Incomding Linux virtio_pci code uses these functions, so port them over.
Signed-off-by: Ahmad Fatoum <ahmad@xxxxxx>
---
drivers/pci/pci.c | 90 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/pci.h | 5 +++
2 files changed, 95 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7d1024d8d1d2..945a983387ed 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -506,6 +506,96 @@ int pci_enable_device(struct pci_dev *dev)
}
EXPORT_SYMBOL(pci_enable_device);
+static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
+ u8 pos, int cap, int *ttl)
+{
+ u8 id;
+ u16 ent;
+
+ pci_bus_read_config_byte(bus, devfn, pos, &pos);
+
+ while ((*ttl)--) {
+ if (pos < 0x40)
+ break;
+ pos &= ~3;
+ pci_bus_read_config_word(bus, devfn, pos, &ent);
+
+ id = ent & 0xff;
+ if (id == 0xff)
+ break;
+ if (id == cap)
+ return pos;
+ pos = (ent >> 8);
+ }
+ return 0;
+}
+
+static u8 __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn,
+ u8 pos, int cap)
+{
+ int ttl = PCI_FIND_CAP_TTL;
+
+ return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl);
+}
+
+u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap)
+{
+ return __pci_find_next_cap(dev->bus, dev->devfn,
+ pos + PCI_CAP_LIST_NEXT, cap);
+}
+EXPORT_SYMBOL_GPL(pci_find_next_capability);
+
+static u8 __pci_bus_find_cap_start(struct pci_bus *bus,
+ unsigned int devfn, u8 hdr_type)
+{
+ u16 status;
+
+ pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status);
+ if (!(status & PCI_STATUS_CAP_LIST))
+ return 0;
+
+ switch (hdr_type) {
+ case PCI_HEADER_TYPE_NORMAL:
+ case PCI_HEADER_TYPE_BRIDGE:
+ return PCI_CAPABILITY_LIST;
+ case PCI_HEADER_TYPE_CARDBUS:
+ return PCI_CB_CAPABILITY_LIST;
+ }
+
+ return 0;
+}
+
+/**
+ * pci_find_capability - query for devices' capabilities
+ * @dev: PCI device to query
+ * @cap: capability code
+ *
+ * Tell if a device supports a given PCI capability.
+ * Returns the address of the requested capability structure within the
+ * device's PCI configuration space or 0 in case the device does not
+ * support it. Possible values for @cap include:
+ *
+ * %PCI_CAP_ID_PM Power Management
+ * %PCI_CAP_ID_AGP Accelerated Graphics Port
+ * %PCI_CAP_ID_VPD Vital Product Data
+ * %PCI_CAP_ID_SLOTID Slot Identification
+ * %PCI_CAP_ID_MSI Message Signalled Interrupts
+ * %PCI_CAP_ID_CHSWP CompactPCI HotSwap
+ * %PCI_CAP_ID_PCIX PCI-X
+ * %PCI_CAP_ID_EXP PCI Express
+ */
+u8 pci_find_capability(struct pci_dev *dev, int cap)
+{
+ u8 pos;
+
+ pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
+ if (pos)
+ pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap);
+
+ return pos;
+}
+EXPORT_SYMBOL(pci_find_capability);
+
static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f,
struct pci_fixup *end)
{
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c742570e3684..0c8fed7c8e0d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -31,6 +31,8 @@
#define PCI_ANY_ID (~0)
+#define PCI_FIND_CAP_TTL 48
+
/*
* The PCI interface treats multi-function devices as independent
* devices. The slot/function address of each device is encoded
@@ -320,6 +322,9 @@ void pci_set_master(struct pci_dev *dev);
void pci_clear_master(struct pci_dev *dev);
int pci_enable_device(struct pci_dev *dev);
+u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap);
+u8 pci_find_capability(struct pci_dev *dev, int cap);
+
extern void __iomem *pci_iomap(struct pci_dev *dev, int bar);
/*
--
2.30.0
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