| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Benjamin Herrenschmidt | 4590 | 99.78% | 5 | 71.43% |
| Edward A. James | 6 | 0.13% | 1 | 14.29% |
| Joel Stanley | 4 | 0.09% | 1 | 14.29% |
| Total | 4600 | 7 |
// 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_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> #include <linux/mm.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_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; }; struct sbefifo_user { struct sbefifo *sbefifo; struct mutex file_lock; void *cmd_page; void *pending_cmd; size_t pending_len; }; 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; 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_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 status, eot_set; unsigned long timeout; bool overflow = false; __be32 data; 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; __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, WRITE, &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 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; 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, WRITE, &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 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); 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: 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 */ 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: 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 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, }; 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); /* * 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"); /* 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); } 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"); 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 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 <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");
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