PCI: mvebu: Handle changes to the bridge windows while enabled

[linux.git] / drivers / pci / host / pci-mvebu.c

diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 45a89d969700bc4dd703be1ce02baa5731e1ceea..90e0b6f134addb720a5f5394eca7cc9a13369766 100644 (file)
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -133,6 +133,12 @@ struct mvebu_pcie {
        int nports;
 };
 
+struct mvebu_pcie_window {
+       phys_addr_t base;
+       phys_addr_t remap;
+       size_t size;
+};
+
 /* Structure representing one PCIe interface */
 struct mvebu_pcie_port {
        char *name;
@@ -150,10 +156,8 @@ struct mvebu_pcie_port {
        struct mvebu_sw_pci_bridge bridge;
        struct device_node *dn;
        struct mvebu_pcie *pcie;
-       phys_addr_t memwin_base;
-       size_t memwin_size;
-       phys_addr_t iowin_base;
-       size_t iowin_size;
+       struct mvebu_pcie_window memwin;
+       struct mvebu_pcie_window iowin;
        u32 saved_pcie_stat;
 };
 
@@ -379,23 +383,45 @@ static void mvebu_pcie_add_windows(struct mvebu_pcie_port *port,
        }
 }
 
+static void mvebu_pcie_set_window(struct mvebu_pcie_port *port,
+                                 unsigned int target, unsigned int attribute,
+                                 const struct mvebu_pcie_window *desired,
+                                 struct mvebu_pcie_window *cur)
+{
+       if (desired->base == cur->base && desired->remap == cur->remap &&
+           desired->size == cur->size)
+               return;
+
+       if (cur->size != 0) {
+               mvebu_pcie_del_windows(port, cur->base, cur->size);
+               cur->size = 0;
+               cur->base = 0;
+
+               /*
+                * If something tries to change the window while it is enabled
+                * the change will not be done atomically. That would be
+                * difficult to do in the general case.
+                */
+       }
+
+       if (desired->size == 0)
+               return;
+
+       mvebu_pcie_add_windows(port, target, attribute, desired->base,
+                              desired->size, desired->remap);
+       *cur = *desired;
+}
+
 static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
 {
-       phys_addr_t iobase;
+       struct mvebu_pcie_window desired = {};
 
        /* Are the new iobase/iolimit values invalid? */
        if (port->bridge.iolimit < port->bridge.iobase ||
            port->bridge.iolimitupper < port->bridge.iobaseupper ||
            !(port->bridge.command & PCI_COMMAND_IO)) {
-
-               /* If a window was configured, remove it */
-               if (port->iowin_base) {
-                       mvebu_pcie_del_windows(port, port->iowin_base,
-                                              port->iowin_size);
-                       port->iowin_base = 0;
-                       port->iowin_size = 0;
-               }
-
+               mvebu_pcie_set_window(port, port->io_target, port->io_attr,
+                                     &desired, &port->iowin);
                return;
        }
 
@@ -412,32 +438,27 @@ static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
         * specifications. iobase is the bus address, port->iowin_base
         * is the CPU address.
         */
-       iobase = ((port->bridge.iobase & 0xF0) << 8) |
-               (port->bridge.iobaseupper << 16);
-       port->iowin_base = port->pcie->io.start + iobase;
-       port->iowin_size = ((0xFFF | ((port->bridge.iolimit & 0xF0) << 8) |
-                           (port->bridge.iolimitupper << 16)) -
-                           iobase) + 1;
-
-       mvebu_pcie_add_windows(port, port->io_target, port->io_attr,
-                              port->iowin_base, port->iowin_size,
-                              iobase);
+       desired.remap = ((port->bridge.iobase & 0xF0) << 8) |
+                       (port->bridge.iobaseupper << 16);
+       desired.base = port->pcie->io.start + desired.remap;
+       desired.size = ((0xFFF | ((port->bridge.iolimit & 0xF0) << 8) |
+                        (port->bridge.iolimitupper << 16)) -
+                       desired.remap) +
+                      1;
+
+       mvebu_pcie_set_window(port, port->io_target, port->io_attr, &desired,
+                             &port->iowin);
 }
 
 static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
 {
+       struct mvebu_pcie_window desired = {.remap = MVEBU_MBUS_NO_REMAP};
+
        /* Are the new membase/memlimit values invalid? */
        if (port->bridge.memlimit < port->bridge.membase ||
            !(port->bridge.command & PCI_COMMAND_MEMORY)) {
-
-               /* If a window was configured, remove it */
-               if (port->memwin_base) {
-                       mvebu_pcie_del_windows(port, port->memwin_base,
-                                              port->memwin_size);
-                       port->memwin_base = 0;
-                       port->memwin_size = 0;
-               }
-
+               mvebu_pcie_set_window(port, port->mem_target, port->mem_attr,
+                                     &desired, &port->memwin);
                return;
        }
 
@@ -447,14 +468,12 @@ static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
         * window to setup, according to the PCI-to-PCI bridge
         * specifications.
         */
-       port->memwin_base  = ((port->bridge.membase & 0xFFF0) << 16);
-       port->memwin_size  =
-               (((port->bridge.memlimit & 0xFFF0) << 16) | 0xFFFFF) -
-               port->memwin_base + 1;
-
-       mvebu_pcie_add_windows(port, port->mem_target, port->mem_attr,
-                              port->memwin_base, port->memwin_size,
-                              MVEBU_MBUS_NO_REMAP);
+       desired.base = ((port->bridge.membase & 0xFFF0) << 16);
+       desired.size = (((port->bridge.memlimit & 0xFFF0) << 16) | 0xFFFFF) -
+                      desired.base + 1;
+
+       mvebu_pcie_set_window(port, port->mem_target, port->mem_attr, &desired,
+                             &port->memwin);
 }
 
 /*