--- /dev/null
+/*
+ * 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);
projects / linux-drm-fsl-dcu.git / blobdiff