Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/csky/mm/cachev1.c b/arch/csky/mm/cachev1.c
new file mode 100644
index 0000000..494ec91
--- /dev/null
+++ b/arch/csky/mm/cachev1.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/spinlock.h>
+#include <asm/cache.h>
+#include <abi/reg_ops.h>
+
+/* for L1-cache */
+#define INS_CACHE		(1 << 0)
+#define DATA_CACHE		(1 << 1)
+#define CACHE_INV		(1 << 4)
+#define CACHE_CLR		(1 << 5)
+#define CACHE_OMS		(1 << 6)
+#define CACHE_ITS		(1 << 7)
+#define CACHE_LICF		(1 << 31)
+
+/* for L2-cache */
+#define CR22_LEVEL_SHIFT	(1)
+#define CR22_SET_SHIFT		(7)
+#define CR22_WAY_SHIFT		(30)
+#define CR22_WAY_SHIFT_L2	(29)
+
+static DEFINE_SPINLOCK(cache_lock);
+
+static inline void cache_op_line(unsigned long i, unsigned int val)
+{
+	mtcr("cr22", i);
+	mtcr("cr17", val);
+}
+
+#define CCR2_L2E (1 << 3)
+static void cache_op_all(unsigned int value, unsigned int l2)
+{
+	mtcr("cr17", value | CACHE_CLR);
+	mb();
+
+	if (l2 && (mfcr_ccr2() & CCR2_L2E)) {
+		mtcr("cr24", value | CACHE_CLR);
+		mb();
+	}
+}
+
+static void cache_op_range(
+	unsigned int start,
+	unsigned int end,
+	unsigned int value,
+	unsigned int l2)
+{
+	unsigned long i, flags;
+	unsigned int val = value | CACHE_CLR | CACHE_OMS;
+	bool l2_sync;
+
+	if (unlikely((end - start) >= PAGE_SIZE) ||
+	    unlikely(start < PAGE_OFFSET) ||
+	    unlikely(start >= PAGE_OFFSET + LOWMEM_LIMIT)) {
+		cache_op_all(value, l2);
+		return;
+	}
+
+	if ((mfcr_ccr2() & CCR2_L2E) && l2)
+		l2_sync = 1;
+	else
+		l2_sync = 0;
+
+	spin_lock_irqsave(&cache_lock, flags);
+
+	i = start & ~(L1_CACHE_BYTES - 1);
+	for (; i < end; i += L1_CACHE_BYTES) {
+		cache_op_line(i, val);
+		if (l2_sync) {
+			mb();
+			mtcr("cr24", val);
+		}
+	}
+	spin_unlock_irqrestore(&cache_lock, flags);
+
+	mb();
+}
+
+void dcache_wb_line(unsigned long start)
+{
+	asm volatile("idly4\n":::"memory");
+	cache_op_line(start, DATA_CACHE|CACHE_CLR);
+	mb();
+}
+
+void icache_inv_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, INS_CACHE|CACHE_INV, 0);
+}
+
+void icache_inv_all(void)
+{
+	cache_op_all(INS_CACHE|CACHE_INV, 0);
+}
+
+void dcache_wb_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, DATA_CACHE|CACHE_CLR, 0);
+}
+
+void dcache_wbinv_all(void)
+{
+	cache_op_all(DATA_CACHE|CACHE_CLR|CACHE_INV, 0);
+}
+
+void cache_wbinv_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, INS_CACHE|DATA_CACHE|CACHE_CLR|CACHE_INV, 0);
+}
+EXPORT_SYMBOL(cache_wbinv_range);
+
+void cache_wbinv_all(void)
+{
+	cache_op_all(INS_CACHE|DATA_CACHE|CACHE_CLR|CACHE_INV, 0);
+}
+
+void dma_wbinv_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, DATA_CACHE|CACHE_CLR|CACHE_INV, 1);
+}
+
+void dma_inv_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, DATA_CACHE|CACHE_CLR|CACHE_INV, 1);
+}
+
+void dma_wb_range(unsigned long start, unsigned long end)
+{
+	cache_op_range(start, end, DATA_CACHE|CACHE_CLR|CACHE_INV, 1);
+}