ARM: Add fixed PCI i/o mapping
This adds a fixed virtual mapping for PCI i/o addresses. The mapping is
located at the last 2MB of vmalloc region (0xfee00000-0xff000000). 2MB
is used to align with PMD size, but IO_SPACE_LIMIT is 1MB. The space
is reserved after .map_io and can be mapped at any time later with
pci_ioremap_io. Platforms which need early i/o mapping (e.g. for vga
console) can call pci_map_io_early in their .map_io function.
This has changed completely from the 1st implementation which only
supported creating the static mapping at .map_io.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 2555250..c3165f0 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -13,6 +13,7 @@
#include <linux/io.h>
#include <asm/mach-types.h>
+#include <asm/mach/map.h>
#include <asm/mach/pci.h>
static int debug_pci;
@@ -627,3 +628,15 @@
return 0;
}
+
+void __init pci_map_io_early(unsigned long pfn)
+{
+ struct map_desc pci_io_desc = {
+ .virtual = PCI_IO_VIRT_BASE,
+ .type = MT_DEVICE,
+ .length = SZ_64K,
+ };
+
+ pci_io_desc.pfn = pfn;
+ iotable_init(&pci_io_desc, 1);
+}