--- /dev/null
+// 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/idr.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.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>
+
+/*
+ * 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, // Unkown, 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_CMD_LEN PAGE_SIZE
+#define SBEFIFO_RESET_MAGIC 0x52534554 /* "RSET" */
+
+struct sbefifo {
+ uint32_t magic;
+#define SBEFIFO_MAGIC 0x53424546 /* "SBEF" */
+ struct fsi_device *fsi_dev;
+ struct miscdevice mdev;
+ struct mutex lock;
+ char name[32];
+ int idx;
+ bool broken;
+ bool async_ffdc;
+};
+
+struct sbefifo_user {
+ struct sbefifo *sbefifo;
+ struct mutex file_lock;
+ void *pending_cmd;
+ size_t pending_len;
+};
+
+static DEFINE_IDA(sbefifo_ida);
+static DEFINE_MUTEX(sbefifo_ffdc_mutex);
+
+
+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;
+
+ mutex_lock(&sbefifo_ffdc_mutex);
+ 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");
+ }
+}
+
+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_IPLING:
+ case SBE_STATE_ISTEP:
+ case SBE_STATE_MPIPL:
+ case SBE_STATE_DMT:
+ return -EBUSY;
+ 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;
+ u32 status, timeout;
+ 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 */
+ for (timeout = 0; timeout < SBEFIFO_RESET_TIMEOUT; timeout++) {
+ 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;
+ }
+
+ msleep(1);
+ }
+ 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_UP, 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) {
+ dev_err(dev, "%s FIFO Timeout ! status=%08x\n", up ? "UP" : "DOWN", sts);
+ return -ETIMEDOUT;
+ }
+ dev_vdbg(dev, "End of wait status: %08x\n", sts);
+
+ *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_vdbg(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);
+
+ 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 data, status, eot_set;
+ unsigned long timeout;
+ bool overflow = false;
+ size_t len;
+ int rc;
+
+ dev_vdbg(dev, "reading response, buflen = %zd\n", iov_iter_count(response));
+
+ timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_RSP);
+ for (;;) {
+ /* Grab FIFO status (this will handle parity errors) */
+ rc = sbefifo_wait(sbefifo, false, &status, timeout);
+ if (rc < 0)
+ return rc;
+ timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_RSP);
+
+ /* Decode status */
+ len = sbefifo_populated(status);
+ eot_set = sbefifo_eot_set(status);
+
+ dev_vdbg(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;
+ u32 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, WRITE | ITER_KVEC, &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 (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 reponse 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 = dev_get_drvdata(dev);
+ struct iov_iter resp_iter;
+ struct kvec resp_iov;
+ size_t rbytes;
+ int rc;
+
+ if (!dev || !sbefifo)
+ return -ENODEV;
+ if (WARN_ON_ONCE(sbefifo->magic != SBEFIFO_MAGIC))
+ return -ENODEV;
+ if (!resp_len || !command || !response || cmd_len > SBEFIFO_MAX_CMD_LEN)
+ 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, WRITE | ITER_KVEC, &resp_iov, 1, rbytes);
+
+ /* Perform the command */
+ mutex_lock(&sbefifo->lock);
+ 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 int sbefifo_user_open(struct inode *inode, struct file *file)
+{
+ struct sbefifo *sbefifo = container_of(file->private_data,
+ struct sbefifo, mdev);
+ struct sbefifo_user *user;
+
+ user = kzalloc(sizeof(struct sbefifo_user), GFP_KERNEL);
+ if (!user)
+ return -ENOMEM;
+
+ file->private_data = user;
+ user->sbefifo = sbefifo;
+ user->pending_cmd = (void *)__get_free_page(GFP_KERNEL);
+ if (!user->pending_cmd) {
+ kfree(user);
+ return -ENOMEM;
+ }
+ mutex_init(&user->file_lock);
+
+ 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, WRITE, &resp_iov, 1, len);
+
+ /* Perform the command */
+ mutex_lock(&sbefifo->lock);
+ rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter);
+ mutex_unlock(&sbefifo->lock);
+ if (rc < 0)
+ goto bail;
+
+ /* Extract the response length */
+ rc = len - iov_iter_count(&resp_iter);
+ bail:
+ user->pending_len = 0;
+ 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_CMD_LEN)
+ return -EINVAL;
+ if (len & 3)
+ return -EINVAL;
+
+ mutex_lock(&user->file_lock);
+
+ /* 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 */
+ mutex_lock(&sbefifo->lock);
+ 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:
+ 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;
+
+ free_page((unsigned long)user->pending_cmd);
+ kfree(user);
+
+ return 0;
+}
+
+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,
+};
+
+/*
+ * 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, child_idx = 0;
+
+ dev_dbg(dev, "Found sbefifo device\n");
+
+ sbefifo = devm_kzalloc(dev, sizeof(*sbefifo), GFP_KERNEL);
+ if (!sbefifo)
+ return -ENOMEM;
+ sbefifo->magic = SBEFIFO_MAGIC;
+ sbefifo->fsi_dev = fsi_dev;
+ mutex_init(&sbefifo->lock);
+
+ /*
+ * Try cleaning up the FIFO. If this fails, we still register the
+ * driver and will try cleaning things up again on the next access.
+ */
+ rc = sbefifo_cleanup_hw(sbefifo);
+ if (rc && rc != -ESHUTDOWN)
+ dev_err(dev, "Initial HW cleanup failed, will retry later\n");
+
+ sbefifo->idx = ida_simple_get(&sbefifo_ida, 1, INT_MAX, GFP_KERNEL);
+ snprintf(sbefifo->name, sizeof(sbefifo->name), "sbefifo%d",
+ sbefifo->idx);
+
+ dev_set_drvdata(dev, sbefifo);
+
+ /* Create misc chardev for userspace access */
+ sbefifo->mdev.minor = MISC_DYNAMIC_MINOR;
+ sbefifo->mdev.fops = &sbefifo_fops;
+ sbefifo->mdev.name = sbefifo->name;
+ sbefifo->mdev.parent = dev;
+ rc = misc_register(&sbefifo->mdev);
+ if (rc) {
+ dev_err(dev, "Failed to register miscdevice: %d\n", rc);
+ ida_simple_remove(&sbefifo_ida, sbefifo->idx);
+ return rc;
+ }
+
+ /* 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",
+ sbefifo->name, 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);
+ }
+
+ return 0;
+}
+
+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");
+
+ misc_deregister(&sbefifo->mdev);
+ device_for_each_child(dev, NULL, sbefifo_unregister_child);
+
+ ida_simple_remove(&sbefifo_ida, sbefifo->idx);
+
+ return 0;
+}
+
+static 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);
+
+ ida_destroy(&sbefifo_ida);
+}
+
+module_init(sbefifo_init);
+module_exit(sbefifo_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Brad Bishop <bradleyb@fuzziesquirrel.com>");
+MODULE_AUTHOR("Eddie James <eajames@linux.vnet.ibm.com>");
+MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("Linux device interface to the POWER Self Boot Engine");
projects / users / jedix / linux-maple.git / commitdiff