projects / lttng-modules.git / blame
| Commit | Line | Data |
|---|---|---|
| b7cdc182 | 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
| 9f36eaed | 2 | * |
| 42d9070d AG |
3 | * wrapper/writeback.h |
| 4 | * | |
| 5 | * wrapper around global_dirty_limit read. Using KALLSYMS with KALLSYMS_ALL | |
| 6 | * to get its address when available, else we need to have a kernel that | |
| 7 | * exports this variable to GPL modules. | |
| 8 | * | |
| 9 | * Copyright (C) 2013 Mentor Graphics Corp. | |
| 42d9070d AG |
10 | */ |
| 11 | ||
| 9f36eaed MJ |
12 | #ifndef _LTTNG_WRAPPER_WRITEBACK_H |
| 13 | #define _LTTNG_WRAPPER_WRITEBACK_H | |
| 14 | ||
| 6284ae7c | 15 | #ifdef CONFIG_KALLSYMS_ALL |
| 9f881196 | 16 | |
| 42d9070d | 17 | #include <linux/kallsyms.h> |
| 5a2f5e92 | 18 | #include <wrapper/kallsyms.h> |
| 42d9070d | 19 | |
| 6284ae7c MJ |
20 | static struct wb_domain *global_wb_domain_sym; |
| 21 | ||
| 22 | static inline | |
| 23 | unsigned long wrapper_global_dirty_limit(void) | |
| 24 | { | |
| 25 | if (!global_wb_domain_sym) | |
| 26 | global_wb_domain_sym = | |
| 27 | (void *) kallsyms_lookup_dataptr("global_wb_domain"); | |
| 28 | if (global_wb_domain_sym) { | |
| 29 | return global_wb_domain_sym->dirty_limit; | |
| 30 | } else { | |
| 31 | printk_once(KERN_WARNING "LTTng: global_wb_domain symbol lookup failed.\n"); | |
| 32 | return 0; | |
| 33 | } | |
| 34 | } | |
| 3dfec228 MJ |
35 | |
| 36 | /* | |
| 37 | * Canary function to check for 'global_wb_domain' at compile time. | |
| 38 | * | |
| 39 | * From 'include/linux/writeback.h': | |
| 40 | * | |
| 41 | * extern struct wb_domain global_wb_domain; | |
| 42 | */ | |
| 43 | static inline | |
| 44 | unsigned long __canary__global_wb_domain(void) | |
| 45 | { | |
| 46 | return global_wb_domain.dirty_limit; | |
| 47 | } | |
| 48 | ||
| 6284ae7c | 49 | #else /* CONFIG_KALLSYMS_ALL */ |
| 42d9070d AG |
50 | |
| 51 | #include <linux/writeback.h> | |
| 52 | ||
| 53 | static inline | |
| 54 | unsigned long wrapper_global_dirty_limit(void) | |
| 55 | { | |
| 56 | return global_dirty_limit; | |
| 57 | } | |
| 58 | ||
| 9f881196 | 59 | #endif /* CONFIG_KALLSYMS_ALL */ |
| 42d9070d AG |
60 | |
| 61 | #endif /* _LTTNG_WRAPPER_WRITEBACK_H */ |