cache-2dmanager: initial work.

Change-Id: Ia2bba7045988e837072970fcf8507fed60679756
Signed-off-by: Jack Yen <jyen@ti.com>

3 files changed, 212 insertions, 0 deletions

diff --git a/drivers/misc/cache-2dmanager/Kconfig b/drivers/misc/cache-2dmanager/Kconfig
new file mode 100644
index 00000000000..4b74fdeb24f
--- /dev/null
+++ b/drivers/misc/cache-2dmanager/Kconfig
@@ -0,0 +1,5 @@
+config CACHE2DMANAGER
+	tristate "2D Cache operation driver"
+	default y
+	help
+           Enable 2D Cache operation support
diff --git a/drivers/misc/cache-2dmanager/Makefile b/drivers/misc/cache-2dmanager/Makefile
new file mode 100644
index 00000000000..c112df1449a
--- /dev/null
+++ b/drivers/misc/cache-2dmanager/Makefile
@@ -0,0 +1,4 @@
+obj-$(CONFIG_CACHE2DMANAGER) += cache2d.o
+
+cache2d-y := \
+	cache-2dmanager.o \
diff --git a/drivers/misc/cache-2dmanager/cache-2dmanager.c b/drivers/misc/cache-2dmanager/cache-2dmanager.c
new file mode 100644
index 00000000000..0e55d28a15b
--- /dev/null
+++ b/drivers/misc/cache-2dmanager/cache-2dmanager.c
@@ -0,0 +1,203 @@
+/*
+ * cache-2dmanager.c
+ *
+ * Copyright (C) 2011-2012 Texas Instruments Corporation.
+ *
+ * This package is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include <linux/cache-2dmanager.h>
+
+static void per_cpu_cache_flush_arm(void *arg)
+{
+	flush_cache_all();
+}
+
+void c2dm_l1cache(int count,		/* number of regions */
+		struct c2dmrgn rgns[],	/* array of regions */
+		int dir)		/* cache operation */
+{
+	unsigned long size = 0;
+	int rgn;
+	for (rgn = 0; rgn < count; rgn++)
+		size += rgns[rgn].span * rgns[rgn].lines;
+
+	/* If the total size of the caller's request exceeds the threshold,
+	 * we can perform the operation on the entire cache instead.
+	 *
+	 * If the caller requests a clean larger than the threshold, we want
+	 * to clean all.  But this function does not exist in the L1 cache
+	 * routines. So we use flush all.
+	 *
+	 * If the caller requests an invalidate larger than the threshold, we
+	 * want to invalidate all. However, if the client does not fill the
+	 * cache, an invalidate all will lose data from other processes, which
+	 * can be catastrophic.  So we must clean the entire cache before we
+	 * invalidate it. Flush all cleans and invalidates in one operation.
+	 */
+	if (size >= L1THRESHOLD) {
+		switch (dir) {
+		case DMA_TO_DEVICE:
+			/* Use clean all when available */
+			/* Fall through for now */
+		case DMA_BIDIRECTIONAL:
+			/* Can't invalidate all without cleaning, so fall
+			 * through to flush all to do both. */
+		case DMA_FROM_DEVICE:
+			on_each_cpu(per_cpu_cache_flush_arm, NULL, 1);
+			break;
+		}
+	} else {
+		int rgn;
+		for (rgn = 0; rgn < count; rgn++) {
+			int line;
+			char *start = rgns[rgn].start;
+			for (line = 0; line < rgns[rgn].lines; line++) {
+				if (dir == DMA_BIDIRECTIONAL)
+					cpu_cache.dma_flush_range(
+						start,
+						start + rgns[rgn].span);
+				else
+					cpu_cache.dma_map_area(
+						start,
+						rgns[rgn].span,
+						dir);
+				start += rgns[rgn].stride;
+			}
+		}
+	}
+}
+EXPORT_SYMBOL(c2dm_l1cache);
+
+static u32 virt2phys(u32 usr)
+{
+	pmd_t *pmd;
+	pte_t *ptep;
+	pgd_t *pgd = pgd_offset(current->mm, usr);
+
+	if (pgd_none(*pgd) || pgd_bad(*pgd))
+		return 0;
+
+	pmd = pmd_offset(pgd, usr);
+	if (pmd_none(*pmd) || pmd_bad(*pmd))
+		return 0;
+
+	ptep = pte_offset_map(pmd, usr);
+	if (ptep && pte_present(*ptep))
+		return (*ptep & PAGE_MASK) | (~PAGE_MASK & usr);
+
+	return 0;
+}
+
+void c2dm_l2cache(int count,		/* number of regions */
+		struct c2dmrgn rgns[],	/* array of regions */
+		int dir)		/* cache operation */
+{
+
+	unsigned long size = 0;
+	int rgn;
+
+	for (rgn = 0; rgn < count; rgn++)
+		size += rgns[rgn].span * rgns[rgn].lines;
+
+	if (size >= L2THRESHOLD) {
+		switch (dir) {
+		case DMA_TO_DEVICE:
+			/* Use clean all when available */
+			/* Fall through for now */
+		case DMA_BIDIRECTIONAL:
+			/* Can't invalidate all without cleaning, so fall
+			 * through to flush all to do both. */
+		case DMA_FROM_DEVICE:
+			outer_flush_all();
+			break;
+		}
+	} else {
+		int rgn;
+		for (rgn = 0; rgn < count; rgn++) {
+
+			int i, j;
+			unsigned long linestart, start;
+			unsigned long page_begin, end, offset,
+				pageremain, lineremain;
+			unsigned long phys, opsize;
+			int page_num;
+
+			/* beginning virtual address of each line */
+			start = (unsigned long)rgns[rgn].start;
+
+			for (i = 0; i < rgns[rgn].lines; i++) {
+
+				linestart = start + (i * rgns[rgn].stride);
+
+				/* beginning of the page for the new line */
+				page_begin = linestart & PAGE_MASK;
+
+				/* end of the new line */
+				end = (unsigned long)linestart +
+						rgns[rgn].span;
+
+				page_num = DIV_ROUND_UP(end-page_begin,
+						PAGE_SIZE);
+
+				/* offset of the new line from page begin */
+				offset = linestart - page_begin;
+
+				/* track how long it is to the end of
+				   the current page */
+				pageremain = PAGE_SIZE - offset;
+
+				/* keep track of how much of the line remains
+				   to be copied */
+				lineremain = rgns[rgn].span;
+
+				for (j = 0; j < page_num; j++) {
+
+					opsize = (lineremain < pageremain) ?
+						lineremain : pageremain;
+
+					phys = virt2phys(page_begin);
+					phys = phys + offset;
+					switch (dir) {
+					case DMA_TO_DEVICE:
+						outer_clean_range(phys,
+							phys + opsize);
+						break;
+					case DMA_FROM_DEVICE:
+						outer_inv_range(phys,
+							phys + opsize);
+						break;
+					case DMA_BIDIRECTIONAL:
+						outer_flush_range(phys,
+							phys + opsize);
+						break;
+					}
+
+					lineremain -= opsize;
+					/* Move to next page */
+					page_begin += PAGE_SIZE;
+
+					/* After first page, start address
+					 * will be page aligned so offset
+					 * is 0 */
+					offset = 0;
+
+					if (!lineremain)
+						break;
+
+					pageremain -= opsize;
+					if (!pageremain)
+						pageremain = PAGE_SIZE;
+
+				}
+			}
+		}
+	}
+}
+EXPORT_SYMBOL(c2dm_l2cache);