1 files changed, 129 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/sram.c b/arch/arm/plat-omap/sram.c
new file mode 100644
index 000000000..0f1eacad7
--- /dev/null
+++ b/arch/arm/plat-omap/sram.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/arch/arm/plat-omap/sram.c
+ *
+ * OMAP SRAM detection and management
+ *
+ * Copyright (C) 2005 Nokia Corporation
+ * Written by Tony Lindgren <tony@atomide.com>
+ *
+ * Copyright (C) 2009-2012 Texas Instruments
+ * Added OMAP4/5 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
+ */
+#undef DEBUG
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+#include <asm/fncpy.h>
+#include <asm/tlb.h>
+#include <asm/cacheflush.h>
+#include <asm/set_memory.h>
+
+#include <asm/mach/map.h>
+
+#include <plat/sram.h>
+
+#define ROUND_DOWN(value,boundary)	((value) & (~((boundary)-1)))
+
+static void __iomem *omap_sram_base;
+static unsigned long omap_sram_skip;
+static unsigned long omap_sram_size;
+static void __iomem *omap_sram_ceil;
+
+/*
+ * Memory allocator for SRAM: calculates the new ceiling address
+ * for pushing a function using the fncpy API.
+ *
+ * Note that fncpy requires the returned address to be aligned
+ * to an 8-byte boundary.
+ */
+static void *omap_sram_push_address(unsigned long size)
+{
+	unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
+
+	available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);
+
+	if (size > available) {
+		pr_err("Not enough space in SRAM\n");
+		return NULL;
+	}
+
+	new_ceil -= size;
+	new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
+	omap_sram_ceil = IOMEM(new_ceil);
+
+	return (void *)omap_sram_ceil;
+}
+
+void *omap_sram_push(void *funcp, unsigned long size)
+{
+	void *sram;
+	unsigned long base;
+	int pages;
+	void *dst = NULL;
+
+	sram = omap_sram_push_address(size);
+	if (!sram)
+		return NULL;
+
+	base = (unsigned long)sram & PAGE_MASK;
+	pages = PAGE_ALIGN(size) / PAGE_SIZE;
+
+	set_memory_rw(base, pages);
+
+	dst = fncpy(sram, funcp, size);
+
+	set_memory_ro(base, pages);
+	set_memory_x(base, pages);
+
+	return dst;
+}
+
+/*
+ * The SRAM context is lost during off-idle and stack
+ * needs to be reset.
+ */
+void omap_sram_reset(void)
+{
+	omap_sram_ceil = omap_sram_base + omap_sram_size;
+}
+
+/*
+ * Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
+ */
+void __init omap_map_sram(unsigned long start, unsigned long size,
+				 unsigned long skip, int cached)
+{
+	unsigned long base;
+	int pages;
+
+	if (size == 0)
+		return;
+
+	start = ROUND_DOWN(start, PAGE_SIZE);
+	omap_sram_size = size;
+	omap_sram_skip = skip;
+	omap_sram_base = __arm_ioremap_exec(start, size, cached);
+	if (!omap_sram_base) {
+		pr_err("SRAM: Could not map\n");
+		return;
+	}
+
+	omap_sram_reset();
+
+	/*
+	 * Looks like we need to preserve some bootloader code at the
+	 * beginning of SRAM for jumping to flash for reboot to work...
+	 */
+	memset_io(omap_sram_base + omap_sram_skip, 0,
+		  omap_sram_size - omap_sram_skip);
+
+	base = (unsigned long)omap_sram_base;
+	pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
+
+	set_memory_ro(base, pages);
+	set_memory_x(base, pages);
+}