drivers/pci: Add function to find an extended capability

PCIe extends device's configuration space to 4k and provides
extended capability. The patch adds function to find them.
The code is ported from Linux PCIe driver.

Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: York Sun <yorksun@freescale.com>

2 files changed, 94 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 157491c..df50b48 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -526,3 +526,56 @@ int pci_find_cap(struct pci_controller *hose, pci_dev_t dev, int pos, int cap)
 	}
 	return 0;
 }
+
+/**
+ * pci_find_next_ext_capability - Find an extended capability
+ *
+ * Returns the address of the next matching extended capability structure
+ * within the device's PCI configuration space or 0 if the device does
+ * not support it.  Some capabilities can occur several times, e.g., the
+ * vendor-specific capability, and this provides a way to find them all.
+ */
+int pci_find_next_ext_capability(struct pci_controller *hose, pci_dev_t dev,
+				 int start, int cap)
+{
+	u32 header;
+	int ttl, pos = PCI_CFG_SPACE_SIZE;
+
+	/* minimum 8 bytes per capability */
+	ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
+
+	if (start)
+		pos = start;
+
+	pci_hose_read_config_dword(hose, dev, pos, &header);
+	if (header == 0xffffffff || header == 0)
+		return 0;
+
+	while (ttl-- > 0) {
+		if (PCI_EXT_CAP_ID(header) == cap && pos != start)
+			return pos;
+
+		pos = PCI_EXT_CAP_NEXT(header);
+		if (pos < PCI_CFG_SPACE_SIZE)
+			break;
+
+		pci_hose_read_config_dword(hose, dev, pos, &header);
+		if (header == 0xffffffff || header == 0)
+			break;
+	}
+
+	return 0;
+}
+
+/**
+ * pci_hose_find_ext_capability - Find an extended capability
+ *
+ * Returns the address of the requested extended capability structure
+ * within the device's PCI configuration space or 0 if the device does
+ * not support it.
+ */
+int pci_hose_find_ext_capability(struct pci_controller *hose, pci_dev_t dev,
+				 int cap)
+{
+	return pci_find_next_ext_capability(hose, dev, 0, cap);
+}
diff --git a/include/pci.h b/include/pci.h
index 94bca97..dce159f 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -11,6 +11,9 @@
 #ifndef _PCI_H
 #define _PCI_H
 
+#define PCI_CFG_SPACE_SIZE	256
+#define PCI_CFG_SPACE_EXP_SIZE	4096
+
 /*
  * Under PCI, each device has 256 bytes of configuration address space,
  * of which the first 64 bytes are standardized as follows:
@@ -413,6 +416,39 @@
 #define PCI_FIND_CAP_TTL 0x48
 #define CAP_START_POS 0x40
 
+/* Extended Capabilities (PCI-X 2.0 and Express) */
+#define PCI_EXT_CAP_ID(header)		(header & 0x0000ffff)
+#define PCI_EXT_CAP_VER(header)		((header >> 16) & 0xf)
+#define PCI_EXT_CAP_NEXT(header)	((header >> 20) & 0xffc)
+
+#define PCI_EXT_CAP_ID_ERR	0x01	/* Advanced Error Reporting */
+#define PCI_EXT_CAP_ID_VC	0x02	/* Virtual Channel Capability */
+#define PCI_EXT_CAP_ID_DSN	0x03	/* Device Serial Number */
+#define PCI_EXT_CAP_ID_PWR	0x04	/* Power Budgeting */
+#define PCI_EXT_CAP_ID_RCLD	0x05	/* Root Complex Link Declaration */
+#define PCI_EXT_CAP_ID_RCILC	0x06	/* Root Complex Internal Link Control */
+#define PCI_EXT_CAP_ID_RCEC	0x07	/* Root Complex Event Collector */
+#define PCI_EXT_CAP_ID_MFVC	0x08	/* Multi-Function VC Capability */
+#define PCI_EXT_CAP_ID_VC9	0x09	/* same as _VC */
+#define PCI_EXT_CAP_ID_RCRB	0x0A	/* Root Complex RB? */
+#define PCI_EXT_CAP_ID_VNDR	0x0B	/* Vendor-Specific */
+#define PCI_EXT_CAP_ID_CAC	0x0C	/* Config Access - obsolete */
+#define PCI_EXT_CAP_ID_ACS	0x0D	/* Access Control Services */
+#define PCI_EXT_CAP_ID_ARI	0x0E	/* Alternate Routing ID */
+#define PCI_EXT_CAP_ID_ATS	0x0F	/* Address Translation Services */
+#define PCI_EXT_CAP_ID_SRIOV	0x10	/* Single Root I/O Virtualization */
+#define PCI_EXT_CAP_ID_MRIOV	0x11	/* Multi Root I/O Virtualization */
+#define PCI_EXT_CAP_ID_MCAST	0x12	/* Multicast */
+#define PCI_EXT_CAP_ID_PRI	0x13	/* Page Request Interface */
+#define PCI_EXT_CAP_ID_AMD_XXX	0x14	/* Reserved for AMD */
+#define PCI_EXT_CAP_ID_REBAR	0x15	/* Resizable BAR */
+#define PCI_EXT_CAP_ID_DPA	0x16	/* Dynamic Power Allocation */
+#define PCI_EXT_CAP_ID_TPH	0x17	/* TPH Requester */
+#define PCI_EXT_CAP_ID_LTR	0x18	/* Latency Tolerance Reporting */
+#define PCI_EXT_CAP_ID_SECPCI	0x19	/* Secondary PCIe Capability */
+#define PCI_EXT_CAP_ID_PMUX	0x1A	/* Protocol Multiplexing */
+#define PCI_EXT_CAP_ID_PASID	0x1B	/* Process Address Space ID */
+
 /* Include the ID list */
 
 #include <pci_ids.h>
@@ -687,6 +723,11 @@ extern int pci_hose_find_cap_start(struct pci_controller *hose, pci_dev_t dev,
 extern int pci_find_cap(struct pci_controller *hose, pci_dev_t dev, int pos,
 			int cap);
 
+int pci_find_next_ext_capability(struct pci_controller *hose,
+				 pci_dev_t dev, int start, int cap);
+int pci_hose_find_ext_capability(struct pci_controller *hose,
+				 pci_dev_t dev, int cap);
+
 #ifdef CONFIG_PCI_FIXUP_DEV
 extern void board_pci_fixup_dev(struct pci_controller *hose, pci_dev_t dev,
 				unsigned short vendor,