The PCI framework supports "quirks" for PCI devices via several DECLARE_PCI_FIXUP_*() macros. These macros allow arch or driver code to match device IDs to provide customizations or workarounds for broken devices.
This mechanism is generally used in code that can only be built into the kernel, but there are a few occasions where this mechanism is used in drivers that can be modules. For example, see commit 574f29036fce ("PCI: iproc: Apply quirk_paxc_bridge() for module as well as built-in").
The PCI fixup mechanism only works for built-in code, however, because pci_fixup_device() only scans the ".pci_fixup_*" linker sections found in the main kernel; it never touches modules.
Extend the fixup approach to modules.
I don't attempt to be clever here; the algorithm here scales with the number of modules in the system.
Signed-off-by: Brian Norris briannorris@chromium.org ---
drivers/pci/quirks.c | 62 ++++++++++++++++++++++++++++++++++++++++++ include/linux/module.h | 18 ++++++++++++ kernel/module/main.c | 26 ++++++++++++++++++ 3 files changed, 106 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index d97335a40193..db5e0ac82ed7 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -207,6 +207,62 @@ extern struct pci_fixup __end_pci_fixups_suspend_late[];
static bool pci_apply_fixup_final_quirks;
+struct pci_fixup_arg { + struct pci_dev *dev; + enum pci_fixup_pass pass; +}; + +static int pci_module_fixup(struct module *mod, void *parm) +{ + struct pci_fixup_arg *arg = parm; + void *start; + unsigned int size; + + switch (arg->pass) { + case pci_fixup_early: + start = mod->pci_fixup_early; + size = mod->pci_fixup_early_size; + break; + case pci_fixup_header: + start = mod->pci_fixup_header; + size = mod->pci_fixup_header_size; + break; + case pci_fixup_final: + start = mod->pci_fixup_final; + size = mod->pci_fixup_final_size; + break; + case pci_fixup_enable: + start = mod->pci_fixup_enable; + size = mod->pci_fixup_enable_size; + break; + case pci_fixup_resume: + start = mod->pci_fixup_resume; + size = mod->pci_fixup_resume_size; + break; + case pci_fixup_suspend: + start = mod->pci_fixup_suspend; + size = mod->pci_fixup_suspend_size; + break; + case pci_fixup_resume_early: + start = mod->pci_fixup_resume_early; + size = mod->pci_fixup_resume_early_size; + break; + case pci_fixup_suspend_late: + start = mod->pci_fixup_suspend_late; + size = mod->pci_fixup_suspend_late_size; + break; + default: + return 0; + } + + if (!size) + return 0; + + pci_do_fixups(arg->dev, start, start + size); + + return 0; +} + void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) { struct pci_fixup *start, *end; @@ -259,6 +315,12 @@ void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) return; } pci_do_fixups(dev, start, end); + + struct pci_fixup_arg arg = { + .dev = dev, + .pass = pass, + }; + module_for_each_mod(pci_module_fixup, &arg); } EXPORT_SYMBOL(pci_fixup_device);
diff --git a/include/linux/module.h b/include/linux/module.h index 3319a5269d28..7faa8987b9eb 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -539,6 +539,24 @@ struct module { int num_kunit_suites; struct kunit_suite **kunit_suites; #endif +#ifdef CONFIG_PCI_QUIRKS + void *pci_fixup_early; + unsigned int pci_fixup_early_size; + void *pci_fixup_header; + unsigned int pci_fixup_header_size; + void *pci_fixup_final; + unsigned int pci_fixup_final_size; + void *pci_fixup_enable; + unsigned int pci_fixup_enable_size; + void *pci_fixup_resume; + unsigned int pci_fixup_resume_size; + void *pci_fixup_suspend; + unsigned int pci_fixup_suspend_size; + void *pci_fixup_resume_early; + unsigned int pci_fixup_resume_early_size; + void *pci_fixup_suspend_late; + unsigned int pci_fixup_suspend_late_size; +#endif
#ifdef CONFIG_LIVEPATCH diff --git a/kernel/module/main.c b/kernel/module/main.c index c66b26184936..50a80c875adc 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2702,6 +2702,32 @@ static int find_module_sections(struct module *mod, struct load_info *info) sizeof(*mod->kunit_init_suites), &mod->num_kunit_init_suites); #endif +#ifdef CONFIG_PCI_QUIRKS + mod->pci_fixup_early = section_objs(info, ".pci_fixup_early", + sizeof(*mod->pci_fixup_early), + &mod->pci_fixup_early_size); + mod->pci_fixup_header = section_objs(info, ".pci_fixup_header", + sizeof(*mod->pci_fixup_header), + &mod->pci_fixup_header_size); + mod->pci_fixup_final = section_objs(info, ".pci_fixup_final", + sizeof(*mod->pci_fixup_final), + &mod->pci_fixup_final_size); + mod->pci_fixup_enable = section_objs(info, ".pci_fixup_enable", + sizeof(*mod->pci_fixup_enable), + &mod->pci_fixup_enable_size); + mod->pci_fixup_resume = section_objs(info, ".pci_fixup_resume", + sizeof(*mod->pci_fixup_resume), + &mod->pci_fixup_resume_size); + mod->pci_fixup_suspend = section_objs(info, ".pci_fixup_suspend", + sizeof(*mod->pci_fixup_suspend), + &mod->pci_fixup_suspend_size); + mod->pci_fixup_resume_early = section_objs(info, ".pci_fixup_resume_early", + sizeof(*mod->pci_fixup_resume_early), + &mod->pci_fixup_resume_early_size); + mod->pci_fixup_suspend_late = section_objs(info, ".pci_fixup_suspend_late", + sizeof(*mod->pci_fixup_suspend_late), + &mod->pci_fixup_suspend_late_size); +#endif
mod->extable = section_objs(info, "__ex_table", sizeof(*mod->extable), &mod->num_exentries);