Initial import

1 files changed, 195 insertions, 0 deletions

diff --git a/arch/sh/mm/cache-sh7705.c b/arch/sh/mm/cache-sh7705.c
new file mode 100644
index 000000000..7729cca72
--- /dev/null
+++ b/arch/sh/mm/cache-sh7705.c
@@ -0,0 +1,195 @@
+/*
+ * arch/sh/mm/cache-sh7705.c
+ *
+ * Copyright (C) 1999, 2000  Niibe Yutaka
+ * Copyright (C) 2004  Alex Song
+ *
+ * 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.
+ *
+ */
+#include <linux/init.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/threads.h>
+#include <asm/addrspace.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/cache.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/pgalloc.h>
+#include <asm/mmu_context.h>
+#include <asm/cacheflush.h>
+
+/*
+ * The 32KB cache on the SH7705 suffers from the same synonym problem
+ * as SH4 CPUs
+ */
+static inline void cache_wback_all(void)
+{
+	unsigned long ways, waysize, addrstart;
+
+	ways = current_cpu_data.dcache.ways;
+	waysize = current_cpu_data.dcache.sets;
+	waysize <<= current_cpu_data.dcache.entry_shift;
+
+	addrstart = CACHE_OC_ADDRESS_ARRAY;
+
+	do {
+		unsigned long addr;
+
+		for (addr = addrstart;
+		     addr < addrstart + waysize;
+		     addr += current_cpu_data.dcache.linesz) {
+			unsigned long data;
+			int v = SH_CACHE_UPDATED | SH_CACHE_VALID;
+
+			data = __raw_readl(addr);
+
+			if ((data & v) == v)
+				__raw_writel(data & ~v, addr);
+
+		}
+
+		addrstart += current_cpu_data.dcache.way_incr;
+	} while (--ways);
+}
+
+/*
+ * Write back the range of D-cache, and purge the I-cache.
+ *
+ * Called from kernel/module.c:sys_init_module and routine for a.out format.
+ */
+static void sh7705_flush_icache_range(void *args)
+{
+	struct flusher_data *data = args;
+	unsigned long start, end;
+
+	start = data->addr1;
+	end = data->addr2;
+
+	__flush_wback_region((void *)start, end - start);
+}
+
+/*
+ * Writeback&Invalidate the D-cache of the page
+ */
+static void __flush_dcache_page(unsigned long phys)
+{
+	unsigned long ways, waysize, addrstart;
+	unsigned long flags;
+
+	phys |= SH_CACHE_VALID;
+
+	/*
+	 * Here, phys is the physical address of the page. We check all the
+	 * tags in the cache for those with the same page number as this page
+	 * (by masking off the lowest 2 bits of the 19-bit tag; these bits are
+	 * derived from the offset within in the 4k page). Matching valid
+	 * entries are invalidated.
+	 *
+	 * Since 2 bits of the cache index are derived from the virtual page
+	 * number, knowing this would reduce the number of cache entries to be
+	 * searched by a factor of 4. However this function exists to deal with
+	 * potential cache aliasing, therefore the optimisation is probably not
+	 * possible.
+	 */
+	local_irq_save(flags);
+	jump_to_uncached();
+
+	ways = current_cpu_data.dcache.ways;
+	waysize = current_cpu_data.dcache.sets;
+	waysize <<= current_cpu_data.dcache.entry_shift;
+
+	addrstart = CACHE_OC_ADDRESS_ARRAY;
+
+	do {
+		unsigned long addr;
+
+		for (addr = addrstart;
+		     addr < addrstart + waysize;
+		     addr += current_cpu_data.dcache.linesz) {
+			unsigned long data;
+
+			data = __raw_readl(addr) & (0x1ffffC00 | SH_CACHE_VALID);
+		        if (data == phys) {
+				data &= ~(SH_CACHE_VALID | SH_CACHE_UPDATED);
+				__raw_writel(data, addr);
+			}
+		}
+
+		addrstart += current_cpu_data.dcache.way_incr;
+	} while (--ways);
+
+	back_to_cached();
+	local_irq_restore(flags);
+}
+
+/*
+ * Write back & invalidate the D-cache of the page.
+ * (To avoid "alias" issues)
+ */
+static void sh7705_flush_dcache_page(void *arg)
+{
+	struct page *page = arg;
+	struct address_space *mapping = page_mapping(page);
+
+	if (mapping && !mapping_mapped(mapping))
+		clear_bit(PG_dcache_clean, &page->flags);
+	else
+		__flush_dcache_page(__pa(page_address(page)));
+}
+
+static void sh7705_flush_cache_all(void *args)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	jump_to_uncached();
+
+	cache_wback_all();
+	back_to_cached();
+	local_irq_restore(flags);
+}
+
+/*
+ * Write back and invalidate I/D-caches for the page.
+ *
+ * ADDRESS: Virtual Address (U0 address)
+ */
+static void sh7705_flush_cache_page(void *args)
+{
+	struct flusher_data *data = args;
+	unsigned long pfn = data->addr2;
+
+	__flush_dcache_page(pfn << PAGE_SHIFT);
+}
+
+/*
+ * This is called when a page-cache page is about to be mapped into a
+ * user process' address space.  It offers an opportunity for a
+ * port to ensure d-cache/i-cache coherency if necessary.
+ *
+ * Not entirely sure why this is necessary on SH3 with 32K cache but
+ * without it we get occasional "Memory fault" when loading a program.
+ */
+static void sh7705_flush_icache_page(void *page)
+{
+	__flush_purge_region(page_address(page), PAGE_SIZE);
+}
+
+void __init sh7705_cache_init(void)
+{
+	local_flush_icache_range	= sh7705_flush_icache_range;
+	local_flush_dcache_page		= sh7705_flush_dcache_page;
+	local_flush_cache_all		= sh7705_flush_cache_all;
+	local_flush_cache_mm		= sh7705_flush_cache_all;
+	local_flush_cache_dup_mm	= sh7705_flush_cache_all;
+	local_flush_cache_range		= sh7705_flush_cache_all;
+	local_flush_cache_page		= sh7705_flush_cache_page;
+	local_flush_icache_page		= sh7705_flush_icache_page;
+}