ARM: footbridge: remove custom DMA address handling

Footbridge is the last Arm platform that has its own
__virt_to_bus()/__bus_to_virt()/phys_to_dma()/dma_to_phys() abstraction,
but this is just a simple offset now.

For PCI devices, the offset that is programmed into the PCI bridge must
also be set in each device using dma_direct_set_offset().  As Arm does
not have a pcibios_bus_add_device() helper yet, just use a bus notifier
for this.

For the ISA DMA, drivers now pass a non-translated physical address into
set_dma_addr(), so they have to be converted back with the corresponding
isa_bus_to_virt() function and then into the correct bus address with
the offset using the isa_dma_dev.

Tested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/arm/include/asm/hardware/dec21285.h b/arch/arm/include/asm/hardware/dec21285.h
index eee390e8d4dc..894f2a635cbb 100644
--- a/arch/arm/include/asm/hardware/dec21285.h
+++ b/arch/arm/include/asm/hardware/dec21285.h
@@ -22,6 +22,13 @@
 #define DC21285_IO(x)		(x)
 #endif
 
+/*
+ * The footbridge is programmed to expose the system RAM at 0xe0000000.
+ * The requirement is that the RAM isn't placed at bus address 0, which
+ * would clash with VGA cards.
+ */
+#define BUS_OFFSET 0xe0000000
+
 #define CSR_PCICMD		DC21285_IO(0x0004)
 #define CSR_CLASSREV		DC21285_IO(0x0008)
 #define CSR_PCICACHELINESIZE	DC21285_IO(0x000c)