From fc2c618c2038dda38830d1bfaea7af5b38944f3f Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Wed, 1 Aug 2018 10:38:30 +0200 Subject: pci: add quirk infrastructure This is a cut down version of the Linux kernel PCI quirk infrastructure, which allows to register and execute some fixups before the driver is loaded. Signed-off-by: Lucas Stach Signed-off-by: Sascha Hauer --- arch/arm/lib32/barebox.lds.S | 12 +++++++++ drivers/pci/pci.c | 63 +++++++++++++++++++++++++++++++++++++++++--- include/linux/pci.h | 54 +++++++++++++++++++++++++++++++++++++ 3 files changed, 125 insertions(+), 4 deletions(-) diff --git a/arch/arm/lib32/barebox.lds.S b/arch/arm/lib32/barebox.lds.S index 594bf56837..7230e5f31f 100644 --- a/arch/arm/lib32/barebox.lds.S +++ b/arch/arm/lib32/barebox.lds.S @@ -106,6 +106,18 @@ SECTIONS __usymtab : { BAREBOX_SYMS } __usymtab_end = .; +#ifdef CONFIG_PCI + __start_pci_fixups_early = .; + .pci_fixup_early : { KEEP(*(.pci_fixup_early)) } + __end_pci_fixups_early = .; + __start_pci_fixups_header = .; + .pci_fixup_header : { KEEP(*(.pci_fixup_header)) } + __end_pci_fixups_header = .; + __start_pci_fixups_enable = .; + .pci_fixup_enable : { KEEP(*(.pci_fixup_enable)) } + __end_pci_fixups_enable = .; +#endif + .oftables : { BAREBOX_CLK_TABLE() } .dtb : { BAREBOX_DTB() } diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index bd8b7278ef..d206c53848 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -253,6 +253,8 @@ static void setup_device(struct pci_dev *dev, int max_bar) } } + pci_fixup_device(pci_fixup_header, dev); + pci_write_config_byte(dev, PCI_COMMAND, cmd); list_add_tail(&dev->bus_list, &dev->bus->devices); } @@ -412,6 +414,10 @@ unsigned int pci_scan_bus(struct pci_bus *bus) class >>= 8; dev->hdr_type = hdr_type; + pci_fixup_device(pci_fixup_early, dev); + /* the fixup may have changed the device class */ + class = dev->class >> 8; + pr_debug("class = %08x, hdr_type = %08x\n", class, hdr_type); pr_debug("%02x:%02x [%04x:%04x]\n", bus->number, dev->devfn, dev->vendor, dev->device); @@ -519,12 +525,61 @@ EXPORT_SYMBOL(pci_clear_master); */ int pci_enable_device(struct pci_dev *dev) { + int ret; u32 t; pci_read_config_dword(dev, PCI_COMMAND, &t); - return pci_write_config_dword(dev, PCI_COMMAND, t - | PCI_COMMAND_IO - | PCI_COMMAND_MEMORY - ); + ret = pci_write_config_dword(dev, PCI_COMMAND, + t | PCI_COMMAND_IO | PCI_COMMAND_MEMORY); + if (ret) + return ret; + + pci_fixup_device(pci_fixup_enable, dev); + + return 0; } EXPORT_SYMBOL(pci_enable_device); + +static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f, + struct pci_fixup *end) +{ + for (; f < end; f++) + if ((f->class == (u32) (dev->class >> f->class_shift) || + f->class == (u32) PCI_ANY_ID) && + (f->vendor == dev->vendor || + f->vendor == (u16) PCI_ANY_ID) && + (f->device == dev->device || + f->device == (u16) PCI_ANY_ID)) { + f->hook(dev); + } +} + +extern struct pci_fixup __start_pci_fixups_early[]; +extern struct pci_fixup __end_pci_fixups_early[]; +extern struct pci_fixup __start_pci_fixups_header[]; +extern struct pci_fixup __end_pci_fixups_header[]; +extern struct pci_fixup __start_pci_fixups_enable[]; +extern struct pci_fixup __end_pci_fixups_enable[]; + +void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev) +{ + struct pci_fixup *start, *end; + + switch (pass) { + case pci_fixup_early: + start = __start_pci_fixups_early; + end = __end_pci_fixups_early; + break; + case pci_fixup_header: + start = __start_pci_fixups_header; + end = __end_pci_fixups_header; + break; + case pci_fixup_enable: + start = __start_pci_fixups_enable; + end = __end_pci_fixups_enable; + break; + default: + unreachable(); + } + pci_do_fixups(dev, start, end); +} diff --git a/include/linux/pci.h b/include/linux/pci.h index 152ba10a04..82f27f21b2 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -29,6 +29,7 @@ #include +#define PCI_ANY_ID (~0) /* * The PCI interface treats multi-function devices as independent @@ -299,4 +300,57 @@ int pci_enable_device(struct pci_dev *dev); extern void __iomem *pci_iomap(struct pci_dev *dev, int bar); +/* + * The world is not perfect and supplies us with broken PCI devices. + * For at least a part of these bugs we need a work-around, so both + * generic (drivers/pci/quirks.c) and per-architecture code can define + * fixup hooks to be called for particular buggy devices. + */ + +struct pci_fixup { + u16 vendor; /* Or PCI_ANY_ID */ + u16 device; /* Or PCI_ANY_ID */ + u32 class; /* Or PCI_ANY_ID */ + unsigned int class_shift; /* should be 0, 8, 16 */ + void (*hook)(struct pci_dev *dev); +}; + +enum pci_fixup_pass { + pci_fixup_early, /* Before probing BARs */ + pci_fixup_header, /* After reading configuration header */ + pci_fixup_enable, /* pci_enable_device() time */ +}; + +/* Anonymous variables would be nice... */ +#define DECLARE_PCI_FIXUP_SECTION(section, name, vendor, device, class, \ + class_shift, hook) \ + static const struct pci_fixup __PASTE(__pci_fixup_##name,__LINE__) __used \ + __attribute__((__section__(#section), aligned((sizeof(void *))))) \ + = { vendor, device, class, class_shift, hook }; + +#define DECLARE_PCI_FIXUP_CLASS_EARLY(vendor, device, class, \ + class_shift, hook) \ + DECLARE_PCI_FIXUP_SECTION(.pci_fixup_early, \ + hook, vendor, device, class, class_shift, hook) +#define DECLARE_PCI_FIXUP_CLASS_HEADER(vendor, device, class, \ + class_shift, hook) \ + DECLARE_PCI_FIXUP_SECTION(.pci_fixup_header, \ + hook, vendor, device, class, class_shift, hook) +#define DECLARE_PCI_FIXUP_CLASS_ENABLE(vendor, device, class, \ + class_shift, hook) \ + DECLARE_PCI_FIXUP_SECTION(.pci_fixup_enable, \ + hook, vendor, device, class, class_shift, hook) + +#define DECLARE_PCI_FIXUP_EARLY(vendor, device, hook) \ + DECLARE_PCI_FIXUP_SECTION(.pci_fixup_early, \ + hook, vendor, device, PCI_ANY_ID, 0, hook) +#define DECLARE_PCI_FIXUP_HEADER(vendor, device, hook) \ + DECLARE_PCI_FIXUP_SECTION(.pci_fixup_header, \ + hook, vendor, device, PCI_ANY_ID, 0, hook) +#define DECLARE_PCI_FIXUP_ENABLE(vendor, device, hook) \ + DECLARE_PCI_FIXUP_SECTION(.pci_fixup_enable, \ + hook, vendor, device, PCI_ANY_ID, 0, hook) + +void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev); + #endif /* LINUX_PCI_H */ -- cgit v1.2.3