/*
* Instruction SRAM accessor functions for the Blackfin
*
* Copyright 2008 Analog Devices Inc.
*
* Licensed under the GPL-2 or later
*/
#define pr_fmt(fmt) "isram: " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <asm/blackfin.h>
#include <asm/dma.h>
/*
* IMPORTANT WARNING ABOUT THESE FUNCTIONS
*
* The emulator will not function correctly if a write command is left in
* ITEST_COMMAND or DTEST_COMMAND AND access to cache memory is needed by
* the emulator. To avoid such problems, ensure that both ITEST_COMMAND
* and DTEST_COMMAND are zero when exiting these functions.
*/
/*
* On the Blackfin, L1 instruction sram (which operates at core speeds) can not
* be accessed by a normal core load, so we need to go through a few hoops to
* read/write it.
* To try to make it easier - we export a memcpy interface, where either src or
* dest can be in this special L1 memory area.
* The low level read/write functions should not be exposed to the rest of the
* kernel, since they operate on 64-bit data, and need specific address alignment
*/
static DEFINE_SPINLOCK(dtest_lock);
/* Takes a void pointer */
#define IADDR2DTEST(x) \
({ unsigned long __addr = (unsigned long)(x); \
((__addr & (1 << 11)) << (26 - 11)) | /* addr bit 11 (Way0/Way1) */ \
(1 << 24) | /* instruction access = 1 */ \
((__addr & (1 << 15)) << (23 - 15)) | /* addr bit 15 (Data Bank) */ \
((__addr & (3 << 12)) << (16 - 12)) | /* addr bits 13:12 (Subbank) */ \
(__addr & 0x47F8) | /* addr bits 14 & 10:3 */ \
(1 << 2); /* data array = 1 */ \
})
/* Takes a pointer, and returns the offset (in bits) which things should be shifted */
#define ADDR2OFFSET(x) ((((unsigned long)(x)) & 0x7) * 8)
/* Takes a pointer, determines if it is the last byte in the isram 64-bit data type */
#define ADDR2LAST(x) ((((unsigned long)x) & 0x7) == 0x7)
static void isram_write(const void *addr, uint64_t data)
{
uint32_t cmd;
unsigned long flags;
if (unlikely(addr >= (void *)(L1_CODE_START + L1_CODE_LENGTH)))
return;
cmd = IADDR2DTEST(addr) | 2; /* write */
/*
* Writes to DTEST_DATA[0:1] need to be atomic with write to DTEST_COMMAND
* While in exception context - atomicity is guaranteed or double fault
*/
spin_lock_irqsave(&dtest_lock, flags);
bfin_write_DTEST_DATA0(data & 0xFFFFFFFF);
bfin_write_DTEST_DATA1(data >> 32);
/* use the builtin, since interrupts are already turned off */
__builtin_bfin_csync();
bfin_write_DTEST_COMMAND(cmd);
__builtin_bfin_csync();
bfin_write_DTEST_COMMAND(0);
__builtin_bfin_csync();
spin_unlock_irqrestore(&dtest_lock, flags);
}
static uint64_t isram_read(const void *addr)
{
uint32_t cmd;
unsigned long flags;
uint64_t ret;
if (unlikely(addr > (void *)(L1_CODE_START + L1_CODE_LENGTH)))
return 0;
cmd = IADDR2DTEST(addr) | 0; /* read */
/*
* Reads of DTEST_DATA[0:1] need to be atomic with write to DTEST_COMMAND
* While in exception context - atomicity is guaranteed or double fault
*/
spin_lock_irqsave(&dtest_lock, flags);
/* use the builtin, since interrupts are already turned off */
__builtin_bfin_csync();
bfin_write_DTEST_COMMAND(cmd);
__builtin_bfin_csync();
ret = bfin_read_DTEST_DATA0() | ((uint64_t)bfin_read_DTEST_DATA1() << 32);
bfin_write_DTEST_COMMAND(0);
__builtin_bfin_csync();
spin_unlock_irqrestore(&dtest_lock, flags);
return ret;
}
static bool isram_check_addr(const void *addr, size_t n)
{
if ((addr >= (void *)L1_CODE_START) &&
(addr < (void *)(L1_CODE_START + L1_CODE_LENGTH))) {
if (unlikely((addr + n) > (void *)(L1_CODE_START + L1_CODE_LENGTH))) {
show_stack(NULL, NULL);
pr_err("copy involving %p length (%zu) too long\n", addr, n);
}
return true;
}
return false;
}
/*
* The isram_memcpy() function copies n bytes from memory area src to memory area dest.
* The isram_memcpy() function returns a pointer to dest.
* Either dest or src can be in L1 instruction sram.
*/
void *isram_memcpy(void *dest, const void *src, size_t n)
{
uint64_t data_in = 0, data_out = 0;
size_t count;
bool dest_in_l1, src_in_l1, need_data, put_data;
unsigned char byte, *src_byte, *dest_byte;
src_byte = (unsigned char *)src;
dest_byte = (unsigned char *)dest;
dest_in_l1 = isram_check_addr(dest, n);
src_in_l1 = isram_check_addr(src, n);
need_data = true;
put_data = true;
for (count = 0; count < n; count++) {
if (src_in_l1) {
if (need_data) {
data_in = isram_read(src + count);
need_data = false;
}
if (ADDR2LAST(src + count))
need_data = true;
byte = (unsigned char)((data_in >> ADDR2OFFSET(src + count)) & 0xff);
} else {
/* src is in L2 or L3 - so just dereference*/
byte = src_byte[count];
}
if (dest_in_l1) {
if (put_data) {
data_out = isram_read(dest + count);
put_data = false;
}
data_out &= ~((uint64_t)0xff << ADDR2OFFSET(dest + count));
data_out |= ((uint64_t)byte << ADDR2OFFSET(dest + count));
if (ADDR2LAST(dest + count)) {
put_data = true;
isram_write(dest + count, data_out);
}
} else {
/* dest in L2 or L3 - so just dereference */
dest_byte[count] = byte;
}
}
/* make sure we dump the last byte if necessary */
if (dest_in_l1 && !put_data)
isram_write(dest + count, data_out);
return dest;
}
EXPORT_SYMBOL(isram_memcpy);
#ifdef CONFIG_BFIN_ISRAM_SELF_TEST
static int test_len = 0x20000;
static __init void hex_dump(unsigned char *buf, int len)
{
while (len--)
pr_cont("%02x", *buf++);
}
static __init int isram_read_test(char *sdram, void *l1inst)
{
int i, ret = 0;
uint64_t data1, data2;
pr_info("INFO: running isram_read tests\n");
/* setup some different data to play with */
for (i = 0; i < test_len; ++i)
sdram[i] = i % 255;
dma_memcpy(l1inst, sdram, test_len);
/* make sure we can read the L1 inst */
for (i = 0; i < test_len; i += sizeof(uint64_t)) {
data1 = isram_read(l1inst + i);
memcpy(&data2, sdram + i, sizeof(data2));
if (data1 != data2) {
pr_err("FAIL: isram_read(%p) returned %#llx but wanted %#llx\n",
l1inst + i, data1, data2);
++ret;
}
}
return ret;
}
static __init int isram_write_test(char *sdram, void *l1inst)
{
int i, ret = 0;
uint64_t data1, data2;
pr_info("INFO: running isram_write tests\n");
/* setup some different data to play with */
memset(sdram, 0, test_len * 2);
dma_memcpy(l1inst, sdram, test_len);
for (i = 0; i < test_len; ++i)
sdram[i] = i % 255;
/* make sure we can write the L1 inst */
for (i = 0; i < test_len; i += sizeof(uint64_t)) {
memcpy(&data1, sdram + i, sizeof(data1));
isram_write(l1inst + i, data1);
data2 = isram_read(l1inst + i);
if (data1 != data2) {
pr_err("FAIL: isram_write(%p, %#llx) != %#llx\n",
l1inst + i, data1, data2);
++ret;
}
}
dma_memcpy(sdram + test_len, l1inst, test_len);
if (memcmp(sdram, sdram + test_len, test_len)) {
pr_err("FAIL: isram_write() did not work properly\n");
++ret;
}
return ret;
}
static __init int
_isram_memcpy_test(char pattern, void *sdram, void *l1inst, const char *smemcpy,
void *(*fmemcpy)(void *, const void *, size_t))
{
memset(sdram, pattern, test_len);
fmemcpy(l1inst, sdram, test_len);
fmemcpy(sdram + test_len, l1inst, test_len);
if (memcmp(sdram, sdram + test_len, test_len)) {
pr_err("FAIL: %s(%p <=> %p, %#x) failed (data is %#x)\n",
smemcpy, l1inst, sdram, test_len, pattern);
return 1;
}
return 0;
}
#define _isram_memcpy_test(a, b, c, d) _isram_memcpy_test(a, b, c, #d, d)
static __init int isram_memcpy_test(char *sdram, void *l1inst)
{
int i, j, thisret, ret = 0;
/* check broad isram_memcpy() */
pr_info("INFO: running broad isram_memcpy tests\n");
for (i = 0xf; i >= 0; --i)
ret += _isram_memcpy_test(i, sdram, l1inst, isram_memcpy);
/* check read of small, unaligned, and hardware 64bit limits */
pr_info("INFO: running isram_memcpy (read) tests\n");
/* setup some different data to play with */
for (i = 0; i < test_len; ++i)
sdram[i] = i % 255;
dma_memcpy(l1inst, sdram, test_len);
thisret = 0;
for (i = 0; i < test_len - 32; ++i) {
unsigned char cmp[32];
for (j = 1; j <= 32; ++j) {
memset(cmp, 0, sizeof(cmp));
isram_memcpy(cmp, l1inst + i, j);
if (memcmp(cmp, sdram + i, j)) {
pr_err("FAIL: %p:", l1inst + 1);
hex_dump(cmp, j);
pr_cont(" SDRAM:");
hex_dump(sdram + i, j);
pr_cont("\n");
if (++thisret > 20) {
pr_err("FAIL: skipping remaining series\n");
i = test_len;
break;
}
}
}
}
ret += thisret;
/* check write of small, unaligned, and hardware 64bit limits */
pr_info("INFO: running isram_memcpy (write) tests\n");
memset(sdram + test_len, 0, test_len);
dma_memcpy(l1inst, sdram + test_len, test_len);
thisret = 0;
for (i = 0; i < test_len - 32; ++i) {
unsigned char cmp[32];
for (j = 1; j <= 32; ++j) {
isram_memcpy(l1inst + i, sdram + i, j);
dma_memcpy(cmp, l1inst + i, j);
if (memcmp(cmp, sdram + i, j)) {
pr_err("FAIL: %p:", l1inst + i);
hex_dump(cmp, j);
pr_cont(" SDRAM:");
hex_dump(sdram + i, j);
pr_cont("\n");
if (++thisret > 20) {
pr_err("FAIL: skipping remaining series\n");
i = test_len;
break;
}
}
}
}
ret += thisret;
return ret;
}
static __init int isram_test_init(void)
{
int ret;
char *sdram;
void *l1inst;
/* Try to test as much of L1SRAM as possible */
while (test_len) {
test_len >>= 1;
l1inst = l1_inst_sram_alloc(test_len);
if (l1inst)
break;
}
if (!l1inst) {
pr_warning("SKIP: could not allocate L1 inst\n");
return 0;
}
pr_info("INFO: testing %#x bytes (%p - %p)\n",
test_len, l1inst, l1inst + test_len);
sdram = kmalloc(test_len * 2, GFP_KERNEL);
if (!sdram) {
sram_free(l1inst);
pr_warning("SKIP: could not allocate sdram\n");
return 0;
}
/* sanity check initial L1 inst state */
ret = 1;
pr_info("INFO: running initial dma_memcpy checks %p\n", sdram);
if (_isram_memcpy_test(0xa, sdram, l1inst, dma_memcpy))
goto abort;
if (_isram_memcpy_test(0x5, sdram, l1inst, dma_memcpy))
goto abort;
ret = 0;
ret += isram_read_test(sdram, l1inst);
ret += isram_write_test(sdram, l1inst);
ret += isram_memcpy_test(sdram, l1inst);
abort:
sram_free(l1inst);
kfree(sdram);
if (ret)
return -EIO;
pr_info("PASS: all tests worked !\n");
return 0;
}
late_initcall(isram_test_init);
static __exit void isram_test_exit(void)
{
/* stub to allow unloading */
}
module_exit(isram_test_exit);
#endif
