1 files changed, 246 insertions, 0 deletions
diff --git a/arch/arm/kernel/tcm.c b/arch/arm/kernel/tcm.c
new file mode 100644
index 00000000000..e50303868f1
--- /dev/null
+++ b/arch/arm/kernel/tcm.c
@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) 2008-2009 ST-Ericsson AB
+ * License terms: GNU General Public License (GPL) version 2
+ * TCM memory handling for ARM systems
+ *
+ * Author: Linus Walleij <linus.walleij@stericsson.com>
+ * Author: Rickard Andersson <rickard.andersson@stericsson.com>
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/ioport.h>
+#include <linux/genalloc.h>
+#include <linux/string.h> /* memcpy */
+#include <asm/page.h> /* PAGE_SHIFT */
+#include <asm/cputype.h>
+#include <asm/mach/map.h>
+#include <mach/memory.h>
+#include "tcm.h"
+
+/* Scream and warn about misuse */
+#if !defined(ITCM_OFFSET) || !defined(ITCM_END) || \
+    !defined(DTCM_OFFSET) || !defined(DTCM_END)
+#error "TCM support selected but offsets not defined!"
+#endif
+
+static struct gen_pool *tcm_pool;
+
+/* TCM section definitions from the linker */
+extern char __itcm_start, __sitcm_text, __eitcm_text;
+extern char __dtcm_start, __sdtcm_data, __edtcm_data;
+
+/*
+ * TCM memory resources
+ */
+static struct resource dtcm_res = {
+	.name = "DTCM RAM",
+	.start = DTCM_OFFSET,
+	.end = DTCM_END,
+	.flags = IORESOURCE_MEM
+};
+
+static struct resource itcm_res = {
+	.name = "ITCM RAM",
+	.start = ITCM_OFFSET,
+	.end = ITCM_END,
+	.flags = IORESOURCE_MEM
+};
+
+static struct map_desc dtcm_iomap[] __initdata = {
+	{
+		.virtual	= DTCM_OFFSET,
+		.pfn		= __phys_to_pfn(DTCM_OFFSET),
+		.length		= (DTCM_END - DTCM_OFFSET + 1),
+		.type		= MT_UNCACHED
+	}
+};
+
+static struct map_desc itcm_iomap[] __initdata = {
+	{
+		.virtual	= ITCM_OFFSET,
+		.pfn		= __phys_to_pfn(ITCM_OFFSET),
+		.length		= (ITCM_END - ITCM_OFFSET + 1),
+		.type		= MT_UNCACHED
+	}
+};
+
+/*
+ * Allocate a chunk of TCM memory
+ */
+void *tcm_alloc(size_t len)
+{
+	unsigned long vaddr;
+
+	if (!tcm_pool)
+		return NULL;
+
+	vaddr = gen_pool_alloc(tcm_pool, len);
+	if (!vaddr)
+		return NULL;
+
+	return (void *) vaddr;
+}
+EXPORT_SYMBOL(tcm_alloc);
+
+/*
+ * Free a chunk of TCM memory
+ */
+void tcm_free(void *addr, size_t len)
+{
+	gen_pool_free(tcm_pool, (unsigned long) addr, len);
+}
+EXPORT_SYMBOL(tcm_free);
+
+
+static void __init setup_tcm_bank(u8 type, u32 offset, u32 expected_size)
+{
+	const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
+				    256, 512, 1024, -1, -1, -1, -1 };
+	u32 tcm_region;
+	int tcm_size;
+
+	/* Read the special TCM region register c9, 0 */
+	if (!type)
+		asm("mrc	p15, 0, %0, c9, c1, 0"
+		    : "=r" (tcm_region));
+	else
+		asm("mrc	p15, 0, %0, c9, c1, 1"
+		    : "=r" (tcm_region));
+
+	tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
+	if (tcm_size < 0) {
+		pr_err("CPU: %sTCM of unknown size!\n",
+			type ? "I" : "D");
+	} else {
+		pr_info("CPU: found %sTCM %dk @ %08x, %senabled\n",
+			type ? "I" : "D",
+			tcm_size,
+			(tcm_region & 0xfffff000U),
+			(tcm_region & 1) ? "" : "not ");
+	}
+
+	if (tcm_size != expected_size) {
+		pr_crit("CPU: %sTCM was detected %dk but expected %dk!\n",
+		       type ? "I" : "D",
+		       tcm_size,
+		       expected_size);
+		/* Adjust to the expected size? what can we do... */
+	}
+
+	/* Force move the TCM bank to where we want it, enable */
+	tcm_region = offset | (tcm_region & 0x00000ffeU) | 1;
+
+	if (!type)
+		asm("mcr	p15, 0, %0, c9, c1, 0"
+		    : /* No output operands */
+		    : "r" (tcm_region));
+	else
+		asm("mcr	p15, 0, %0, c9, c1, 1"
+		    : /* No output operands */
+		    : "r" (tcm_region));
+
+	pr_debug("CPU: moved %sTCM %dk to %08x, enabled\n",
+		 type ? "I" : "D",
+		 tcm_size,
+		 (tcm_region & 0xfffff000U));
+}
+
+/*
+ * This initializes the TCM memory
+ */
+void __init tcm_init(void)
+{
+	u32 tcm_status = read_cpuid_tcmstatus();
+	char *start;
+	char *end;
+	char *ram;
+
+	/* Setup DTCM if present */
+	if (tcm_status & (1 << 16)) {
+		setup_tcm_bank(0, DTCM_OFFSET,
+			       (DTCM_END - DTCM_OFFSET + 1) >> 10);
+		request_resource(&iomem_resource, &dtcm_res);
+		iotable_init(dtcm_iomap, 1);
+		/* Copy data from RAM to DTCM */
+		start = &__sdtcm_data;
+		end   = &__edtcm_data;
+		ram   = &__dtcm_start;
+		memcpy(start, ram, (end-start));
+		pr_debug("CPU DTCM: copied data from %p - %p\n", start, end);
+	}
+
+	/* Setup ITCM if present */
+	if (tcm_status & 1) {
+		setup_tcm_bank(1, ITCM_OFFSET,
+			       (ITCM_END - ITCM_OFFSET + 1) >> 10);
+		request_resource(&iomem_resource, &itcm_res);
+		iotable_init(itcm_iomap, 1);
+		/* Copy code from RAM to ITCM */
+		start = &__sitcm_text;
+		end   = &__eitcm_text;
+		ram   = &__itcm_start;
+		memcpy(start, ram, (end-start));
+		pr_debug("CPU ITCM: copied code from %p - %p\n", start, end);
+	}
+}
+
+/*
+ * This creates the TCM memory pool and has to be done later,
+ * during the core_initicalls, since the allocator is not yet
+ * up and running when the first initialization runs.
+ */
+static int __init setup_tcm_pool(void)
+{
+	u32 tcm_status = read_cpuid_tcmstatus();
+	u32 dtcm_pool_start = (u32) &__edtcm_data;
+	u32 itcm_pool_start = (u32) &__eitcm_text;
+	int ret;
+
+	/*
+	 * Set up malloc pool, 2^2 = 4 bytes granularity since
+	 * the TCM is sometimes just 4 KiB. NB: pages and cache
+	 * line alignments does not matter in TCM!
+	 */
+	tcm_pool = gen_pool_create(2, -1);
+
+	pr_debug("Setting up TCM memory pool\n");
+
+	/* Add the rest of DTCM to the TCM pool */
+	if (tcm_status & (1 << 16)) {
+		if (dtcm_pool_start < DTCM_END) {
+			ret = gen_pool_add(tcm_pool, dtcm_pool_start,
+					   DTCM_END - dtcm_pool_start + 1, -1);
+			if (ret) {
+				pr_err("CPU DTCM: could not add DTCM " \
+				       "remainder to pool!\n");
+				return ret;
+			}
+			pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
+				 "the TCM memory pool\n",
+				 DTCM_END - dtcm_pool_start + 1,
+				 dtcm_pool_start);
+		}
+	}
+
+	/* Add the rest of ITCM to the TCM pool */
+	if (tcm_status & 1) {
+		if (itcm_pool_start < ITCM_END) {
+			ret = gen_pool_add(tcm_pool, itcm_pool_start,
+					   ITCM_END - itcm_pool_start + 1, -1);
+			if (ret) {
+				pr_err("CPU ITCM: could not add ITCM " \
+				       "remainder to pool!\n");
+				return ret;
+			}
+			pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
+				 "the TCM memory pool\n",
+				 ITCM_END - itcm_pool_start + 1,
+				 itcm_pool_start);
+		}
+	}
+	return 0;
+}
+
+core_initcall(setup_tcm_pool);