 0;
+
+	tmp = (config2 >> 8) & 0x0f;
+	if (0 <= tmp && tmp <= 7)
+		c->scache.sets = 64 << tmp;
+	else
+		return 0;
+
+	tmp = (config2 >> 0) & 0x0f;
+	if (0 <= tmp && tmp <= 7)
+		c->scache.ways = tmp + 1;
+	else
+		return 0;
+
+	c->scache.waysize = c->scache.sets * c->scache.linesz;
+	c->scache.waybit = __ffs(c->scache.waysize);
+
+	c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
+
+	return 1;
+}
+
+int mips_sc_init(void)
+{
+	int found = mips_sc_probe();
+	if (found) {
+		mips_sc_enable();
+		bcops = &mips_sc_ops;
+	}
+	return found;
+}