In the address decoding code, we implement two new functions:
orion_alloc_cpu_win() and orion_free_cpu_win(). The first function
finds an unused address decoding window, and configures it according
to the given arguments (in terms of base address, size, target,
attributes). The second function frees an address decoding window,
given a physical base address.

Those two new functions will be used by the PCIe code, which needs to
dynamically register address decoding windows depending on the PCIe
devices that are detected.

The orion_free_cpu_win() function is only here to handle error cases
in the PCIe devices initialization, in the normal case, address
decoding windows are never freed.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 arch/arm/plat-orion/addr-map.c              |   50 +++++++++++++++++++++++++++
 arch/arm/plat-orion/include/plat/addr-map.h |    7 ++++
 2 files changed, 57 insertions(+)

--- a/arch/arm/plat-orion/addr-map.c
+++ b/arch/arm/plat-orion/addr-map.c
@@ -109,6 +109,56 @@ static void __init orion_disable_cpu_win
 }
 
 /*
+ * Find an unused address decoding window, and enable it according to
+ * the arguments passed (base, size, target, attributes, remap).
+ */
+int __init orion_alloc_cpu_win(const struct orion_addr_map_cfg *cfg,
+			       const u32 base, const u32 size,
+			       const u8 target, const u8 attr, const int remap)
+{
+	int win;
+
+	for (win = 0; win < cfg->num_wins; win++) {
+		void __iomem *addr = cfg->win_cfg_base(cfg, win);
+		u32 ctrl = readl(addr + WIN_CTRL_OFF);
+		if (!(ctrl & WIN_CTRL_ENABLE))
+			break;
+	}
+
+	/* No more windows available */
+	if (win == cfg->num_wins)
+		return -ENOMEM;
+
+	orion_setup_cpu_win(cfg, win, base, size, target, attr, remap);
+	return 0;
+}
+
+/*
+ * Free an address decoding window, given its base address.
+ */
+int __init orion_free_cpu_win(const struct orion_addr_map_cfg *cfg,
+			      const u32 base)
+{
+	int win;
+
+	for (win = 0; win < cfg->num_wins; win++) {
+		void __iomem *addr = cfg->win_cfg_base(cfg, win);
+		u32 winbase = readl(addr + WIN_BASE_OFF);
+		u32 ctrl = readl(addr + WIN_CTRL_OFF);
+
+		if (!(ctrl & WIN_CTRL_ENABLE))
+			continue;
+
+		if (winbase == (base & 0xffff0000)) {
+			orion_disable_cpu_win(cfg, win);
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+/*
  * Configure a number of windows.
  */
 static void __init orion_setup_cpu_wins(const struct orion_addr_map_cfg * cfg,
--- a/arch/arm/plat-orion/include/plat/addr-map.h
+++ b/arch/arm/plat-orion/include/plat/addr-map.h
@@ -49,6 +49,13 @@ void __init orion_setup_cpu_win(const st
 				const u32 size, const u8 target,
 				const u8 attr, const int remap);
 
+int __init orion_alloc_cpu_win(const struct orion_addr_map_cfg *cfg,
+			       const u32 base, const u32 size,
+			       const u8 target, const u8 attr, const int remap);
+
+int __init orion_free_cpu_win(const struct orion_addr_map_cfg *cfg,
+			      const u32 base);
+
 void __init orion_setup_cpu_mbus_target(const struct orion_addr_map_cfg *cfg,
 					const void __iomem *ddr_window_cpu_base);
 #endif