This PCIe bridge only has a 32 bit bus master interface, thus truncating
the DMA capability of all PCIe devices attached beneath it. This caps
the child device capability so that these devices work on systems with
physical memory beyond the 4GiB threshold.

This fixes: [    0.010000] cpu cpu0: Error -2 creating of_node link
... which you get for every CPU on all architectures with a OF cpu/ node.

This affects riscv, nios, etc.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

There isn't a hard dependency of the Xilinx AXI-PCIe host bridge on any
architecture.  For example: at SiFive we map RISC-V cores to Xilinx
FPGAs and connect the Xilinx IP via a TileLink adapter, so the RISC-V
Linux port will need to be able to enable PCIE_XILINX in order to have
PCIe support.

This patch decouples the PCIE_XILINX support from ARCH.  Instead it just
depends on OF_PCI, which I believe is the only true dependency.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

Without this patch we can't use the 4th legacy PCIe interrupt.  This
is a workaround: there are only 4 legacy interrupts, but since they're
numbered starting from 1 instead of 0 this just adds a 5th interrupt.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Wesley W. Terpstra <wesley@sifive.com>

Multiple architectures define this as an empty function, and I'm adding
another one as part of the RISC-V port.  This adds a __weak version of
pci_fixup_bios and deletes the now obselete ones in a handful of ports.

The only functional change should be that microblaze used to export
pcibios_fixup_bus.  None of the other architectures export this, so I
just dropped it.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

Multiple architectures define this as trivial function, and I'm adding
another one as part of the RISC-V port.  This adds a __weak version of
pcibios_align_resource and deletes the now obselete ones in a handful of
ports.

The only functional change should be that a handful of ports used to
export pcibios_fixup_bus.  Only some architectures export this, so I
just dropped it.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch contains all the build infrastructure that actually enables
the RISC-V port.  This includes Makefiles, linker scripts, and Kconfig
files.  It also contains the only top-level change, which adds RISC-V to
the list of architectures that need a sed run to produce the ARCH
variable when building locally.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling.  It also contains some generic code that is ABI visible.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch contains code to manage the RISC-V MMU, including definitions
of the page tables and the page walking code.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch contains code that interfaces with devices that are mandated
by the RISC-V supervisor specification and that don't have explicit
drivers anywhere else in the tree.  This includes the staticly defined
interrupts, the CSR-mapped timer, and virtualized SBI devices.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch contains the implementation of tasks on RISC-V, most of which
is involved in task switching.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch contains the code that interfaces with ELF objects on RISC-V
systems, the vast majority of which is present to load kernel modules.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch contains code that is more specific to the RISC-V ISA than it
is to Linux.  It contains string and math operations, C wrappers for
various assembly instructions, stack walking code, and uaccess.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This contains all the code that directly interfaces with the RISC-V
memory model.  While this code corforms to the current RISC-V ISA
specifications (user 2.2 and priv 1.10), the memory model is somewhat
underspecified in those documents.  There is a working group that hopes
to produce a formal memory model by the end of the year, but my
understanding is that the basic definitions we're relying on here won't
change significantly.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system.  When a file was
init-related this patch contains the entire file.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

The RISC-V ISA defines a simple console that is availiable via SBI calls
on all systems.  This patch adds a driver for this console interface
that can act as both a target for early printk and as the system
console.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch adds a driver for the Platform Level Interrupt Controller
(PLIC) specified as part of the RISC-V supervisor level ISA manual.
The PLIC connocts global interrupt sources to the local interrupt
controller on each hart.  A PLIC is present on all RISC-V systems.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch adds a driver that manages the local interrupts on each
RISC-V hart, as specifiec by the RISC-V supervisor level ISA manual.
The local interrupt controller manages software interrupts, timer
interrupts, and hardware interrupts (which are routed via the
platform level interrupt controller).  Per-hart local interrupt
controllers are found on all RISC-V systems.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

The RISC-V ISA defines a per-hart real-time clock and timer, which is
present on all systems.  The clock is accessed via the 'rdtime'
pseudo-instruction (which reads a CSR), and the timer is set via an SBI
call.

This driver attempts to split out the RISC-V ISA specific mechanisms of
accessing the hardware from the clocksource driver by taking a pair of
function pointers to issue the actual RISC-V specific instructions.

Signed-off-by: Dmitriy Cherkasov <dmitriy@oss-tech.org>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch adds device tree bindings for RISC-V CPUs, patterned after
the ARM device tree CPU bindings.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch adds documentation for the platform-level interrupt
controller (PLIC) found in all RISC-V systems.  This interrupt
controller routes interrupts from all the devices in the system to each
hart-local interrupt controller.

Note: the DTS bindings for the PLIC aren't set in stone yet, as we might
want to change how we're specifying holes in the hart list.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

This patch adds documentation on the RISC-V local interrupt controller,
which is a per-hart interrupt controller that manages all interrupts
entering a RISC-V hart.  This interrupt controller is present on all
RISC-V systems.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>