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-rw-r--r--arch/mips/mm/sc-rm7k.c270
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));
+}