[PATCH 1/4] PCI: dwc: Change to use an array to store the structure of functions

[Zhiqiang Hou]

From: Hou Zhiqiang <zhiqiang....@nxp.com>

As there isn't dynamically adding and deleting a function's structure,
the list_head is not necessary for this case. Array is easier and
more efficient to search.

Signed-off-by: Hou Zhiqiang <zhiqiang....@nxp.com>
---
 .../pci/controller/dwc/pcie-designware-ep.c   | 33 ++++++++-----------
 drivers/pci/controller/dwc/pcie-designware.h  |  3 +-
 2 files changed, 15 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c 
b/drivers/pci/controller/dwc/pcie-designware-ep.c
index bcd1cd9ba8c8..e583700b5ba3 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -34,12 +34,8 @@ EXPORT_SYMBOL_GPL(dw_pcie_ep_init_notify);
 struct dw_pcie_ep_func *
 dw_pcie_ep_get_func_from_ep(struct dw_pcie_ep *ep, u8 func_no)
 {
-       struct dw_pcie_ep_func *ep_func;
-
-       list_for_each_entry(ep_func, &ep->func_list, list) {
-               if (ep_func->func_no == func_no)
-                       return ep_func;
-       }
+       if (func_no < ep->epc->max_functions)
+               return ep->funcs + func_no;
 
        return NULL;
 }
@@ -675,9 +671,9 @@ EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);
 
 int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 {
+       u8 i;
        int ret;
        void *addr;
-       u8 func_no;
        struct resource *res;
        struct pci_epc *epc;
        struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
@@ -685,9 +681,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
        struct platform_device *pdev = to_platform_device(dev);
        struct device_node *np = dev->of_node;
        const struct pci_epc_features *epc_features;
-       struct dw_pcie_ep_func *ep_func;
-
-       INIT_LIST_HEAD(&ep->func_list);
+       struct dw_pcie_ep_func *funcs;
 
        if (!pci->dbi_base) {
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
@@ -750,18 +744,19 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
        if (ret < 0)
                epc->max_functions = 1;
 
-       for (func_no = 0; func_no < epc->max_functions; func_no++) {
-               ep_func = devm_kzalloc(dev, sizeof(*ep_func), GFP_KERNEL);
-               if (!ep_func)
-                       return -ENOMEM;
+       funcs = devm_kcalloc(dev, epc->max_functions, sizeof(*funcs),
+                            GFP_KERNEL);
+       if (!funcs)
+               return -ENOMEM;
+
+       ep->funcs = funcs;
 
-               ep_func->func_no = func_no;
-               ep_func->msi_cap = dw_pcie_ep_find_capability(ep, func_no,
+       for (i = 0; i < epc->max_functions; i++) {
+               funcs[i].func_no = i;
+               funcs[i].msi_cap = dw_pcie_ep_find_capability(ep, i,
                                                              PCI_CAP_ID_MSI);
-               ep_func->msix_cap = dw_pcie_ep_find_capability(ep, func_no,
+               funcs[i].msix_cap = dw_pcie_ep_find_capability(ep, i,
                                                               PCI_CAP_ID_MSIX);
-
-               list_add_tail(&ep_func->list, &ep->func_list);
        }
 
        if (ep->ops->ep_init)
diff --git a/drivers/pci/controller/dwc/pcie-designware.h 
b/drivers/pci/controller/dwc/pcie-designware.h
index 98710bf5ab0e..16d239c4d09b 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -221,7 +221,6 @@ struct dw_pcie_ep_ops {
 };
 
 struct dw_pcie_ep_func {
-       struct list_head        list;
        u8                      func_no;
        u8                      msi_cap;        /* MSI capability offset */
        u8                      msix_cap;       /* MSI-X capability offset */
@@ -229,7 +228,7 @@ struct dw_pcie_ep_func {
 
 struct dw_pcie_ep {
        struct pci_epc          *epc;
-       struct list_head        func_list;
+       struct dw_pcie_ep_func  *funcs;
        const struct dw_pcie_ep_ops *ops;
        phys_addr_t             phys_base;
        size_t                  addr_size;
-- 
2.17.1