[PATCH V7 04/15] PCI: dwc: Move config space capability search API

[Vidya Sagar <vidyas@nvidia.com>]

Move PCIe config space capability search API to common DesignWare file
as this can be used by both host and ep mode codes.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Changes since [v6]:
* Exported dw_pcie_find_capability() API

Changes since [v5]:
* None

Changes since [v4]:
* Removed redundant APIs in pcie-designware-ep.c file after moving them
  to pcie-designware.c file based on Bjorn's comments.

Changes since [v3]:
* Rebased to linux-next top of the tree

Changes since [v2]:
* None

Changes since [v1]:
* Removed dw_pcie_find_next_ext_capability() API from here and made a
  separate patch for that

 .../pci/controller/dwc/pcie-designware-ep.c   | 37 +----------------
 drivers/pci/controller/dwc/pcie-designware.c  | 40 +++++++++++++++++++
 drivers/pci/controller/dwc/pcie-designware.h  |  2 +
 3 files changed, 44 insertions(+), 35 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 2bf5a35c0570..65f479250087 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -40,39 +40,6 @@ void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
 	__dw_pcie_ep_reset_bar(pci, bar, 0);
 }
 
-static u8 __dw_pcie_ep_find_next_cap(struct dw_pcie *pci, u8 cap_ptr,
-			      u8 cap)
-{
-	u8 cap_id, next_cap_ptr;
-	u16 reg;
-
-	if (!cap_ptr)
-		return 0;
-
-	reg = dw_pcie_readw_dbi(pci, cap_ptr);
-	cap_id = (reg & 0x00ff);
-
-	if (cap_id > PCI_CAP_ID_MAX)
-		return 0;
-
-	if (cap_id == cap)
-		return cap_ptr;
-
-	next_cap_ptr = (reg & 0xff00) >> 8;
-	return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap);
-}
-
-static u8 dw_pcie_ep_find_capability(struct dw_pcie *pci, u8 cap)
-{
-	u8 next_cap_ptr;
-	u16 reg;
-
-	reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST);
-	next_cap_ptr = (reg & 0x00ff);
-
-	return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap);
-}
-
 static int dw_pcie_ep_write_header(struct pci_epc *epc, u8 func_no,
 				   struct pci_epf_header *hdr)
 {
@@ -612,9 +579,9 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 		dev_err(dev, "Failed to reserve memory for MSI/MSI-X\n");
 		return -ENOMEM;
 	}
-	ep->msi_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSI);
+	ep->msi_cap = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
 
-	ep->msix_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSIX);
+	ep->msix_cap = dw_pcie_find_capability(pci, PCI_CAP_ID_MSIX);
 
 	offset = dw_pcie_ep_find_ext_capability(pci, PCI_EXT_CAP_ID_REBAR);
 	if (offset) {
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 83cdd2ce2486..8f53ce63d17e 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -14,6 +14,46 @@
 
 #include "pcie-designware.h"
 
+/*
+ * These APIs are different from standard pci_find_*capability() APIs in the
+ * sense that former can only be used post device enumeration as they require
+ * 'struct pci_dev *' pointer whereas these APIs require 'struct dw_pcie *'
+ * pointer and can be used before link up also.
+ */
+static u8 __dw_pcie_find_next_cap(struct dw_pcie *pci, u8 cap_ptr,
+				  u8 cap)
+{
+	u8 cap_id, next_cap_ptr;
+	u16 reg;
+
+	if (!cap_ptr)
+		return 0;
+
+	reg = dw_pcie_readw_dbi(pci, cap_ptr);
+	cap_id = (reg & 0x00ff);
+
+	if (cap_id > PCI_CAP_ID_MAX)
+		return 0;
+
+	if (cap_id == cap)
+		return cap_ptr;
+
+	next_cap_ptr = (reg & 0xff00) >> 8;
+	return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap);
+}
+
+u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap)
+{
+	u8 next_cap_ptr;
+	u16 reg;
+
+	reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST);
+	next_cap_ptr = (reg & 0x00ff);
+
+	return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_find_capability);
+
 int dw_pcie_read(void __iomem *addr, int size, u32 *val)
 {
 	if (!IS_ALIGNED((uintptr_t)addr, size)) {
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 14762e262758..6cb978132469 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -251,6 +251,8 @@ struct dw_pcie {
 #define to_dw_pcie_from_ep(endpoint)   \
 		container_of((endpoint), struct dw_pcie, ep)
 
+u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap);
+
 int dw_pcie_read(void __iomem *addr, int size, u32 *val);
 int dw_pcie_write(void __iomem *addr, int size, u32 val);
 
-- 
2.17.1