From 918da95176beb743ff47b3bbfb0a4ee420658a95 Mon Sep 17 00:00:00 2001 From: Andrew Jeffery Date: Tue, 20 Feb 2018 14:48:33 +1030 Subject: fsi: gpio: Trace busy count An observation from trace output of the existing FSI tracepoints was that the remote device was sometimes reporting as busy. Add a new tracepoint reporting the busy count in order to get a better grip on how often this is the case. Signed-off-by: Andrew Jeffery Acked-by: Eddie James Signed-off-by: Benjamin Herrenschmidt Tested-by: Joel Stanley --- include/trace/events/fsi_master_gpio.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include') diff --git a/include/trace/events/fsi_master_gpio.h b/include/trace/events/fsi_master_gpio.h index f95cf3264bf9..33e928c5acf3 100644 --- a/include/trace/events/fsi_master_gpio.h +++ b/include/trace/events/fsi_master_gpio.h @@ -64,6 +64,22 @@ TRACE_EVENT(fsi_master_gpio_break, ) ); + +TRACE_EVENT(fsi_master_gpio_poll_response_busy, + TP_PROTO(const struct fsi_master_gpio *master, int busy), + TP_ARGS(master, busy), + TP_STRUCT__entry( + __field(int, master_idx) + __field(int, busy) + ), + TP_fast_assign( + __entry->master_idx = master->master.idx; + __entry->busy = busy; + ), + TP_printk("fsi-gpio%d: device reported busy %d times", + __entry->master_idx, __entry->busy) +); + #endif /* _TRACE_FSI_MASTER_GPIO_H */ #include -- cgit v1.2.3 From 4e56828a5db19e2de8f8dc464c6df2e7e9ff4e13 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 15 May 2018 16:14:43 +1000 Subject: fsi/fsi-master-gpio: Implement CRC error recovery The FSI protocol defines two modes of recovery from CRC errors, this implements both: - If the device returns an ECRC (it detected a CRC error in the command), then we simply issue the command again. - If the master detects a CRC error in the response, we send an E_POLL command which requests a resend of the response without actually re-executing the command (which could otherwise have unwanted side effects such as dequeuing a FIFO twice). Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Christopher Bostic Tested-by: Joel Stanley --- Note: This was actually tested by removing some of my fixes, thus causing us to hit occasional CRC errors during high LPC activity. --- drivers/fsi/fsi-master-gpio.c | 90 +++++++++++++++++++++++++++------- include/trace/events/fsi_master_gpio.h | 27 ++++++++++ 2 files changed, 99 insertions(+), 18 deletions(-) (limited to 'include') diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c index 0a6799bda294..351c12f2ac55 100644 --- a/drivers/fsi/fsi-master-gpio.c +++ b/drivers/fsi/fsi-master-gpio.c @@ -22,20 +22,23 @@ #define FSI_BREAK_CLOCKS 256 /* Number of clocks to issue break */ #define FSI_POST_BREAK_CLOCKS 16000 /* Number clocks to set up cfam */ #define FSI_INIT_CLOCKS 5000 /* Clock out any old data */ +#define FSI_GPIO_DPOLL_CLOCKS 50 /* < 21 will cause slave to hang */ +#define FSI_GPIO_EPOLL_CLOCKS 50 /* Number of clocks for E_POLL retry */ #define FSI_GPIO_STD_DELAY 10 /* Standard GPIO delay in nS */ /* todo: adjust down as low as */ /* possible or eliminate */ +#define FSI_CRC_ERR_RETRIES 10 + #define FSI_GPIO_CMD_DPOLL 0x2 +#define FSI_GPIO_CMD_EPOLL 0x3 #define FSI_GPIO_CMD_TERM 0x3f #define FSI_GPIO_CMD_ABS_AR 0x4 #define FSI_GPIO_CMD_REL_AR 0x5 #define FSI_GPIO_CMD_SAME_AR 0x3 /* but only a 2-bit opcode... */ - -#define FSI_GPIO_DPOLL_CLOCKS 50 /* < 21 will cause slave to hang */ - -/* Bus errors */ -#define FSI_GPIO_ERR_BUSY 1 /* Slave stuck in busy state */ +/* Slave responses */ +#define FSI_GPIO_RESP_ACK 0 /* Success */ +#define FSI_GPIO_RESP_BUSY 1 /* Slave busy */ #define FSI_GPIO_RESP_ERRA 2 /* Any (misc) Error */ #define FSI_GPIO_RESP_ERRC 3 /* Slave reports master CRC error */ #define FSI_GPIO_MTOE 4 /* Master time out error */ @@ -330,6 +333,16 @@ static void build_dpoll_command(struct fsi_gpio_msg *cmd, uint8_t slave_id) msg_push_crc(cmd); } +static void build_epoll_command(struct fsi_gpio_msg *cmd, uint8_t slave_id) +{ + cmd->bits = 0; + cmd->msg = 0; + + msg_push_bits(cmd, slave_id, 2); + msg_push_bits(cmd, FSI_GPIO_CMD_EPOLL, 3); + msg_push_crc(cmd); +} + static void echo_delay(struct fsi_master_gpio *master) { set_sda_output(master, 1); @@ -355,6 +368,12 @@ static void fsi_master_gpio_error(struct fsi_master_gpio *master, int error) } +/* + * Note: callers rely specifically on this returning -EAGAIN for + * a CRC error detected in the response. Use other error code + * for other situations. It will be converted to something else + * higher up the stack before it reaches userspace. + */ static int read_one_response(struct fsi_master_gpio *master, uint8_t data_size, struct fsi_gpio_msg *msgp, uint8_t *tagp) { @@ -379,7 +398,7 @@ static int read_one_response(struct fsi_master_gpio *master, "Master time out waiting for response\n"); fsi_master_gpio_error(master, FSI_GPIO_MTOE); spin_unlock_irqrestore(&master->bit_lock, flags); - return -EIO; + return -ETIMEDOUT; } msg.bits = 0; @@ -405,7 +424,7 @@ static int read_one_response(struct fsi_master_gpio *master, if (crc) { dev_dbg(master->dev, "ERR response CRC\n"); fsi_master_gpio_error(master, FSI_GPIO_CRC_INVAL); - return -EIO; + return -EAGAIN; } if (msgp) @@ -451,11 +470,33 @@ static int poll_for_response(struct fsi_master_gpio *master, unsigned long flags; uint8_t tag; uint8_t *data_byte = data; - + int crc_err_retries = 0; retry: rc = read_one_response(master, size, &response, &tag); - if (rc) - return rc; + + /* Handle retries on CRC errors */ + if (rc == -EAGAIN) { + /* Too many retries ? */ + if (crc_err_retries++ > FSI_CRC_ERR_RETRIES) { + /* + * Pass it up as a -EIO otherwise upper level will retry + * the whole command which isn't what we want here. + */ + rc = -EIO; + goto fail; + } + dev_dbg(master->dev, + "CRC error retry %d\n", crc_err_retries); + trace_fsi_master_gpio_crc_rsp_error(master); + build_epoll_command(&cmd, slave); + spin_lock_irqsave(&master->bit_lock, flags); + clock_zeros(master, FSI_GPIO_EPOLL_CLOCKS); + serial_out(master, &cmd); + echo_delay(master); + spin_unlock_irqrestore(&master->bit_lock, flags); + goto retry; + } else if (rc) + goto fail; switch (tag) { case FSI_GPIO_RESP_ACK: @@ -496,18 +537,21 @@ retry: break; case FSI_GPIO_RESP_ERRA: - case FSI_GPIO_RESP_ERRC: - dev_dbg(master->dev, "ERR%c received: 0x%x\n", - tag == FSI_GPIO_RESP_ERRA ? 'A' : 'C', - (int)response.msg); + dev_dbg(master->dev, "ERRA received: 0x%x\n", (int)response.msg); fsi_master_gpio_error(master, response.msg); rc = -EIO; break; + case FSI_GPIO_RESP_ERRC: + dev_dbg(master->dev, "ERRC received: 0x%x\n", (int)response.msg); + fsi_master_gpio_error(master, response.msg); + trace_fsi_master_gpio_crc_cmd_error(master); + rc = -EAGAIN; + break; } if (busy_count > 0) trace_fsi_master_gpio_poll_response_busy(master, busy_count); - + fail: /* Clock the slave enough to be ready for next operation */ spin_lock_irqsave(&master->bit_lock, flags); clock_zeros(master, FSI_GPIO_PRIME_SLAVE_CLOCKS); @@ -536,11 +580,21 @@ static int send_request(struct fsi_master_gpio *master, static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave, struct fsi_gpio_msg *cmd, size_t resp_len, void *resp) { - int rc; + int rc = -EAGAIN, retries = 0; - rc = send_request(master, cmd); - if (!rc) + while ((retries++) < FSI_CRC_ERR_RETRIES) { + rc = send_request(master, cmd); + if (rc) + break; rc = poll_for_response(master, slave, resp_len, resp); + if (rc != -EAGAIN) + break; + rc = -EIO; + dev_warn(master->dev, "ECRC retry %d\n", retries); + + /* Pace it a bit before retry */ + msleep(1); + } return rc; } diff --git a/include/trace/events/fsi_master_gpio.h b/include/trace/events/fsi_master_gpio.h index 33e928c5acf3..389082132433 100644 --- a/include/trace/events/fsi_master_gpio.h +++ b/include/trace/events/fsi_master_gpio.h @@ -64,6 +64,33 @@ TRACE_EVENT(fsi_master_gpio_break, ) ); +TRACE_EVENT(fsi_master_gpio_crc_cmd_error, + TP_PROTO(const struct fsi_master_gpio *master), + TP_ARGS(master), + TP_STRUCT__entry( + __field(int, master_idx) + ), + TP_fast_assign( + __entry->master_idx = master->master.idx; + ), + TP_printk("fsi-gpio%d ----CRC command retry---", + __entry->master_idx + ) +); + +TRACE_EVENT(fsi_master_gpio_crc_rsp_error, + TP_PROTO(const struct fsi_master_gpio *master), + TP_ARGS(master), + TP_STRUCT__entry( + __field(int, master_idx) + ), + TP_fast_assign( + __entry->master_idx = master->master.idx; + ), + TP_printk("fsi-gpio%d ----CRC response---", + __entry->master_idx + ) +); TRACE_EVENT(fsi_master_gpio_poll_response_busy, TP_PROTO(const struct fsi_master_gpio *master, int busy), -- cgit v1.2.3 From 9f4a8a2d7f9d71093f41c4bb0ef8707e8145bad3 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 17 May 2018 15:58:00 +1000 Subject: fsi/sbefifo: Add driver for the SBE FIFO 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 Tested-by: Joel Stanley --- --- drivers/fsi/Kconfig | 7 + drivers/fsi/Makefile | 1 + drivers/fsi/fsi-sbefifo.c | 1005 +++++++++++++++++++++++++++++++++++++++++++ include/linux/fsi-sbefifo.h | 33 ++ 4 files changed, 1046 insertions(+) create mode 100644 drivers/fsi/fsi-sbefifo.c create mode 100644 include/linux/fsi-sbefifo.h (limited to 'include') diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig index a326ed663d3c..24f84a96b8b9 100644 --- a/drivers/fsi/Kconfig +++ b/drivers/fsi/Kconfig @@ -32,4 +32,11 @@ config FSI_SCOM ---help--- This option enables an FSI based SCOM device driver. +config FSI_SBEFIFO + tristate "SBEFIFO FSI client device driver" + ---help--- + This option enables an FSI based SBEFIFO device driver. The SBEFIFO is + a pipe-like FSI device for communicating with the self boot engine + (SBE) on POWER processors. + endif diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile index 65eb99dfafdb..851182e1cd9e 100644 --- a/drivers/fsi/Makefile +++ b/drivers/fsi/Makefile @@ -3,3 +3,4 @@ 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 diff --git a/drivers/fsi/fsi-sbefifo.c b/drivers/fsi/fsi-sbefifo.c new file mode 100644 index 000000000000..9b8b6b346af6 --- /dev/null +++ b/drivers/fsi/fsi-sbefifo.c @@ -0,0 +1,1005 @@ +// 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * The SBEFIFO is a pipe-like FSI device for communicating with + * the self boot engine on POWER processors. + */ + +#define DEVICE_NAME "sbefifo" +#define FSI_ENGID_SBE 0x22 + +/* + * Register layout + */ + +/* Register banks */ +#define SBEFIFO_UP 0x00 /* FSI -> Host */ +#define SBEFIFO_DOWN 0x40 /* Host -> FSI */ + +/* Per-bank registers */ +#define SBEFIFO_FIFO 0x00 /* The FIFO itself */ +#define SBEFIFO_STS 0x04 /* Status register */ +#define SBEFIFO_STS_PARITY_ERR 0x20000000 +#define SBEFIFO_STS_RESET_REQ 0x02000000 +#define SBEFIFO_STS_GOT_EOT 0x00800000 +#define SBEFIFO_STS_MAX_XFER_LIMIT 0x00400000 +#define SBEFIFO_STS_FULL 0x00200000 +#define SBEFIFO_STS_EMPTY 0x00100000 +#define SBEFIFO_STS_ECNT_MASK 0x000f0000 +#define SBEFIFO_STS_ECNT_SHIFT 16 +#define SBEFIFO_STS_VALID_MASK 0x0000ff00 +#define SBEFIFO_STS_VALID_SHIFT 8 +#define SBEFIFO_STS_EOT_MASK 0x000000ff +#define SBEFIFO_STS_EOT_SHIFT 0 +#define SBEFIFO_EOT_RAISE 0x08 /* (Up only) Set End Of Transfer */ +#define SBEFIFO_REQ_RESET 0x0C /* (Up only) Reset Request */ +#define SBEFIFO_PERFORM_RESET 0x10 /* (Down only) Perform Reset */ +#define SBEFIFO_EOT_ACK 0x14 /* (Down only) Acknowledge EOT */ +#define SBEFIFO_DOWN_MAX 0x18 /* (Down only) Max transfer */ + +/* CFAM GP Mailbox SelfBoot Message register */ +#define CFAM_GP_MBOX_SBM_ADDR 0x2824 /* Converted 0x2809 */ + +#define CFAM_SBM_SBE_BOOTED 0x80000000 +#define CFAM_SBM_SBE_ASYNC_FFDC 0x40000000 +#define CFAM_SBM_SBE_STATE_MASK 0x00f00000 +#define CFAM_SBM_SBE_STATE_SHIFT 20 + +enum sbe_state +{ + SBE_STATE_UNKNOWN = 0x0, // Unkown, initial state + SBE_STATE_IPLING = 0x1, // IPL'ing - autonomous mode (transient) + SBE_STATE_ISTEP = 0x2, // ISTEP - Running IPL by steps (transient) + SBE_STATE_MPIPL = 0x3, // MPIPL + SBE_STATE_RUNTIME = 0x4, // SBE Runtime + SBE_STATE_DMT = 0x5, // Dead Man Timer State (transient) + SBE_STATE_DUMP = 0x6, // Dumping + SBE_STATE_FAILURE = 0x7, // Internal SBE failure + SBE_STATE_QUIESCE = 0x8, // Final state - needs SBE reset to get out +}; + +/* FIFO depth */ +#define SBEFIFO_FIFO_DEPTH 8 + +/* Helpers */ +#define sbefifo_empty(sts) ((sts) & SBEFIFO_STS_EMPTY) +#define sbefifo_full(sts) ((sts) & SBEFIFO_STS_FULL) +#define sbefifo_parity_err(sts) ((sts) & SBEFIFO_STS_PARITY_ERR) +#define sbefifo_populated(sts) (((sts) & SBEFIFO_STS_ECNT_MASK) >> SBEFIFO_STS_ECNT_SHIFT) +#define sbefifo_vacant(sts) (SBEFIFO_FIFO_DEPTH - sbefifo_populated(sts)) +#define sbefifo_eot_set(sts) (((sts) & SBEFIFO_STS_EOT_MASK) >> SBEFIFO_STS_EOT_SHIFT) + +/* Reset request timeout in ms */ +#define SBEFIFO_RESET_TIMEOUT 10000 + +/* Timeouts for commands in ms */ +#define SBEFIFO_TIMEOUT_START_CMD 10000 +#define SBEFIFO_TIMEOUT_IN_CMD 1000 +#define SBEFIFO_TIMEOUT_START_RSP 10000 +#define SBEFIFO_TIMEOUT_IN_RSP 1000 + +/* Other constants */ +#define SBEFIFO_MAX_CMD_LEN PAGE_SIZE +#define SBEFIFO_RESET_MAGIC 0x52534554 /* "RSET" */ + +struct sbefifo { + uint32_t magic; +#define SBEFIFO_MAGIC 0x53424546 /* "SBEF" */ + struct fsi_device *fsi_dev; + struct miscdevice mdev; + struct mutex lock; + char name[32]; + int idx; + bool broken; + bool async_ffdc; +}; + +struct sbefifo_user { + struct sbefifo *sbefifo; + struct mutex file_lock; + void *pending_cmd; + size_t pending_len; +}; + +static DEFINE_IDA(sbefifo_ida); +static DEFINE_MUTEX(sbefifo_ffdc_mutex); + + +static void sbefifo_dump_ffdc(struct device *dev, const __be32 *ffdc, + size_t ffdc_sz, bool internal) +{ + int pack = 0; +#define FFDC_LSIZE 60 + static char ffdc_line[FFDC_LSIZE]; + char *p = ffdc_line; + + mutex_lock(&sbefifo_ffdc_mutex); + while (ffdc_sz) { + u32 w0, w1, w2, i; + if (ffdc_sz < 3) { + dev_err(dev, "SBE invalid FFDC package size %zd\n", ffdc_sz); + return; + } + w0 = be32_to_cpu(*(ffdc++)); + w1 = be32_to_cpu(*(ffdc++)); + w2 = be32_to_cpu(*(ffdc++)); + ffdc_sz -= 3; + if ((w0 >> 16) != 0xFFDC) { + dev_err(dev, "SBE invalid FFDC package signature %08x %08x %08x\n", + w0, w1, w2); + break; + } + w0 &= 0xffff; + if (w0 > ffdc_sz) { + dev_err(dev, "SBE FFDC package len %d words but only %zd remaining\n", + w0, ffdc_sz); + w0 = ffdc_sz; + break; + } + if (internal) { + dev_warn(dev, "+---- SBE FFDC package %d for async err -----+\n", + pack++); + } else { + dev_warn(dev, "+---- SBE FFDC package %d for cmd %02x:%02x -----+\n", + pack++, (w1 >> 8) & 0xff, w1 & 0xff); + } + dev_warn(dev, "| Response code: %08x |\n", w2); + dev_warn(dev, "|-------------------------------------------|\n"); + for (i = 0; i < w0; i++) { + if ((i & 3) == 0) { + p = ffdc_line; + p += sprintf(p, "| %04x:", i << 4); + } + p += sprintf(p, " %08x", be32_to_cpu(*(ffdc++))); + ffdc_sz--; + if ((i & 3) == 3 || i == (w0 - 1)) { + while ((i & 3) < 3) { + p += sprintf(p, " "); + i++; + } + dev_warn(dev, "%s |\n", ffdc_line); + } + } + dev_warn(dev, "+-------------------------------------------+\n"); + } +} + +int sbefifo_parse_status(struct device *dev, u16 cmd, __be32 *response, + size_t resp_len, size_t *data_len) +{ + u32 dh, s0, s1; + size_t ffdc_sz; + + if (resp_len < 3) { + pr_debug("sbefifo: cmd %04x, response too small: %zd\n", + cmd, resp_len); + return -ENXIO; + } + dh = be32_to_cpu(response[resp_len - 1]); + if (dh > resp_len || dh < 3) { + dev_err(dev, "SBE cmd %02x:%02x status offset out of range: %d/%zd\n", + cmd >> 8, cmd & 0xff, dh, resp_len); + return -ENXIO; + } + s0 = be32_to_cpu(response[resp_len - dh]); + s1 = be32_to_cpu(response[resp_len - dh + 1]); + if (((s0 >> 16) != 0xC0DE) || ((s0 & 0xffff) != cmd)) { + dev_err(dev, "SBE cmd %02x:%02x, status signature invalid: 0x%08x 0x%08x\n", + cmd >> 8, cmd & 0xff, s0, s1); + return -ENXIO; + } + if (s1 != 0) { + ffdc_sz = dh - 3; + dev_warn(dev, "SBE error cmd %02x:%02x status=%04x:%04x\n", + cmd >> 8, cmd & 0xff, s1 >> 16, s1 & 0xffff); + if (ffdc_sz) + sbefifo_dump_ffdc(dev, &response[resp_len - dh + 2], + ffdc_sz, false); + } + if (data_len) + *data_len = resp_len - dh; + + /* + * Primary status don't have the top bit set, so can't be confused with + * Linux negative error codes, so return the status word whole. + */ + return s1; +} +EXPORT_SYMBOL_GPL(sbefifo_parse_status); + +static int sbefifo_regr(struct sbefifo *sbefifo, int reg, u32 *word) +{ + __be32 raw_word; + int rc; + + rc = fsi_device_read(sbefifo->fsi_dev, reg, &raw_word, + sizeof(raw_word)); + if (rc) + return rc; + + *word = be32_to_cpu(raw_word); + + return 0; +} + +static int sbefifo_regw(struct sbefifo *sbefifo, int reg, u32 word) +{ + __be32 raw_word = cpu_to_be32(word); + + return fsi_device_write(sbefifo->fsi_dev, reg, &raw_word, + sizeof(raw_word)); +} + +static int sbefifo_check_sbe_state(struct sbefifo *sbefifo) +{ + __be32 raw_word; + u32 sbm; + int rc; + + rc = fsi_slave_read(sbefifo->fsi_dev->slave, CFAM_GP_MBOX_SBM_ADDR, + &raw_word, sizeof(raw_word)); + if (rc) + return rc; + sbm = be32_to_cpu(raw_word); + + /* SBE booted at all ? */ + if (!(sbm & CFAM_SBM_SBE_BOOTED)) + return -ESHUTDOWN; + + /* Check its state */ + switch ((sbm & CFAM_SBM_SBE_STATE_MASK) >> CFAM_SBM_SBE_STATE_SHIFT) { + case SBE_STATE_UNKNOWN: + return -ESHUTDOWN; + case SBE_STATE_IPLING: + case SBE_STATE_ISTEP: + case SBE_STATE_MPIPL: + case SBE_STATE_DMT: + return -EBUSY; + case SBE_STATE_RUNTIME: + case SBE_STATE_DUMP: /* Not sure about that one */ + break; + case SBE_STATE_FAILURE: + case SBE_STATE_QUIESCE: + return -ESHUTDOWN; + } + + /* Is there async FFDC available ? Remember it */ + if (sbm & CFAM_SBM_SBE_ASYNC_FFDC) + sbefifo->async_ffdc = true; + + return 0; +} + +/* Don't flip endianness of data to/from FIFO, just pass through. */ +static int sbefifo_down_read(struct sbefifo *sbefifo, __be32 *word) +{ + return fsi_device_read(sbefifo->fsi_dev, SBEFIFO_DOWN, word, + sizeof(*word)); +} + +static int sbefifo_up_write(struct sbefifo *sbefifo, __be32 word) +{ + return fsi_device_write(sbefifo->fsi_dev, SBEFIFO_UP, &word, + sizeof(word)); +} + +static int sbefifo_request_reset(struct sbefifo *sbefifo) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + u32 status, timeout; + int rc; + + dev_dbg(dev, "Requesting FIFO reset\n"); + + /* Mark broken first, will be cleared if reset succeeds */ + sbefifo->broken = true; + + /* Send reset request */ + rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_REQ_RESET, 1); + if (rc) { + dev_err(dev, "Sending reset request failed, rc=%d\n", rc); + return rc; + } + + /* Wait for it to complete */ + for (timeout = 0; timeout < SBEFIFO_RESET_TIMEOUT; timeout++) { + rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &status); + if (rc) { + dev_err(dev, "Failed to read UP fifo status during reset" + " , rc=%d\n", rc); + return rc; + } + + if (!(status & SBEFIFO_STS_RESET_REQ)) { + dev_dbg(dev, "FIFO reset done\n"); + sbefifo->broken = false; + return 0; + } + + msleep(1); + } + dev_err(dev, "FIFO reset timed out\n"); + + return -ETIMEDOUT; +} + +static int sbefifo_cleanup_hw(struct sbefifo *sbefifo) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + u32 up_status, down_status; + bool need_reset = false; + int rc; + + rc = sbefifo_check_sbe_state(sbefifo); + if (rc) { + dev_dbg(dev, "SBE state=%d\n", rc); + return rc; + } + + /* If broken, we don't need to look at status, go straight to reset */ + if (sbefifo->broken) + goto do_reset; + + rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &up_status); + if (rc) { + dev_err(dev, "Cleanup: Reading UP status failed, rc=%d\n", rc); + + /* Will try reset again on next attempt at using it */ + sbefifo->broken = true; + return rc; + } + + rc = sbefifo_regr(sbefifo, SBEFIFO_DOWN | SBEFIFO_STS, &down_status); + if (rc) { + dev_err(dev, "Cleanup: Reading DOWN status failed, rc=%d\n", rc); + + /* Will try reset again on next attempt at using it */ + sbefifo->broken = true; + return rc; + } + + /* The FIFO already contains a reset request from the SBE ? */ + if (down_status & SBEFIFO_STS_RESET_REQ) { + dev_info(dev, "Cleanup: FIFO reset request set, resetting\n"); + rc = sbefifo_regw(sbefifo, SBEFIFO_UP, SBEFIFO_PERFORM_RESET); + if (rc) { + sbefifo->broken = true; + dev_err(dev, "Cleanup: Reset reg write failed, rc=%d\n", rc); + return rc; + } + sbefifo->broken = false; + return 0; + } + + /* Parity error on either FIFO ? */ + if ((up_status | down_status) & SBEFIFO_STS_PARITY_ERR) + need_reset = true; + + /* Either FIFO not empty ? */ + if (!((up_status & down_status) & SBEFIFO_STS_EMPTY)) + need_reset = true; + + if (!need_reset) + return 0; + + dev_info(dev, "Cleanup: FIFO not clean (up=0x%08x down=0x%08x)\n", + up_status, down_status); + + do_reset: + + /* Mark broken, will be cleared if/when reset succeeds */ + return sbefifo_request_reset(sbefifo); +} + +static int sbefifo_wait(struct sbefifo *sbefifo, bool up, + u32 *status, unsigned long timeout) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + unsigned long end_time; + bool ready = false; + u32 addr, sts = 0; + int rc; + + dev_vdbg(dev, "Wait on %s fifo...\n", up ? "up" : "down"); + + addr = (up ? SBEFIFO_UP : SBEFIFO_DOWN) | SBEFIFO_STS; + + end_time = jiffies + timeout; + while (!time_after(jiffies, end_time)) { + cond_resched(); + rc = sbefifo_regr(sbefifo, addr, &sts); + if (rc < 0) { + dev_err(dev, "FSI error %d reading status register\n", rc); + return rc; + } + if (!up && sbefifo_parity_err(sts)) { + dev_err(dev, "Parity error in DOWN FIFO\n"); + return -ENXIO; + } + ready = !(up ? sbefifo_full(sts) : sbefifo_empty(sts)); + if (ready) + break; + } + if (!ready) { + dev_err(dev, "%s FIFO Timeout ! status=%08x\n", up ? "UP" : "DOWN", sts); + return -ETIMEDOUT; + } + dev_vdbg(dev, "End of wait status: %08x\n", sts); + + *status = sts; + + return 0; +} + +static int sbefifo_send_command(struct sbefifo *sbefifo, + const __be32 *command, size_t cmd_len) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + size_t len, chunk, vacant = 0, remaining = cmd_len; + unsigned long timeout; + u32 status; + int rc; + + dev_vdbg(dev, "sending command (%zd words, cmd=%04x)\n", + cmd_len, be32_to_cpu(command[1])); + + /* As long as there's something to send */ + timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_CMD); + while (remaining) { + /* Wait for room in the FIFO */ + rc = sbefifo_wait(sbefifo, true, &status, timeout); + if (rc < 0) + return rc; + timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_CMD); + + vacant = sbefifo_vacant(status); + len = chunk = min(vacant, remaining); + + dev_vdbg(dev, " status=%08x vacant=%zd chunk=%zd\n", + status, vacant, chunk); + + /* Write as much as we can */ + while (len--) { + rc = sbefifo_up_write(sbefifo, *(command++)); + if (rc) { + dev_err(dev, "FSI error %d writing UP FIFO\n", rc); + return rc; + } + } + remaining -= chunk; + vacant -= chunk; + } + + /* If there's no room left, wait for some to write EOT */ + if (!vacant) { + rc = sbefifo_wait(sbefifo, true, &status, timeout); + if (rc) + return rc; + } + + /* Send an EOT */ + rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_EOT_RAISE, 0); + if (rc) + dev_err(dev, "FSI error %d writing EOT\n", rc); + return rc; +} + +static int sbefifo_read_response(struct sbefifo *sbefifo, struct iov_iter *response) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + u32 data, status, eot_set; + unsigned long timeout; + bool overflow = false; + size_t len; + int rc; + + dev_vdbg(dev, "reading response, buflen = %zd\n", iov_iter_count(response)); + + timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_RSP); + for (;;) { + /* Grab FIFO status (this will handle parity errors) */ + rc = sbefifo_wait(sbefifo, false, &status, timeout); + if (rc < 0) + return rc; + timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_RSP); + + /* Decode status */ + len = sbefifo_populated(status); + eot_set = sbefifo_eot_set(status); + + dev_vdbg(dev, " chunk size %zd eot_set=0x%x\n", len, eot_set); + + /* Go through the chunk */ + while(len--) { + /* Read the data */ + rc = sbefifo_down_read(sbefifo, &data); + if (rc < 0) + return rc; + + /* Was it an EOT ? */ + if (eot_set & 0x80) { + /* + * There should be nothing else in the FIFO, + * if there is, mark broken, this will force + * a reset on next use, but don't fail the + * command. + */ + if (len) { + dev_warn(dev, "FIFO read hit" + " EOT with still %zd data\n", + len); + sbefifo->broken = true; + } + + /* We are done */ + rc = sbefifo_regw(sbefifo, + SBEFIFO_DOWN | SBEFIFO_EOT_ACK, 0); + + /* + * If that write fail, still complete the request but mark + * the fifo as broken for subsequent reset (not much else + * we can do here). + */ + if (rc) { + dev_err(dev, "FSI error %d ack'ing EOT\n", rc); + sbefifo->broken = true; + } + + /* Tell whether we overflowed */ + return overflow ? -EOVERFLOW : 0; + } + + /* Store it if there is room */ + if (iov_iter_count(response) >= sizeof(__be32)) { + if (copy_to_iter(&data, sizeof(__be32), response) < sizeof(__be32)) + return -EFAULT; + } else { + dev_vdbg(dev, "Response overflowed !\n"); + + overflow = true; + } + + /* Next EOT bit */ + eot_set <<= 1; + } + } + /* Shouldn't happen */ + return -EIO; +} + +static int sbefifo_do_command(struct sbefifo *sbefifo, + const __be32 *command, size_t cmd_len, + struct iov_iter *response) +{ + /* Try sending the command */ + int rc = sbefifo_send_command(sbefifo, command, cmd_len); + if (rc) + return rc; + + /* Now, get the response */ + return sbefifo_read_response(sbefifo, response); +} + +static void sbefifo_collect_async_ffdc(struct sbefifo *sbefifo) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + struct iov_iter ffdc_iter; + struct kvec ffdc_iov; + __be32 *ffdc; + size_t ffdc_sz; + u32 cmd[2]; + int rc; + + sbefifo->async_ffdc = false; + ffdc = vmalloc(SBEFIFO_MAX_FFDC_SIZE); + if (!ffdc) { + dev_err(dev, "Failed to allocate SBE FFDC buffer\n"); + return; + } + ffdc_iov.iov_base = ffdc; + ffdc_iov.iov_len = SBEFIFO_MAX_FFDC_SIZE;; + iov_iter_kvec(&ffdc_iter, WRITE | ITER_KVEC, &ffdc_iov, 1, SBEFIFO_MAX_FFDC_SIZE); + cmd[0] = cpu_to_be32(2); + cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_SBE_FFDC); + rc = sbefifo_do_command(sbefifo, cmd, 2, &ffdc_iter); + if (rc != 0) { + dev_err(dev, "Error %d retrieving SBE FFDC\n", rc); + goto bail; + } + ffdc_sz = SBEFIFO_MAX_FFDC_SIZE - iov_iter_count(&ffdc_iter); + ffdc_sz /= sizeof(__be32); + rc = sbefifo_parse_status(dev, SBEFIFO_CMD_GET_SBE_FFDC, ffdc, + ffdc_sz, &ffdc_sz); + if (rc != 0) { + dev_err(dev, "Error %d decoding SBE FFDC\n", rc); + goto bail; + } + if (ffdc_sz > 0) + sbefifo_dump_ffdc(dev, ffdc, ffdc_sz, true); + bail: + vfree(ffdc); + +} + +static int __sbefifo_submit(struct sbefifo *sbefifo, + const __be32 *command, size_t cmd_len, + struct iov_iter *response) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + int rc; + + if (cmd_len < 2 || be32_to_cpu(command[0]) != cmd_len) { + dev_vdbg(dev, "Invalid command len %zd (header: %d)\n", + cmd_len, be32_to_cpu(command[0])); + return -EINVAL; + } + + /* First ensure the HW is in a clean state */ + rc = sbefifo_cleanup_hw(sbefifo); + if (rc) + return rc; + + /* Look for async FFDC first if any */ + if (sbefifo->async_ffdc) + sbefifo_collect_async_ffdc(sbefifo); + + rc = sbefifo_do_command(sbefifo, command, cmd_len, response); + if (rc != 0 && rc != -EOVERFLOW) + goto fail; + return rc; + fail: + /* + * On failure, attempt a reset. Ignore the result, it will mark + * the fifo broken if the reset fails + */ + sbefifo_request_reset(sbefifo); + + /* Return original error */ + return rc; +} + +/** + * sbefifo_submit() - Submit and SBE fifo command and receive response + * @dev: The sbefifo device + * @command: The raw command data + * @cmd_len: The command size (in 32-bit words) + * @response: The output response buffer + * @resp_len: In: Response buffer size, Out: Response size + * + * This will perform the entire operation. If the reponse buffer + * overflows, returns -EOVERFLOW + */ +int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len, + __be32 *response, size_t *resp_len) +{ + struct sbefifo *sbefifo = dev_get_drvdata(dev); + struct iov_iter resp_iter; + struct kvec resp_iov; + size_t rbytes; + int rc; + + if (!dev || !sbefifo) + return -ENODEV; + if (WARN_ON_ONCE(sbefifo->magic != SBEFIFO_MAGIC)) + return -ENODEV; + if (!resp_len || !command || !response || cmd_len > SBEFIFO_MAX_CMD_LEN) + return -EINVAL; + + /* Prepare iov iterator */ + rbytes = (*resp_len) * sizeof(__be32); + resp_iov.iov_base = response; + resp_iov.iov_len = rbytes; + iov_iter_kvec(&resp_iter, WRITE | ITER_KVEC, &resp_iov, 1, rbytes); + + /* Perform the command */ + mutex_lock(&sbefifo->lock); + rc = __sbefifo_submit(sbefifo, command, cmd_len, &resp_iter); + mutex_unlock(&sbefifo->lock); + + /* Extract the response length */ + rbytes -= iov_iter_count(&resp_iter); + *resp_len = rbytes / sizeof(__be32); + + return rc; +} +EXPORT_SYMBOL_GPL(sbefifo_submit); + +/* + * Char device interface + */ +static int sbefifo_user_open(struct inode *inode, struct file *file) +{ + struct sbefifo *sbefifo = container_of(file->private_data, + struct sbefifo, mdev); + struct sbefifo_user *user; + + user = kzalloc(sizeof(struct sbefifo_user), GFP_KERNEL); + if (!user) + return -ENOMEM; + + file->private_data = user; + user->sbefifo = sbefifo; + user->pending_cmd = (void *)__get_free_page(GFP_KERNEL); + if (!user->pending_cmd) { + kfree(user); + return -ENOMEM; + } + mutex_init(&user->file_lock); + + return 0; +} + +static ssize_t sbefifo_user_read(struct file *file, char __user *buf, + size_t len, loff_t *offset) +{ + struct sbefifo_user *user = file->private_data; + struct sbefifo *sbefifo; + struct iov_iter resp_iter; + struct iovec resp_iov; + size_t cmd_len; + int rc; + + if (!user) + return -EINVAL; + sbefifo = user->sbefifo; + if (len & 3) + return -EINVAL; + + mutex_lock(&user->file_lock); + + /* Cronus relies on -EAGAIN after a short read */ + if (user->pending_len == 0) { + rc = -EAGAIN; + goto bail; + } + if (user->pending_len < 8) { + rc = -EINVAL; + goto bail; + } + cmd_len = user->pending_len >> 2; + + /* Prepare iov iterator */ + resp_iov.iov_base = buf; + resp_iov.iov_len = len; + iov_iter_init(&resp_iter, WRITE, &resp_iov, 1, len); + + /* Perform the command */ + mutex_lock(&sbefifo->lock); + rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter); + mutex_unlock(&sbefifo->lock); + if (rc < 0) + goto bail; + + /* Extract the response length */ + rc = len - iov_iter_count(&resp_iter); + bail: + user->pending_len = 0; + mutex_unlock(&user->file_lock); + return rc; +} + +static ssize_t sbefifo_user_write(struct file *file, const char __user *buf, + size_t len, loff_t *offset) +{ + struct sbefifo_user *user = file->private_data; + struct sbefifo *sbefifo; + int rc = len; + + if (!user) + return -EINVAL; + sbefifo = user->sbefifo; + if (len > SBEFIFO_MAX_CMD_LEN) + return -EINVAL; + if (len & 3) + return -EINVAL; + + mutex_lock(&user->file_lock); + + /* Copy the command into the staging buffer */ + if (copy_from_user(user->pending_cmd, buf, len)) { + rc = -EFAULT; + goto bail; + } + + /* Check for the magic reset command */ + if (len == 4 && be32_to_cpu(*(__be32 *)user->pending_cmd) == + SBEFIFO_RESET_MAGIC) { + + /* Clear out any pending command */ + user->pending_len = 0; + + /* Trigger reset request */ + mutex_lock(&sbefifo->lock); + rc = sbefifo_request_reset(user->sbefifo); + mutex_unlock(&sbefifo->lock); + if (rc == 0) + rc = 4; + goto bail; + } + + /* Update the staging buffer size */ + user->pending_len = len; + bail: + mutex_unlock(&user->file_lock); + + /* And that's it, we'll issue the command on a read */ + return rc; +} + +static int sbefifo_user_release(struct inode *inode, struct file *file) +{ + struct sbefifo_user *user = file->private_data; + + if (!user) + return -EINVAL; + + free_page((unsigned long)user->pending_cmd); + kfree(user); + + return 0; +} + +static const struct file_operations sbefifo_fops = { + .owner = THIS_MODULE, + .open = sbefifo_user_open, + .read = sbefifo_user_read, + .write = sbefifo_user_write, + .release = sbefifo_user_release, +}; + +/* + * Probe/remove + */ + +static int sbefifo_probe(struct device *dev) +{ + struct fsi_device *fsi_dev = to_fsi_dev(dev); + struct sbefifo *sbefifo; + struct device_node *np; + struct platform_device *child; + char child_name[32]; + int rc, child_idx = 0; + + dev_dbg(dev, "Found sbefifo device\n"); + + sbefifo = devm_kzalloc(dev, sizeof(*sbefifo), GFP_KERNEL); + if (!sbefifo) + return -ENOMEM; + sbefifo->magic = SBEFIFO_MAGIC; + sbefifo->fsi_dev = fsi_dev; + mutex_init(&sbefifo->lock); + + /* + * Try cleaning up the FIFO. If this fails, we still register the + * driver and will try cleaning things up again on the next access. + */ + rc = sbefifo_cleanup_hw(sbefifo); + if (rc && rc != -ESHUTDOWN) + dev_err(dev, "Initial HW cleanup failed, will retry later\n"); + + sbefifo->idx = ida_simple_get(&sbefifo_ida, 1, INT_MAX, GFP_KERNEL); + snprintf(sbefifo->name, sizeof(sbefifo->name), "sbefifo%d", + sbefifo->idx); + + dev_set_drvdata(dev, sbefifo); + + /* Create misc chardev for userspace access */ + sbefifo->mdev.minor = MISC_DYNAMIC_MINOR; + sbefifo->mdev.fops = &sbefifo_fops; + sbefifo->mdev.name = sbefifo->name; + sbefifo->mdev.parent = dev; + rc = misc_register(&sbefifo->mdev); + if (rc) { + dev_err(dev, "Failed to register miscdevice: %d\n", rc); + ida_simple_remove(&sbefifo_ida, sbefifo->idx); + return rc; + } + + /* Create platform devs for dts child nodes (occ, etc) */ + for_each_available_child_of_node(dev->of_node, np) { + snprintf(child_name, sizeof(child_name), "%s-dev%d", + sbefifo->name, child_idx++); + child = of_platform_device_create(np, child_name, dev); + if (!child) + dev_warn(dev, "failed to create child %s dev\n", + child_name); + } + + return 0; +} + +static int sbefifo_unregister_child(struct device *dev, void *data) +{ + struct platform_device *child = to_platform_device(dev); + + of_device_unregister(child); + if (dev->of_node) + of_node_clear_flag(dev->of_node, OF_POPULATED); + + return 0; +} + +static int sbefifo_remove(struct device *dev) +{ + struct sbefifo *sbefifo = dev_get_drvdata(dev); + + dev_dbg(dev, "Removing sbefifo device...\n"); + + misc_deregister(&sbefifo->mdev); + device_for_each_child(dev, NULL, sbefifo_unregister_child); + + ida_simple_remove(&sbefifo_ida, sbefifo->idx); + + return 0; +} + +static struct fsi_device_id sbefifo_ids[] = { + { + .engine_type = FSI_ENGID_SBE, + .version = FSI_VERSION_ANY, + }, + { 0 } +}; + +static struct fsi_driver sbefifo_drv = { + .id_table = sbefifo_ids, + .drv = { + .name = DEVICE_NAME, + .bus = &fsi_bus_type, + .probe = sbefifo_probe, + .remove = sbefifo_remove, + } +}; + +static int sbefifo_init(void) +{ + return fsi_driver_register(&sbefifo_drv); +} + +static void sbefifo_exit(void) +{ + fsi_driver_unregister(&sbefifo_drv); + + ida_destroy(&sbefifo_ida); +} + +module_init(sbefifo_init); +module_exit(sbefifo_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Brad Bishop "); +MODULE_AUTHOR("Eddie James "); +MODULE_AUTHOR("Andrew Jeffery "); +MODULE_AUTHOR("Benjamin Herrenschmidt "); +MODULE_DESCRIPTION("Linux device interface to the POWER Self Boot Engine"); diff --git a/include/linux/fsi-sbefifo.h b/include/linux/fsi-sbefifo.h new file mode 100644 index 000000000000..13f9ebeaa25e --- /dev/null +++ b/include/linux/fsi-sbefifo.h @@ -0,0 +1,33 @@ +/* + * 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 + +#define SBEFIFO_CMD_PUT_OCC_SRAM 0xa404 +#define SBEFIFO_CMD_GET_OCC_SRAM 0xa403 +#define SBEFIFO_CMD_GET_SBE_FFDC 0xa801 + +#define SBEFIFO_MAX_FFDC_SIZE 0x2000 + +struct device; + +int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len, + __be32 *response, size_t *resp_len); + +int sbefifo_parse_status(struct device *dev, u16 cmd, __be32 *response, + size_t resp_len, size_t *data_len); + +#endif /* LINUX_FSI_SBEFIFO_H */ -- cgit v1.2.3