1dbd30e989
This changes the TCM handling so that a fixed area is reserved at 0xfffe0000-0xfffeffff for TCM. This areas is used by XScale but XScale does not have TCM so the mechanisms are mutually exclusive. This change is needed to make TCM detection more dynamic while still being able to compile code into it, and is a must for the unified ARM goals: the current TCM allocation at different places in memory for each machine would be a nightmare if you want to compile a single image for more than one machine with TCM so it has to be nailed down in one place. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
275 lines
6.5 KiB
C
275 lines
6.5 KiB
C
/*
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* Copyright (C) 2008-2009 ST-Ericsson AB
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* License terms: GNU General Public License (GPL) version 2
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* TCM memory handling for ARM systems
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*
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* Author: Linus Walleij <linus.walleij@stericsson.com>
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* Author: Rickard Andersson <rickard.andersson@stericsson.com>
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/stddef.h>
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#include <linux/ioport.h>
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#include <linux/genalloc.h>
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#include <linux/string.h> /* memcpy */
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#include <asm/cputype.h>
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#include <asm/mach/map.h>
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#include <mach/memory.h>
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#include "tcm.h"
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static struct gen_pool *tcm_pool;
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/* TCM section definitions from the linker */
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extern char __itcm_start, __sitcm_text, __eitcm_text;
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extern char __dtcm_start, __sdtcm_data, __edtcm_data;
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/* These will be increased as we run */
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u32 dtcm_end = DTCM_OFFSET;
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u32 itcm_end = ITCM_OFFSET;
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/*
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* TCM memory resources
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*/
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static struct resource dtcm_res = {
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.name = "DTCM RAM",
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.start = DTCM_OFFSET,
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.end = DTCM_OFFSET,
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.flags = IORESOURCE_MEM
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};
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static struct resource itcm_res = {
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.name = "ITCM RAM",
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.start = ITCM_OFFSET,
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.end = ITCM_OFFSET,
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.flags = IORESOURCE_MEM
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};
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static struct map_desc dtcm_iomap[] __initdata = {
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{
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.virtual = DTCM_OFFSET,
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.pfn = __phys_to_pfn(DTCM_OFFSET),
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.length = 0,
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.type = MT_MEMORY_DTCM
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}
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};
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static struct map_desc itcm_iomap[] __initdata = {
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{
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.virtual = ITCM_OFFSET,
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.pfn = __phys_to_pfn(ITCM_OFFSET),
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.length = 0,
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.type = MT_MEMORY_ITCM
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}
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};
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/*
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* Allocate a chunk of TCM memory
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*/
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void *tcm_alloc(size_t len)
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{
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unsigned long vaddr;
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if (!tcm_pool)
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return NULL;
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vaddr = gen_pool_alloc(tcm_pool, len);
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if (!vaddr)
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return NULL;
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return (void *) vaddr;
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}
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EXPORT_SYMBOL(tcm_alloc);
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/*
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* Free a chunk of TCM memory
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*/
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void tcm_free(void *addr, size_t len)
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{
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gen_pool_free(tcm_pool, (unsigned long) addr, len);
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}
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EXPORT_SYMBOL(tcm_free);
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static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
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u32 *offset)
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{
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const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
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256, 512, 1024, -1, -1, -1, -1 };
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u32 tcm_region;
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int tcm_size;
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/*
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* If there are more than one TCM bank of this type,
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* select the TCM bank to operate on in the TCM selection
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* register.
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*/
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if (banks > 1)
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asm("mcr p15, 0, %0, c9, c2, 0"
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: /* No output operands */
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: "r" (bank));
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/* Read the special TCM region register c9, 0 */
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if (!type)
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asm("mrc p15, 0, %0, c9, c1, 0"
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: "=r" (tcm_region));
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else
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asm("mrc p15, 0, %0, c9, c1, 1"
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: "=r" (tcm_region));
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tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
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if (tcm_size < 0) {
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pr_err("CPU: %sTCM%d of unknown size\n",
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type ? "I" : "D", bank);
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return -EINVAL;
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} else if (tcm_size > 32) {
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pr_err("CPU: %sTCM%d larger than 32k found\n",
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type ? "I" : "D", bank);
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return -EINVAL;
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} else {
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pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
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type ? "I" : "D",
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bank,
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tcm_size,
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(tcm_region & 0xfffff000U),
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(tcm_region & 1) ? "" : "not ");
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}
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/* Force move the TCM bank to where we want it, enable */
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tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1;
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if (!type)
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asm("mcr p15, 0, %0, c9, c1, 0"
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: /* No output operands */
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: "r" (tcm_region));
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else
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asm("mcr p15, 0, %0, c9, c1, 1"
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: /* No output operands */
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: "r" (tcm_region));
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/* Increase offset */
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*offset += (tcm_size << 10);
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pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
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type ? "I" : "D",
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bank,
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tcm_size,
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(tcm_region & 0xfffff000U));
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return 0;
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}
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/*
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* This initializes the TCM memory
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*/
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void __init tcm_init(void)
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{
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u32 tcm_status = read_cpuid_tcmstatus();
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u8 dtcm_banks = (tcm_status >> 16) & 0x03;
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u8 itcm_banks = (tcm_status & 0x03);
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char *start;
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char *end;
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char *ram;
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int ret;
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int i;
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/* Setup DTCM if present */
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if (dtcm_banks > 0) {
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for (i = 0; i < dtcm_banks; i++) {
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ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
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if (ret)
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return;
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}
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dtcm_res.end = dtcm_end - 1;
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request_resource(&iomem_resource, &dtcm_res);
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dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
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iotable_init(dtcm_iomap, 1);
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/* Copy data from RAM to DTCM */
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start = &__sdtcm_data;
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end = &__edtcm_data;
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ram = &__dtcm_start;
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/* This means you compiled more code than fits into DTCM */
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BUG_ON((end - start) > (dtcm_end - DTCM_OFFSET));
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memcpy(start, ram, (end-start));
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pr_debug("CPU DTCM: copied data from %p - %p\n", start, end);
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}
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/* Setup ITCM if present */
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if (itcm_banks > 0) {
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for (i = 0; i < itcm_banks; i++) {
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ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
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if (ret)
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return;
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}
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itcm_res.end = itcm_end - 1;
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request_resource(&iomem_resource, &itcm_res);
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itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
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iotable_init(itcm_iomap, 1);
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/* Copy code from RAM to ITCM */
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start = &__sitcm_text;
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end = &__eitcm_text;
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ram = &__itcm_start;
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/* This means you compiled more code than fits into ITCM */
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BUG_ON((end - start) > (itcm_end - ITCM_OFFSET));
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memcpy(start, ram, (end-start));
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pr_debug("CPU ITCM: copied code from %p - %p\n", start, end);
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}
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}
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/*
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* This creates the TCM memory pool and has to be done later,
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* during the core_initicalls, since the allocator is not yet
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* up and running when the first initialization runs.
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*/
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static int __init setup_tcm_pool(void)
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{
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u32 tcm_status = read_cpuid_tcmstatus();
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u32 dtcm_pool_start = (u32) &__edtcm_data;
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u32 itcm_pool_start = (u32) &__eitcm_text;
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int ret;
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/*
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* Set up malloc pool, 2^2 = 4 bytes granularity since
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* the TCM is sometimes just 4 KiB. NB: pages and cache
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* line alignments does not matter in TCM!
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*/
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tcm_pool = gen_pool_create(2, -1);
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pr_debug("Setting up TCM memory pool\n");
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/* Add the rest of DTCM to the TCM pool */
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if (tcm_status & (0x03 << 16)) {
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if (dtcm_pool_start < dtcm_end) {
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ret = gen_pool_add(tcm_pool, dtcm_pool_start,
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dtcm_end - dtcm_pool_start, -1);
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if (ret) {
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pr_err("CPU DTCM: could not add DTCM " \
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"remainder to pool!\n");
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return ret;
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}
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pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
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"the TCM memory pool\n",
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dtcm_end - dtcm_pool_start,
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dtcm_pool_start);
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}
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}
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/* Add the rest of ITCM to the TCM pool */
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if (tcm_status & 0x03) {
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if (itcm_pool_start < itcm_end) {
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ret = gen_pool_add(tcm_pool, itcm_pool_start,
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itcm_end - itcm_pool_start, -1);
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if (ret) {
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pr_err("CPU ITCM: could not add ITCM " \
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"remainder to pool!\n");
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return ret;
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}
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pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
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"the TCM memory pool\n",
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itcm_end - itcm_pool_start,
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itcm_pool_start);
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}
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}
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return 0;
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}
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core_initcall(setup_tcm_pool);
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