Previously, DCR support was configured at compile time to either use
MMIO or native dcr instructions. Although this works for most
platforms, it fails on FPGA platforms:
1) Systems may include more than one DCR bus.
2) Systems may be native DCR capable and still use memory mapped DCR interface.
This patch provides runtime support based on the device trees for the
case where CONFIG_PPC_DCR_MMIO and CONFIG_PPC_DCR_NATIVE are both
selected. Previously, this was a poorly defined configuration, which
happened to provide NATIVE support. The runtime selection is made
based on the dcr-controller having a 'dcr-access-method' attribute
in the device tree. If only one of the above options is selected,
then the code uses #defines to select only the used code in order to
avoid introducing overhead in existing usage.
Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
The new dcr code does not currently compile when configured for native
DCR access on ARCH=powerpc. This patch fixes the problems.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On 85xx we don't build in dcr support because the core doesn't implement the
instructions. This caused problems when building an 85xx kernel. Additionally
made it so we only build __mtdcr/__mfdcr if we are CONFIG_PPC_DCR_NATIVE.
The 85xx build issue wasPointed out by Dai Haruki.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This patch adds new dcr_map/dcr_read/dcr_write accessors for DCRs that
can be used by drivers to transparently address either native DCRs or
memory mapped DCRs. The implementation for memory mapped DCRs is done
after the binding being currently worked on for SLOF and the Axon
chipset. This patch enables it for the cell native platform
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
