1 files changed, 270 insertions, 0 deletions
diff --git a/arch/mips/mm/sc-rm7k.c b/arch/mips/mm/sc-rm7k.c
new file mode 100644
index 000000000..e9e3777a7
--- /dev/null
+++ b/arch/mips/mm/sc-rm7k.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sc-rm7k.c: RM7000 cache management functions.
+ *
+ * Copyright (C) 1997, 2001, 2003, 2004 Ralf Baechle (ralf@linux-mips.org)
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/bitops.h>
+
+#include <asm/addrspace.h>
+#include <asm/bcache.h>
+#include <asm/cacheops.h>
+#include <asm/mipsregs.h>
+#include <asm/processor.h>
+#include <asm/sections.h>
+#include <asm/cacheflush.h> /* for run_uncached() */
+
+/* Primary cache parameters. */
+#define sc_lsize	32
+#define tc_pagesize	(32*128)
+
+/* Secondary cache parameters. */
+#define scache_size	(256*1024)	/* Fixed to 256KiB on RM7000 */
+
+/* Tertiary cache parameters */
+#define tc_lsize	32
+
+extern unsigned long icache_way_size, dcache_way_size;
+static unsigned long tcache_size;
+
+#include <asm/r4kcache.h>
+
+static int rm7k_tcache_init;
+
+/*
+ * Writeback and invalidate the primary cache dcache before DMA.
+ * (XXX These need to be fixed ...)
+ */
+static void rm7k_sc_wback_inv(unsigned long addr, unsigned long size)
+{
+	unsigned long end, a;
+
+	pr_debug("rm7k_sc_wback_inv[%08lx,%08lx]", addr, size);
+
+	/* Catch bad driver code */
+	BUG_ON(size == 0);
+
+	blast_scache_range(addr, addr + size);
+
+	if (!rm7k_tcache_init)
+		return;
+
+	a = addr & ~(tc_pagesize - 1);
+	end = (addr + size - 1) & ~(tc_pagesize - 1);
+	while(1) {
+		invalidate_tcache_page(a);	/* Page_Invalidate_T */
+		if (a == end)
+			break;
+		a += tc_pagesize;
+	}
+}
+
+static void rm7k_sc_inv(unsigned long addr, unsigned long size)
+{
+	unsigned long end, a;
+
+	pr_debug("rm7k_sc_inv[%08lx,%08lx]", addr, size);
+
+	/* Catch bad driver code */
+	BUG_ON(size == 0);
+
+	blast_inv_scache_range(addr, addr + size);
+
+	if (!rm7k_tcache_init)
+		return;
+
+	a = addr & ~(tc_pagesize - 1);
+	end = (addr + size - 1) & ~(tc_pagesize - 1);
+	while(1) {
+		invalidate_tcache_page(a);	/* Page_Invalidate_T */
+		if (a == end)
+			break;
+		a += tc_pagesize;
+	}
+}
+
+static void blast_rm7k_tcache(void)
+{
+	unsigned long start = CKSEG0ADDR(0);
+	unsigned long end = start + tcache_size;
+
+	write_c0_taglo(0);
+
+	while (start < end) {
+		cache_op(Page_Invalidate_T, start);
+		start += tc_pagesize;
+	}
+}
+
+/*
+ * This function is executed in uncached address space.
+ */
+static void __rm7k_tc_enable(void)
+{
+	int i;
+
+	set_c0_config(RM7K_CONF_TE);
+
+	write_c0_taglo(0);
+	write_c0_taghi(0);
+
+	for (i = 0; i < tcache_size; i += tc_lsize)
+		cache_op(Index_Store_Tag_T, CKSEG0ADDR(i));
+}
+
+static void rm7k_tc_enable(void)
+{
+	if (read_c0_config() & RM7K_CONF_TE)
+		return;
+
+	BUG_ON(tcache_size == 0);
+
+	run_uncached(__rm7k_tc_enable);
+}
+
+/*
+ * This function is executed in uncached address space.
+ */
+static void __rm7k_sc_enable(void)
+{
+	int i;
+
+	set_c0_config(RM7K_CONF_SE);
+
+	write_c0_taglo(0);
+	write_c0_taghi(0);
+
+	for (i = 0; i < scache_size; i += sc_lsize)
+		cache_op(Index_Store_Tag_SD, CKSEG0ADDR(i));
+}
+
+static void rm7k_sc_enable(void)
+{
+	if (read_c0_config() & RM7K_CONF_SE)
+		return;
+
+	pr_info("Enabling secondary cache...\n");
+	run_uncached(__rm7k_sc_enable);
+
+	if (rm7k_tcache_init)
+		rm7k_tc_enable();
+}
+
+static void rm7k_tc_disable(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	blast_rm7k_tcache();
+	clear_c0_config(RM7K_CONF_TE);
+	local_irq_restore(flags);
+}
+
+static void rm7k_sc_disable(void)
+{
+	clear_c0_config(RM7K_CONF_SE);
+
+	if (rm7k_tcache_init)
+		rm7k_tc_disable();
+}
+
+static struct bcache_ops rm7k_sc_ops = {
+	.bc_enable = rm7k_sc_enable,
+	.bc_disable = rm7k_sc_disable,
+	.bc_wback_inv = rm7k_sc_wback_inv,
+	.bc_inv = rm7k_sc_inv
+};
+
+/*
+ * This is a probing function like the one found in c-r4k.c, we look for the
+ * wrap around point with different addresses.
+ */
+static void __probe_tcache(void)
+{
+	unsigned long flags, addr, begin, end, pow2;
+
+	begin = (unsigned long) &_stext;
+	begin  &= ~((8 * 1024 * 1024) - 1);
+	end = begin + (8 * 1024 * 1024);
+
+	local_irq_save(flags);
+
+	set_c0_config(RM7K_CONF_TE);
+
+	/* Fill size-multiple lines with a valid tag */
+	pow2 = (256 * 1024);
+	for (addr = begin; addr <= end; addr = (begin + pow2)) {
+		unsigned long *p = (unsigned long *) addr;
+		__asm__ __volatile__("nop" : : "r" (*p));
+		pow2 <<= 1;
+	}
+
+	/* Load first line with a 0 tag, to check after */
+	write_c0_taglo(0);
+	write_c0_taghi(0);
+	cache_op(Index_Store_Tag_T, begin);
+
+	/* Look for the wrap-around */
+	pow2 = (512 * 1024);
+	for (addr = begin + (512 * 1024); addr <= end; addr = begin + pow2) {
+		cache_op(Index_Load_Tag_T, addr);
+		if (!read_c0_taglo())
+			break;
+		pow2 <<= 1;
+	}
+
+	addr -= begin;
+	tcache_size = addr;
+
+	clear_c0_config(RM7K_CONF_TE);
+
+	local_irq_restore(flags);
+}
+
+void rm7k_sc_init(void)
+{
+	struct cpuinfo_mips *c = &current_cpu_data;
+	unsigned int config = read_c0_config();
+
+	if ((config & RM7K_CONF_SC))
+		return;
+
+	c->scache.linesz = sc_lsize;
+	c->scache.ways = 4;
+	c->scache.waybit= __ffs(scache_size / c->scache.ways);
+	c->scache.waysize = scache_size / c->scache.ways;
+	c->scache.sets = scache_size / (c->scache.linesz * c->scache.ways);
+	printk(KERN_INFO "Secondary cache size %dK, linesize %d bytes.\n",
+	       (scache_size >> 10), sc_lsize);
+
+	if (!(config & RM7K_CONF_SE))
+		rm7k_sc_enable();
+
+	bcops = &rm7k_sc_ops;
+
+	/*
+	 * While we're at it let's deal with the tertiary cache.
+	 */
+
+	rm7k_tcache_init = 0;
+	tcache_size = 0;
+
+	if (config & RM7K_CONF_TC)
+		return;
+
+	/*
+	 * No efficient way to ask the hardware for the size of the tcache,
+	 * so must probe for it.
+	 */
+	run_uncached(__probe_tcache);
+	rm7k_tc_enable();
+	rm7k_tcache_init = 1;
+	c->tcache.linesz = tc_lsize;
+	c->tcache.ways = 1;
+	pr_info("Tertiary cache size %ldK.\n", (tcache_size >> 10));
+}