summaryrefslogtreecommitdiff
path: root/arch/sh/mm/cache-sh7705.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/sh/mm/cache-sh7705.c
Initial import
Diffstat (limited to 'arch/sh/mm/cache-sh7705.c')
-rw-r--r--arch/sh/mm/cache-sh7705.c195
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;
+}