[PATCH V4 06/16] PCI: dwc: Add ext config space capability search API

Vidya Sagar
2019-04-23T08:28:27Z

Add extended configuration space capability search API using struct dw_pcie *
pointer

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
Changes from [v3]:
* None

Changes from [v2]:
* None

Changes from [v1]:
* This is a new patch in v2 series

drivers/pci/controller/dwc/pcie-designware.c | 41 ++++++++++++++++++++
drivers/pci/controller/dwc/pcie-designware.h | 1 +
2 files changed, 42 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 6a98135244d6..ecf5fe8842f6 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -53,6 +53,47 @@ u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap)
return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap);
}

+static int dw_pcie_find_next_ext_capability(struct dw_pcie *pci, int start,
+ int cap)
+{
+ u32 header;
+ int ttl;
+ int 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;
+
+ header = dw_pcie_readl_dbi(pci, pos);
+ /*
+ * If we have no capabilities, this is indicated by cap ID,
+ * cap version and next pointer all being 0.
+ */
+ if (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;
+
+ header = dw_pcie_readl_dbi(pci, pos);
+ }
+
+ return 0;
+}
+
+int dw_pcie_find_ext_capability(struct dw_pcie *pci, int cap)
+{
+ return dw_pcie_find_next_ext_capability(pci, 0, cap);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_find_ext_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 35160b4ce929..67307842e003 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -249,6 +249,7 @@ struct dw_pcie {
container_of((endpoint), struct dw_pcie, ep)

u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap);
+int dw_pcie_find_ext_capability(struct dw_pcie *pci, int 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