/*
* 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);
