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 000000000000..e50303868f1b
--- /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);