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 <l.stach@xxxxxxxxxxxxxx>
---
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 594bf5683796..7230e5f31f80 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 bd8b7278ef19..d206c538481c 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 152ba10a04d9..82f27f21b247 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -29,6 +29,7 @@
#include <linux/pci_ids.h>
+#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 */
--
2.18.0
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