The generic GPIO reset driver has two entries in the match table:
"gpio-poweroff", "gpio-reset". Only the first entry is considered by
fdt_reset_init().

Define "gpio-poweroff" and "gpio-reset" as compatibility strings of two
separate reset drivers. They still can share code.

Fixes: e3d6919d

 ("lib: utils/reset: Add generic GPIO reset driver")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

The value of variable current_driver is unused. Remove the variable.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

Instruction TLB can fail to respect a non-global SFENCE thus we need to
flush the TLB using SFENCE.VMA x0, x0

See full description of CIP-1200 in Errata_FU740-C000_20210205 from
https://www.sifive.com/boards/hifive-unmatched



Signed-off-by: David Abdurachmanov <david.abdurachmanov@sifive.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

The previous code uses _start as the load address, this default .entry is
the first segment, using _fw_start does not need to make this assumption.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

When generating code with -mno-relax, GCC puts .option norelax in
the generated assembly, and so doesn’t bother passing on -mno-relax
to the assembler. This has the unfortunate effect that, when using
GCC to assemble hand-written assembly, -mno-relax does nothing,
and we have to pass -Wa,-mno-relax to manually forward it to the
assembler.

This is an old GCC bug that was fixed [1] recently. For the time
being, let's pass "-Wa,-mno-relax" to ASFLAGS for the GCC + LLD
combination to work, e.g.:

  $ make CC=riscv64-unknown-elf-gcc LLVM=1 PLATFORM=generic

[1] https://github.com/gcc-mirror/gcc/commit/3b0a7d624e64eeb81e4d5e8c62c46d86ef521857



Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

Recent FW_PIC=y changes actually require toolchains with PIE support
and it is on by default. Existing doc uses a GNU bare-metal toolchain
as examples but it does not support PIE.

Replace references of bare-metal toolchain prefix with Linux toolchain
prefix everywhere in documentation.

Also indicate that "riscv64-unknown-freebsd-" as an alternative to
"riscv64-linux-" GNU toolchain.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

FW_PIC=y is on by default, but the doc is missing when this was
introduced. Add some description for it.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

This updates documentation to describe parameters passed to firmware
from previous booting stage, and corresponding address alignment
requirement.

This also fixes a typo in fw_dynamic.md (it's => its).

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

If the device tree is at an address that is not __SIZEOF_POINTER__
aligned, the fdt relocation code tries to align both source and
destination address to __SIZEOF_POINTER__ before the memory copy.
But such alignment can lead to unexpected results if either source
or destination address is not aligned.

In fact libfdt requires that the device tree must be at an 8-byte
aligned address. Hence remove the unhelpful alignment codes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

Clang provides a __builtin_offsetof which can be detected using
__has_builtin().

Signed-off-by: Alex Richardson <Alexander.Richardson@cl.cam.ac.uk>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

The fields are of type unsigned long and are not pointers. While this
happens to be the same for RV32/RV64, it is not correct when compiling
for a CHERI-RISC-V system where pointers are twice the size of long.

Signed-off-by: Alex Richardson <Alexander.Richardson@cl.cam.ac.uk>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

We add generic GPIO reset driver inspired from gpio-restart
and gpio-poweroff drivers of Linux kernel.

Signed-off-by: Green Wan <green.wan@sifive.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We add a minimal SiFive GPIO driver so that we can do GPIO based
system power-off and reset.

Signed-off-by: Green Wan <green.wan@sifive.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We add a simple FDT based GPIO framework which is built on top
of generic GPIO library. The phandle of FDT GPIO chip DT node
is treated as unique GPIO chip ID required by the generic GPIO
library. The FDT based GPIO chip drivers will be probed on-demand
from fdt_gpio_pin_get() called by the GPIO client drivers.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We add generic GPIO configuration library which is independent of
hardware description format (FDT or ACPI). The OpenSBI platform
support or GPIO drivers can register GPIO chip instances which
can be discovered and used by different GPIO clients. Each GPIO
chip instance has a unique ID which can be used by GPIO clients
to lookup GPIO chip instance.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

The libfdt project does not have a generic API to parse phandle
with args from a DT node so we add fdt_parse_phandle_with_args()
for this purpose. This new API will be useful to FDT based drivers.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

We only need libgcc for 64-bit division on RV32. Whilst GCC toolchains
bundle libgcc, Clang toolchains tend not to ship libclang_rt.builtins
given every compiler is a cross-compiler for every target and so you
would need a silly number of builds of it, with only the native library
available; only vendor-provided Clang toolchains specifically for bare
metal cross-compiling are likely to provide it.

Thus, import part of FreeBSD's implementation of the division support
functions needed and stop linking against libgcc.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Anup Patel <anup.patel@wdc.com>

This is intended to mirror the Linux kernel. Building with CC=clang will
use Clang as the compiler but default to using the existing binutils.
Building with LLVM=1 will default to using Clang and LLVM binutils.

Whilst GCC will accept the -N linker option and forward it on to the
linker, Clang will not, and so in order to support both compilers we
must use -Wl, to forward it to the linker as is required for most other
linker options.

Note that there is currently a bug when using Clang as the compiler and
riscv64-linux-gnu-ld as the linker for FW_PIC=y. At first glance this
appears to be a bug in GNU binutils, but this could also be Clang or
OpenSBI at fault in some subtle way. Thus, for now, advise that this
combination be avoided.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Anup Patel <anup.patel@wdc.com>

Bare-metal GNU ld does not support PIE, so if using it this will result
in a failure to build. Instead, default to FW_PIC=n if not supported.
Note that an explicit FW_PIC=y is not overridden, to ensure the build
fails rather than silently producing a position-dependent binary.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

When using Clang with a bare-metal triple, -pie does not get passed to
the linker as it's not normally a thing that makes sense, unlike GCC
which will unconditionally forward it on and potentially result in a
linker error. However, LLD does support it, and manually forwarding it
on works as desired, so do so to fully support FW_PIC with Clang and
LLD.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

The -N linker option is supposed to make .text writable, but GNU ld and
LLD differ in interpreting what that means. GNU ld will happily let you
have relocations in it, but LLD will see that the input section is
read-only (even though the output section is writable) and give an
error. It's unclear if either of them intend to have that behaviour in
this edge case, but regardless there's no reason not to just put the
data in a writable .data section.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

These are mutually exclusive. GNU as and LLVM both let later binding
directives override earlier ones so this works as intended, but LLVM 12
turned this into a warning as there's no good reason to do such a thing
and could be a potential bug. Thus, remove the redundant and incorrect
.globl directive for fw_platform_init.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

The sbi_pmu_exit() crashes on systems not having MCOUNTINHIBIT csr
so to fix this we check SBI_HART_HAS_MCOUNTINHIBIT feature in
sbi_pmu_exit() and do nothing if it is not available.

Fixes: 13d40f21

 ("lib: sbi: Add PMU support")
Signed-off-by: Anup Patel <anup.patel@wdc.com>

Avoid using a magic number, instead use a macro for the version of
struct fw_dynamic_info.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

The sanity checks on the magic and version was already done in
fw_boot_hart(), which happens before fw_save_info() is called.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

At present in the rendered platform guide, all instances of <xyz>
are missing. Use &lt; and &gt; to replace <> to make them visible.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

It's riscv-pk, not riskv-pk.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

Before entering _scratch_init(), register t3 already holds a copy
of the firmware end address, hence there is no need to calculate
it again. This reduces 3 instructions in each _scratch_init() loop.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

Add PMU support for generic platform. Generic platform solely relies on
the device tree to parse all pmu related information. If any event is
not described in device tree, generic platform will not support it.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

Follow the standard conventon for static function names:

	All global functions should be start with sbi_<module name>_
	All static functions should be start with <module name>_

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

RISC-V SBI v0.3 specification defines a set of firmware events that can
provide additional information about the current firmware context. All
of the firmware event monitoring are enabled now. The firmware
events must be defined as raw perf event with MSB set as specified in the
specification.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

RISC-V SBI specfication 0.3 defines a PMU extension that allows supervisor
mode to start/stop/configure pmu related events. This patch implements
all of the functionality defined in the specification.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

The PMU DT node bindings are defined in docs/pmu_support.md
Add few fdt helper functions to parse the DT node and update the
event-counter mapping tables.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

RISC-V SBI v0.3 specification defined a PMU extension to configure/start/stop
the hardware/firmware pmu events.

Implement PMU support in OpenSBI library. The implementation is agnostic of
event to counter mapping & mhpmevent value configuration. That means, it
expects platform hooks will be used to set up the mapping and provide
the mhpmevent value at runtime.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

A platform hook to initialize PMU allows platform vendors to provide
their own mechanism to define pmu event-counter mappings in addition
to the DT based approach.

Another platform hook that allows platform vendors customize the
final mhpmevent value configuration.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

Currently, csr_read/write_num functions are used to read/write PMP related
CSRs where CSR value is decided at runtime. Expand this function to include
PMU related CSRs as well.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

This patch removes redundant print from sbi_boot_print_hart().

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

Implement a list helper function that checks for empty lists.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

Currently, all bits in mcountern are enabled unconditionally at boot time.
With SBI PMU extension, all the programmable counters should enabled only
during performance monitoring for a particular event. However, this is done
only if mcountinhibit is implemented because the supervisor mode can not
start/stop any event without mcountinhibit.

Similarly, supervisor should take care enabling scounteren which allows
U-mode to access programmable pmu counters. All the non-programmable ones
(CY, TM, IR) should be enabled in M-mode because some userspace may rely on
builtins such as __builtin_readcyclecounter. Supervisor OS can still disable
them during initial configuration.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>

RISC-V privilege specification allows the implementation to have less
than 64 bits.

Add a function to detect the number of implemented bits in mhpmcounter
dynamically at runtime.

Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>