// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) IBM Corporation 2017
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/fsi.h>
#include <linux/fsi-sbefifo.h>
#include <linux/kernel.h>
#include <linux/cdev.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/uio.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <uapi/linux/fsi.h>
/*
* The SBEFIFO is a pipe-like FSI device for communicating with
* the self boot engine on POWER processors.
*/
#define DEVICE_NAME "sbefifo"
#define FSI_ENGID_SBE 0x22
/*
* Register layout
*/
/* Register banks */
#define SBEFIFO_UP 0x00 /* FSI -> Host */
#define SBEFIFO_DOWN 0x40 /* Host -> FSI */
/* Per-bank registers */
#define SBEFIFO_FIFO 0x00 /* The FIFO itself */
#define SBEFIFO_STS 0x04 /* Status register */
#define SBEFIFO_STS_PARITY_ERR 0x20000000
#define SBEFIFO_STS_RESET_REQ 0x02000000
#define SBEFIFO_STS_GOT_EOT 0x00800000
#define SBEFIFO_STS_MAX_XFER_LIMIT 0x00400000
#define SBEFIFO_STS_FULL 0x00200000
#define SBEFIFO_STS_EMPTY 0x00100000
#define SBEFIFO_STS_ECNT_MASK 0x000f0000
#define SBEFIFO_STS_ECNT_SHIFT 16
#define SBEFIFO_STS_VALID_MASK 0x0000ff00
#define SBEFIFO_STS_VALID_SHIFT 8
#define SBEFIFO_STS_EOT_MASK 0x000000ff
#define SBEFIFO_STS_EOT_SHIFT 0
#define SBEFIFO_EOT_RAISE 0x08 /* (Up only) Set End Of Transfer */
#define SBEFIFO_REQ_RESET 0x0C /* (Up only) Reset Request */
#define SBEFIFO_PERFORM_RESET 0x10 /* (Down only) Perform Reset */
#define SBEFIFO_EOT_ACK 0x14 /* (Down only) Acknowledge EOT */
#define SBEFIFO_DOWN_MAX 0x18 /* (Down only) Max transfer */
/* CFAM GP Mailbox SelfBoot Message register */
#define CFAM_GP_MBOX_SBM_ADDR 0x2824 /* Converted 0x2809 */
#define CFAM_SBM_SBE_BOOTED 0x80000000
#define CFAM_SBM_SBE_ASYNC_FFDC 0x40000000
#define CFAM_SBM_SBE_STATE_MASK 0x00f00000
#define CFAM_SBM_SBE_STATE_SHIFT 20
enum sbe_state
{
SBE_STATE_UNKNOWN = 0x0, // Unknown, initial state
SBE_STATE_IPLING = 0x1, // IPL'ing - autonomous mode (transient)
SBE_STATE_ISTEP = 0x2, // ISTEP - Running IPL by steps (transient)
SBE_STATE_MPIPL = 0x3, // MPIPL
SBE_STATE_RUNTIME = 0x4, // SBE Runtime
SBE_STATE_DMT = 0x5, // Dead Man Timer State (transient)
SBE_STATE_DUMP = 0x6, // Dumping
SBE_STATE_FAILURE = 0x7, // Internal SBE failure
SBE_STATE_QUIESCE = 0x8, // Final state - needs SBE reset to get out
};
/* FIFO depth */
#define SBEFIFO_FIFO_DEPTH 8
/* Helpers */
#define sbefifo_empty(sts) ((sts) & SBEFIFO_STS_EMPTY)
#define sbefifo_full(sts) ((sts) & SBEFIFO_STS_FULL)
#define sbefifo_parity_err(sts) ((sts) & SBEFIFO_STS_PARITY_ERR)
#define sbefifo_populated(sts) (((sts) & SBEFIFO_STS_ECNT_MASK) >> SBEFIFO_STS_ECNT_SHIFT)
#define sbefifo_vacant(sts) (SBEFIFO_FIFO_DEPTH - sbefifo_populated(sts))
#define sbefifo_eot_set(sts) (((sts) & SBEFIFO_STS_EOT_MASK) >> SBEFIFO_STS_EOT_SHIFT)
/* Reset request timeout in ms */
#define SBEFIFO_RESET_TIMEOUT 10000
/* Timeouts for commands in ms */
#define SBEFIFO_TIMEOUT_START_CMD 10000
#define SBEFIFO_TIMEOUT_IN_CMD 1000
#define SBEFIFO_TIMEOUT_START_RSP 10000
#define SBEFIFO_TIMEOUT_IN_RSP 1000
/* Other constants */
#define SBEFIFO_MAX_USER_CMD_LEN (0x100000 + PAGE_SIZE)
#define SBEFIFO_RESET_MAGIC 0x52534554 /* "RSET" */
struct sbefifo {
uint32_t magic;
#define SBEFIFO_MAGIC 0x53424546 /* "SBEF" */
struct fsi_device *fsi_dev;
struct device dev;
struct cdev cdev;
struct mutex lock;
bool broken;
bool dead;
bool async_ffdc;
bool timed_out;
u32 timeout_in_cmd_ms;
u32 timeout_start_rsp_ms;
};
struct sbefifo_user {
struct sbefifo *sbefifo;
struct mutex file_lock;
void *cmd_page;
void *pending_cmd;
size_t pending_len;
u32 cmd_timeout_ms;
u32 read_timeout_ms;
};
static DEFINE_MUTEX(sbefifo_ffdc_mutex);
static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct sbefifo *sbefifo = container_of(dev, struct sbefifo, dev);
return sysfs_emit(buf, "%d\n", sbefifo->timed_out ? 1 : 0);
}
static DEVICE_ATTR_RO(timeout);
static void __sbefifo_dump_ffdc(struct device *dev, const __be32 *ffdc,
size_t ffdc_sz, bool internal)
{
int pack = 0;
#define FFDC_LSIZE 60
static char ffdc_line[FFDC_LSIZE];
char *p = ffdc_line;
while (ffdc_sz) {
u32 w0, w1, w2, i;
if (ffdc_sz < 3) {
dev_err(dev, "SBE invalid FFDC package size %zd\n", ffdc_sz);
return;
}
w0 = be32_to_cpu(*(ffdc++));
w1 = be32_to_cpu(*(ffdc++));
w2 = be32_to_cpu(*(ffdc++));
ffdc_sz -= 3;
if ((w0 >> 16) != 0xFFDC) {
dev_err(dev, "SBE invalid FFDC package signature %08x %08x %08x\n",
w0, w1, w2);
break;
}
w0 &= 0xffff;
if (w0 > ffdc_sz) {
dev_err(dev, "SBE FFDC package len %d words but only %zd remaining\n",
w0, ffdc_sz);
w0 = ffdc_sz;
break;
}
if (internal) {
dev_warn(dev, "+---- SBE FFDC package %d for async err -----+\n",
pack++);
} else {
dev_warn(dev, "+---- SBE FFDC package %d for cmd %02x:%02x -----+\n",
pack++, (w1 >> 8) & 0xff, w1 & 0xff);
}
dev_warn(dev, "| Response code: %08x |\n", w2);
dev_warn(dev, "|-------------------------------------------|\n");
for (i = 0; i < w0; i++) {
if ((i & 3) == 0) {
p = ffdc_line;
p += sprintf(p, "| %04x:", i << 4);
}
p += sprintf(p, " %08x", be32_to_cpu(*(ffdc++)));
ffdc_sz--;
if ((i & 3) == 3 || i == (w0 - 1)) {
while ((i & 3) < 3) {
p += sprintf(p, " ");
i++;
}
dev_warn(dev, "%s |\n", ffdc_line);
}
}
dev_warn(dev, "+-------------------------------------------+\n");
}
}
static void sbefifo_dump_ffdc(struct device *dev, const __be32 *ffdc,
size_t ffdc_sz, bool internal)
{
mutex_lock(&sbefifo_ffdc_mutex);
__sbefifo_dump_ffdc(dev, ffdc, ffdc_sz, internal);
mutex_unlock(&sbefifo_ffdc_mutex);
}
int sbefifo_parse_status(struct device *dev, u16 cmd, __be32 *response,
size_t resp_len, size_t *data_len)
{
u32 dh, s0, s1;
size_t ffdc_sz;
if (resp_len < 3) {
pr_debug("sbefifo: cmd %04x, response too small: %zd\n",
cmd, resp_len);
return -ENXIO;
}
dh = be32_to_cpu(response[resp_len - 1]);
if (dh > resp_len || dh < 3) {
dev_err(dev, "SBE cmd %02x:%02x status offset out of range: %d/%zd\n",
cmd >> 8, cmd & 0xff, dh, resp_len);
return -ENXIO;
}
s0 = be32_to_cpu(response[resp_len - dh]);
s1 = be32_to_cpu(response[resp_len - dh + 1]);
if (((s0 >> 16) != 0xC0DE) || ((s0 & 0xffff) != cmd)) {
dev_err(dev, "SBE cmd %02x:%02x, status signature invalid: 0x%08x 0x%08x\n",
cmd >> 8, cmd & 0xff, s0, s1);
return -ENXIO;
}
if (s1 != 0) {
ffdc_sz = dh - 3;
dev_warn(dev, "SBE error cmd %02x:%02x status=%04x:%04x\n",
cmd >> 8, cmd & 0xff, s1 >> 16, s1 & 0xffff);
if (ffdc_sz)
sbefifo_dump_ffdc(dev, &response[resp_len - dh + 2],
ffdc_sz, false);
}
if (data_len)
*data_len = resp_len - dh;
/*
* Primary status don't have the top bit set, so can't be confused with
* Linux negative error codes, so return the status word whole.
*/
return s1;
}
EXPORT_SYMBOL_GPL(sbefifo_parse_status);
static int sbefifo_regr(struct sbefifo *sbefifo, int reg, u32 *word)
{
__be32 raw_word;
int rc;
rc = fsi_device_read(sbefifo->fsi_dev, reg, &raw_word,
sizeof(raw_word));
if (rc)
return rc;
*word = be32_to_cpu(raw_word);
return 0;
}
static int sbefifo_regw(struct sbefifo *sbefifo, int reg, u32 word)
{
__be32 raw_word = cpu_to_be32(word);
return fsi_device_write(sbefifo->fsi_dev, reg, &raw_word,
sizeof(raw_word));
}
static int sbefifo_check_sbe_state(struct sbefifo *sbefifo)
{
__be32 raw_word;
u32 sbm;
int rc;
rc = fsi_slave_read(sbefifo->fsi_dev->slave, CFAM_GP_MBOX_SBM_ADDR,
&raw_word, sizeof(raw_word));
if (rc)
return rc;
sbm = be32_to_cpu(raw_word);
/* SBE booted at all ? */
if (!(sbm & CFAM_SBM_SBE_BOOTED))
return -ESHUTDOWN;
/* Check its state */
switch ((sbm & CFAM_SBM_SBE_STATE_MASK) >> CFAM_SBM_SBE_STATE_SHIFT) {
case SBE_STATE_UNKNOWN:
return -ESHUTDOWN;
case SBE_STATE_DMT:
return -EBUSY;
case SBE_STATE_IPLING:
case SBE_STATE_ISTEP:
case SBE_STATE_MPIPL:
case SBE_STATE_RUNTIME:
case SBE_STATE_DUMP: /* Not sure about that one */
break;
case SBE_STATE_FAILURE:
case SBE_STATE_QUIESCE:
return -ESHUTDOWN;
}
/* Is there async FFDC available ? Remember it */
if (sbm & CFAM_SBM_SBE_ASYNC_FFDC)
sbefifo->async_ffdc = true;
return 0;
}
/* Don't flip endianness of data to/from FIFO, just pass through. */
static int sbefifo_down_read(struct sbefifo *sbefifo, __be32 *word)
{
return fsi_device_read(sbefifo->fsi_dev, SBEFIFO_DOWN, word,
sizeof(*word));
}
static int sbefifo_up_write(struct sbefifo *sbefifo, __be32 word)
{
return fsi_device_write(sbefifo->fsi_dev, SBEFIFO_UP, &word,
sizeof(word));
}
static int sbefifo_request_reset(struct sbefifo *sbefifo)
{
struct device *dev = &sbefifo->fsi_dev->dev;
unsigned long end_time;
u32 status;
int rc;
dev_dbg(dev, "Requesting FIFO reset\n");
/* Mark broken first, will be cleared if reset succeeds */
sbefifo->broken = true;
/* Send reset request */
rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_REQ_RESET, 1);
if (rc) {
dev_err(dev, "Sending reset request failed, rc=%d\n", rc);
return rc;
}
/* Wait for it to complete */
end_time = jiffies + msecs_to_jiffies(SBEFIFO_RESET_TIMEOUT);
while (!time_after(jiffies, end_time)) {
rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &status);
if (rc) {
dev_err(dev, "Failed to read UP fifo status during reset"
" , rc=%d\n", rc);
return rc;
}
if (!(status & SBEFIFO_STS_RESET_REQ)) {
dev_dbg(dev, "FIFO reset done\n");
sbefifo->broken = false;
return 0;
}
cond_resched();
}
dev_err(dev, "FIFO reset timed out\n");
return -ETIMEDOUT;
}
static int sbefifo_cleanup_hw(struct sbefifo *sbefifo)
{
struct device *dev = &sbefifo->fsi_dev->dev;
u32 up_status, down_status;
bool need_reset = false;
int rc;
rc = sbefifo_check_sbe_state(sbefifo);
if (rc) {
dev_dbg(dev, "SBE state=%d\n", rc);
return rc;
}
/* If broken, we don't need to look at status, go straight to reset */
if (sbefifo->broken)
goto do_reset;
rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &up_status);
if (rc) {
dev_err(dev, "Cleanup: Reading UP status failed, rc=%d\n", rc);
/* Will try reset again on next attempt at using it */
sbefifo->broken = true;
return rc;
}
rc = sbefifo_regr(sbefifo, SBEFIFO_DOWN | SBEFIFO_STS, &down_status);
if (rc) {
dev_err(dev, "Cleanup: Reading DOWN status failed, rc=%d\n", rc);
/* Will try reset again on next attempt at using it */
sbefifo->broken = true;
return rc;
}
/* The FIFO already contains a reset request from the SBE ? */
if (down_status & SBEFIFO_STS_RESET_REQ) {
dev_info(dev, "Cleanup: FIFO reset request set, resetting\n");
rc = sbefifo_regw(sbefifo, SBEFIFO_DOWN, SBEFIFO_PERFORM_RESET);
if (rc) {
sbefifo->broken = true;
dev_err(dev, "Cleanup: Reset reg write failed, rc=%d\n", rc);
return rc;
}
sbefifo->broken = false;
return 0;
}
/* Parity error on either FIFO ? */
if ((up_status | down_status) & SBEFIFO_STS_PARITY_ERR)
need_reset = true;
/* Either FIFO not empty ? */
if (!((up_status & down_status) & SBEFIFO_STS_EMPTY))
need_reset = true;
if (!need_reset)
return 0;
dev_info(dev, "Cleanup: FIFO not clean (up=0x%08x down=0x%08x)\n",
up_status, down_status);
do_reset:
/* Mark broken, will be cleared if/when reset succeeds */
return sbefifo_request_reset(sbefifo);
}
static int sbefifo_wait(struct sbefifo *sbefifo, bool up,
u32 *status, unsigned long timeout)
{
struct device *dev = &sbefifo->fsi_dev->dev;
unsigned long end_time;
bool ready = false;
u32 addr, sts = 0;
int rc;
dev_vdbg(dev, "Wait on %s fifo...\n", up ? "up" : "down");
addr = (up ? SBEFIFO_UP : SBEFIFO_DOWN) | SBEFIFO_STS;
end_time = jiffies + timeout;
while (!time_after(jiffies, end_time)) {
cond_resched();
rc = sbefifo_regr(sbefifo, addr, &sts);
if (rc < 0) {
dev_err(dev, "FSI error %d reading status register\n", rc);
return rc;
}
if (!up && sbefifo_parity_err(sts)) {
dev_err(dev, "Parity error in DOWN FIFO\n");
return -ENXIO;
}
ready = !(up ? sbefifo_full(sts) : sbefifo_empty(sts));
if (ready)
break;
}
if (!ready) {
sysfs_notify(&sbefifo->dev.kobj, NULL, dev_attr_timeout.attr.name);
sbefifo->timed_out = true;
dev_err(dev, "%s FIFO Timeout (%u ms)! status=%08x\n",
up ? "UP" : "DOWN", jiffies_to_msecs(timeout), sts);
return -ETIMEDOUT;
}
dev_vdbg(dev, "End of wait status: %08x\n", sts);
sbefifo->timed_out = false;
*status = sts;
return 0;
}
static int sbefifo_send_command(struct sbefifo *sbefifo,
const __be32 *command, size_t cmd_len)
{
struct device *dev = &sbefifo->fsi_dev->dev;
size_t len, chunk, vacant = 0, remaining = cmd_len;
unsigned long timeout;
u32 status;
int rc;
dev_dbg(dev, "sending command (%zd words, cmd=%04x)\n",
cmd_len, be32_to_cpu(command[1]));
/* As long as there's something to send */
timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_CMD);
while (remaining) {
/* Wait for room in the FIFO */
rc = sbefifo_wait(sbefifo, true, &status, timeout);
if (rc < 0)
return rc;
timeout = msecs_to_jiffies(sbefifo->timeout_in_cmd_ms);
vacant = sbefifo_vacant(status);
len = chunk = min(vacant, remaining);
dev_vdbg(dev, " status=%08x vacant=%zd chunk=%zd\n",
status, vacant, chunk);
/* Write as much as we can */
while (len--) {
rc = sbefifo_up_write(sbefifo, *(command++));
if (rc) {
dev_err(dev, "FSI error %d writing UP FIFO\n", rc);
return rc;
}
}
remaining -= chunk;
vacant -= chunk;
}
/* If there's no room left, wait for some to write EOT */
if (!vacant) {
rc = sbefifo_wait(sbefifo, true, &status, timeout);
if (rc)
return rc;
}
/* Send an EOT */
rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_EOT_RAISE, 0);
if (rc)
dev_err(dev, "FSI error %d writing EOT\n", rc);
return rc;
}
static int sbefifo_read_response(struct sbefifo *sbefifo, struct iov_iter *response)
{
struct device *dev = &sbefifo->fsi_dev->dev;
u32 status, eot_set;
unsigned long timeout;
bool overflow = false;
__be32 data;
size_t len;
int rc;
dev_dbg(dev, "reading response, buflen = %zd\n", iov_iter_count(response));
timeout = msecs_to_jiffies(sbefifo->timeout_start_rsp_ms);
for (;;) {
/* Grab FIFO status (this will handle parity errors) */
rc = sbefifo_wait(sbefifo, false, &status, timeout);
if (rc < 0) {
dev_dbg(dev, "timeout waiting (%u ms)\n", jiffies_to_msecs(timeout));
return rc;
}
timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_RSP);
/* Decode status */
len = sbefifo_populated(status);
eot_set = sbefifo_eot_set(status);
dev_dbg(dev, " chunk size %zd eot_set=0x%x\n", len, eot_set);
/* Go through the chunk */
while(len--) {
/* Read the data */
rc = sbefifo_down_read(sbefifo, &data);
if (rc < 0)
return rc;
/* Was it an EOT ? */
if (eot_set & 0x80) {
/*
* There should be nothing else in the FIFO,
* if there is, mark broken, this will force
* a reset on next use, but don't fail the
* command.
*/
if (len) {
dev_warn(dev, "FIFO read hit"
" EOT with still %zd data\n",
len);
sbefifo->broken = true;
}
/* We are done */
rc = sbefifo_regw(sbefifo,
SBEFIFO_DOWN | SBEFIFO_EOT_ACK, 0);
/*
* If that write fail, still complete the request but mark
* the fifo as broken for subsequent reset (not much else
* we can do here).
*/
if (rc) {
dev_err(dev, "FSI error %d ack'ing EOT\n", rc);
sbefifo->broken = true;
}
/* Tell whether we overflowed */
return overflow ? -EOVERFLOW : 0;
}
/* Store it if there is room */
if (iov_iter_count(response) >= sizeof(__be32)) {
if (copy_to_iter(&data, sizeof(__be32), response) < sizeof(__be32))
return -EFAULT;
} else {
dev_vdbg(dev, "Response overflowed !\n");
overflow = true;
}
/* Next EOT bit */
eot_set <<= 1;
}
}
/* Shouldn't happen */
return -EIO;
}
static int sbefifo_do_command(struct sbefifo *sbefifo,
const __be32 *command, size_t cmd_len,
struct iov_iter *response)
{
/* Try sending the command */
int rc = sbefifo_send_command(sbefifo, command, cmd_len);
if (rc)
return rc;
/* Now, get the response */
return sbefifo_read_response(sbefifo, response);
}
static void sbefifo_collect_async_ffdc(struct sbefifo *sbefifo)
{
struct device *dev = &sbefifo->fsi_dev->dev;
struct iov_iter ffdc_iter;
struct kvec ffdc_iov;
__be32 *ffdc;
size_t ffdc_sz;
__be32 cmd[2];
int rc;
sbefifo->async_ffdc = false;
ffdc = vmalloc(SBEFIFO_MAX_FFDC_SIZE);
if (!ffdc) {
dev_err(dev, "Failed to allocate SBE FFDC buffer\n");
return;
}
ffdc_iov.iov_base = ffdc;
ffdc_iov.iov_len = SBEFIFO_MAX_FFDC_SIZE;
iov_iter_kvec(&ffdc_iter, ITER_DEST, &ffdc_iov, 1, SBEFIFO_MAX_FFDC_SIZE);
cmd[0] = cpu_to_be32(2);
cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_SBE_FFDC);
rc = sbefifo_do_command(sbefifo, cmd, 2, &ffdc_iter);
if (rc != 0) {
dev_err(dev, "Error %d retrieving SBE FFDC\n", rc);
goto bail;
}
ffdc_sz = SBEFIFO_MAX_FFDC_SIZE - iov_iter_count(&ffdc_iter);
ffdc_sz /= sizeof(__be32);
rc = sbefifo_parse_status(dev, SBEFIFO_CMD_GET_SBE_FFDC, ffdc,
ffdc_sz, &ffdc_sz);
if (rc != 0) {
dev_err(dev, "Error %d decoding SBE FFDC\n", rc);
goto bail;
}
if (ffdc_sz > 0)
sbefifo_dump_ffdc(dev, ffdc, ffdc_sz, true);
bail:
vfree(ffdc);
}
static int __sbefifo_submit(struct sbefifo *sbefifo,
const __be32 *command, size_t cmd_len,
struct iov_iter *response)
{
struct device *dev = &sbefifo->fsi_dev->dev;
int rc;
if (sbefifo->dead)
return -ENODEV;
if (cmd_len < 2 || be32_to_cpu(command[0]) != cmd_len) {
dev_vdbg(dev, "Invalid command len %zd (header: %d)\n",
cmd_len, be32_to_cpu(command[0]));
return -EINVAL;
}
/* First ensure the HW is in a clean state */
rc = sbefifo_cleanup_hw(sbefifo);
if (rc)
return rc;
/* Look for async FFDC first if any */
if (sbefifo->async_ffdc)
sbefifo_collect_async_ffdc(sbefifo);
rc = sbefifo_do_command(sbefifo, command, cmd_len, response);
if (rc != 0 && rc != -EOVERFLOW)
goto fail;
return rc;
fail:
/*
* On failure, attempt a reset. Ignore the result, it will mark
* the fifo broken if the reset fails
*/
sbefifo_request_reset(sbefifo);
/* Return original error */
return rc;
}
/**
* sbefifo_submit() - Submit and SBE fifo command and receive response
* @dev: The sbefifo device
* @command: The raw command data
* @cmd_len: The command size (in 32-bit words)
* @response: The output response buffer
* @resp_len: In: Response buffer size, Out: Response size
*
* This will perform the entire operation. If the response buffer
* overflows, returns -EOVERFLOW
*/
int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len,
__be32 *response, size_t *resp_len)
{
struct sbefifo *sbefifo;
struct iov_iter resp_iter;
struct kvec resp_iov;
size_t rbytes;
int rc;
if (!dev)
return -ENODEV;
sbefifo = dev_get_drvdata(dev);
if (!sbefifo)
return -ENODEV;
if (WARN_ON_ONCE(sbefifo->magic != SBEFIFO_MAGIC))
return -ENODEV;
if (!resp_len || !command || !response)
return -EINVAL;
/* Prepare iov iterator */
rbytes = (*resp_len) * sizeof(__be32);
resp_iov.iov_base = response;
resp_iov.iov_len = rbytes;
iov_iter_kvec(&resp_iter, ITER_DEST, &resp_iov, 1, rbytes);
/* Perform the command */
rc = mutex_lock_interruptible(&sbefifo->lock);
if (rc)
return rc;
rc = __sbefifo_submit(sbefifo, command, cmd_len, &resp_iter);
mutex_unlock(&sbefifo->lock);
/* Extract the response length */
rbytes -= iov_iter_count(&resp_iter);
*resp_len = rbytes / sizeof(__be32);
return rc;
}
EXPORT_SYMBOL_GPL(sbefifo_submit);
/*
* Char device interface
*/
static void sbefifo_release_command(struct sbefifo_user *user)
{
if (is_vmalloc_addr(user->pending_cmd))
vfree(user->pending_cmd);
user->pending_cmd = NULL;
user->pending_len = 0;
}
static int sbefifo_user_open(struct inode *inode, struct file *file)
{
struct sbefifo *sbefifo = container_of(inode->i_cdev, struct sbefifo, cdev);
struct sbefifo_user *user;
user = kzalloc(sizeof(struct sbefifo_user), GFP_KERNEL);
if (!user)
return -ENOMEM;
file->private_data = user;
user->sbefifo = sbefifo;
user->cmd_page = (void *)__get_free_page(GFP_KERNEL);
if (!user->cmd_page) {
kfree(user);
return -ENOMEM;
}
mutex_init(&user->file_lock);
user->cmd_timeout_ms = SBEFIFO_TIMEOUT_IN_CMD;
user->read_timeout_ms = SBEFIFO_TIMEOUT_START_RSP;
return 0;
}
static ssize_t sbefifo_user_read(struct file *file, char __user *buf,
size_t len, loff_t *offset)
{
struct sbefifo_user *user = file->private_data;
struct sbefifo *sbefifo;
struct iov_iter resp_iter;
struct iovec resp_iov;
size_t cmd_len;
int rc;
if (!user)
return -EINVAL;
sbefifo = user->sbefifo;
if (len & 3)
return -EINVAL;
mutex_lock(&user->file_lock);
/* Cronus relies on -EAGAIN after a short read */
if (user->pending_len == 0) {
rc = -EAGAIN;
goto bail;
}
if (user->pending_len < 8) {
rc = -EINVAL;
goto bail;
}
cmd_len = user->pending_len >> 2;
/* Prepare iov iterator */
resp_iov.iov_base = buf;
resp_iov.iov_len = len;
iov_iter_init(&resp_iter, ITER_DEST, &resp_iov, 1, len);
/* Perform the command */
rc = mutex_lock_interruptible(&sbefifo->lock);
if (rc)
goto bail;
sbefifo->timeout_in_cmd_ms = user->cmd_timeout_ms;
sbefifo->timeout_start_rsp_ms = user->read_timeout_ms;
rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter);
sbefifo->timeout_start_rsp_ms = SBEFIFO_TIMEOUT_START_RSP;
sbefifo->timeout_in_cmd_ms = SBEFIFO_TIMEOUT_IN_CMD;
mutex_unlock(&sbefifo->lock);
if (rc < 0)
goto bail;
/* Extract the response length */
rc = len - iov_iter_count(&resp_iter);
bail:
sbefifo_release_command(user);
mutex_unlock(&user->file_lock);
return rc;
}
static ssize_t sbefifo_user_write(struct file *file, const char __user *buf,
size_t len, loff_t *offset)
{
struct sbefifo_user *user = file->private_data;
struct sbefifo *sbefifo;
int rc = len;
if (!user)
return -EINVAL;
sbefifo = user->sbefifo;
if (len > SBEFIFO_MAX_USER_CMD_LEN)
return -EINVAL;
if (len & 3)
return -EINVAL;
mutex_lock(&user->file_lock);
/* Can we use the pre-allocate buffer ? If not, allocate */
if (len <= PAGE_SIZE)
user->pending_cmd = user->cmd_page;
else
user->pending_cmd = vmalloc(len);
if (!user->pending_cmd) {
rc = -ENOMEM;
goto bail;
}
/* Copy the command into the staging buffer */
if (copy_from_user(user->pending_cmd, buf, len)) {
rc = -EFAULT;
goto bail;
}
/* Check for the magic reset command */
if (len == 4 && be32_to_cpu(*(__be32 *)user->pending_cmd) ==
SBEFIFO_RESET_MAGIC) {
/* Clear out any pending command */
user->pending_len = 0;
/* Trigger reset request */
rc = mutex_lock_interruptible(&sbefifo->lock);
if (rc)
goto bail;
rc = sbefifo_request_reset(user->sbefifo);
mutex_unlock(&sbefifo->lock);
if (rc == 0)
rc = 4;
goto bail;
}
/* Update the staging buffer size */
user->pending_len = len;
bail:
if (!user->pending_len)
sbefifo_release_command(user);
mutex_unlock(&user->file_lock);
/* And that's it, we'll issue the command on a read */
return rc;
}
static int sbefifo_user_release(struct inode *inode, struct file *file)
{
struct sbefifo_user *user = file->private_data;
if (!user)
return -EINVAL;
sbefifo_release_command(user);
free_page((unsigned long)user->cmd_page);
kfree(user);
return 0;
}
static int sbefifo_cmd_timeout(struct sbefifo_user *user, void __user *argp)
{
struct device *dev = &user->sbefifo->dev;
u32 timeout;
if (get_user(timeout, (__u32 __user *)argp))
return -EFAULT;
if (timeout == 0) {
user->cmd_timeout_ms = SBEFIFO_TIMEOUT_IN_CMD;
dev_dbg(dev, "Command timeout reset to %us\n", user->cmd_timeout_ms / 1000);
return 0;
}
user->cmd_timeout_ms = timeout * 1000; /* user timeout is in sec */
dev_dbg(dev, "Command timeout set to %us\n", timeout);
return 0;
}
static int sbefifo_read_timeout(struct sbefifo_user *user, void __user *argp)
{
struct device *dev = &user->sbefifo->dev;
u32 timeout;
if (get_user(timeout, (__u32 __user *)argp))
return -EFAULT;
if (timeout == 0) {
user->read_timeout_ms = SBEFIFO_TIMEOUT_START_RSP;
dev_dbg(dev, "Timeout reset to %us\n", user->read_timeout_ms / 1000);
return 0;
}
user->read_timeout_ms = timeout * 1000; /* user timeout is in sec */
dev_dbg(dev, "Timeout set to %us\n", timeout);
return 0;
}
static long sbefifo_user_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct sbefifo_user *user = file->private_data;
int rc = -ENOTTY;
if (!user)
return -EINVAL;
mutex_lock(&user->file_lock);
switch (cmd) {
case FSI_SBEFIFO_CMD_TIMEOUT_SECONDS:
rc = sbefifo_cmd_timeout(user, (void __user *)arg);
break;
case FSI_SBEFIFO_READ_TIMEOUT_SECONDS:
rc = sbefifo_read_timeout(user, (void __user *)arg);
break;
}
mutex_unlock(&user->file_lock);
return rc;
}
static const struct file_operations sbefifo_fops = {
.owner = THIS_MODULE,
.open = sbefifo_user_open,
.read = sbefifo_user_read,
.write = sbefifo_user_write,
.release = sbefifo_user_release,
.unlocked_ioctl = sbefifo_user_ioctl,
};
static void sbefifo_free(struct device *dev)
{
struct sbefifo *sbefifo = container_of(dev, struct sbefifo, dev);
put_device(&sbefifo->fsi_dev->dev);
kfree(sbefifo);
}
/*
* Probe/remove
*/
static int sbefifo_probe(struct device *dev)
{
struct fsi_device *fsi_dev = to_fsi_dev(dev);
struct sbefifo *sbefifo;
struct device_node *np;
struct platform_device *child;
char child_name[32];
int rc, didx, child_idx = 0;
dev_dbg(dev, "Found sbefifo device\n");
sbefifo = kzalloc(sizeof(*sbefifo), GFP_KERNEL);
if (!sbefifo)
return -ENOMEM;
/* Grab a reference to the device (parent of our cdev), we'll drop it later */
if (!get_device(dev)) {
kfree(sbefifo);
return -ENODEV;
}
sbefifo->magic = SBEFIFO_MAGIC;
sbefifo->fsi_dev = fsi_dev;
dev_set_drvdata(dev, sbefifo);
mutex_init(&sbefifo->lock);
sbefifo->timeout_in_cmd_ms = SBEFIFO_TIMEOUT_IN_CMD;
sbefifo->timeout_start_rsp_ms = SBEFIFO_TIMEOUT_START_RSP;
/* Create chardev for userspace access */
sbefifo->dev.type = &fsi_cdev_type;
sbefifo->dev.parent = dev;
sbefifo->dev.release = sbefifo_free;
device_initialize(&sbefifo->dev);
/* Allocate a minor in the FSI space */
rc = fsi_get_new_minor(fsi_dev, fsi_dev_sbefifo, &sbefifo->dev.devt, &didx);
if (rc)
goto err;
dev_set_name(&sbefifo->dev, "sbefifo%d", didx);
cdev_init(&sbefifo->cdev, &sbefifo_fops);
rc = cdev_device_add(&sbefifo->cdev, &sbefifo->dev);
if (rc) {
dev_err(dev, "Error %d creating char device %s\n",
rc, dev_name(&sbefifo->dev));
goto err_free_minor;
}
/* Create platform devs for dts child nodes (occ, etc) */
for_each_available_child_of_node(dev->of_node, np) {
snprintf(child_name, sizeof(child_name), "%s-dev%d",
dev_name(&sbefifo->dev), child_idx++);
child = of_platform_device_create(np, child_name, dev);
if (!child)
dev_warn(dev, "failed to create child %s dev\n",
child_name);
}
device_create_file(&sbefifo->dev, &dev_attr_timeout);
return 0;
err_free_minor:
fsi_free_minor(sbefifo->dev.devt);
err:
put_device(&sbefifo->dev);
return rc;
}
static int sbefifo_unregister_child(struct device *dev, void *data)
{
struct platform_device *child = to_platform_device(dev);
of_device_unregister(child);
if (dev->of_node)
of_node_clear_flag(dev->of_node, OF_POPULATED);
return 0;
}
static int sbefifo_remove(struct device *dev)
{
struct sbefifo *sbefifo = dev_get_drvdata(dev);
dev_dbg(dev, "Removing sbefifo device...\n");
device_remove_file(&sbefifo->dev, &dev_attr_timeout);
mutex_lock(&sbefifo->lock);
sbefifo->dead = true;
mutex_unlock(&sbefifo->lock);
cdev_device_del(&sbefifo->cdev, &sbefifo->dev);
fsi_free_minor(sbefifo->dev.devt);
device_for_each_child(dev, NULL, sbefifo_unregister_child);
put_device(&sbefifo->dev);
return 0;
}
static const struct fsi_device_id sbefifo_ids[] = {
{
.engine_type = FSI_ENGID_SBE,
.version = FSI_VERSION_ANY,
},
{ 0 }
};
static struct fsi_driver sbefifo_drv = {
.id_table = sbefifo_ids,
.drv = {
.name = DEVICE_NAME,
.bus = &fsi_bus_type,
.probe = sbefifo_probe,
.remove = sbefifo_remove,
}
};
static int sbefifo_init(void)
{
return fsi_driver_register(&sbefifo_drv);
}
static void sbefifo_exit(void)
{
fsi_driver_unregister(&sbefifo_drv);
}
module_init(sbefifo_init);
module_exit(sbefifo_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Brad Bishop <[email protected]>");
MODULE_AUTHOR("Eddie James <[email protected]>");
MODULE_AUTHOR("Andrew Jeffery <[email protected]>");
MODULE_AUTHOR("Benjamin Herrenschmidt <[email protected]>");
MODULE_DESCRIPTION("Linux device interface to the POWER Self Boot Engine");
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