90b9222ec6
The Integrator AP/CP can have a varying set of core modules, some (like ARM920T) are so old that trying to read the TCM status register with CP15 will make them hang. So we need to make sure that we are running on v5 or later in order to be able to activate this for the Integrator. (The Integrator with CM926EJ-S has 32+32 kb of TCM memory.) Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
337 lines
8.1 KiB
C
337 lines
8.1 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 <asm/memory.h>
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#include "tcm.h"
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static struct gen_pool *tcm_pool;
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static bool dtcm_present;
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static bool itcm_present;
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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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bool tcm_dtcm_present(void)
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{
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return dtcm_present;
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}
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EXPORT_SYMBOL(tcm_dtcm_present);
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bool tcm_itcm_present(void)
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{
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return itcm_present;
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}
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EXPORT_SYMBOL(tcm_itcm_present);
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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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/* Not much fun you can do with a size 0 bank */
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if (tcm_size == 0)
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return 0;
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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;
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u8 dtcm_banks;
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u8 itcm_banks;
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size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data;
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size_t itcm_code_sz = &__eitcm_text - &__sitcm_text;
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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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/*
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* Prior to ARMv5 there is no TCM, and trying to read the status
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* register will hang the processor.
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*/
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if (cpu_architecture() < CPU_ARCH_ARMv5) {
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if (dtcm_code_sz || itcm_code_sz)
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pr_info("CPU TCM: %u bytes of DTCM and %u bytes of "
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"ITCM code compiled in, but no TCM present "
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"in pre-v5 CPU\n", dtcm_code_sz, itcm_code_sz);
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return;
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}
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tcm_status = read_cpuid_tcmstatus();
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dtcm_banks = (tcm_status >> 16) & 0x03;
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itcm_banks = (tcm_status & 0x03);
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/* Values greater than 2 for D/ITCM banks are "reserved" */
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if (dtcm_banks > 2)
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dtcm_banks = 0;
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if (itcm_banks > 2)
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itcm_banks = 0;
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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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/* This means you compiled more code than fits into DTCM */
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if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) {
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pr_info("CPU DTCM: %u bytes of code compiled to "
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"DTCM but only %lu bytes of DTCM present\n",
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dtcm_code_sz, (dtcm_end - DTCM_OFFSET));
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goto no_dtcm;
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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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memcpy(start, ram, dtcm_code_sz);
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pr_debug("CPU DTCM: copied data from %p - %p\n",
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start, end);
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dtcm_present = true;
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} else if (dtcm_code_sz) {
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pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
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"DTCM banks present in CPU\n", dtcm_code_sz);
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}
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no_dtcm:
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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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/* This means you compiled more code than fits into ITCM */
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if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) {
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pr_info("CPU ITCM: %u bytes of code compiled to "
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"ITCM but only %lu bytes of ITCM present\n",
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itcm_code_sz, (itcm_end - ITCM_OFFSET));
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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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memcpy(start, ram, itcm_code_sz);
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pr_debug("CPU ITCM: copied code from %p - %p\n",
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start, end);
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itcm_present = true;
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} else if (itcm_code_sz) {
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pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
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"ITCM banks present in CPU\n", itcm_code_sz);
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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 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 (dtcm_present) {
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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 (itcm_present) {
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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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