diff options
author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-07 17:02:35 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-07 17:02:35 +0200 |
commit | 5c74f27bf6ca9e2b30ba5d7ae11831f89c41b37a (patch) | |
tree | 940838336352c14370ec7f1ae00a36c816d80da2 /drivers | |
parent | a59f95c7a2c35031264eafc62e684df07f5f2a8f (diff) | |
parent | 9f4a8a2d7f9d71093f41c4bb0ef8707e8145bad3 (diff) | |
download | linux-5c74f27bf6ca9e2b30ba5d7ae11831f89c41b37a.tar.bz2 |
Merge tag 'fsi-updates-2018-06-12' of https://git.kernel.org/pub/scm/linux/kernel/git/benh/linux-fsi into char-misc-next
Ben writes:
FSI updates and sbefifo driver
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/fsi/Kconfig | 7 | ||||
-rw-r--r-- | drivers/fsi/Makefile | 1 | ||||
-rw-r--r-- | drivers/fsi/fsi-master-gpio.c | 349 | ||||
-rw-r--r-- | drivers/fsi/fsi-sbefifo.c | 1005 | ||||
-rw-r--r-- | drivers/fsi/fsi-scom.c | 8 |
5 files changed, 1283 insertions, 87 deletions
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-master-gpio.c b/drivers/fsi/fsi-master-gpio.c index 3f487449a277..084e9da8d151 100644 --- a/drivers/fsi/fsi-master-gpio.c +++ b/drivers/fsi/fsi-master-gpio.c @@ -8,11 +8,11 @@ #include <linux/fsi.h> #include <linux/gpio/consumer.h> #include <linux/io.h> +#include <linux/irqflags.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/slab.h> -#include <linux/spinlock.h> #include "fsi-master.h" @@ -22,45 +22,48 @@ #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 100 /* < 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 */ -#define FSI_GPIO_CRC_INVAL 5 /* Master reports slave CRC error */ -/* Normal slave responses */ -#define FSI_GPIO_RESP_BUSY 1 -#define FSI_GPIO_RESP_ACK 0 -#define FSI_GPIO_RESP_ACKD 4 - -#define FSI_GPIO_MAX_BUSY 100 +#define FSI_GPIO_MAX_BUSY 200 #define FSI_GPIO_MTOE_COUNT 1000 #define FSI_GPIO_DRAIN_BITS 20 #define FSI_GPIO_CRC_SIZE 4 #define FSI_GPIO_MSG_ID_SIZE 2 #define FSI_GPIO_MSG_RESPID_SIZE 2 -#define FSI_GPIO_PRIME_SLAVE_CLOCKS 100 +#define FSI_GPIO_PRIME_SLAVE_CLOCKS 20 + +#define LAST_ADDR_INVALID 0x1 struct fsi_master_gpio { struct fsi_master master; struct device *dev; - spinlock_t cmd_lock; /* Lock for commands */ + struct mutex cmd_lock; /* mutex for command ordering */ struct gpio_desc *gpio_clk; struct gpio_desc *gpio_data; struct gpio_desc *gpio_trans; /* Voltage translator */ struct gpio_desc *gpio_enable; /* FSI enable */ struct gpio_desc *gpio_mux; /* Mux control */ bool external_mode; + bool no_delays; + uint32_t last_addr; }; #define CREATE_TRACE_POINTS @@ -78,19 +81,31 @@ static void clock_toggle(struct fsi_master_gpio *master, int count) int i; for (i = 0; i < count; i++) { - ndelay(FSI_GPIO_STD_DLY); + if (!master->no_delays) + ndelay(FSI_GPIO_STD_DLY); gpiod_set_value(master->gpio_clk, 0); - ndelay(FSI_GPIO_STD_DLY); + if (!master->no_delays) + ndelay(FSI_GPIO_STD_DLY); gpiod_set_value(master->gpio_clk, 1); } } -static int sda_in(struct fsi_master_gpio *master) +static int sda_clock_in(struct fsi_master_gpio *master) { int in; - ndelay(FSI_GPIO_STD_DLY); + if (!master->no_delays) + ndelay(FSI_GPIO_STD_DLY); + gpiod_set_value(master->gpio_clk, 0); + + /* Dummy read to feed the synchronizers */ + gpiod_get_value(master->gpio_data); + + /* Actual data read */ in = gpiod_get_value(master->gpio_data); + if (!master->no_delays) + ndelay(FSI_GPIO_STD_DLY); + gpiod_set_value(master->gpio_clk, 1); return in ? 1 : 0; } @@ -125,8 +140,7 @@ static void serial_in(struct fsi_master_gpio *master, struct fsi_gpio_msg *msg, set_sda_input(master); for (bit = 0; bit < num_bits; bit++) { - clock_toggle(master, 1); - in_bit = sda_in(master); + in_bit = sda_clock_in(master); msg->msg <<= 1; msg->msg |= ~in_bit & 0x1; /* Data is active low */ } @@ -191,22 +205,89 @@ static void msg_push_crc(struct fsi_gpio_msg *msg) msg_push_bits(msg, crc, 4); } +static bool check_same_address(struct fsi_master_gpio *master, int id, + uint32_t addr) +{ + /* this will also handle LAST_ADDR_INVALID */ + return master->last_addr == (((id & 0x3) << 21) | (addr & ~0x3)); +} + +static bool check_relative_address(struct fsi_master_gpio *master, int id, + uint32_t addr, uint32_t *rel_addrp) +{ + uint32_t last_addr = master->last_addr; + int32_t rel_addr; + + if (last_addr == LAST_ADDR_INVALID) + return false; + + /* We may be in 23-bit addressing mode, which uses the id as the + * top two address bits. So, if we're referencing a different ID, + * use absolute addresses. + */ + if (((last_addr >> 21) & 0x3) != id) + return false; + + /* remove the top two bits from any 23-bit addressing */ + last_addr &= (1 << 21) - 1; + + /* We know that the addresses are limited to 21 bits, so this won't + * overflow the signed rel_addr */ + rel_addr = addr - last_addr; + if (rel_addr > 255 || rel_addr < -256) + return false; + + *rel_addrp = (uint32_t)rel_addr; + + return true; +} + +static void last_address_update(struct fsi_master_gpio *master, + int id, bool valid, uint32_t addr) +{ + if (!valid) + master->last_addr = LAST_ADDR_INVALID; + else + master->last_addr = ((id & 0x3) << 21) | (addr & ~0x3); +} + /* - * Encode an Absolute Address command + * Encode an Absolute/Relative/Same Address command */ -static void build_abs_ar_command(struct fsi_gpio_msg *cmd, - uint8_t id, uint32_t addr, size_t size, const void *data) +static void build_ar_command(struct fsi_master_gpio *master, + struct fsi_gpio_msg *cmd, uint8_t id, + uint32_t addr, size_t size, const void *data) { + int i, addr_bits, opcode_bits; bool write = !!data; - uint8_t ds; - int i; + uint8_t ds, opcode; + uint32_t rel_addr; cmd->bits = 0; cmd->msg = 0; - msg_push_bits(cmd, id, 2); - msg_push_bits(cmd, FSI_GPIO_CMD_ABS_AR, 3); - msg_push_bits(cmd, write ? 0 : 1, 1); + /* we have 21 bits of address max */ + addr &= ((1 << 21) - 1); + + /* cmd opcodes are variable length - SAME_AR is only two bits */ + opcode_bits = 3; + + if (check_same_address(master, id, addr)) { + /* we still address the byte offset within the word */ + addr_bits = 2; + opcode_bits = 2; + opcode = FSI_GPIO_CMD_SAME_AR; + + } else if (check_relative_address(master, id, addr, &rel_addr)) { + /* 8 bits plus sign */ + addr_bits = 9; + addr = rel_addr; + opcode = FSI_GPIO_CMD_REL_AR; + + } else { + addr_bits = 21; + opcode = FSI_GPIO_CMD_ABS_AR; + } /* * The read/write size is encoded in the lower bits of the address @@ -223,7 +304,10 @@ static void build_abs_ar_command(struct fsi_gpio_msg *cmd, if (size == 4) addr |= 1; - msg_push_bits(cmd, addr & ((1 << 21) - 1), 21); + msg_push_bits(cmd, id, 2); + msg_push_bits(cmd, opcode, opcode_bits); + msg_push_bits(cmd, write ? 0 : 1, 1); + msg_push_bits(cmd, addr, addr_bits); msg_push_bits(cmd, ds, 1); for (i = 0; write && i < size; i++) msg_push_bits(cmd, ((uint8_t *)data)[i], 8); @@ -241,6 +325,16 @@ 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); @@ -258,22 +352,22 @@ static void build_term_command(struct fsi_gpio_msg *cmd, uint8_t slave_id) } /* - * Store information on master errors so handler can detect and clean - * up the bus + * 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 void fsi_master_gpio_error(struct fsi_master_gpio *master, int error) -{ - -} - static int read_one_response(struct fsi_master_gpio *master, uint8_t data_size, struct fsi_gpio_msg *msgp, uint8_t *tagp) { struct fsi_gpio_msg msg; - uint8_t id, tag; + unsigned long flags; uint32_t crc; + uint8_t tag; int i; + local_irq_save(flags); + /* wait for the start bit */ for (i = 0; i < FSI_GPIO_MTOE_COUNT; i++) { msg.bits = 0; @@ -285,8 +379,8 @@ static int read_one_response(struct fsi_master_gpio *master, if (i == FSI_GPIO_MTOE_COUNT) { dev_dbg(master->dev, "Master time out waiting for response\n"); - fsi_master_gpio_error(master, FSI_GPIO_MTOE); - return -EIO; + local_irq_restore(flags); + return -ETIMEDOUT; } msg.bits = 0; @@ -295,7 +389,6 @@ static int read_one_response(struct fsi_master_gpio *master, /* Read slave ID & response tag */ serial_in(master, &msg, 4); - id = (msg.msg >> FSI_GPIO_MSG_RESPID_SIZE) & 0x3; tag = msg.msg & 0x3; /* If we have an ACK and we're expecting data, clock the data in too */ @@ -305,13 +398,18 @@ static int read_one_response(struct fsi_master_gpio *master, /* read CRC */ serial_in(master, &msg, FSI_GPIO_CRC_SIZE); + local_irq_restore(flags); + /* we have a whole message now; check CRC */ crc = crc4(0, 1, 1); crc = crc4(crc, msg.msg, msg.bits); if (crc) { - dev_dbg(master->dev, "ERR response CRC\n"); - fsi_master_gpio_error(master, FSI_GPIO_CRC_INVAL); - return -EIO; + /* Check if it's all 1's, that probably means the host is off */ + if (((~msg.msg) & ((1ull << msg.bits) - 1)) == 0) + return -ENODEV; + dev_dbg(master->dev, "ERR response CRC msg: 0x%016llx (%d bits)\n", + msg.msg, msg.bits); + return -EAGAIN; } if (msgp) @@ -325,12 +423,16 @@ static int read_one_response(struct fsi_master_gpio *master, static int issue_term(struct fsi_master_gpio *master, uint8_t slave) { struct fsi_gpio_msg cmd; + unsigned long flags; uint8_t tag; int rc; build_term_command(&cmd, slave); + + local_irq_save(flags); serial_out(master, &cmd); echo_delay(master); + local_irq_restore(flags); rc = read_one_response(master, 0, NULL, &tag); if (rc < 0) { @@ -350,13 +452,36 @@ static int poll_for_response(struct fsi_master_gpio *master, { struct fsi_gpio_msg response, cmd; int busy_count = 0, rc, i; + 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); + local_irq_save(flags); + clock_zeros(master, FSI_GPIO_EPOLL_CLOCKS); + serial_out(master, &cmd); + echo_delay(master); + local_irq_restore(flags); + goto retry; + } else if (rc) + goto fail; switch (tag) { case FSI_GPIO_RESP_ACK: @@ -378,51 +503,80 @@ retry: * d-poll, not indicated in the hardware protocol * spec. < 20 clocks causes slave to hang, 21 ok. */ - clock_zeros(master, FSI_GPIO_DPOLL_CLOCKS); if (busy_count++ < FSI_GPIO_MAX_BUSY) { build_dpoll_command(&cmd, slave); + local_irq_save(flags); + clock_zeros(master, FSI_GPIO_DPOLL_CLOCKS); serial_out(master, &cmd); echo_delay(master); + local_irq_restore(flags); goto retry; } dev_warn(master->dev, "ERR slave is stuck in busy state, issuing TERM\n"); + local_irq_save(flags); + clock_zeros(master, FSI_GPIO_DPOLL_CLOCKS); + local_irq_restore(flags); issue_term(master, slave); rc = -EIO; 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); - fsi_master_gpio_error(master, response.msg); + dev_dbg(master->dev, "ERRA received: 0x%x\n", (int)response.msg); rc = -EIO; break; + case FSI_GPIO_RESP_ERRC: + dev_dbg(master->dev, "ERRC received: 0x%x\n", (int)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 */ + local_irq_save(flags); clock_zeros(master, FSI_GPIO_PRIME_SLAVE_CLOCKS); + local_irq_restore(flags); + return rc; } -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) +static int send_request(struct fsi_master_gpio *master, + struct fsi_gpio_msg *cmd) { unsigned long flags; - int rc; - spin_lock_irqsave(&master->cmd_lock, flags); - - if (master->external_mode) { - spin_unlock_irqrestore(&master->cmd_lock, flags); + if (master->external_mode) return -EBUSY; - } + local_irq_save(flags); serial_out(master, cmd); echo_delay(master); - rc = poll_for_response(master, slave, resp_len, resp); - spin_unlock_irqrestore(&master->cmd_lock, flags); + local_irq_restore(flags); + + return 0; +} + +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 = -EAGAIN, retries = 0; + + 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; } @@ -432,12 +586,18 @@ static int fsi_master_gpio_read(struct fsi_master *_master, int link, { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); struct fsi_gpio_msg cmd; + int rc; if (link != 0) return -ENODEV; - build_abs_ar_command(&cmd, id, addr, size, NULL); - return fsi_master_gpio_xfer(master, id, &cmd, size, val); + mutex_lock(&master->cmd_lock); + build_ar_command(master, &cmd, id, addr, size, NULL); + rc = fsi_master_gpio_xfer(master, id, &cmd, size, val); + last_address_update(master, id, rc == 0, addr); + mutex_unlock(&master->cmd_lock); + + return rc; } static int fsi_master_gpio_write(struct fsi_master *_master, int link, @@ -445,12 +605,18 @@ static int fsi_master_gpio_write(struct fsi_master *_master, int link, { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); struct fsi_gpio_msg cmd; + int rc; if (link != 0) return -ENODEV; - build_abs_ar_command(&cmd, id, addr, size, val); - return fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); + mutex_lock(&master->cmd_lock); + build_ar_command(master, &cmd, id, addr, size, val); + rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); + last_address_update(master, id, rc == 0, addr); + mutex_unlock(&master->cmd_lock); + + return rc; } static int fsi_master_gpio_term(struct fsi_master *_master, @@ -458,12 +624,18 @@ static int fsi_master_gpio_term(struct fsi_master *_master, { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); struct fsi_gpio_msg cmd; + int rc; if (link != 0) return -ENODEV; + mutex_lock(&master->cmd_lock); build_term_command(&cmd, id); - return fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); + rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); + last_address_update(master, id, false, 0); + mutex_unlock(&master->cmd_lock); + + return rc; } static int fsi_master_gpio_break(struct fsi_master *_master, int link) @@ -476,11 +648,14 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) trace_fsi_master_gpio_break(master); - spin_lock_irqsave(&master->cmd_lock, flags); + mutex_lock(&master->cmd_lock); if (master->external_mode) { - spin_unlock_irqrestore(&master->cmd_lock, flags); + mutex_unlock(&master->cmd_lock); return -EBUSY; } + + local_irq_save(flags); + set_sda_output(master, 1); sda_out(master, 1); clock_toggle(master, FSI_PRE_BREAK_CLOCKS); @@ -489,7 +664,11 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) echo_delay(master); sda_out(master, 1); clock_toggle(master, FSI_POST_BREAK_CLOCKS); - spin_unlock_irqrestore(&master->cmd_lock, flags); + + local_irq_restore(flags); + + last_address_update(master, 0, false, 0); + mutex_unlock(&master->cmd_lock); /* Wait for logic reset to take effect */ udelay(200); @@ -499,6 +678,8 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) static void fsi_master_gpio_init(struct fsi_master_gpio *master) { + unsigned long flags; + gpiod_direction_output(master->gpio_mux, 1); gpiod_direction_output(master->gpio_trans, 1); gpiod_direction_output(master->gpio_enable, 1); @@ -506,7 +687,9 @@ static void fsi_master_gpio_init(struct fsi_master_gpio *master) gpiod_direction_output(master->gpio_data, 1); /* todo: evaluate if clocks can be reduced */ + local_irq_save(flags); clock_zeros(master, FSI_INIT_CLOCKS); + local_irq_restore(flags); } static void fsi_master_gpio_init_external(struct fsi_master_gpio *master) @@ -521,18 +704,17 @@ static void fsi_master_gpio_init_external(struct fsi_master_gpio *master) static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link) { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); - unsigned long flags; int rc = -EBUSY; if (link != 0) return -ENODEV; - spin_lock_irqsave(&master->cmd_lock, flags); + mutex_lock(&master->cmd_lock); if (!master->external_mode) { gpiod_set_value(master->gpio_enable, 1); rc = 0; } - spin_unlock_irqrestore(&master->cmd_lock, flags); + mutex_unlock(&master->cmd_lock); return rc; } @@ -550,7 +732,7 @@ static ssize_t external_mode_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsi_master_gpio *master = dev_get_drvdata(dev); - unsigned long flags, val; + unsigned long val; bool external_mode; int err; @@ -560,10 +742,10 @@ static ssize_t external_mode_store(struct device *dev, external_mode = !!val; - spin_lock_irqsave(&master->cmd_lock, flags); + mutex_lock(&master->cmd_lock); if (external_mode == master->external_mode) { - spin_unlock_irqrestore(&master->cmd_lock, flags); + mutex_unlock(&master->cmd_lock); return count; } @@ -572,7 +754,8 @@ static ssize_t external_mode_store(struct device *dev, fsi_master_gpio_init_external(master); else fsi_master_gpio_init(master); - spin_unlock_irqrestore(&master->cmd_lock, flags); + + mutex_unlock(&master->cmd_lock); fsi_master_rescan(&master->master); @@ -595,6 +778,7 @@ static int fsi_master_gpio_probe(struct platform_device *pdev) master->dev = &pdev->dev; master->master.dev.parent = master->dev; master->master.dev.of_node = of_node_get(dev_of_node(master->dev)); + master->last_addr = LAST_ADDR_INVALID; gpio = devm_gpiod_get(&pdev->dev, "clock", 0); if (IS_ERR(gpio)) { @@ -632,6 +816,13 @@ static int fsi_master_gpio_probe(struct platform_device *pdev) } master->gpio_mux = gpio; + /* + * Check if GPIO block is slow enought that no extra delays + * are necessary. This improves performance on ast2500 by + * an order of magnitude. + */ + master->no_delays = device_property_present(&pdev->dev, "no-gpio-delays"); + master->master.n_links = 1; master->master.flags = FSI_MASTER_FLAG_SWCLOCK; master->master.read = fsi_master_gpio_read; @@ -640,7 +831,7 @@ static int fsi_master_gpio_probe(struct platform_device *pdev) master->master.send_break = fsi_master_gpio_break; master->master.link_enable = fsi_master_gpio_link_enable; platform_set_drvdata(pdev, master); - spin_lock_init(&master->cmd_lock); + mutex_init(&master->cmd_lock); fsi_master_gpio_init(master); 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 <linux/device.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/fsi.h> +#include <linux/fsi-sbefifo.h> +#include <linux/idr.h> +#include <linux/kernel.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/delay.h> +#include <linux/uio.h> +#include <linux/vmalloc.h> + +/* + * The SBEFIFO is a pipe-like FSI device for communicating with + * the self boot engine on POWER processors. + */ + +#define DEVICE_NAME "sbefifo" +#define FSI_ENGID_SBE 0x22 + +/* + * Register layout + */ + +/* Register banks */ +#define SBEFIFO_UP 0x00 /* FSI -> Host */ +#define SBEFIFO_DOWN 0x40 /* Host -> FSI */ + +/* Per-bank registers */ +#define SBEFIFO_FIFO 0x00 /* The FIFO itself */ +#define SBEFIFO_STS 0x04 /* Status register */ +#define SBEFIFO_STS_PARITY_ERR 0x20000000 +#define SBEFIFO_STS_RESET_REQ 0x02000000 +#define SBEFIFO_STS_GOT_EOT 0x00800000 +#define SBEFIFO_STS_MAX_XFER_LIMIT 0x00400000 +#define SBEFIFO_STS_FULL 0x00200000 +#define SBEFIFO_STS_EMPTY 0x00100000 +#define SBEFIFO_STS_ECNT_MASK 0x000f0000 +#define SBEFIFO_STS_ECNT_SHIFT 16 +#define SBEFIFO_STS_VALID_MASK 0x0000ff00 +#define SBEFIFO_STS_VALID_SHIFT 8 +#define SBEFIFO_STS_EOT_MASK 0x000000ff +#define SBEFIFO_STS_EOT_SHIFT 0 +#define SBEFIFO_EOT_RAISE 0x08 /* (Up only) Set End Of Transfer */ +#define SBEFIFO_REQ_RESET 0x0C /* (Up only) Reset Request */ +#define SBEFIFO_PERFORM_RESET 0x10 /* (Down only) Perform Reset */ +#define SBEFIFO_EOT_ACK 0x14 /* (Down only) Acknowledge EOT */ +#define SBEFIFO_DOWN_MAX 0x18 /* (Down only) Max transfer */ + +/* CFAM GP Mailbox SelfBoot Message register */ +#define CFAM_GP_MBOX_SBM_ADDR 0x2824 /* Converted 0x2809 */ + +#define CFAM_SBM_SBE_BOOTED 0x80000000 +#define CFAM_SBM_SBE_ASYNC_FFDC 0x40000000 +#define CFAM_SBM_SBE_STATE_MASK 0x00f00000 +#define CFAM_SBM_SBE_STATE_SHIFT 20 + +enum sbe_state +{ + SBE_STATE_UNKNOWN = 0x0, // Unkown, initial state + SBE_STATE_IPLING = 0x1, // IPL'ing - autonomous mode (transient) + SBE_STATE_ISTEP = 0x2, // ISTEP - Running IPL by steps (transient) + SBE_STATE_MPIPL = 0x3, // MPIPL + SBE_STATE_RUNTIME = 0x4, // SBE Runtime + SBE_STATE_DMT = 0x5, // Dead Man Timer State (transient) + SBE_STATE_DUMP = 0x6, // Dumping + SBE_STATE_FAILURE = 0x7, // Internal SBE failure + SBE_STATE_QUIESCE = 0x8, // Final state - needs SBE reset to get out +}; + +/* FIFO depth */ +#define SBEFIFO_FIFO_DEPTH 8 + +/* Helpers */ +#define sbefifo_empty(sts) ((sts) & SBEFIFO_STS_EMPTY) +#define sbefifo_full(sts) ((sts) & SBEFIFO_STS_FULL) +#define sbefifo_parity_err(sts) ((sts) & SBEFIFO_STS_PARITY_ERR) +#define sbefifo_populated(sts) (((sts) & SBEFIFO_STS_ECNT_MASK) >> SBEFIFO_STS_ECNT_SHIFT) +#define sbefifo_vacant(sts) (SBEFIFO_FIFO_DEPTH - sbefifo_populated(sts)) +#define sbefifo_eot_set(sts) (((sts) & SBEFIFO_STS_EOT_MASK) >> SBEFIFO_STS_EOT_SHIFT) + +/* Reset request timeout in ms */ +#define SBEFIFO_RESET_TIMEOUT 10000 + +/* Timeouts for commands in ms */ +#define SBEFIFO_TIMEOUT_START_CMD 10000 +#define SBEFIFO_TIMEOUT_IN_CMD 1000 +#define SBEFIFO_TIMEOUT_START_RSP 10000 +#define SBEFIFO_TIMEOUT_IN_RSP 1000 + +/* Other constants */ +#define SBEFIFO_MAX_CMD_LEN PAGE_SIZE +#define SBEFIFO_RESET_MAGIC 0x52534554 /* "RSET" */ + +struct sbefifo { + uint32_t magic; +#define SBEFIFO_MAGIC 0x53424546 /* "SBEF" */ + struct fsi_device *fsi_dev; + struct miscdevice mdev; + struct mutex lock; + char name[32]; + int idx; + bool broken; + bool async_ffdc; +}; + +struct sbefifo_user { + struct sbefifo *sbefifo; + struct mutex file_lock; + void *pending_cmd; + size_t pending_len; +}; + +static DEFINE_IDA(sbefifo_ida); +static DEFINE_MUTEX(sbefifo_ffdc_mutex); + + +static void sbefifo_dump_ffdc(struct device *dev, const __be32 *ffdc, + size_t ffdc_sz, bool internal) +{ + int pack = 0; +#define FFDC_LSIZE 60 + static char ffdc_line[FFDC_LSIZE]; + char *p = ffdc_line; + + mutex_lock(&sbefifo_ffdc_mutex); + while (ffdc_sz) { + u32 w0, w1, w2, i; + if (ffdc_sz < 3) { + dev_err(dev, "SBE invalid FFDC package size %zd\n", ffdc_sz); + return; + } + w0 = be32_to_cpu(*(ffdc++)); + w1 = be32_to_cpu(*(ffdc++)); + w2 = be32_to_cpu(*(ffdc++)); + ffdc_sz -= 3; + if ((w0 >> 16) != 0xFFDC) { + dev_err(dev, "SBE invalid FFDC package signature %08x %08x %08x\n", + w0, w1, w2); + break; + } + w0 &= 0xffff; + if (w0 > ffdc_sz) { + dev_err(dev, "SBE FFDC package len %d words but only %zd remaining\n", + w0, ffdc_sz); + w0 = ffdc_sz; + break; + } + if (internal) { + dev_warn(dev, "+---- SBE FFDC package %d for async err -----+\n", + pack++); + } else { + dev_warn(dev, "+---- SBE FFDC package %d for cmd %02x:%02x -----+\n", + pack++, (w1 >> 8) & 0xff, w1 & 0xff); + } + dev_warn(dev, "| Response code: %08x |\n", w2); + dev_warn(dev, "|-------------------------------------------|\n"); + for (i = 0; i < w0; i++) { + if ((i & 3) == 0) { + p = ffdc_line; + p += sprintf(p, "| %04x:", i << 4); + } + p += sprintf(p, " %08x", be32_to_cpu(*(ffdc++))); + ffdc_sz--; + if ((i & 3) == 3 || i == (w0 - 1)) { + while ((i & 3) < 3) { + p += sprintf(p, " "); + i++; + } + dev_warn(dev, "%s |\n", ffdc_line); + } + } + dev_warn(dev, "+-------------------------------------------+\n"); + } +} + +int sbefifo_parse_status(struct device *dev, u16 cmd, __be32 *response, + size_t resp_len, size_t *data_len) +{ + u32 dh, s0, s1; + size_t ffdc_sz; + + if (resp_len < 3) { + pr_debug("sbefifo: cmd %04x, response too small: %zd\n", + cmd, resp_len); + return -ENXIO; + } + dh = be32_to_cpu(response[resp_len - 1]); + if (dh > resp_len || dh < 3) { + dev_err(dev, "SBE cmd %02x:%02x status offset out of range: %d/%zd\n", + cmd >> 8, cmd & 0xff, dh, resp_len); + return -ENXIO; + } + s0 = be32_to_cpu(response[resp_len - dh]); + s1 = be32_to_cpu(response[resp_len - dh + 1]); + if (((s0 >> 16) != 0xC0DE) || ((s0 & 0xffff) != cmd)) { + dev_err(dev, "SBE cmd %02x:%02x, status signature invalid: 0x%08x 0x%08x\n", + cmd >> 8, cmd & 0xff, s0, s1); + return -ENXIO; + } + if (s1 != 0) { + ffdc_sz = dh - 3; + dev_warn(dev, "SBE error cmd %02x:%02x status=%04x:%04x\n", + cmd >> 8, cmd & 0xff, s1 >> 16, s1 & 0xffff); + if (ffdc_sz) + sbefifo_dump_ffdc(dev, &response[resp_len - dh + 2], + ffdc_sz, false); + } + if (data_len) + *data_len = resp_len - dh; + + /* + * Primary status don't have the top bit set, so can't be confused with + * Linux negative error codes, so return the status word whole. + */ + return s1; +} +EXPORT_SYMBOL_GPL(sbefifo_parse_status); + +static int sbefifo_regr(struct sbefifo *sbefifo, int reg, u32 *word) +{ + __be32 raw_word; + int rc; + + rc = fsi_device_read(sbefifo->fsi_dev, reg, &raw_word, + sizeof(raw_word)); + if (rc) + return rc; + + *word = be32_to_cpu(raw_word); + + return 0; +} + +static int sbefifo_regw(struct sbefifo *sbefifo, int reg, u32 word) +{ + __be32 raw_word = cpu_to_be32(word); + + return fsi_device_write(sbefifo->fsi_dev, reg, &raw_word, + sizeof(raw_word)); +} + +static int sbefifo_check_sbe_state(struct sbefifo *sbefifo) +{ + __be32 raw_word; + u32 sbm; + int rc; + + rc = fsi_slave_read(sbefifo->fsi_dev->slave, CFAM_GP_MBOX_SBM_ADDR, + &raw_word, sizeof(raw_word)); + if (rc) + return rc; + sbm = be32_to_cpu(raw_word); + + /* SBE booted at all ? */ + if (!(sbm & CFAM_SBM_SBE_BOOTED)) + return -ESHUTDOWN; + + /* Check its state */ + switch ((sbm & CFAM_SBM_SBE_STATE_MASK) >> CFAM_SBM_SBE_STATE_SHIFT) { + case SBE_STATE_UNKNOWN: + return -ESHUTDOWN; + case SBE_STATE_IPLING: + case SBE_STATE_ISTEP: + case SBE_STATE_MPIPL: + case SBE_STATE_DMT: + return -EBUSY; + case SBE_STATE_RUNTIME: + case SBE_STATE_DUMP: /* Not sure about that one */ + break; + case SBE_STATE_FAILURE: + case SBE_STATE_QUIESCE: + return -ESHUTDOWN; + } + + /* Is there async FFDC available ? Remember it */ + if (sbm & CFAM_SBM_SBE_ASYNC_FFDC) + sbefifo->async_ffdc = true; + + return 0; +} + +/* Don't flip endianness of data to/from FIFO, just pass through. */ +static int sbefifo_down_read(struct sbefifo *sbefifo, __be32 *word) +{ + return fsi_device_read(sbefifo->fsi_dev, SBEFIFO_DOWN, word, + sizeof(*word)); +} + +static int sbefifo_up_write(struct sbefifo *sbefifo, __be32 word) +{ + return fsi_device_write(sbefifo->fsi_dev, SBEFIFO_UP, &word, + sizeof(word)); +} + +static int sbefifo_request_reset(struct sbefifo *sbefifo) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + u32 status, timeout; + int rc; + + dev_dbg(dev, "Requesting FIFO reset\n"); + + /* Mark broken first, will be cleared if reset succeeds */ + sbefifo->broken = true; + + /* Send reset request */ + rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_REQ_RESET, 1); + if (rc) { + dev_err(dev, "Sending reset request failed, rc=%d\n", rc); + return rc; + } + + /* Wait for it to complete */ + for (timeout = 0; timeout < SBEFIFO_RESET_TIMEOUT; timeout++) { + rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &status); + if (rc) { + dev_err(dev, "Failed to read UP fifo status during reset" + " , rc=%d\n", rc); + return rc; + } + + if (!(status & SBEFIFO_STS_RESET_REQ)) { + dev_dbg(dev, "FIFO reset done\n"); + sbefifo->broken = false; + return 0; + } + + msleep(1); + } + dev_err(dev, "FIFO reset timed out\n"); + + return -ETIMEDOUT; +} + +static int sbefifo_cleanup_hw(struct sbefifo *sbefifo) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + u32 up_status, down_status; + bool need_reset = false; + int rc; + + rc = sbefifo_check_sbe_state(sbefifo); + if (rc) { + dev_dbg(dev, "SBE state=%d\n", rc); + return rc; + } + + /* If broken, we don't need to look at status, go straight to reset */ + if (sbefifo->broken) + goto do_reset; + + rc = sbefifo_regr(sbefifo, SBEFIFO_UP | SBEFIFO_STS, &up_status); + if (rc) { + dev_err(dev, "Cleanup: Reading UP status failed, rc=%d\n", rc); + + /* Will try reset again on next attempt at using it */ + sbefifo->broken = true; + return rc; + } + + rc = sbefifo_regr(sbefifo, SBEFIFO_DOWN | SBEFIFO_STS, &down_status); + if (rc) { + dev_err(dev, "Cleanup: Reading DOWN status failed, rc=%d\n", rc); + + /* Will try reset again on next attempt at using it */ + sbefifo->broken = true; + return rc; + } + + /* The FIFO already contains a reset request from the SBE ? */ + if (down_status & SBEFIFO_STS_RESET_REQ) { + dev_info(dev, "Cleanup: FIFO reset request set, resetting\n"); + rc = sbefifo_regw(sbefifo, SBEFIFO_UP, SBEFIFO_PERFORM_RESET); + if (rc) { + sbefifo->broken = true; + dev_err(dev, "Cleanup: Reset reg write failed, rc=%d\n", rc); + return rc; + } + sbefifo->broken = false; + return 0; + } + + /* Parity error on either FIFO ? */ + if ((up_status | down_status) & SBEFIFO_STS_PARITY_ERR) + need_reset = true; + + /* Either FIFO not empty ? */ + if (!((up_status & down_status) & SBEFIFO_STS_EMPTY)) + need_reset = true; + + if (!need_reset) + return 0; + + dev_info(dev, "Cleanup: FIFO not clean (up=0x%08x down=0x%08x)\n", + up_status, down_status); + + do_reset: + + /* Mark broken, will be cleared if/when reset succeeds */ + return sbefifo_request_reset(sbefifo); +} + +static int sbefifo_wait(struct sbefifo *sbefifo, bool up, + u32 *status, unsigned long timeout) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + unsigned long end_time; + bool ready = false; + u32 addr, sts = 0; + int rc; + + dev_vdbg(dev, "Wait on %s fifo...\n", up ? "up" : "down"); + + addr = (up ? SBEFIFO_UP : SBEFIFO_DOWN) | SBEFIFO_STS; + + end_time = jiffies + timeout; + while (!time_after(jiffies, end_time)) { + cond_resched(); + rc = sbefifo_regr(sbefifo, addr, &sts); + if (rc < 0) { + dev_err(dev, "FSI error %d reading status register\n", rc); + return rc; + } + if (!up && sbefifo_parity_err(sts)) { + dev_err(dev, "Parity error in DOWN FIFO\n"); + return -ENXIO; + } + ready = !(up ? sbefifo_full(sts) : sbefifo_empty(sts)); + if (ready) + break; + } + if (!ready) { + dev_err(dev, "%s FIFO Timeout ! status=%08x\n", up ? "UP" : "DOWN", sts); + return -ETIMEDOUT; + } + dev_vdbg(dev, "End of wait status: %08x\n", sts); + + *status = sts; + + return 0; +} + +static int sbefifo_send_command(struct sbefifo *sbefifo, + const __be32 *command, size_t cmd_len) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + size_t len, chunk, vacant = 0, remaining = cmd_len; + unsigned long timeout; + u32 status; + int rc; + + dev_vdbg(dev, "sending command (%zd words, cmd=%04x)\n", + cmd_len, be32_to_cpu(command[1])); + + /* As long as there's something to send */ + timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_CMD); + while (remaining) { + /* Wait for room in the FIFO */ + rc = sbefifo_wait(sbefifo, true, &status, timeout); + if (rc < 0) + return rc; + timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_CMD); + + vacant = sbefifo_vacant(status); + len = chunk = min(vacant, remaining); + + dev_vdbg(dev, " status=%08x vacant=%zd chunk=%zd\n", + status, vacant, chunk); + + /* Write as much as we can */ + while (len--) { + rc = sbefifo_up_write(sbefifo, *(command++)); + if (rc) { + dev_err(dev, "FSI error %d writing UP FIFO\n", rc); + return rc; + } + } + remaining -= chunk; + vacant -= chunk; + } + + /* If there's no room left, wait for some to write EOT */ + if (!vacant) { + rc = sbefifo_wait(sbefifo, true, &status, timeout); + if (rc) + return rc; + } + + /* Send an EOT */ + rc = sbefifo_regw(sbefifo, SBEFIFO_UP | SBEFIFO_EOT_RAISE, 0); + if (rc) + dev_err(dev, "FSI error %d writing EOT\n", rc); + return rc; +} + +static int sbefifo_read_response(struct sbefifo *sbefifo, struct iov_iter *response) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + u32 data, status, eot_set; + unsigned long timeout; + bool overflow = false; + size_t len; + int rc; + + dev_vdbg(dev, "reading response, buflen = %zd\n", iov_iter_count(response)); + + timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_START_RSP); + for (;;) { + /* Grab FIFO status (this will handle parity errors) */ + rc = sbefifo_wait(sbefifo, false, &status, timeout); + if (rc < 0) + return rc; + timeout = msecs_to_jiffies(SBEFIFO_TIMEOUT_IN_RSP); + + /* Decode status */ + len = sbefifo_populated(status); + eot_set = sbefifo_eot_set(status); + + dev_vdbg(dev, " chunk size %zd eot_set=0x%x\n", len, eot_set); + + /* Go through the chunk */ + while(len--) { + /* Read the data */ + rc = sbefifo_down_read(sbefifo, &data); + if (rc < 0) + return rc; + + /* Was it an EOT ? */ + if (eot_set & 0x80) { + /* + * There should be nothing else in the FIFO, + * if there is, mark broken, this will force + * a reset on next use, but don't fail the + * command. + */ + if (len) { + dev_warn(dev, "FIFO read hit" + " EOT with still %zd data\n", + len); + sbefifo->broken = true; + } + + /* We are done */ + rc = sbefifo_regw(sbefifo, + SBEFIFO_DOWN | SBEFIFO_EOT_ACK, 0); + + /* + * If that write fail, still complete the request but mark + * the fifo as broken for subsequent reset (not much else + * we can do here). + */ + if (rc) { + dev_err(dev, "FSI error %d ack'ing EOT\n", rc); + sbefifo->broken = true; + } + + /* Tell whether we overflowed */ + return overflow ? -EOVERFLOW : 0; + } + + /* Store it if there is room */ + if (iov_iter_count(response) >= sizeof(__be32)) { + if (copy_to_iter(&data, sizeof(__be32), response) < sizeof(__be32)) + return -EFAULT; + } else { + dev_vdbg(dev, "Response overflowed !\n"); + + overflow = true; + } + + /* Next EOT bit */ + eot_set <<= 1; + } + } + /* Shouldn't happen */ + return -EIO; +} + +static int sbefifo_do_command(struct sbefifo *sbefifo, + const __be32 *command, size_t cmd_len, + struct iov_iter *response) +{ + /* Try sending the command */ + int rc = sbefifo_send_command(sbefifo, command, cmd_len); + if (rc) + return rc; + + /* Now, get the response */ + return sbefifo_read_response(sbefifo, response); +} + +static void sbefifo_collect_async_ffdc(struct sbefifo *sbefifo) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + struct iov_iter ffdc_iter; + struct kvec ffdc_iov; + __be32 *ffdc; + size_t ffdc_sz; + u32 cmd[2]; + int rc; + + sbefifo->async_ffdc = false; + ffdc = vmalloc(SBEFIFO_MAX_FFDC_SIZE); + if (!ffdc) { + dev_err(dev, "Failed to allocate SBE FFDC buffer\n"); + return; + } + ffdc_iov.iov_base = ffdc; + ffdc_iov.iov_len = SBEFIFO_MAX_FFDC_SIZE;; + iov_iter_kvec(&ffdc_iter, WRITE | ITER_KVEC, &ffdc_iov, 1, SBEFIFO_MAX_FFDC_SIZE); + cmd[0] = cpu_to_be32(2); + cmd[1] = cpu_to_be32(SBEFIFO_CMD_GET_SBE_FFDC); + rc = sbefifo_do_command(sbefifo, cmd, 2, &ffdc_iter); + if (rc != 0) { + dev_err(dev, "Error %d retrieving SBE FFDC\n", rc); + goto bail; + } + ffdc_sz = SBEFIFO_MAX_FFDC_SIZE - iov_iter_count(&ffdc_iter); + ffdc_sz /= sizeof(__be32); + rc = sbefifo_parse_status(dev, SBEFIFO_CMD_GET_SBE_FFDC, ffdc, + ffdc_sz, &ffdc_sz); + if (rc != 0) { + dev_err(dev, "Error %d decoding SBE FFDC\n", rc); + goto bail; + } + if (ffdc_sz > 0) + sbefifo_dump_ffdc(dev, ffdc, ffdc_sz, true); + bail: + vfree(ffdc); + +} + +static int __sbefifo_submit(struct sbefifo *sbefifo, + const __be32 *command, size_t cmd_len, + struct iov_iter *response) +{ + struct device *dev = &sbefifo->fsi_dev->dev; + int rc; + + if (cmd_len < 2 || be32_to_cpu(command[0]) != cmd_len) { + dev_vdbg(dev, "Invalid command len %zd (header: %d)\n", + cmd_len, be32_to_cpu(command[0])); + return -EINVAL; + } + + /* First ensure the HW is in a clean state */ + rc = sbefifo_cleanup_hw(sbefifo); + if (rc) + return rc; + + /* Look for async FFDC first if any */ + if (sbefifo->async_ffdc) + sbefifo_collect_async_ffdc(sbefifo); + + rc = sbefifo_do_command(sbefifo, command, cmd_len, response); + if (rc != 0 && rc != -EOVERFLOW) + goto fail; + return rc; + fail: + /* + * On failure, attempt a reset. Ignore the result, it will mark + * the fifo broken if the reset fails + */ + sbefifo_request_reset(sbefifo); + + /* Return original error */ + return rc; +} + +/** + * sbefifo_submit() - Submit and SBE fifo command and receive response + * @dev: The sbefifo device + * @command: The raw command data + * @cmd_len: The command size (in 32-bit words) + * @response: The output response buffer + * @resp_len: In: Response buffer size, Out: Response size + * + * This will perform the entire operation. If the reponse buffer + * overflows, returns -EOVERFLOW + */ +int sbefifo_submit(struct device *dev, const __be32 *command, size_t cmd_len, + __be32 *response, size_t *resp_len) +{ + struct sbefifo *sbefifo = dev_get_drvdata(dev); + struct iov_iter resp_iter; + struct kvec resp_iov; + size_t rbytes; + int rc; + + if (!dev || !sbefifo) + return -ENODEV; + if (WARN_ON_ONCE(sbefifo->magic != SBEFIFO_MAGIC)) + return -ENODEV; + if (!resp_len || !command || !response || cmd_len > SBEFIFO_MAX_CMD_LEN) + return -EINVAL; + + /* Prepare iov iterator */ + rbytes = (*resp_len) * sizeof(__be32); + resp_iov.iov_base = response; + resp_iov.iov_len = rbytes; + iov_iter_kvec(&resp_iter, WRITE | ITER_KVEC, &resp_iov, 1, rbytes); + + /* Perform the command */ + mutex_lock(&sbefifo->lock); + rc = __sbefifo_submit(sbefifo, command, cmd_len, &resp_iter); + mutex_unlock(&sbefifo->lock); + + /* Extract the response length */ + rbytes -= iov_iter_count(&resp_iter); + *resp_len = rbytes / sizeof(__be32); + + return rc; +} +EXPORT_SYMBOL_GPL(sbefifo_submit); + +/* + * Char device interface + */ +static int sbefifo_user_open(struct inode *inode, struct file *file) +{ + struct sbefifo *sbefifo = container_of(file->private_data, + struct sbefifo, mdev); + struct sbefifo_user *user; + + user = kzalloc(sizeof(struct sbefifo_user), GFP_KERNEL); + if (!user) + return -ENOMEM; + + file->private_data = user; + user->sbefifo = sbefifo; + user->pending_cmd = (void *)__get_free_page(GFP_KERNEL); + if (!user->pending_cmd) { + kfree(user); + return -ENOMEM; + } + mutex_init(&user->file_lock); + + return 0; +} + +static ssize_t sbefifo_user_read(struct file *file, char __user *buf, + size_t len, loff_t *offset) +{ + struct sbefifo_user *user = file->private_data; + struct sbefifo *sbefifo; + struct iov_iter resp_iter; + struct iovec resp_iov; + size_t cmd_len; + int rc; + + if (!user) + return -EINVAL; + sbefifo = user->sbefifo; + if (len & 3) + return -EINVAL; + + mutex_lock(&user->file_lock); + + /* Cronus relies on -EAGAIN after a short read */ + if (user->pending_len == 0) { + rc = -EAGAIN; + goto bail; + } + if (user->pending_len < 8) { + rc = -EINVAL; + goto bail; + } + cmd_len = user->pending_len >> 2; + + /* Prepare iov iterator */ + resp_iov.iov_base = buf; + resp_iov.iov_len = len; + iov_iter_init(&resp_iter, WRITE, &resp_iov, 1, len); + + /* Perform the command */ + mutex_lock(&sbefifo->lock); + rc = __sbefifo_submit(sbefifo, user->pending_cmd, cmd_len, &resp_iter); + mutex_unlock(&sbefifo->lock); + if (rc < 0) + goto bail; + + /* Extract the response length */ + rc = len - iov_iter_count(&resp_iter); + bail: + user->pending_len = 0; + mutex_unlock(&user->file_lock); + return rc; +} + +static ssize_t sbefifo_user_write(struct file *file, const char __user *buf, + size_t len, loff_t *offset) +{ + struct sbefifo_user *user = file->private_data; + struct sbefifo *sbefifo; + int rc = len; + + if (!user) + return -EINVAL; + sbefifo = user->sbefifo; + if (len > SBEFIFO_MAX_CMD_LEN) + return -EINVAL; + if (len & 3) + return -EINVAL; + + mutex_lock(&user->file_lock); + + /* Copy the command into the staging buffer */ + if (copy_from_user(user->pending_cmd, buf, len)) { + rc = -EFAULT; + goto bail; + } + + /* Check for the magic reset command */ + if (len == 4 && be32_to_cpu(*(__be32 *)user->pending_cmd) == + SBEFIFO_RESET_MAGIC) { + + /* Clear out any pending command */ + user->pending_len = 0; + + /* Trigger reset request */ + mutex_lock(&sbefifo->lock); + rc = sbefifo_request_reset(user->sbefifo); + mutex_unlock(&sbefifo->lock); + if (rc == 0) + rc = 4; + goto bail; + } + + /* Update the staging buffer size */ + user->pending_len = len; + bail: + mutex_unlock(&user->file_lock); + + /* And that's it, we'll issue the command on a read */ + return rc; +} + +static int sbefifo_user_release(struct inode *inode, struct file *file) +{ + struct sbefifo_user *user = file->private_data; + + if (!user) + return -EINVAL; + + free_page((unsigned long)user->pending_cmd); + kfree(user); + + return 0; +} + +static const struct file_operations sbefifo_fops = { + .owner = THIS_MODULE, + .open = sbefifo_user_open, + .read = sbefifo_user_read, + .write = sbefifo_user_write, + .release = sbefifo_user_release, +}; + +/* + * Probe/remove + */ + +static int sbefifo_probe(struct device *dev) +{ + struct fsi_device *fsi_dev = to_fsi_dev(dev); + struct sbefifo *sbefifo; + struct device_node *np; + struct platform_device *child; + char child_name[32]; + int rc, child_idx = 0; + + dev_dbg(dev, "Found sbefifo device\n"); + + sbefifo = devm_kzalloc(dev, sizeof(*sbefifo), GFP_KERNEL); + if (!sbefifo) + return -ENOMEM; + sbefifo->magic = SBEFIFO_MAGIC; + sbefifo->fsi_dev = fsi_dev; + mutex_init(&sbefifo->lock); + + /* + * Try cleaning up the FIFO. If this fails, we still register the + * driver and will try cleaning things up again on the next access. + */ + rc = sbefifo_cleanup_hw(sbefifo); + if (rc && rc != -ESHUTDOWN) + dev_err(dev, "Initial HW cleanup failed, will retry later\n"); + + sbefifo->idx = ida_simple_get(&sbefifo_ida, 1, INT_MAX, GFP_KERNEL); + snprintf(sbefifo->name, sizeof(sbefifo->name), "sbefifo%d", + sbefifo->idx); + + dev_set_drvdata(dev, sbefifo); + + /* Create misc chardev for userspace access */ + sbefifo->mdev.minor = MISC_DYNAMIC_MINOR; + sbefifo->mdev.fops = &sbefifo_fops; + sbefifo->mdev.name = sbefifo->name; + sbefifo->mdev.parent = dev; + rc = misc_register(&sbefifo->mdev); + if (rc) { + dev_err(dev, "Failed to register miscdevice: %d\n", rc); + ida_simple_remove(&sbefifo_ida, sbefifo->idx); + return rc; + } + + /* Create platform devs for dts child nodes (occ, etc) */ + for_each_available_child_of_node(dev->of_node, np) { + snprintf(child_name, sizeof(child_name), "%s-dev%d", + sbefifo->name, child_idx++); + child = of_platform_device_create(np, child_name, dev); + if (!child) + dev_warn(dev, "failed to create child %s dev\n", + child_name); + } + + return 0; +} + +static int sbefifo_unregister_child(struct device *dev, void *data) +{ + struct platform_device *child = to_platform_device(dev); + + of_device_unregister(child); + if (dev->of_node) + of_node_clear_flag(dev->of_node, OF_POPULATED); + + return 0; +} + +static int sbefifo_remove(struct device *dev) +{ + struct sbefifo *sbefifo = dev_get_drvdata(dev); + + dev_dbg(dev, "Removing sbefifo device...\n"); + + misc_deregister(&sbefifo->mdev); + device_for_each_child(dev, NULL, sbefifo_unregister_child); + + ida_simple_remove(&sbefifo_ida, sbefifo->idx); + + return 0; +} + +static struct fsi_device_id sbefifo_ids[] = { + { + .engine_type = FSI_ENGID_SBE, + .version = FSI_VERSION_ANY, + }, + { 0 } +}; + +static struct fsi_driver sbefifo_drv = { + .id_table = sbefifo_ids, + .drv = { + .name = DEVICE_NAME, + .bus = &fsi_bus_type, + .probe = sbefifo_probe, + .remove = sbefifo_remove, + } +}; + +static int sbefifo_init(void) +{ + return fsi_driver_register(&sbefifo_drv); +} + +static void sbefifo_exit(void) +{ + fsi_driver_unregister(&sbefifo_drv); + + ida_destroy(&sbefifo_ida); +} + +module_init(sbefifo_init); +module_exit(sbefifo_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Brad Bishop <bradleyb@fuzziesquirrel.com>"); +MODULE_AUTHOR("Eddie James <eajames@linux.vnet.ibm.com>"); +MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>"); +MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); +MODULE_DESCRIPTION("Linux device interface to the POWER Self Boot Engine"); diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c index e13353a2fd7c..c8eb5e5b94a7 100644 --- a/drivers/fsi/fsi-scom.c +++ b/drivers/fsi/fsi-scom.c @@ -26,15 +26,11 @@ #define FSI_ENGID_SCOM 0x5 -#define SCOM_FSI2PIB_DELAY 50 - /* SCOM engine register set */ #define SCOM_DATA0_REG 0x00 #define SCOM_DATA1_REG 0x04 #define SCOM_CMD_REG 0x08 -#define SCOM_RESET_REG 0x1C -#define SCOM_RESET_CMD 0x80000000 #define SCOM_WRITE_CMD 0x80000000 struct scom_device { @@ -180,7 +176,6 @@ static const struct file_operations scom_fops = { static int scom_probe(struct device *dev) { - uint32_t data; struct fsi_device *fsi_dev = to_fsi_dev(dev); struct scom_device *scom; @@ -197,9 +192,6 @@ static int scom_probe(struct device *dev) scom->mdev.parent = dev; list_add(&scom->link, &scom_devices); - data = cpu_to_be32(SCOM_RESET_CMD); - fsi_device_write(fsi_dev, SCOM_RESET_REG, &data, sizeof(uint32_t)); - return misc_register(&scom->mdev); } |