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/clk/axis/Makefile | 2 + drivers/clk/axis/clk-artpec6.c | 239 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 241 insertions(+) create mode 100644 drivers/clk/axis/Makefile create mode 100644 drivers/clk/axis/clk-artpec6.c (limited to 'drivers/clk/axis') diff --git a/drivers/clk/axis/Makefile b/drivers/clk/axis/Makefile new file mode 100644 index 000000000..a6a9bbe7f --- /dev/null +++ b/drivers/clk/axis/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_MACH_ARTPEC6) += clk-artpec6.o diff --git a/drivers/clk/axis/clk-artpec6.c b/drivers/clk/axis/clk-artpec6.c new file mode 100644 index 000000000..a6f149962 --- /dev/null +++ b/drivers/clk/axis/clk-artpec6.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ARTPEC-6 clock initialization + * + * Copyright 2015-2016 Axis Communications AB. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define NUM_I2S_CLOCKS 2 + +struct artpec6_clkctrl_drvdata { + struct clk *clk_table[ARTPEC6_CLK_NUMCLOCKS]; + void __iomem *syscon_base; + struct clk_onecell_data clk_data; + spinlock_t i2scfg_lock; +}; + +static struct artpec6_clkctrl_drvdata *clkdata; + +static const char *const i2s_clk_names[NUM_I2S_CLOCKS] = { + "i2s0", + "i2s1", +}; + +static const int i2s_clk_indexes[NUM_I2S_CLOCKS] = { + ARTPEC6_CLK_I2S0_CLK, + ARTPEC6_CLK_I2S1_CLK, +}; + +static void of_artpec6_clkctrl_setup(struct device_node *np) +{ + int i; + const char *sys_refclk_name; + u32 pll_mode, pll_m, pll_n; + struct clk **clks; + + /* Mandatory parent clock. */ + i = of_property_match_string(np, "clock-names", "sys_refclk"); + if (i < 0) + return; + + sys_refclk_name = of_clk_get_parent_name(np, i); + + clkdata = kzalloc_obj(*clkdata); + if (!clkdata) + return; + + clks = clkdata->clk_table; + + for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i) + clks[i] = ERR_PTR(-EPROBE_DEFER); + + clkdata->syscon_base = of_iomap(np, 0); + BUG_ON(clkdata->syscon_base == NULL); + + /* Read PLL1 factors configured by boot strap pins. */ + pll_mode = (readl(clkdata->syscon_base) >> 6) & 3; + switch (pll_mode) { + case 0: /* DDR3-2133 mode */ + pll_m = 4; + pll_n = 85; + break; + case 1: /* DDR3-1866 mode */ + pll_m = 6; + pll_n = 112; + break; + case 2: /* DDR3-1600 mode */ + pll_m = 4; + pll_n = 64; + break; + case 3: /* DDR3-1333 mode */ + pll_m = 8; + pll_n = 106; + break; + } + + clks[ARTPEC6_CLK_CPU] = + clk_register_fixed_factor(NULL, "cpu", sys_refclk_name, 0, pll_n, + pll_m); + clks[ARTPEC6_CLK_CPU_PERIPH] = + clk_register_fixed_factor(NULL, "cpu_periph", "cpu", 0, 1, 2); + + /* EPROBE_DEFER on the apb_clock is not handled in amba devices. */ + clks[ARTPEC6_CLK_UART_PCLK] = + clk_register_fixed_factor(NULL, "uart_pclk", "cpu", 0, 1, 8); + clks[ARTPEC6_CLK_UART_REFCLK] = + clk_register_fixed_rate(NULL, "uart_ref", sys_refclk_name, 0, + 50000000); + + clks[ARTPEC6_CLK_SPI_PCLK] = + clk_register_fixed_factor(NULL, "spi_pclk", "cpu", 0, 1, 8); + clks[ARTPEC6_CLK_SPI_SSPCLK] = + clk_register_fixed_rate(NULL, "spi_sspclk", sys_refclk_name, 0, + 50000000); + + clks[ARTPEC6_CLK_DBG_PCLK] = + clk_register_fixed_factor(NULL, "dbg_pclk", "cpu", 0, 1, 8); + + clkdata->clk_data.clks = clkdata->clk_table; + clkdata->clk_data.clk_num = ARTPEC6_CLK_NUMCLOCKS; + + of_clk_add_provider(np, of_clk_src_onecell_get, &clkdata->clk_data); +} + +CLK_OF_DECLARE_DRIVER(artpec6_clkctrl, "axis,artpec6-clkctrl", + of_artpec6_clkctrl_setup); + +static int artpec6_clkctrl_probe(struct platform_device *pdev) +{ + int propidx; + struct device_node *np = pdev->dev.of_node; + struct device *dev = &pdev->dev; + struct clk **clks = clkdata->clk_table; + const char *sys_refclk_name; + const char *i2s_refclk_name = NULL; + const char *frac_clk_name[2] = { NULL, NULL }; + const char *i2s_mux_parents[2]; + u32 muxreg; + int i; + int err = 0; + + /* Mandatory parent clock. */ + propidx = of_property_match_string(np, "clock-names", "sys_refclk"); + if (propidx < 0) + return -EINVAL; + + sys_refclk_name = of_clk_get_parent_name(np, propidx); + + /* Find clock names of optional parent clocks. */ + propidx = of_property_match_string(np, "clock-names", "i2s_refclk"); + if (propidx >= 0) + i2s_refclk_name = of_clk_get_parent_name(np, propidx); + + propidx = of_property_match_string(np, "clock-names", "frac_clk0"); + if (propidx >= 0) + frac_clk_name[0] = of_clk_get_parent_name(np, propidx); + propidx = of_property_match_string(np, "clock-names", "frac_clk1"); + if (propidx >= 0) + frac_clk_name[1] = of_clk_get_parent_name(np, propidx); + + spin_lock_init(&clkdata->i2scfg_lock); + + clks[ARTPEC6_CLK_NAND_CLKA] = + clk_register_fixed_factor(dev, "nand_clka", "cpu", 0, 1, 8); + clks[ARTPEC6_CLK_NAND_CLKB] = + clk_register_fixed_rate(dev, "nand_clkb", sys_refclk_name, 0, + 100000000); + clks[ARTPEC6_CLK_ETH_ACLK] = + clk_register_fixed_factor(dev, "eth_aclk", "cpu", 0, 1, 4); + clks[ARTPEC6_CLK_DMA_ACLK] = + clk_register_fixed_factor(dev, "dma_aclk", "cpu", 0, 1, 4); + clks[ARTPEC6_CLK_PTP_REF] = + clk_register_fixed_rate(dev, "ptp_ref", sys_refclk_name, 0, + 100000000); + clks[ARTPEC6_CLK_SD_PCLK] = + clk_register_fixed_rate(dev, "sd_pclk", sys_refclk_name, 0, + 100000000); + clks[ARTPEC6_CLK_SD_IMCLK] = + clk_register_fixed_rate(dev, "sd_imclk", sys_refclk_name, 0, + 100000000); + clks[ARTPEC6_CLK_I2S_HST] = + clk_register_fixed_factor(dev, "i2s_hst", "cpu", 0, 1, 8); + + for (i = 0; i < NUM_I2S_CLOCKS; ++i) { + if (i2s_refclk_name && frac_clk_name[i]) { + i2s_mux_parents[0] = frac_clk_name[i]; + i2s_mux_parents[1] = i2s_refclk_name; + + clks[i2s_clk_indexes[i]] = + clk_register_mux(dev, i2s_clk_names[i], + i2s_mux_parents, 2, + CLK_SET_RATE_NO_REPARENT | + CLK_SET_RATE_PARENT, + clkdata->syscon_base + 0x14, i, 1, + 0, &clkdata->i2scfg_lock); + } else if (frac_clk_name[i]) { + /* Lock the mux for internal clock reference. */ + muxreg = readl(clkdata->syscon_base + 0x14); + muxreg &= ~BIT(i); + writel(muxreg, clkdata->syscon_base + 0x14); + clks[i2s_clk_indexes[i]] = + clk_register_fixed_factor(dev, i2s_clk_names[i], + frac_clk_name[i], 0, 1, + 1); + } else if (i2s_refclk_name) { + /* Lock the mux for external clock reference. */ + muxreg = readl(clkdata->syscon_base + 0x14); + muxreg |= BIT(i); + writel(muxreg, clkdata->syscon_base + 0x14); + clks[i2s_clk_indexes[i]] = + clk_register_fixed_factor(dev, i2s_clk_names[i], + i2s_refclk_name, 0, 1, 1); + } + } + + clks[ARTPEC6_CLK_I2C] = + clk_register_fixed_rate(dev, "i2c", sys_refclk_name, 0, 100000000); + + clks[ARTPEC6_CLK_SYS_TIMER] = + clk_register_fixed_rate(dev, "timer", sys_refclk_name, 0, + 100000000); + clks[ARTPEC6_CLK_FRACDIV_IN] = + clk_register_fixed_rate(dev, "fracdiv_in", sys_refclk_name, 0, + 600000000); + + for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i) { + if (IS_ERR(clks[i]) && PTR_ERR(clks[i]) != -EPROBE_DEFER) { + dev_err(dev, + "Failed to register clock at index %d err=%ld\n", + i, PTR_ERR(clks[i])); + err = PTR_ERR(clks[i]); + } + } + + return err; +} + +static const struct of_device_id artpec_clkctrl_of_match[] = { + { .compatible = "axis,artpec6-clkctrl" }, + {} +}; + +static struct platform_driver artpec6_clkctrl_driver = { + .probe = artpec6_clkctrl_probe, + .driver = { + .name = "artpec6_clkctrl", + .of_match_table = artpec_clkctrl_of_match, + }, +}; + +builtin_platform_driver(artpec6_clkctrl_driver); -- cgit v1.3.1