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/net/ipa/reg.h | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 drivers/net/ipa/reg.h (limited to 'drivers/net/ipa/reg.h') diff --git a/drivers/net/ipa/reg.h b/drivers/net/ipa/reg.h new file mode 100644 index 000000000..53c16e594 --- /dev/null +++ b/drivers/net/ipa/reg.h @@ -0,0 +1,136 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* Copyright (C) 2022-2024 Linaro Ltd. */ + +#ifndef _REG_H_ +#define _REG_H_ + +#include +#include +#include +#include +#include + +/** + * struct reg - A register descriptor + * @offset: Register offset relative to base of register memory + * @stride: Distance between two instances, if parameterized + * @fcount: Number of entries in the @fmask array + * @fmask: Array of mask values defining position and width of fields + * @name: Upper-case name of the register + */ +struct reg { + u32 offset; + u32 stride; + u32 fcount; + const u32 *fmask; /* BIT(nr) or GENMASK(h, l) */ + const char *name; +}; + +/* Helper macro for defining "simple" (non-parameterized) registers */ +#define REG(__NAME, __reg_id, __offset) \ + REG_STRIDE(__NAME, __reg_id, __offset, 0) + +/* Helper macro for defining parameterized registers, specifying stride */ +#define REG_STRIDE(__NAME, __reg_id, __offset, __stride) \ + static const struct reg reg_ ## __reg_id = { \ + .name = #__NAME, \ + .offset = __offset, \ + .stride = __stride, \ + } + +#define REG_FIELDS(__NAME, __name, __offset) \ + REG_STRIDE_FIELDS(__NAME, __name, __offset, 0) + +#define REG_STRIDE_FIELDS(__NAME, __name, __offset, __stride) \ + static const struct reg reg_ ## __name = { \ + .name = #__NAME, \ + .offset = __offset, \ + .stride = __stride, \ + .fcount = ARRAY_SIZE(reg_ ## __name ## _fmask), \ + .fmask = reg_ ## __name ## _fmask, \ + } + +/** + * struct regs - Description of registers supported by hardware + * @reg_count: Number of registers in the @reg[] array + * @reg: Array of register descriptors + */ +struct regs { + u32 reg_count; + const struct reg **reg; +}; + +static inline const struct reg *reg(const struct regs *regs, u32 reg_id) +{ + if (WARN(reg_id >= regs->reg_count, + "reg out of range (%u > %u)\n", reg_id, regs->reg_count - 1)) + return NULL; + + return regs->reg[reg_id]; +} + +/* Return the field mask for a field in a register, or 0 on error */ +static inline u32 reg_fmask(const struct reg *reg, u32 field_id) +{ + if (!reg || WARN_ON(field_id >= reg->fcount)) + return 0; + + return reg->fmask[field_id]; +} + +/* Return the mask for a single-bit field in a register, or 0 on error */ +static inline u32 reg_bit(const struct reg *reg, u32 field_id) +{ + u32 fmask = reg_fmask(reg, field_id); + + if (WARN_ON(!is_power_of_2(fmask))) + return 0; + + return fmask; +} + +/* Return the maximum value representable by the given field; always 2^n - 1 */ +static inline u32 reg_field_max(const struct reg *reg, u32 field_id) +{ + u32 fmask = reg_fmask(reg, field_id); + + return fmask ? fmask >> __ffs(fmask) : 0; +} + +/* Encode a value into the given field of a register */ +static inline u32 reg_encode(const struct reg *reg, u32 field_id, u32 val) +{ + u32 fmask = reg_fmask(reg, field_id); + + if (!fmask) + return 0; + + val <<= __ffs(fmask); + if (WARN_ON(val & ~fmask)) + return 0; + + return val; +} + +/* Given a register value, decode (extract) the value in the given field */ +static inline u32 reg_decode(const struct reg *reg, u32 field_id, u32 val) +{ + u32 fmask = reg_fmask(reg, field_id); + + return fmask ? (val & fmask) >> __ffs(fmask) : 0; +} + +/* Returns 0 for NULL reg; warning should have already been issued */ +static inline u32 reg_offset(const struct reg *reg) +{ + return reg ? reg->offset : 0; +} + +/* Returns 0 for NULL reg; warning should have already been issued */ +static inline u32 reg_n_offset(const struct reg *reg, u32 n) +{ + return reg ? reg->offset + n * reg->stride : 0; +} + +#endif /* _REG_H_ */ -- cgit v1.3.1