linux/arch/arm/kernel/tcm.c
Linus Walleij 598509779e ARM: 6223/1: support multiple TCM banks
CPUs v6 and up support multiple TCM banks, for example an ITCM of
8k is supplied in two 4k banks. This makes the TCM work on the
1176JZF-S devchip.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-18 20:29:48 +01:00

270 lines
6.6 KiB
C

/*
* 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 <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_MEMORY_DTCM
}
};
static struct map_desc itcm_iomap[] __initdata = {
{
.virtual = ITCM_OFFSET,
.pfn = __phys_to_pfn(ITCM_OFFSET),
.length = (ITCM_END - ITCM_OFFSET + 1),
.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);
static void __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
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;
/*
* 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);
} else {
pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
type ? "I" : "D",
bank,
tcm_size,
(tcm_region & 0xfffff000U),
(tcm_region & 1) ? "" : "not ");
}
if (tcm_size != (expected_size >> 10)) {
pr_crit("CPU: %sTCM%d was detected %dk but expected %dk!\n",
type ? "I" : "D",
bank,
tcm_size,
(expected_size >> 10));
/* 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_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
type ? "I" : "D",
bank,
tcm_size,
(tcm_region & 0xfffff000U));
}
/* We expect to find what is configured for the platform */
#define DTCM_EXPECTED (DTCM_END - DTCM_OFFSET + 1)
#define ITCM_EXPECTED (ITCM_END - ITCM_OFFSET + 1)
/*
* This initializes the TCM memory
*/
void __init tcm_init(void)
{
u32 tcm_status = read_cpuid_tcmstatus();
u8 dtcm_banks = (tcm_status >> 16) & 0x03;
u32 dtcm_banksize = DTCM_EXPECTED / dtcm_banks;
u8 itcm_banks = (tcm_status & 0x03);
u32 itcm_banksize = ITCM_EXPECTED / itcm_banks;
char *start;
char *end;
char *ram;
int i;
/* Setup DTCM if present */
for (i = 0; i < dtcm_banks; i++) {
setup_tcm_bank(0, i, dtcm_banks,
DTCM_OFFSET + (i * dtcm_banksize),
dtcm_banksize);
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 */
for (i = 0; i < itcm_banks; i++) {
setup_tcm_bank(1, i, itcm_banks,
ITCM_OFFSET + (i * itcm_banksize),
itcm_banksize);
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 & (0x03 << 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 & 0x03) {
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);