Some platforms may not be fully compliant with generic set of PCI config
accessors. For these cases we implement the way to overwrite accessors
set prior to PCI buses enumeration. Algorithm traverses available quirk
list, matches against <platform ID (DMI), domain, bus number> tuple and
returns corresponding accessors. All quirks can be defined using:
DECLARE_ACPI_MCFG_FIXUP() and kept self contained. Example,
static const struct dmi_system_id foo_dmi[] = {
{
.ident = "<Platform ident string>",
.callback = <handler>,
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "<system vendor>"),
DMI_MATCH(DMI_PRODUCT_NAME, "<product name>"),
DMI_MATCH(DMI_PRODUCT_VERSION, "product version"),
},
},
{ }
};
static struct pci_ops foo_ecam_pci_ops = {
.map_bus = pci_mcfg_dev_base,
.read = foo_ecam_config_read,
.write = foo_ecam_config_write,
};
DECLARE_ACPI_MCFG_FIXUP(foo_dmi, NULL, &foo_ecam_pci_ops, <domain_nr>, <bus_nr>);
More custom (non-DMI) matching can be done via an extra call.
Note that there is possibility to assign quirk related private data to
root->sysdata which will be available along read/wriate accessor, example:
static int boo_match(struct pci_mcfg_fixup *fixup, struct acpi_pci_root *root)
{
return [condition] ? 1 : 0;
}
int boo_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
struct acpi_pci_root *root = bus->sysdata;
struct boo_priv_data *boo_data = root->sysdata;
[..]
}
static struct pci_ops boo_ecam_pci_ops = {
.map_bus = pci_mcfg_dev_base,
.read = boo_ecam_config_read,
.write = boo_ecam_config_write,
};
DECLARE_ACPI_MCFG_FIXUP(NULL, boo_match, &boo_ecam_pci_ops, <domain_nr>, <bus_nr>);
Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
Tested-by: Duc Dang <dhdang@xxxxxxx>
Tested-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Tested-by: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
Tested-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
---
drivers/acpi/pci_mcfg.c | 32 ++++++++++++++++++++++++++++++--
include/acpi/acpi_bus.h | 1 +
include/asm-generic/vmlinux.lds.h | 7 +++++++
include/linux/pci-acpi.h | 18 ++++++++++++++++++
4 files changed, 56 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
index 0062257..b343547 100644
--- a/drivers/acpi/pci_mcfg.c
+++ b/drivers/acpi/pci_mcfg.c
@@ -41,6 +41,29 @@ int __weak raw_pci_write(unsigned int domain, unsigned int bus,
return PCIBIOS_DEVICE_NOT_FOUND;
}
+extern struct pci_mcfg_fixup __start_acpi_mcfg_fixups[];
+extern struct pci_mcfg_fixup __end_acpi_mcfg_fixups[];
+
+static struct pci_ops *pci_mcfg_check_quirks(struct acpi_pci_root *root)
+{
+ struct pci_mcfg_fixup *f;
+ int bus_num = root->secondary.start;
+ int domain = root->segment;
+
+ /*
+ * First match against PCI topology <domain:bus> then use DMI or
+ * custom match handler.
+ */
+ for (f = __start_acpi_mcfg_fixups; f < __end_acpi_mcfg_fixups; f++) {
+ if ((f->domain == domain || f->domain == PCI_MCFG_DOMAIN_ANY) &&
+ (f->bus_num == bus_num || f->bus_num == PCI_MCFG_BUS_ANY) &&
+ (f->system ? dmi_check_system(f->system) : 1 &&
+ f->match ? f->match(f, root) : 1))
