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-rw-r--r--arch/arm/kernel/tcm.c337
1 files changed, 337 insertions, 0 deletions
diff --git a/arch/arm/kernel/tcm.c b/arch/arm/kernel/tcm.c
new file mode 100644
index 00000000..30ae6bb4
--- /dev/null
+++ b/arch/arm/kernel/tcm.c
@@ -0,0 +1,337 @@
+/*
+ * 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/cputype.h>
+#include <asm/mach/map.h>
+#include <asm/memory.h>
+#include <asm/system_info.h>
+#include "tcm.h"
+
+static struct gen_pool *tcm_pool;
+static bool dtcm_present;
+static bool itcm_present;
+
+/* TCM section definitions from the linker */
+extern char __itcm_start, __sitcm_text, __eitcm_text;
+extern char __dtcm_start, __sdtcm_data, __edtcm_data;
+
+/* These will be increased as we run */
+u32 dtcm_end = DTCM_OFFSET;
+u32 itcm_end = ITCM_OFFSET;
+
+/*
+ * TCM memory resources
+ */
+static struct resource dtcm_res = {
+ .name = "DTCM RAM",
+ .start = DTCM_OFFSET,
+ .end = DTCM_OFFSET,
+ .flags = IORESOURCE_MEM
+};
+
+static struct resource itcm_res = {
+ .name = "ITCM RAM",
+ .start = ITCM_OFFSET,
+ .end = ITCM_OFFSET,
+ .flags = IORESOURCE_MEM
+};
+
+static struct map_desc dtcm_iomap[] __initdata = {
+ {
+ .virtual = DTCM_OFFSET,
+ .pfn = __phys_to_pfn(DTCM_OFFSET),
+ .length = 0,
+ .type = MT_MEMORY_DTCM
+ }
+};
+
+static struct map_desc itcm_iomap[] __initdata = {
+ {
+ .virtual = ITCM_OFFSET,
+ .pfn = __phys_to_pfn(ITCM_OFFSET),
+ .length = 0,
+ .type = MT_MEMORY_ITCM
+ }
+};
+
+/*
+ * 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);
+
+bool tcm_dtcm_present(void)
+{
+ return dtcm_present;
+}
+EXPORT_SYMBOL(tcm_dtcm_present);
+
+bool tcm_itcm_present(void)
+{
+ return itcm_present;
+}
+EXPORT_SYMBOL(tcm_itcm_present);
+
+static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
+ u32 *offset)
+{
+ 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;
+
+ /*
+ * If there are more than one TCM bank of this type,
+ * select the TCM bank to operate on in the TCM selection
+ * register.
+ */
+ if (banks > 1)
+ asm("mcr p15, 0, %0, c9, c2, 0"
+ : /* No output operands */
+ : "r" (bank));
+
+ /* 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%d of unknown size\n",
+ type ? "I" : "D", bank);
+ return -EINVAL;
+ } else if (tcm_size > 32) {
+ pr_err("CPU: %sTCM%d larger than 32k found\n",
+ type ? "I" : "D", bank);
+ return -EINVAL;
+ } else {
+ pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
+ type ? "I" : "D",
+ bank,
+ tcm_size,
+ (tcm_region & 0xfffff000U),
+ (tcm_region & 1) ? "" : "not ");
+ }
+
+ /* Not much fun you can do with a size 0 bank */
+ if (tcm_size == 0)
+ return 0;
+
+ /* 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));
+
+ /* Increase offset */
+ *offset += (tcm_size << 10);
+
+ pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
+ type ? "I" : "D",
+ bank,
+ tcm_size,
+ (tcm_region & 0xfffff000U));
+ return 0;
+}
+
+/*
+ * This initializes the TCM memory
+ */
+void __init tcm_init(void)
+{
+ u32 tcm_status;
+ u8 dtcm_banks;
+ u8 itcm_banks;
+ size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data;
+ size_t itcm_code_sz = &__eitcm_text - &__sitcm_text;
+ char *start;
+ char *end;
+ char *ram;
+ int ret;
+ int i;
+
+ /*
+ * Prior to ARMv5 there is no TCM, and trying to read the status
+ * register will hang the processor.
+ */
+ if (cpu_architecture() < CPU_ARCH_ARMv5) {
+ if (dtcm_code_sz || itcm_code_sz)
+ pr_info("CPU TCM: %u bytes of DTCM and %u bytes of "
+ "ITCM code compiled in, but no TCM present "
+ "in pre-v5 CPU\n", dtcm_code_sz, itcm_code_sz);
+ return;
+ }
+
+ tcm_status = read_cpuid_tcmstatus();
+ dtcm_banks = (tcm_status >> 16) & 0x03;
+ itcm_banks = (tcm_status & 0x03);
+
+ /* Values greater than 2 for D/ITCM banks are "reserved" */
+ if (dtcm_banks > 2)
+ dtcm_banks = 0;
+ if (itcm_banks > 2)
+ itcm_banks = 0;
+
+ /* Setup DTCM if present */
+ if (dtcm_banks > 0) {
+ for (i = 0; i < dtcm_banks; i++) {
+ ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
+ if (ret)
+ return;
+ }
+ /* This means you compiled more code than fits into DTCM */
+ if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) {
+ pr_info("CPU DTCM: %u bytes of code compiled to "
+ "DTCM but only %lu bytes of DTCM present\n",
+ dtcm_code_sz, (dtcm_end - DTCM_OFFSET));
+ goto no_dtcm;
+ }
+ dtcm_res.end = dtcm_end - 1;
+ request_resource(&iomem_resource, &dtcm_res);
+ dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
+ iotable_init(dtcm_iomap, 1);
+ /* Copy data from RAM to DTCM */
+ start = &__sdtcm_data;
+ end = &__edtcm_data;
+ ram = &__dtcm_start;
+ memcpy(start, ram, dtcm_code_sz);
+ pr_debug("CPU DTCM: copied data from %p - %p\n",
+ start, end);
+ dtcm_present = true;
+ } else if (dtcm_code_sz) {
+ pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
+ "DTCM banks present in CPU\n", dtcm_code_sz);
+ }
+
+no_dtcm:
+ /* Setup ITCM if present */
+ if (itcm_banks > 0) {
+ for (i = 0; i < itcm_banks; i++) {
+ ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
+ if (ret)
+ return;
+ }
+ /* This means you compiled more code than fits into ITCM */
+ if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) {
+ pr_info("CPU ITCM: %u bytes of code compiled to "
+ "ITCM but only %lu bytes of ITCM present\n",
+ itcm_code_sz, (itcm_end - ITCM_OFFSET));
+ return;
+ }
+ itcm_res.end = itcm_end - 1;
+ request_resource(&iomem_resource, &itcm_res);
+ itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
+ iotable_init(itcm_iomap, 1);
+ /* Copy code from RAM to ITCM */
+ start = &__sitcm_text;
+ end = &__eitcm_text;
+ ram = &__itcm_start;
+ memcpy(start, ram, itcm_code_sz);
+ pr_debug("CPU ITCM: copied code from %p - %p\n",
+ start, end);
+ itcm_present = true;
+ } else if (itcm_code_sz) {
+ pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
+ "ITCM banks present in CPU\n", itcm_code_sz);
+ }
+}
+
+/*
+ * 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 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 (dtcm_present) {
+ if (dtcm_pool_start < dtcm_end) {
+ ret = gen_pool_add(tcm_pool, dtcm_pool_start,
+ dtcm_end - dtcm_pool_start, -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,
+ dtcm_pool_start);
+ }
+ }
+
+ /* Add the rest of ITCM to the TCM pool */
+ if (itcm_present) {
+ if (itcm_pool_start < itcm_end) {
+ ret = gen_pool_add(tcm_pool, itcm_pool_start,
+ itcm_end - itcm_pool_start, -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,
+ itcm_pool_start);
+ }
+ }
+ return 0;
+}
+
+core_initcall(setup_tcm_pool);
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