From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/peci/controller/peci-npcm.c | 297 ++++++++++++++++++++++++++++++++++++ 1 file changed, 297 insertions(+) create mode 100644 drivers/peci/controller/peci-npcm.c (limited to 'drivers/peci/controller/peci-npcm.c') diff --git a/drivers/peci/controller/peci-npcm.c b/drivers/peci/controller/peci-npcm.c new file mode 100644 index 000000000..931868991 --- /dev/null +++ b/drivers/peci/controller/peci-npcm.c @@ -0,0 +1,297 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2019 Nuvoton Technology corporation + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* NPCM GCR module */ +#define NPCM_INTCR3_OFFSET 0x9C +#define NPCM_INTCR3_PECIVSEL BIT(19) + +/* NPCM PECI Registers */ +#define NPCM_PECI_CTL_STS 0x00 +#define NPCM_PECI_RD_LENGTH 0x04 +#define NPCM_PECI_ADDR 0x08 +#define NPCM_PECI_CMD 0x0C +#define NPCM_PECI_CTL2 0x10 +#define NPCM_PECI_WR_LENGTH 0x1C +#define NPCM_PECI_PDDR 0x2C +#define NPCM_PECI_DAT_INOUT(n) (0x100 + ((n) * 4)) + +#define NPCM_PECI_MAX_REG 0x200 + +/* NPCM_PECI_CTL_STS - 0x00 : Control Register */ +#define NPCM_PECI_CTRL_DONE_INT_EN BIT(6) +#define NPCM_PECI_CTRL_ABRT_ERR BIT(4) +#define NPCM_PECI_CTRL_CRC_ERR BIT(3) +#define NPCM_PECI_CTRL_DONE BIT(1) +#define NPCM_PECI_CTRL_START_BUSY BIT(0) + +/* NPCM_PECI_RD_LENGTH - 0x04 : Command Register */ +#define NPCM_PECI_RD_LEN_MASK GENMASK(6, 0) + +/* NPCM_PECI_CMD - 0x10 : Command Register */ +#define NPCM_PECI_CTL2_MASK GENMASK(7, 6) + +/* NPCM_PECI_WR_LENGTH - 0x1C : Command Register */ +#define NPCM_PECI_WR_LEN_MASK GENMASK(6, 0) + +/* NPCM_PECI_PDDR - 0x2C : Command Register */ +#define NPCM_PECI_PDDR_MASK GENMASK(4, 0) + +#define NPCM_PECI_INT_MASK (NPCM_PECI_CTRL_ABRT_ERR | \ + NPCM_PECI_CTRL_CRC_ERR | \ + NPCM_PECI_CTRL_DONE) + +#define NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC (50 * USEC_PER_MSEC) +#define NPCM_PECI_IDLE_CHECK_INTERVAL_USEC (10 * USEC_PER_MSEC) +#define NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT 1000 +#define NPCM_PECI_CMD_TIMEOUT_MS_MAX 60000 +#define NPCM_PECI_HOST_NEG_BIT_RATE_DEFAULT 15 +#define NPCM_PECI_PULL_DOWN_DEFAULT 0 + +struct npcm_peci { + u32 cmd_timeout_ms; + struct completion xfer_complete; + struct regmap *regmap; + u32 status; + spinlock_t lock; /* to sync completion status handling */ + struct peci_controller *controller; + struct device *dev; + struct clk *clk; + int irq; +}; + +static int npcm_peci_xfer(struct peci_controller *controller, u8 addr, struct peci_request *req) +{ + struct npcm_peci *priv = dev_get_drvdata(controller->dev.parent); + unsigned long timeout = msecs_to_jiffies(priv->cmd_timeout_ms); + unsigned int msg_rd; + u32 cmd_sts; + int i, ret; + + /* Check command sts and bus idle state */ + ret = regmap_read_poll_timeout(priv->regmap, NPCM_PECI_CTL_STS, cmd_sts, + !(cmd_sts & NPCM_PECI_CTRL_START_BUSY), + NPCM_PECI_IDLE_CHECK_INTERVAL_USEC, + NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC); + if (ret) + return ret; /* -ETIMEDOUT */ + + spin_lock_irq(&priv->lock); + reinit_completion(&priv->xfer_complete); + + regmap_write(priv->regmap, NPCM_PECI_ADDR, addr); + regmap_write(priv->regmap, NPCM_PECI_RD_LENGTH, NPCM_PECI_WR_LEN_MASK & req->rx.len); + regmap_write(priv->regmap, NPCM_PECI_WR_LENGTH, NPCM_PECI_WR_LEN_MASK & req->tx.len); + + if (req->tx.len) { + regmap_write(priv->regmap, NPCM_PECI_CMD, req->tx.buf[0]); + + for (i = 0; i < (req->tx.len - 1); i++) + regmap_write(priv->regmap, NPCM_PECI_DAT_INOUT(i), req->tx.buf[i + 1]); + } + +#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) + dev_dbg(priv->dev, "addr : %#02x, tx.len : %#02x, rx.len : %#02x\n", + addr, req->tx.len, req->rx.len); + print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, req->tx.buf, req->tx.len); +#endif + + priv->status = 0; + regmap_update_bits(priv->regmap, NPCM_PECI_CTL_STS, NPCM_PECI_CTRL_START_BUSY, + NPCM_PECI_CTRL_START_BUSY); + + spin_unlock_irq(&priv->lock); + + ret = wait_for_completion_interruptible_timeout(&priv->xfer_complete, timeout); + if (ret < 0) + return ret; + + if (ret == 0) { + dev_dbg(priv->dev, "timeout waiting for a response\n"); + return -ETIMEDOUT; + } + + spin_lock_irq(&priv->lock); + + if (priv->status != NPCM_PECI_CTRL_DONE) { + spin_unlock_irq(&priv->lock); + dev_dbg(priv->dev, "no valid response, status: %#02x\n", priv->status); + return -EIO; + } + + regmap_write(priv->regmap, NPCM_PECI_CMD, 0); + + for (i = 0; i < req->rx.len; i++) { + regmap_read(priv->regmap, NPCM_PECI_DAT_INOUT(i), &msg_rd); + req->rx.buf[i] = (u8)msg_rd; + } + + spin_unlock_irq(&priv->lock); + +#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) + print_hex_dump_bytes("RX : ", DUMP_PREFIX_NONE, req->rx.buf, req->rx.len); +#endif + return 0; +} + +static irqreturn_t npcm_peci_irq_handler(int irq, void *arg) +{ + struct npcm_peci *priv = arg; + u32 status_ack = 0; + u32 status; + + spin_lock(&priv->lock); + regmap_read(priv->regmap, NPCM_PECI_CTL_STS, &status); + priv->status |= (status & NPCM_PECI_INT_MASK); + + if (status & NPCM_PECI_CTRL_CRC_ERR) + status_ack |= NPCM_PECI_CTRL_CRC_ERR; + + if (status & NPCM_PECI_CTRL_ABRT_ERR) + status_ack |= NPCM_PECI_CTRL_ABRT_ERR; + + /* + * All commands should be ended up with a NPCM_PECI_CTRL_DONE + * bit set even in an error case. + */ + if (status & NPCM_PECI_CTRL_DONE) { + status_ack |= NPCM_PECI_CTRL_DONE; + complete(&priv->xfer_complete); + } + + regmap_write_bits(priv->regmap, NPCM_PECI_CTL_STS, NPCM_PECI_INT_MASK, status_ack); + + spin_unlock(&priv->lock); + return IRQ_HANDLED; +} + +static int npcm_peci_init_ctrl(struct npcm_peci *priv) +{ + u32 cmd_sts; + int ret; + + priv->clk = devm_clk_get_enabled(priv->dev, NULL); + if (IS_ERR(priv->clk)) { + dev_err(priv->dev, "failed to get ref clock\n"); + return PTR_ERR(priv->clk); + } + + ret = device_property_read_u32(priv->dev, "cmd-timeout-ms", &priv->cmd_timeout_ms); + if (ret) { + priv->cmd_timeout_ms = NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT; + } else if (priv->cmd_timeout_ms > NPCM_PECI_CMD_TIMEOUT_MS_MAX || + priv->cmd_timeout_ms == 0) { + dev_warn(priv->dev, "invalid cmd-timeout-ms: %u, falling back to: %u\n", + priv->cmd_timeout_ms, NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT); + + priv->cmd_timeout_ms = NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT; + } + + regmap_update_bits(priv->regmap, NPCM_PECI_CTL2, NPCM_PECI_CTL2_MASK, + NPCM_PECI_PULL_DOWN_DEFAULT << 6); + + regmap_update_bits(priv->regmap, NPCM_PECI_PDDR, NPCM_PECI_PDDR_MASK, + NPCM_PECI_HOST_NEG_BIT_RATE_DEFAULT); + + ret = regmap_read_poll_timeout(priv->regmap, NPCM_PECI_CTL_STS, cmd_sts, + !(cmd_sts & NPCM_PECI_CTRL_START_BUSY), + NPCM_PECI_IDLE_CHECK_INTERVAL_USEC, + NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC); + if (ret) + return ret; /* -ETIMEDOUT */ + + /* PECI interrupt enable */ + regmap_update_bits(priv->regmap, NPCM_PECI_CTL_STS, NPCM_PECI_CTRL_DONE_INT_EN, + NPCM_PECI_CTRL_DONE_INT_EN); + + return 0; +} + +static const struct regmap_config npcm_peci_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = NPCM_PECI_MAX_REG, +}; + +static const struct peci_controller_ops npcm_ops = { + .xfer = npcm_peci_xfer, +}; + +static int npcm_peci_probe(struct platform_device *pdev) +{ + struct peci_controller *controller; + struct npcm_peci *priv; + void __iomem *base; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = &pdev->dev; + dev_set_drvdata(&pdev->dev, priv); + + base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(base)) + return PTR_ERR(base); + + priv->regmap = devm_regmap_init_mmio(&pdev->dev, base, &npcm_peci_regmap_config); + if (IS_ERR(priv->regmap)) + return PTR_ERR(priv->regmap); + + priv->irq = platform_get_irq(pdev, 0); + if (priv->irq < 0) + return priv->irq; + + ret = devm_request_irq(&pdev->dev, priv->irq, npcm_peci_irq_handler, + 0, "peci-npcm-irq", priv); + if (ret) + return ret; + + init_completion(&priv->xfer_complete); + spin_lock_init(&priv->lock); + + ret = npcm_peci_init_ctrl(priv); + if (ret) + return ret; + + controller = devm_peci_controller_add(priv->dev, &npcm_ops); + if (IS_ERR(controller)) + return dev_err_probe(priv->dev, PTR_ERR(controller), + "failed to add npcm peci controller\n"); + + priv->controller = controller; + + return 0; +} + +static const struct of_device_id npcm_peci_of_table[] = { + { .compatible = "nuvoton,npcm750-peci", }, + { .compatible = "nuvoton,npcm845-peci", }, + { } +}; +MODULE_DEVICE_TABLE(of, npcm_peci_of_table); + +static struct platform_driver npcm_peci_driver = { + .probe = npcm_peci_probe, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = npcm_peci_of_table, + }, +}; +module_platform_driver(npcm_peci_driver); + +MODULE_AUTHOR("Tomer Maimon "); +MODULE_DESCRIPTION("NPCM PECI driver"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS("PECI"); -- cgit v1.3.1