Signed-off-by: Atish Patra <atishp@rivosinc.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

Support for RISC-V is not in the tree yet, but the work is in progress
and it is able to boot riscv-guest already.

This extension is meant to provide a way for supervisor-mode software to
request changes of some feature handling provided by the M-mode
firmware. Two new functions are added to get and set theses feature with
specific values. This first FWFT extension version documents the
following features:
- MISALIGNED_EXC_DELEG: Delegate misaligned access exception
- SOFTWARE_CHECK_EXC_DELEG: Delegate software check exception for
  supervisor-mode[1]
- LANDING_PAD: Control Landing Pad for supervisor-mode[1]
- SHADOW_STACK: Control Shadow Stack for supervisor-mode [1]
- DOUBLE_TRAP: Control Double Trap support for supervisor-mode [2]
- PTE_AD_HW_UPDATING: Control hardware updating of PTE A/D bits

An openSBI implementation is visible at [3] as well a kvm-unit-tests
with MISALIGNED_EXC_DELEG testing at [4].

Link: https://github.com/riscv/riscv-cfi [1]
Link: https://github.com/ved-rivos/riscv-double-trap [2]
Link: https://github.com/rivosinc/opensbi/tree/dev/cleger/fwft [3]
Link: https://github.com/clementleger/kvm-unit-tests/tree/dev/cleger/fwft

 [4]
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

This patch defines the SBI Supervisor Software Event (SSE) extension.

Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>

SBI_ERR_INVALID_STATE to refer to invalid state of a state machine.
SBI_ERR_BAD_RANGE to refer to a value having value out of valid range.

Signed-off-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>

coreboot has had its own SBI since 2015, and
we are in the process of updating it.

oreboot is in the process of creating its own.

Signed-off-by: Ronald G Minnich <rminnich@gmail.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

The *_set_shmem calls set up the shared memory on the calling hart
only. Every active hart intend to use the shared memory must invoke
this once to set it up. Clarify it in the PMU snapshot function.

Signed-off-by: Atish Patra <atishp@rivosinc.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

S-mode may allocate more memory than necessary for the steal-time
shared memory region. Clarify that the SBI implementation is only
obliged to zero the 64 bytes required.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>

The counter start/stop function clearly states that snapshot shared memory
area is only valid for the counters being stopped/started in the respective
calls. That means the logical counter index modified must be relative to the
counter base provided in the start/stop call. Add more clarification to avoid
any ambiguity.

Signed-off-by: Atish Patra <atishp@rivosinc.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

The PMU snapshot function is an optional function and the SBI implementation
may not implement it. It may be useful to distinguish that from other error
to allow further clarification to the user.

Signed-off-by: Atish Patra <atishp@rivosinc.com>

If the suspend/resume operation is successful, execution continues at
`resume_addr`, as described in the text. The function does not return.

Reported-by: Wesley Norris <repnop@outlook.com>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

The special start/size values only control which addresses are affected,
not which ASIDs are affected. The same rules apply to the legacy remote
fence functions, so document the behavior there as well.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>

The two parameters are the start and size of the address range,
not the start and end of the range.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

* Correct indentation.
* Remove duplicate 'only'.
* A function does not 'pass' but 'take' arguments.
* Add missing 'the'.
* It is not the 'SBI function' but the 'SBI function caller' that passes
  information about harts to the higher privilege mode.
* It is not that 'multiple instances of a function' are invoked,
  but the function is invoked 'multiple times'.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

Zhouqi Jiang is my legal name for publications. Thanks!

Signed-off-by: Luo Jia / Zhouqi Jiang <me@luojia.cc>

As per the RVI policy, remove the non-member entries from the contributor
list as determined by the RVI tool. The information may be stale and
If the authors are a member now or wish to be a RVI member, please
reach out to help@riscv.org. We would be happy to add them to the contributor
list.

Signed-off-by: Atish Patra <atishp@rivosinc.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

Because my aist.go.jp mail address is no longer accessible, this commit
updates the contact information up to date.

Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

Signed-off-by: Atish Patra <atishp@rivosinc.com>

There are usage of "is assumed to be" for normative statements. The meaning
of it subjective and ambiguous. As the the intention was to use normative
verbs anyways, lets just use "must" to provide more clarification.

Signed-off-by: Atish Patra <atishp@rivosinc.com>

Let us move images to a dedicated directory which results in having
only text files in root directory.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

For ease in maintainence, we split the specification into multiple
adoc files under a separate src directory.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

We will be splitting riscv-sbi.adoc into multiple adoc files so the
Makefile should have a way to capture dependency.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

Let us adjust width of CPPC register table columns to make register
IDs and names more readable.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

The flags parameter of sbi_steal_time_set_shmem() should be unsigned
long for consistency with sbi_nacl_set_shmem().

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

We update the PMU snapshot documentation to make it consistent with
other SBI extensions namely NACL and STA. In the process, we also
add mechanism to disable snapshot shared memory (just like other
SBI extensions).

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

To be consistent with other SBI extensions, let us add flags
parameter to sbi_pmu_snapshot_set_shmem() function.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

The 'make clean' command should remove the autogenerated directory
along with build targets.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

Just like other RVI specs, the pre-compiled riscv-sbi.pdf should be
attached to the release tag instead of having it in spec sources.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>

When making a fresh build the process will output something like

  diff: .../autogenerated/revision.adoc-snippet: No such file or directory

Avoid the error by checking for the file first.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>