fsi: Remove old sbefifo driver

This driver provides an in-kernel and a user API for accessing the command FIFO of the SBE (Self Boot Engine) of the POWER9 processor, via the FSI bus.

It provides an in-kernel interface to submit command and receive responses, along with a helper to locate and analyse the response status block. It's a simple synchronous submit() type API.

The user interface uses the write/read interface that an earlier version of this driver already provided, however it has some specific limitations in order to keep the driver simple and avoid using up a lot of kernel memory:

- The user should perform a single write() with the command and a single read() to get the response (with a buffer big enough to hold the entire response).

- On a write() the command is simply "stored" into a kernel buffer, it is submitted as one operation on the subsequent read(). This allows to have the code write directly from the FIFO into the user buffer and avoid hogging the SBE between the write() and read() syscall as it's critical that the SBE be freed asap to respond to the host. An extra write() will simply replace the previously written command.

- A write of a single 4 bytes containing the value 0x52534554 in big endian will trigger a reset request. No read is necessary, the write() call will return when the reset has been acknowledged or times out.

- The command is limited to 4K bytes.

Signed-off-by Benjamin Herrenschmidt <[email protected]>

---

v2. Return -EAGAIN on read() when there's no pending message as
to be compatible with existing userspace (cronus) expectations

v3. Don't print "Initial HW cleanup failed" when the error is
-ESHUTDOWN (is the host is not booted).

---
 drivers/fsi/Makefile        |   2 +-
 drivers/fsi/fsi-sbefifo.c   | 867 ++++++++++++++++++++++++++++++++++++
 include/linux/fsi-sbefifo.h |  26 ++
 3 files changed, 894 insertions(+), 1 deletion(-)
 create mode 100644 drivers/fsi/fsi-sbefifo.c
 create mode 100644 include/linux/fsi-sbefifo.h

drivers/fsi/Makefile +1 -1

index 61e8e420c7ed..f331e929423c 100644
@@ -3,5 +3,5 @@ obj-$(CONFIG_FSI) += fsi-core.o
 obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
-#obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
+obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
 #obj-$(CONFIG_FSI_OCC) += fsi-occ.o

drivers/fsi/fsi-sbefifo.c new file +2 -0

new file mode 100644
index 000000000000..f78e51a959bf
@@ -0,0 +1,867 @@
+/*
+ * Copyright (C) IBM Corporation 2017

drivers/fsi/fsi-sbefifo.c new file +87 -0

+
+#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>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/sbefifo.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_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)

drivers/fsi/fsi-sbefifo.c new file +48 -0

+
+/* 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;
+};
+
+struct sbefifo_user {
+	struct sbefifo		*sbefifo;
+	struct mutex		file_lock;
+	void			*pending_cmd;
+	size_t			pending_len;
+};
+
+static DEFINE_IDA(sbefifo_ida);
+
+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;
+}

drivers/fsi/fsi-sbefifo.c new file +186 -0

+{
+	__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;
+	}
+	return 0;
+}
+
+/* Don't flip endianness of data to/from FIFO, just pass through. */
+static int sbefifo_down_read(struct sbefifo *sbefifo, u32 *word)
+{
+	return fsi_device_read(sbefifo->fsi_dev, SBEFIFO_DOWN, word,
+			       sizeof(*word));
+}
+
+static int sbefifo_up_write(struct sbefifo *sbefifo, u32 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_get_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);

drivers/fsi/fsi-sbefifo.c new file +203 -0

+		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 (%d 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=%d chunk=%d\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,
+				 __be32 __user *response, size_t *resp_len)
+{
+	struct device *dev = &sbefifo->fsi_dev->dev;
+	u32 data, status, eot_set;
+	size_t len, remaining;
+	unsigned long timeout;
+	bool overflow = false;
+	int rc;
+
+	remaining = *resp_len;
+	*resp_len = 0;
+
+	dev_vdbg(dev, "reading response, buflen = %d\n", remaining);
+
+	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 %d 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 %d 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;
+				}
+
+				dev_vdbg(dev, "got %d words response%s\n", *resp_len,
+					 overflow ? "with overflow !" : "");
+
+				/* Tell whether we overflowed */
+				return overflow ? -EOVERFLOW : 0;
+			}
+
+			/* Store it if there is room */
+			if (remaining) {
+				rc = put_user(data, response++);
+				if (rc)
+					return rc;
+				remaining--;
+				(*resp_len)++;
+			} else
+				overflow = true;
+
+			/* Next EOT bit */
+			eot_set <<= 1;
+		}
+	}
+	/* Shouldn't happen */
+	return -EIO;
+}
+
+static int __sbefifo_submit(struct sbefifo *sbefifo,
+			    const __be32 *command, size_t cmd_len,
+			    __be32 __user *response, size_t *resp_len)
+{
+	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 %d (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;
+
+	/* Try sending the command */
+	rc = sbefifo_send_command(sbefifo, command, cmd_len);
+	if (rc)
+		goto fail;
+
+	/* Now, get the response */
+	rc = sbefifo_read_response(sbefifo, response, resp_len);
+	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,

drivers/fsi/fsi-sbefifo.c new file +11 -0

+		   __be32 *response, size_t *resp_len)
+{
+	struct sbefifo *sbefifo = dev_get_drvdata(dev);
+	mm_segment_t old_fs;
+	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)

drivers/fsi/fsi-sbefifo.c new file +6 -0

+	mutex_unlock(&sbefifo->lock);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(sbefifo_submit);
+
+int sbefifo_parse_status(u16 cmd, __be32 *response, size_t resp_len, 

size_t *data_len)

drivers/fsi/fsi-sbefifo.c new file +18 -0

+{
+	u32 dh, s0, s1;
+
+	if (resp_len < 3) {
+		pr_debug("sbefifo: cmd %04x, response too small: %d\n",
+			 cmd, resp_len);
+		return -ENXIO;
+	}
+	dh = be32_to_cpu(response[resp_len - 1]);
+	if (dh > resp_len || dh < 3) {
+		pr_debug("sbefifo: cmd %04x, status offset out of range: %d/%d\n",
+			 cmd, 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)) {
+		pr_debug("sbefifo: cmd %04x, status signature invalid: 0x%08x 0x%08x

\n",

drivers/fsi/fsi-sbefifo.c new file +84 -0

+			 cmd, s0, s1);
+		return -ENXIO;
+	}
+	if (s1 != 0) {
+		pr_debug("sbefifo: cmd %04x, error status: prim=%04x sec=%04x\n",
+			 cmd, s1 >> 16, s1 & 0xffff);
+	}
+	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);
+
+/*
+ * 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;
+	size_t clen, rlen;
+	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;
+	}
+	mutex_lock(&sbefifo->lock);
+	clen = user->pending_len >> 2;
+	rlen = len >> 2;
+	rc = __sbefifo_submit(sbefifo, user->pending_cmd, clen,
+			      (__be32 __user *)buf, &rlen);
+	mutex_unlock(&sbefifo->lock);
+	if (rc < 0)
+		goto bail;
+	rc = rlen << 2;
+ 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,

drivers/fsi/fsi-sbefifo.c new file +192 -0

+				  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 <[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");

include/linux/fsi-sbefifo.h new file +21 -0

new file mode 100644
index 000000000000..15729b3194a2
@@ -0,0 +1,26 @@
+/*
+ * SBEFIFO FSI Client device driver
+ *
+ * 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.
+ */
+
+#ifndef LINUX_FSI_SBEFIFO_H
+#define LINUX_FSI_SBEFIFO_H
+
+struct device;
+
+int sbefifo_submit(struct device *dev, const __be32 *command, size_t 

cmd_len,

include/linux/fsi-sbefifo.h new file +3 -0

+		   __be32 *response, size_t *resp_len);
+
+int sbefifo_parse_status(u16 cmd, __be32 *response, size_t resp_len, 

size_t *data_len);

include/linux/fsi-sbefifo.h new file +2 -0

+
+#endif /* LINUX_FSI_SBEFIFO_H */

Signature · 1 line

2.17.0

Quoted 9 lines

drivers/fsi/fsi-sbefifo.c new file +6 -0

@@ -0,0 +1,867 @@
+/*
+ * 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.

drivers/fsi/fsi-sbefifo.c line 12

Quoted 6 lines

drivers/fsi/fsi-sbefifo.c new file +6 -0

+ *
+ * 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.
+ */

Should be SPDX-style?

Quoted 1 line

Quoted 1 line

+static int sbefifo_get_sbe_state(struct sbefifo *sbefifo)

This isn't so much getting the state as ensuring it's in a usable state, or it's conflating error codes with the SBE state. Maybe sbefifo_is_ready()?

Quoted 25 lines

drivers/fsi/fsi-sbefifo.c new file +12 -0

+/**
+ * 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,

drivers/fsi/fsi-sbefifo.c new file +11 -0

+		   __be32 *response, size_t *resp_len)
+{
+	struct sbefifo *sbefifo = dev_get_drvdata(dev);
+	mm_segment_t old_fs;
+	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)

drivers/fsi/fsi-sbefifo.c line 567

Quoted 8 lines

drivers/fsi/fsi-sbefifo.c new file +8 -0

+		return -EINVAL;
+
+	mutex_lock(&sbefifo->lock);
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+	rc = __sbefifo_submit(sbefifo, command, cmd_len,
+			      response, resp_len);
+	set_fs(old_fs);

Can you talk about why the get_fs()/set_fs()/set_fs() sequence is the right way to go here when there's been discussion in the past about removing the whole show?

https://lwn.net/Articles/722267/

+Nick (see question about iovec)

Quoted 9 lines

Quoted 9 lines

drivers/fsi/fsi-sbefifo.c new file +6 -0

@@ -0,0 +1,867 @@
+/*
+ * 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.

Quoted 8 lines

drivers/fsi/fsi-sbefifo.c line 12

Quoted 6 lines

drivers/fsi/fsi-sbefifo.c new file +6 -0

+ *
+ * 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.
+ */  

Should be SPDX-style?

Yup, keep forgetting about that new thing :)

Quoted 1 line

Quoted 1 line

.../...

Quoted 5 lines

Quoted 1 line

+static int sbefifo_get_sbe_state(struct sbefifo *sbefifo)

This isn't so much getting the state as ensuring it's in a usable state, or it's conflating error codes with the SBE state. Maybe sbefifo_is_ready()?

Hrm... I would expect something called is_something() to return a boolean, while here I have 3 different result codes as I want to differenciate busy. I'm also adding some more in the next version to extract the bit indicating that an SBE async FFDC is present.

So what about calling it sbefifo_check_sbe_state() instead ?

IE. It's not a "getter" ..

.../...

Quoted 29 lines

Quoted 29 lines

drivers/fsi/fsi-sbefifo.c new file +12 -0

+/**
+ * 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,

drivers/fsi/fsi-sbefifo.c new file +11 -0

+		   __be32 *response, size_t *resp_len)
+{
+	struct sbefifo *sbefifo = dev_get_drvdata(dev);
+	mm_segment_t old_fs;
+	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)

drivers/fsi/fsi-sbefifo.c new file +4 -0

+		return -EINVAL;
+
+	mutex_lock(&sbefifo->lock);
+	old_fs = get_fs();

Quoted 10 lines

drivers/fsi/fsi-sbefifo.c line 567

Quoted 4 lines

drivers/fsi/fsi-sbefifo.c new file +4 -0

+	set_fs(KERNEL_DS);
+	rc = __sbefifo_submit(sbefifo, command, cmd_len,
+			      response, resp_len);
+	set_fs(old_fs);  

Can you talk about why the get_fs()/set_fs()/set_fs() sequence is the right way to go here when there's been discussion in the past about removing the whole show?

Interesting, I had missed that conversation/debate, it's an old API but I've been around for a long time :-) It used to be the way to do that sort of thing.

The above use is a rather safe since the oops case has been fixed, but if it's actively being phased out then I should try to find a different way, though sadly nothing will be as simple and efficient as the above.

Nick, you added some of that iovec stuff, what do you think is the right construct here ?

I read from the HW fifo synchronously and currently just put_user() one word at a time into the destination buffer, which can be either a user address (read() syscall to the driver) or a kernel address (in-kernel API).

The old code just had 2 pointer argument, one kernel pointer and one user pointer and would write to which ever was populated, which I thought was gross.

The iovec stuff looks ... complicated for such a simple use case.

Replace open/close/write/read API with the simple submit() API and the helper to parse status.

This doesn't yet extract FFDC

Signed-off-by Benjamin Herrenschmidt <[email protected]>

---
 drivers/fsi/Makefile       |   2 +-
 drivers/fsi/fsi-occ.c      | 202 +++++++++++++++++--------------------
 drivers/hwmon/occ/Makefile |   2 +-
 3 files changed, 94 insertions(+), 112 deletions(-)

drivers/fsi/Makefile +1 -1

index f331e929423c..75fdc6d8cfc4 100644
@@ -4,4 +4,4 @@ obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
 obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
-#obj-$(CONFIG_FSI_OCC) += fsi-occ.o
+obj-$(CONFIG_FSI_OCC) += fsi-occ.o

drivers/fsi/fsi-occ.c +46 -78

index d368b62e5471..bdee26096688 100644
@@ -36,6 +36,13 @@
 #define OCC_CMD_DATA_BYTES	4090
 #define OCC_RESP_DATA_BYTES	4089
 
+/*
+ * Assume we don't have FFDC, if we do we'll overflow and
+ * fail the command. This needs to be big enough for simple
+ * commands as well.
+ */
+#define OCC_SBE_STATUS_WORDS	16
+
 #define OCC_TIMEOUT_MS		1000
 #define OCC_CMD_IN_PRG_WAIT_MS	50
 

@@ -447,110 +454,71 @@ static int occ_verify_checksum(struct 
 occ_response *resp, u16 data_length)
 	return 0;
 }
 
-static int occ_write_sbefifo(struct sbefifo_client *client, const char *buf,
-			     ssize_t len)
-{
-	int rc;
-	ssize_t total = 0;
-
-	do {
-		rc = sbefifo_drv_write(client, &buf[total], len - total);
-		if (rc < 0)
-			return rc;
-		else if (!rc)
-			break;
-
-		total += rc;
-	} while (total < len);
-
-	return (total == len) ? 0 : -ENOSPC;
-}
-
-static int occ_read_sbefifo(struct sbefifo_client *client, char *buf,
-			    ssize_t len)
-{
-	int rc;
-	ssize_t total = 0;
-
-	do {
-		rc = sbefifo_drv_read(client, &buf[total], len - total);
-		if (rc < 0)
-			return rc;
-		else if (!rc)
-			break;
-
-		total += rc;
-	} while (total < len);
-
-	return (total == len) ? 0 : -ENODATA;
-}
-
 static int occ_getsram(struct device *sbefifo, u32 address, u8 *data,
 		       ssize_t len)
 {
-	int rc;
-	u8 *resp;
-	__be32 buf[5];
 	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
-	struct sbefifo_client *client;
+	size_t resp_len, resp_data_len;
+	__be32 *resp, cmd[5];
+	int rc;
 
 	/*
 	 * Magic sequence to do SBE getsram command. SBE will fetch data from
 	 * specified SRAM address.
 	 */
-	buf[0] = cpu_to_be32(0x5);
-	buf[1] = cpu_to_be32(0xa403);
-	buf[2] = cpu_to_be32(1);
-	buf[3] = cpu_to_be32(address);
-	buf[4] = cpu_to_be32(data_len);
-
-	client = sbefifo_drv_open(sbefifo, 0);
-	if (!client)
-		return -ENODEV;
-
-	rc = occ_write_sbefifo(client, (const char *)buf, sizeof(buf));
-	if (rc)
-		goto done;
-
-	resp = kzalloc(data_len, GFP_KERNEL);
-	if (!resp) {
-		rc = -ENOMEM;
-		goto done;
-	}
+	cmd[0] = cpu_to_be32(0x5);
+	cmd[1] = cpu_to_be32(0xa403);
+	cmd[2] = cpu_to_be32(1);
+	cmd[3] = cpu_to_be32(address);
+	cmd[4] = cpu_to_be32(data_len);
+
+	resp_len = (data_len >> 2) + OCC_SBE_STATUS_WORDS;
+	resp = kzalloc(resp_len << 2 , GFP_KERNEL);
+	if (!resp)
+		return -ENOMEM;
 
-	rc = occ_read_sbefifo(client, (char *)resp, data_len);
+	rc = sbefifo_submit(sbefifo, cmd, 5, resp, &resp_len);
 	if (rc)
 		goto free;
-
-	/* check for good response */
-	rc = occ_read_sbefifo(client, (char *)buf, 8);
+	rc = sbefifo_parse_status(0xa403, resp, resp_len, &resp_len);
 	if (rc)
 		goto free;
 
-	if ((be32_to_cpu(buf[0]) == data_len) &&
-	    (be32_to_cpu(buf[1]) == 0xC0DEA403))
-		memcpy(data, resp, len);
-	else
+	resp_data_len = be32_to_cpu(resp[resp_len - 1]);
+	if (resp_data_len != data_len) {
+		pr_err("occ: SRAM read expected %d bytes got %d\n",
+		       data_len, resp_data_len);
 		rc = -EBADMSG;
+	} else {
+		memcpy(data, resp, len);
+	}
 
 free:
+	/* Convert positive SBEI status */
+	if (rc > 0) {
+		pr_err("occ: SRAM read returned failure status: %08x\n", rc);
+		rc = -EBADMSG;
+	}
 	kfree(resp);
-
-done:
-	sbefifo_drv_release(client);
 	return rc;
 }
 
 static int occ_putsram(struct device *sbefifo, u32 address, u8 *data,
 		       ssize_t len)
 {
-	int rc;
-	__be32 *buf;
+	size_t cmd_len, buf_len, resp_len, resp_data_len;
 	u32 data_len = ((len + 7) / 8) * 8;	/* must be multiples of 8 B */
-	size_t cmd_len = data_len + 20;
-	struct sbefifo_client *client;
+	__be32 *buf;
+	int rc;
 
-	buf = kzalloc(cmd_len, GFP_KERNEL);
+	/*
+	 * We use the same buffer for command and response, make
+	 * sure it's big enough
+	 */
+	resp_len = OCC_SBE_STATUS_WORDS;
+	cmd_len = (data_len >> 2) + 5;
+	buf_len = max(cmd_len, resp_len);
+	buf = kzalloc(buf_len << 2, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;

@@ -558,7 +526,7 @@ static int occ_putsram(struct device *sbefifo, u32 
 address, u8 *data,
 	 * Magic sequence to do SBE putsram command. SBE will transfer
 	 * data to specified SRAM address.
 	 */
-	buf[0] = cpu_to_be32(0x5 + (data_len / 4));
+	buf[0] = cpu_to_be32(cmd_len);
 	buf[1] = cpu_to_be32(0xa404);
 	buf[2] = cpu_to_be32(1);

drivers/fsi/fsi-occ.c +25 -19

 	buf[3] = cpu_to_be32(address);

@@ -566,37 +534,43 @@ static int occ_putsram(struct device *sbefifo, u32 
 address, u8 *data,
 
 	memcpy(&buf[5], data, len);
 
-	client = sbefifo_drv_open(sbefifo, 0);
-	if (!client) {
-		rc = -ENODEV;
-		goto free;
-	}
-
-	rc = occ_write_sbefifo(client, (const char *)buf, cmd_len);
+	rc = sbefifo_submit(sbefifo, buf, cmd_len, buf, &resp_len);
 	if (rc)
-		goto done;
-
-	rc = occ_read_sbefifo(client, (char *)buf, 8);
+		goto free;
+	rc = sbefifo_parse_status(0xa404, buf, resp_len, &resp_len);
 	if (rc)
-		goto done;
+		goto free;
 
-	/* check for good response */
-	if ((be32_to_cpu(buf[0]) != data_len) ||
-	    (be32_to_cpu(buf[1]) != 0xC0DEA404))
+	if (resp_len != 1) {
+		pr_err("occ: SRAM write response lenght invalid: %d\n",
+		       resp_len);
 		rc = -EBADMSG;
-
-done:
-	sbefifo_drv_release(client);
+	} else {
+		resp_data_len = be32_to_cpu(buf[0]);
+		if (resp_data_len != data_len) {
+			pr_err("occ: SRAM write expected %d bytes got %d\n",
+			       data_len, resp_data_len);
+			rc = -EBADMSG;
+		}
+	}
 free:
+	/* Convert positive SBEI status */
+	if (rc > 0) {
+		pr_err("occ: SRAM write returned failure status: %08x\n", rc);
+		rc = -EBADMSG;
+	}
 	kfree(buf);
 	return rc;
 }
 
 static int occ_trigger_attn(struct device *sbefifo)
 {
+	__be32 buf[OCC_SBE_STATUS_WORDS];
+	size_t resp_len, resp_data_len;
 	int rc;
-	__be32 buf[7];
-	struct sbefifo_client *client;
+
+	BUILD_BUG_ON(OCC_SBE_STATUS_WORDS < 7);
+	resp_len = OCC_SBE_STATUS_WORDS;
 
 	buf[0] = cpu_to_be32(0x5 + 0x2);        /* Chip-op length in words */

drivers/fsi/fsi-occ.c +21 -13

 	buf[1] = cpu_to_be32(0xa404);           /* PutOCCSRAM */

@@ -606,24 +580,32 @@ static int occ_trigger_attn(struct device *sbefifo)
 	buf[5] = cpu_to_be32(0x20010000);       /* Trigger OCC attention */
 	buf[6] = 0;
 
-	client = sbefifo_drv_open(sbefifo, 0);
-	if (!client)
-		return -ENODEV;
-
-	rc = occ_write_sbefifo(client, (const char *)buf, sizeof(buf));
+	rc = sbefifo_submit(sbefifo, buf, 7, buf, &resp_len);
 	if (rc)
-		goto done;
-
-	rc = occ_read_sbefifo(client, (char *)buf, 8);
+		goto error;
+	rc = sbefifo_parse_status(0xa404, buf, resp_len, &resp_len);
 	if (rc)
-		goto done;
+		goto error;
 
-	/* check for good response */
-	if ((be32_to_cpu(buf[0]) != 8) || (be32_to_cpu(buf[1]) != 0xC0DEA404))
+	if (resp_len != 1) {
+		pr_err("occ: SRAM attn response lenght invalid: %d\n",
+		       resp_len);
 		rc = -EBADMSG;
+	} else {
+		resp_data_len = be32_to_cpu(buf[0]);
+		if (resp_data_len != 8) {
+			pr_err("occ: SRAM attn expected 8 bytes got %d\n",
+			       resp_data_len);
+			rc = -EBADMSG;
+		}
+	}
+ error:
+	/* Convert positive SBEI status */
+	if (rc > 0) {
+		pr_err("occ: SRAM attn returned failure status: %08x\n", rc);
+		rc = -EBADMSG;
+	}
 
-done:
-	sbefifo_drv_release(client);
 
 	return rc;
 }

drivers/hwmon/occ/Makefile +1 -1

index ca6d25ae9da8..ab5c3e965ccb 100644
@@ -1,7 +1,7 @@
 occ-hwmon-objs := common.o
 
 ifeq ($(CONFIG_SENSORS_OCC_P9_SBE), y)
-#occ-hwmon-objs += p9_sbe.o
+occ-hwmon-objs += p9_sbe.o
 endif
 
 ifeq ($(CONFIG_SENSORS_OCC_P8_I2C), y)

Signature · 1 line

2.17.0

And remporarily disable build of fsi-occ

---
 drivers/fsi/Makefile        |    4 +-
 drivers/fsi/fsi-sbefifo.c   | 1071 -----------------------------------
 drivers/hwmon/occ/Makefile  |    2 +-
 include/linux/fsi-sbefifo.h |   30 -
 4 files changed, 3 insertions(+), 1104 deletions(-)
 delete mode 100644 drivers/fsi/fsi-sbefifo.c
 delete mode 100644 include/linux/fsi-sbefifo.h

drivers/fsi/Makefile +2 -2

index 75fdc6d8cfc4..61e8e420c7ed 100644
@@ -3,5 +3,5 @@ obj-$(CONFIG_FSI) += fsi-core.o
 obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
-obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
-obj-$(CONFIG_FSI_OCC) += fsi-occ.o
+#obj-$(CONFIG_FSI_SBEFIFO) += fsi-sbefifo.o
+#obj-$(CONFIG_FSI_OCC) += fsi-occ.o

drivers/fsi/fsi-sbefifo.c deleted +0 -1071

deleted file mode 100644
index cc9b9e36ac72..000000000000
@@ -1,1071 +0,0 @@
-/*
- * 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/kref.h>
-#include <linux/list.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/poll.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/uaccess.h>
-#include <linux/wait.h>
-#include <linux/workqueue.h>
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/sbefifo.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
-#define SBEFIFO_BUF_CNT		32
-
-#define SBEFIFO_UP		0x00	/* Up register offset */
-#define SBEFIFO_DWN		0x40	/* Down register offset */
-
-#define SBEFIFO_STS		0x04
-#define   SBEFIFO_EMPTY			BIT(20)
-#define   SBEFIFO_STS_RESET_REQ		BIT(25)
-#define SBEFIFO_EOT_RAISE	0x08
-#define   SBEFIFO_EOT_MAGIC		0xffffffff
-#define SBEFIFO_REQ_RESET	0x0C
-#define SBEFIFO_EOT_ACK		0x14
-
-#define SBEFIFO_RESCHEDULE	msecs_to_jiffies(500)
-#define SBEFIFO_MAX_RESCHDULE	msecs_to_jiffies(5000)
-
-struct sbefifo {
-	struct delayed_work work;
-	struct fsi_device *fsi_dev;
-	struct miscdevice mdev;
-	wait_queue_head_t wait;
-	struct list_head xfrs;
-	struct kref kref;
-	struct mutex list_lock;		/* lock access to the xfrs list */
-	struct mutex sbefifo_lock;	/* lock access to the hardware */
-	char name[32];
-	int idx;
-	int rc;
-};
-
-struct sbefifo_buf {
-	u32 buf[SBEFIFO_BUF_CNT];
-	unsigned long flags;
-#define SBEFIFO_BUF_FULL		1
-	u32 *rpos;
-	u32 *wpos;
-};
-
-struct sbefifo_xfr {
-	unsigned long wait_data_timeout;
-	struct sbefifo_buf *rbuf;
-	struct sbefifo_buf *wbuf;
-	struct list_head client;
-	struct list_head xfrs;
-	unsigned long flags;
-#define SBEFIFO_XFR_WRITE_DONE		1
-#define SBEFIFO_XFR_RESP_PENDING	2
-#define SBEFIFO_XFR_COMPLETE		3
-#define SBEFIFO_XFR_CANCEL		4
-};
-
-struct sbefifo_client {
-	struct sbefifo_buf rbuf;
-	struct sbefifo_buf wbuf;
-	struct list_head xfrs;
-	struct sbefifo *dev;
-	struct kref kref;
-	unsigned long f_flags;
-};
-
-static struct workqueue_struct *sbefifo_wq;
-
-static DEFINE_IDA(sbefifo_ida);
-
-static int sbefifo_inw(struct sbefifo *sbefifo, int reg, u32 *word)
-{
-	int rc;
-	__be32 raw_word;
-
-	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_outw(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));
-}
-
-/* Don't flip endianness of data to/from FIFO, just pass through. */
-static int sbefifo_readw(struct sbefifo *sbefifo, u32 *word)
-{
-	return fsi_device_read(sbefifo->fsi_dev, SBEFIFO_DWN, word,
-			       sizeof(*word));
-}
-
-static int sbefifo_writew(struct sbefifo *sbefifo, u32 word)
-{
-	return fsi_device_write(sbefifo->fsi_dev, SBEFIFO_UP, &word,
-				sizeof(word));
-}
-
-static int sbefifo_ack_eot(struct sbefifo *sbefifo)
-{
-	u32 discard;
-	int ret;
-
-	 /* Discard the EOT word. */
-	ret = sbefifo_readw(sbefifo, &discard);
-	if (ret)
-		return ret;
-
-	return sbefifo_outw(sbefifo, SBEFIFO_DWN | SBEFIFO_EOT_ACK,
-			    SBEFIFO_EOT_MAGIC);
-}
-
-static size_t sbefifo_dev_nwreadable(u32 sts)
-{
-	static const u32 FIFO_NTRY_CNT_MSK = 0x000f0000;
-	static const unsigned int FIFO_NTRY_CNT_SHIFT = 16;
-
-	return (sts & FIFO_NTRY_CNT_MSK) >> FIFO_NTRY_CNT_SHIFT;
-}
-
-static size_t sbefifo_dev_nwwriteable(u32 sts)
-{
-	static const size_t FIFO_DEPTH = 8;
-
-	return FIFO_DEPTH - sbefifo_dev_nwreadable(sts);
-}
-
-static void sbefifo_buf_init(struct sbefifo_buf *buf)
-{
-	WRITE_ONCE(buf->flags, 0);
-	WRITE_ONCE(buf->rpos, buf->buf);
-	WRITE_ONCE(buf->wpos, buf->buf);
-}
-
-static size_t sbefifo_buf_nbreadable(struct sbefifo_buf *buf)
-{
-	size_t n;
-	u32 *rpos = READ_ONCE(buf->rpos);
-	u32 *wpos = READ_ONCE(buf->wpos);
-
-	if (test_bit(SBEFIFO_BUF_FULL, &buf->flags))
-		n = SBEFIFO_BUF_CNT;
-	else if (rpos <= wpos)
-		n = wpos - rpos;
-	else
-		n = (buf->buf + SBEFIFO_BUF_CNT) - rpos;
-
-	return n << 2;
-}
-
-static size_t sbefifo_buf_nbwriteable(struct sbefifo_buf *buf)
-{
-	size_t n;
-	u32 *rpos = READ_ONCE(buf->rpos);
-	u32 *wpos = READ_ONCE(buf->wpos);
-
-	if (test_bit(SBEFIFO_BUF_FULL, &buf->flags))
-		n = 0;
-	else if (wpos < rpos)
-		n = rpos - wpos;
-	else
-		n = (buf->buf + SBEFIFO_BUF_CNT) - wpos;
-
-	return n << 2;
-}
-
-/*
- * Update pointers and flags after doing a buffer read.  Return true if the
- * buffer is now empty;
- */
-static bool sbefifo_buf_readnb(struct sbefifo_buf *buf, size_t n)
-{
-	u32 *rpos = READ_ONCE(buf->rpos);
-	u32 *wpos = READ_ONCE(buf->wpos);
-
-	if (n)
-		clear_bit(SBEFIFO_BUF_FULL, &buf->flags);
-
-	rpos += (n >> 2);
-	if (rpos == buf->buf + SBEFIFO_BUF_CNT)
-		rpos = buf->buf;
-
-	WRITE_ONCE(buf->rpos, rpos);
-
-	return rpos == wpos;
-}
-
-/*
- * Update pointers and flags after doing a buffer write.  Return true if the
- * buffer is now full.
- */
-static bool sbefifo_buf_wrotenb(struct sbefifo_buf *buf, size_t n)
-{
-	u32 *rpos = READ_ONCE(buf->rpos);
-	u32 *wpos = READ_ONCE(buf->wpos);
-
-	wpos += (n >> 2);
-	if (wpos == buf->buf + SBEFIFO_BUF_CNT)
-		wpos = buf->buf;
-	if (wpos == rpos)
-		set_bit(SBEFIFO_BUF_FULL, &buf->flags);
-
-	WRITE_ONCE(buf->wpos, wpos);
-
-	return rpos == wpos;
-}
-
-static void sbefifo_free(struct kref *kref)
-{
-	struct sbefifo *sbefifo = container_of(kref, struct sbefifo, kref);
-
-	kfree(sbefifo);
-}
-
-static void sbefifo_get(struct sbefifo *sbefifo)
-{
-	kref_get(&sbefifo->kref);
-}
-
-static void sbefifo_put(struct sbefifo *sbefifo)
-{
-	kref_put(&sbefifo->kref, sbefifo_free);
-}
-
-static struct sbefifo_xfr *sbefifo_enq_xfr(struct sbefifo_client *client)
-{
-	struct sbefifo *sbefifo = client->dev;
-	struct sbefifo_xfr *xfr;
-
-	if (READ_ONCE(sbefifo->rc))
-		return ERR_PTR(sbefifo->rc);
-
-	xfr = kzalloc(sizeof(*xfr), GFP_KERNEL);
-	if (!xfr)
-		return ERR_PTR(-ENOMEM);
-
-	trace_sbefifo_enq_xfer(client, xfr);
-
-	xfr->rbuf = &client->rbuf;
-	xfr->wbuf = &client->wbuf;
-	list_add_tail(&xfr->xfrs, &sbefifo->xfrs);
-	list_add_tail(&xfr->client, &client->xfrs);
-
-	return xfr;
-}
-
-static bool sbefifo_xfr_rsp_pending(struct sbefifo_client *client)
-{
-	struct sbefifo_xfr *xfr = list_first_entry_or_null(&client->xfrs,
-							   struct sbefifo_xfr,
-							   client);
-
-	if (xfr && test_bit(SBEFIFO_XFR_RESP_PENDING, &xfr->flags))
-		return true;
-
-	return false;
-}
-
-static struct sbefifo_client *sbefifo_new_client(struct sbefifo *sbefifo)
-{
-	struct sbefifo_client *client;
-
-	client = kzalloc(sizeof(*client), GFP_KERNEL);
-	if (!client)
-		return NULL;
-
-	trace_sbefifo_new_client(client);
-
-	kref_init(&client->kref);
-	client->dev = sbefifo;
-	sbefifo_buf_init(&client->rbuf);
-	sbefifo_buf_init(&client->wbuf);
-	INIT_LIST_HEAD(&client->xfrs);
-
-	sbefifo_get(sbefifo);
-
-	return client;
-}
-
-static void sbefifo_release_client(struct kref *kref)
-{
-	struct sbefifo *sbefifo;
-	struct sbefifo_client *client;
-	struct sbefifo_xfr *xfr, *tmp;
-
-	client = container_of(kref, struct sbefifo_client, kref);
-	sbefifo = client->dev;
-
-	if (!READ_ONCE(sbefifo->rc)) {
-		list_for_each_entry_safe(xfr, tmp, &client->xfrs, client) {
-			if (test_bit(SBEFIFO_XFR_COMPLETE, &xfr->flags)) {
-				list_del(&xfr->client);
-				kfree(xfr);
-				continue;
-			}
-
-			/*
-			 * The client left with pending or running xfrs.
-			 * Cancel them.
-			 */
-			set_bit(SBEFIFO_XFR_CANCEL, &xfr->flags);
-			sbefifo_get(sbefifo);
-			if (!queue_work(sbefifo_wq, &sbefifo->work.work))
-				sbefifo_put(sbefifo);
-		}
-	}
-
-	sbefifo_put(sbefifo);
-	trace_sbefifo_release_client(client);
-	kfree(client);
-}
-
-static void sbefifo_get_client(struct sbefifo_client *client)
-{
-	kref_get(&client->kref);
-}
-
-static void sbefifo_put_client(struct sbefifo_client *client)
-{
-	kref_put(&client->kref, sbefifo_release_client);
-}
-
-static struct sbefifo_xfr *sbefifo_next_xfr(struct sbefifo *sbefifo)
-{
-	struct sbefifo_xfr *xfr, *tmp;
-
-	list_for_each_entry_safe(xfr, tmp, &sbefifo->xfrs, xfrs) {
-		if (unlikely(test_bit(SBEFIFO_XFR_CANCEL, &xfr->flags))) {
-			/* Discard cancelled transfers. */
-			list_del(&xfr->xfrs);
-			kfree(xfr);
-			continue;
-		}
-
-		return xfr;
-	}
-
-	return NULL;
-}
-
-static void sbefifo_worker(struct work_struct *work)
-{
-	static const unsigned long EOT_MASK = 0x000000ff;
-	struct delayed_work *dwork = to_delayed_work(work);
-	struct sbefifo *sbefifo = container_of(dwork, struct sbefifo, work);
-	struct sbefifo_buf *rbuf, *wbuf;
-	struct sbefifo_xfr *xfr, *tmp;
-	struct sbefifo_buf drain;
-	size_t devn, bufn;
-	int eot = 0;
-	int ret = 0;
-	u32 sts;
-	int i;
-
-	mutex_lock(&sbefifo->list_lock);
-	xfr = list_first_entry_or_null(&sbefifo->xfrs, struct sbefifo_xfr,
-				       xfrs);
-	mutex_unlock(&sbefifo->list_lock);
-	if (!xfr)
-		return;
-
-	mutex_lock(&sbefifo->sbefifo_lock);
-
-	trace_sbefifo_begin_xfer(xfr);
-
-again:
-	rbuf = xfr->rbuf;
-	wbuf = xfr->wbuf;
-
-	if (unlikely(test_bit(SBEFIFO_XFR_CANCEL, &xfr->flags))) {
-		/* The client left. */
-		rbuf = &drain;
-		wbuf = &drain;
-		sbefifo_buf_init(&drain);
-		if (!test_bit(SBEFIFO_XFR_RESP_PENDING, &xfr->flags))
-			set_bit(SBEFIFO_XFR_WRITE_DONE, &xfr->flags);
-	}
-
-	 /* Drain the write buffer. */
-	while ((bufn = sbefifo_buf_nbreadable(wbuf))) {
-		ret = sbefifo_inw(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &sts);
-		if (ret)
-			goto out;
-
-		devn = sbefifo_dev_nwwriteable(sts);
-		if (devn == 0) {
-			/* No open slot for write.  Reschedule. */
-			queue_delayed_work(sbefifo_wq, &sbefifo->work,
-					   SBEFIFO_RESCHEDULE);
-			goto out_unlock;
-		}
-
-		devn = min_t(size_t, devn, bufn >> 2);
-		for (i = 0; i < devn; i++) {
-			ret = sbefifo_writew(sbefifo, *wbuf->rpos);
-			if (ret)
-				goto out;
-
-			sbefifo_buf_readnb(wbuf, 1 << 2);
-		}
-	}
-
-	 /* Send EOT if the writer is finished. */
-	if (test_and_clear_bit(SBEFIFO_XFR_WRITE_DONE, &xfr->flags)) {
-		ret = sbefifo_outw(sbefifo, SBEFIFO_UP | SBEFIFO_EOT_RAISE,
-				   SBEFIFO_EOT_MAGIC);
-		if (ret)
-			goto out;
-
-		/* Inform reschedules that the writer is finished. */
-		set_bit(SBEFIFO_XFR_RESP_PENDING, &xfr->flags);
-	}
-
-	/* Nothing left to do if the writer is not finished. */
-	if (!test_bit(SBEFIFO_XFR_RESP_PENDING, &xfr->flags))
-		goto out;
-
-	 /* Fill the read buffer. */
-	while ((bufn = sbefifo_buf_nbwriteable(rbuf))) {
-		ret = sbefifo_inw(sbefifo, SBEFIFO_DWN | SBEFIFO_STS, &sts);
-		if (ret)
-			goto out;
-
-		devn = sbefifo_dev_nwreadable(sts);
-		if (devn == 0) {
-			/*
-			 * Limit the maximum waiting period for data in the
-			 * FIFO. If the SBE isn't running, we will wait
-			 * forever.
-			 */
-			if (!xfr->wait_data_timeout) {
-				xfr->wait_data_timeout =
-					jiffies + SBEFIFO_MAX_RESCHDULE;
-			} else if (time_after(jiffies,
-					      xfr->wait_data_timeout)) {
-				ret = -ETIME;
-				goto out;
-			}
-
-			/* No data yet.  Reschedule. */
-			queue_delayed_work(sbefifo_wq, &sbefifo->work,
-					   SBEFIFO_RESCHEDULE);
-			goto out_unlock;
-		} else {
-			xfr->wait_data_timeout = 0;
-		}
-
-		/* Fill.  The EOT word is discarded.  */
-		devn = min_t(size_t, devn, bufn >> 2);
-		eot = (sts & EOT_MASK) != 0;
-		if (eot)
-			devn--;
-
-		for (i = 0; i < devn; i++) {
-			ret = sbefifo_readw(sbefifo, rbuf->wpos);
-			if (ret)
-				goto out;
-
-			if (likely(!test_bit(SBEFIFO_XFR_CANCEL, &xfr->flags)))
-				sbefifo_buf_wrotenb(rbuf, 1 << 2);
-		}
-
-		if (eot) {
-			ret = sbefifo_ack_eot(sbefifo);
-			if (ret)
-				goto out;
-
-			set_bit(SBEFIFO_XFR_COMPLETE, &xfr->flags);
-
-			mutex_lock(&sbefifo->list_lock);
-			list_del(&xfr->xfrs);
-			mutex_unlock(&sbefifo->list_lock);
-
-			if (unlikely(test_bit(SBEFIFO_XFR_CANCEL,
-					      &xfr->flags)))
-				kfree(xfr);
-			break;
-		}
-	}
-
-out:
-	trace_sbefifo_end_xfer(xfr, ret);
-
-	if (unlikely(ret)) {
-		sbefifo->rc = ret;
-		dev_err(&sbefifo->fsi_dev->dev,
-			"Fatal bus access failure: %d\n", ret);
-
-		mutex_lock(&sbefifo->list_lock);
-		list_for_each_entry_safe(xfr, tmp, &sbefifo->xfrs, xfrs) {
-			list_del(&xfr->xfrs);
-			kfree(xfr);
-		}
-		INIT_LIST_HEAD(&sbefifo->xfrs);
-		mutex_unlock(&sbefifo->list_lock);
-	} else if (eot) {
-		mutex_lock(&sbefifo->list_lock);
-		xfr = sbefifo_next_xfr(sbefifo);
-		mutex_unlock(&sbefifo->list_lock);
-
-		if (xfr) {
-			wake_up_interruptible(&sbefifo->wait);
-			goto again;
-		}
-	}
-
-	sbefifo_put(sbefifo);
-	wake_up_interruptible(&sbefifo->wait);
-
-out_unlock:
-	mutex_unlock(&sbefifo->sbefifo_lock);
-}
-
-static int sbefifo_open(struct inode *inode, struct file *file)
-{
-	struct sbefifo *sbefifo = container_of(file->private_data,
-					       struct sbefifo, mdev);
-	struct sbefifo_client *client;
-	int ret;
-
-	ret = READ_ONCE(sbefifo->rc);
-	if (ret)
-		return ret;
-
-	client = sbefifo_new_client(sbefifo);
-	if (!client)
-		return -ENOMEM;
-
-	file->private_data = client;
-	client->f_flags = file->f_flags;
-
-	return 0;
-}
-
-static unsigned int sbefifo_poll(struct file *file, poll_table *wait)
-{
-	struct sbefifo_client *client = file->private_data;
-	struct sbefifo *sbefifo = client->dev;
-	unsigned int mask = 0;
-
-	poll_wait(file, &sbefifo->wait, wait);
-
-	if (READ_ONCE(sbefifo->rc))
-		mask |= POLLERR;
-
-	if (sbefifo_buf_nbreadable(&client->rbuf))
-		mask |= POLLIN;
-
-	if (sbefifo_buf_nbwriteable(&client->wbuf))
-		mask |= POLLOUT;
-
-	return mask;
-}
-
-static bool sbefifo_read_ready(struct sbefifo *sbefifo,
-			       struct sbefifo_client *client, size_t *n,
-			       size_t *ret)
-{
-	struct sbefifo_xfr *xfr = list_first_entry_or_null(&client->xfrs,
-							   struct sbefifo_xfr,
-							   client);
-
-	*n = sbefifo_buf_nbreadable(&client->rbuf);
-	*ret = READ_ONCE(sbefifo->rc);
-
-	return *ret || *n ||
-		(xfr && test_bit(SBEFIFO_XFR_COMPLETE, &xfr->flags));
-}
-
-static ssize_t sbefifo_read_common(struct sbefifo_client *client,
-				   char __user *ubuf, char *kbuf, size_t len)
-{
-	struct sbefifo *sbefifo = client->dev;
-	struct sbefifo_xfr *xfr;
-	size_t n;
-	ssize_t ret = 0;
-
-	if ((len >> 2) << 2 != len)
-		return -EINVAL;
-
-	if ((client->f_flags & O_NONBLOCK) && !sbefifo_xfr_rsp_pending(client))
-		return -EAGAIN;
-
-	sbefifo_get_client(client);
-	if (wait_event_interruptible(sbefifo->wait,
-				     sbefifo_read_ready(sbefifo, client, &n,
-							&ret))) {
-		ret = -ERESTARTSYS;
-		goto out;
-	}
-
-	if (ret) {
-		INIT_LIST_HEAD(&client->xfrs);
-		goto out;
-	}
-
-	trace_sbefifo_deq_xfer(client, list_first_entry_or_null(&client->xfrs,
-							   struct sbefifo_xfr,
-							   client));
-
-	n = min_t(size_t, n, len);
-
-	if (ubuf) {
-		if (copy_to_user(ubuf, READ_ONCE(client->rbuf.rpos), n)) {
-			ret = -EFAULT;
-			goto out;
-		}
-	} else {
-		memcpy(kbuf, READ_ONCE(client->rbuf.rpos), n);
-	}
-
-	if (sbefifo_buf_readnb(&client->rbuf, n)) {
-		xfr = list_first_entry_or_null(&client->xfrs,
-					       struct sbefifo_xfr, client);
-		if (!xfr) {
-			/* should be impossible to not have an xfr here */
-			WARN_ONCE(1, "no xfr in queue");
-			ret = -EPROTO;
-			goto out;
-		}
-
-		if (!test_bit(SBEFIFO_XFR_COMPLETE, &xfr->flags)) {
-			/* Fill the read buffer back up. */
-			sbefifo_get(sbefifo);
-			if (!queue_work(sbefifo_wq, &sbefifo->work.work))
-				sbefifo_put(sbefifo);
-		} else {
-			list_del(&xfr->client);
-			kfree(xfr);
-			wake_up_interruptible(&sbefifo->wait);
-		}
-	}
-
-	ret = n;
-
-out:
-	sbefifo_put_client(client);
-	return ret;
-}
-
-static ssize_t sbefifo_read(struct file *file, char __user *buf, size_t len,
-			    loff_t *offset)
-{
-	struct sbefifo_client *client = file->private_data;
-
-	return sbefifo_read_common(client, buf, NULL, len);
-}
-
-static bool sbefifo_write_ready(struct sbefifo *sbefifo,
-				struct sbefifo_xfr *xfr,
-				struct sbefifo_client *client, size_t *n)
-{
-	struct sbefifo_xfr *next = list_first_entry_or_null(&client->xfrs,
-							    struct sbefifo_xfr,
-							    client);
-
-	*n = sbefifo_buf_nbwriteable(&client->wbuf);
-	return READ_ONCE(sbefifo->rc) || (next == xfr && *n);
-}
-
-static ssize_t sbefifo_write_common(struct sbefifo_client *client,
-				    const char __user *ubuf, const char *kbuf,
-				    size_t len)
-{
-	struct sbefifo *sbefifo = client->dev;
-	struct sbefifo_xfr *xfr;
-	ssize_t ret = 0;
-	size_t n;
-
-	if ((len >> 2) << 2 != len)
-		return -EINVAL;
-
-	if (!len)
-		return 0;
-
-	sbefifo_get_client(client);
-	n = sbefifo_buf_nbwriteable(&client->wbuf);
-
-	mutex_lock(&sbefifo->list_lock);
- 
-	/* next xfr to be executed */
-	xfr = list_first_entry_or_null(&sbefifo->xfrs, struct sbefifo_xfr,
-				       xfrs);
-
-	if ((client->f_flags & O_NONBLOCK) && xfr && n < len) {
-		mutex_unlock(&sbefifo->list_lock);
-		ret = -EAGAIN;
-		goto out;
-	}
-
-	xfr = sbefifo_enq_xfr(client);		/* this xfr queued up */
-	if (IS_ERR(xfr)) {
-		mutex_unlock(&sbefifo->list_lock);
-		ret = PTR_ERR(xfr);
-		goto out;
-	}
-
-	mutex_unlock(&sbefifo->list_lock);
-
-	/*
-	 * Partial writes are not really allowed in that EOT is sent exactly
-	 * once per write.
-	 */
-	while (len) {
-		if (wait_event_interruptible(sbefifo->wait,
-					     sbefifo_write_ready(sbefifo, xfr,
-								 client,
-								 &n))) {
-			set_bit(SBEFIFO_XFR_CANCEL, &xfr->flags);
-			sbefifo_get(sbefifo);
-			if (!queue_work(sbefifo_wq, &sbefifo->work.work))
-				sbefifo_put(sbefifo);
-
-			ret = -ERESTARTSYS;
-			goto out;
-		}
-
-		if (sbefifo->rc) {
-			INIT_LIST_HEAD(&client->xfrs);
-			ret = sbefifo->rc;
-			goto out;
-		}
-
-		n = min_t(size_t, n, len);
-
-		if (ubuf) {
-			if (copy_from_user(READ_ONCE(client->wbuf.wpos), ubuf,
-			    n)) {
-				set_bit(SBEFIFO_XFR_CANCEL, &xfr->flags);
-				sbefifo_get(sbefifo);
-				if (!queue_work(sbefifo_wq,
-						&sbefifo->work.work))
-					sbefifo_put(sbefifo);
-				ret = -EFAULT;
-				goto out;
-			}
-
-			ubuf += n;
-		} else {
-			memcpy(READ_ONCE(client->wbuf.wpos), kbuf, n);
-			kbuf += n;
-		}
-
-		sbefifo_buf_wrotenb(&client->wbuf, n);
-		len -= n;
-		ret += n;
-
-		/*
-		 * Set this before starting timer to avoid race condition on
-		 * this flag with the timer function writer.
-		 */
-		if (!len)
-			set_bit(SBEFIFO_XFR_WRITE_DONE, &xfr->flags);
-
-		/* Drain the write buffer. */
-		sbefifo_get(sbefifo);
-		if (!queue_work(sbefifo_wq, &sbefifo->work.work))
-			sbefifo_put(sbefifo);
-	}
-
-out:
-	sbefifo_put_client(client);
-	return ret;
-}
-
-static ssize_t sbefifo_write(struct file *file, const char __user *buf,
-			     size_t len, loff_t *offset)
-{
-	struct sbefifo_client *client = file->private_data;
-
-	return sbefifo_write_common(client, buf, NULL, len);
-}
-
-static int sbefifo_release(struct inode *inode, struct file *file)
-{
-	struct sbefifo_client *client = file->private_data;
-	struct sbefifo *sbefifo = client->dev;
-
-	sbefifo_put_client(client);
-
-	return READ_ONCE(sbefifo->rc);
-}
-
-static const struct file_operations sbefifo_fops = {
-	.owner		= THIS_MODULE,
-	.open		= sbefifo_open,
-	.read		= sbefifo_read,
-	.write		= sbefifo_write,
-	.poll		= sbefifo_poll,
-	.release	= sbefifo_release,
-};
-
-struct sbefifo_client *sbefifo_drv_open(struct device *dev,
-					unsigned long flags)
-{
-	struct sbefifo_client *client;
-	struct sbefifo *sbefifo = dev_get_drvdata(dev);
-
-	if (!sbefifo)
-		return NULL;
-
-	client = sbefifo_new_client(sbefifo);
-	if (client)
-		client->f_flags = flags;
-
-	return client;
-}
-EXPORT_SYMBOL_GPL(sbefifo_drv_open);
-
-int sbefifo_drv_read(struct sbefifo_client *client, char *buf, size_t len)
-{
-	return sbefifo_read_common(client, NULL, buf, len);
-}
-EXPORT_SYMBOL_GPL(sbefifo_drv_read);
-
-int sbefifo_drv_write(struct sbefifo_client *client, const char *buf,
-		      size_t len)
-{
-	return sbefifo_write_common(client, NULL, buf, len);
-}
-EXPORT_SYMBOL_GPL(sbefifo_drv_write);
-
-void sbefifo_drv_release(struct sbefifo_client *client)
-{
-	if (!client)
-		return;
-
-	sbefifo_put_client(client);
-}
-EXPORT_SYMBOL_GPL(sbefifo_drv_release);
-
-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_request_reset(struct sbefifo *sbefifo)
-{
-	int ret;
-	u32 status;
-	unsigned long start;
-	const unsigned int wait_time = 5;	/* jiffies */
-	const unsigned long timeout = msecs_to_jiffies(250);
-
-	ret = sbefifo_outw(sbefifo, SBEFIFO_UP | SBEFIFO_REQ_RESET, 1);
-	if (ret)
-		return ret;
-
-	start = jiffies;
-
-	do {
-		ret = sbefifo_inw(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &status);
-		if (ret)
-			return ret;
-
-		if (!(status & SBEFIFO_STS_RESET_REQ))
-			return 0;
-
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (schedule_timeout(wait_time) > 0)
-			return -EINTR;
-	} while (time_after(start + timeout, jiffies));
-
-	return -ETIME;
-}
-
-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];
-	u32 up, down;
-	int ret, child_idx = 0;
-
-	dev_dbg(dev, "Found sbefifo device\n");
-	sbefifo = kzalloc(sizeof(*sbefifo), GFP_KERNEL);
-	if (!sbefifo)
-		return -ENOMEM;
-
-	sbefifo->fsi_dev = fsi_dev;
-
-	ret = sbefifo_inw(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &up);
-	if (ret)
-		return ret;
-
-	ret = sbefifo_inw(sbefifo, SBEFIFO_DWN | SBEFIFO_STS, &down);
-	if (ret)
-		return ret;
-
-	if (!(up & SBEFIFO_EMPTY) || !(down & SBEFIFO_EMPTY)) {
-		ret = sbefifo_request_reset(sbefifo);
-		if (ret) {
-			dev_err(dev,
-				"fifos weren't empty and failed the reset\n");
-			return ret;
-		}
-	}
-
-	mutex_init(&sbefifo->list_lock);
-	mutex_init(&sbefifo->sbefifo_lock);
-	kref_init(&sbefifo->kref);
-	init_waitqueue_head(&sbefifo->wait);
-	INIT_LIST_HEAD(&sbefifo->xfrs);
-
-	sbefifo->idx = ida_simple_get(&sbefifo_ida, 1, INT_MAX, GFP_KERNEL);
-	snprintf(sbefifo->name, sizeof(sbefifo->name), "sbefifo%d",
-		 sbefifo->idx);
-
-	/* This bit of silicon doesn't offer any interrupts... */
-	INIT_DELAYED_WORK(&sbefifo->work, sbefifo_worker);
-
-	sbefifo->mdev.minor = MISC_DYNAMIC_MINOR;
-	sbefifo->mdev.fops = &sbefifo_fops;
-	sbefifo->mdev.name = sbefifo->name;
-	sbefifo->mdev.parent = dev;
-	ret = misc_register(&sbefifo->mdev);
-	if (ret) {
-		dev_err(dev, "failed to register miscdevice: %d\n", ret);
-		ida_simple_remove(&sbefifo_ida, sbefifo->idx);
-		sbefifo_put(sbefifo);
-		return ret;
-	}
-
-	/* 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);
-	}
-
-	dev_set_drvdata(dev, sbefifo);
-
-	return 0;
-}
-
-static int sbefifo_remove(struct device *dev)
-{
-	struct sbefifo *sbefifo = dev_get_drvdata(dev);
-	struct sbefifo_xfr *xfr, *tmp;
-
-	/* lock the sbefifo so to prevent deleting an ongoing xfr */
-	mutex_lock(&sbefifo->sbefifo_lock);
-	mutex_lock(&sbefifo->list_lock);
-
-	WRITE_ONCE(sbefifo->rc, -ENODEV);
-	list_for_each_entry_safe(xfr, tmp, &sbefifo->xfrs, xfrs) {
-		list_del(&xfr->xfrs);
-		kfree(xfr);
-	}
-
-	INIT_LIST_HEAD(&sbefifo->xfrs);
-
-	mutex_unlock(&sbefifo->list_lock);
-	mutex_unlock(&sbefifo->sbefifo_lock);
-
-	wake_up_all(&sbefifo->wait);
-
-	misc_deregister(&sbefifo->mdev);
-	device_for_each_child(dev, NULL, sbefifo_unregister_child);
-
-	ida_simple_remove(&sbefifo_ida, sbefifo->idx);
-
-	if (cancel_delayed_work_sync(&sbefifo->work))
-		sbefifo_put(sbefifo);
-
-	sbefifo_put(sbefifo);
-
-	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)
-{
-	sbefifo_wq = create_singlethread_workqueue("sbefifo");
-	if (!sbefifo_wq)
-		return -ENOMEM;
-
-	return fsi_driver_register(&sbefifo_drv);
-}
-
-static void sbefifo_exit(void)
-{
-	destroy_workqueue(sbefifo_wq);
-
-	fsi_driver_unregister(&sbefifo_drv);
-
-	ida_destroy(&sbefifo_ida);
-}
-
-module_init(sbefifo_init);
-module_exit(sbefifo_exit);
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Brad Bishop <[email protected]>");
-MODULE_AUTHOR("Eddie James <[email protected]>");
-MODULE_DESCRIPTION("Linux device interface to the POWER Self Boot Engine");

drivers/hwmon/occ/Makefile +1 -1

index ab5c3e965ccb..ca6d25ae9da8 100644
@@ -1,7 +1,7 @@
 occ-hwmon-objs := common.o
 
 ifeq ($(CONFIG_SENSORS_OCC_P9_SBE), y)
-occ-hwmon-objs += p9_sbe.o
+#occ-hwmon-objs += p9_sbe.o
 endif
 
 ifeq ($(CONFIG_SENSORS_OCC_P8_I2C), y)

include/linux/fsi-sbefifo.h deleted +0 -30

deleted file mode 100644
index 8e55891963a5..000000000000
@@ -1,30 +0,0 @@
-/*
- * SBEFIFO FSI Client device driver
- *
- * 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.
- */
-
-#ifndef LINUX_FSI_SBEFIFO_H
-#define LINUX_FSI_SBEFIFO_H
-
-struct device;
-struct sbefifo_client;
-
-extern struct sbefifo_client *sbefifo_drv_open(struct device *dev,
-					       unsigned long flags);
-extern int sbefifo_drv_read(struct sbefifo_client *client, char *buf,
-			    size_t len);
-extern int sbefifo_drv_write(struct sbefifo_client *client, const char *buf,
-			     size_t len);
-extern void sbefifo_drv_release(struct sbefifo_client *client);
-
-#endif /* LINUX_FSI_SBEFIFO_H */

Signature · 1 line

2.17.0