The list loop below that check is actually not looping if the list is
empty so there was no need for this check.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Rather than checking 32bits overflow with some absolute value, check the
value to be different from the cast itself.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

There was a naming incoherency between enabled events list lock/unlock.
Rename sse_hart_unlock() to sse_enabled_event_unlock() to be coherent
and reword comments above lock()/unlock() functions.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Fix some errors spotted by Samuel while reviewing the SSE implementation.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Implement the test which covers some of the functions from the
`riscv_locks.h` file. This test consists of 3 test cases:

1) For lock/unlock functions
2) Unsuccessful trylock (the lock was previously taken)
3) Successful trylock (the lock is free and can be taken)

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Implement the test which covers some of the functions from the
`riscv_atomic.h` header file. The test contains 9 test cases:

1) atomic read/write test
2) add/return test
3) sub/return test
4) cmpxchg test
5) atomic_xchg test
6) atomic_raw_set_bit test
7) atomic_raw_clear_bit test
8) atomic_set_bit test
9) atomic_clear_bit test

Some of the test cases operate on the `test_atomic` variable. It gets
initialized in the suite init function.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Allow to define an init function for the test suite. It could help us
to initialize global variable once, and use them in multiple test cases
after the initialization.

For instance, if multiple test cases use the same atomic_t var, it
could be helpful to call ATOMIC_INIT once during the suite
initialization.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Now opensbi can run at any address via dynamic relocation. We can
remove FW_TEXT_START.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>

After calling fdt_node_offset_by_compatible() we must check its return
value and not an unrelated value.

Addresses-Coverity-ID: 1584993 Logically dead code
Fixes: 67ce5a76

 ("platform: generic: Add support for specify coldboot harts in DT")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

sse_event_get() may return NULL. We should not dereference the return value
in sbi_sse_exit() without checking.

Fixes: c8cdf01d

 ("lib: sbi: Add support for Supervisor Software Events extension")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

The sbi_hart_ext[] array is missing these two extensions ids. It is
expected that this array contains all the extensions declaration at the
same index of the SBI_HART_EXT_* define. Without this, when adding a new
extension, there is a mismatch between ids and extension names and it
can even display corrupted extension names.

Addresses-Coverity-ID: 1584994 Out-of-bounds read
Fixes: 6bb6b61c

 ("lib: sbi: Add support for smcsrind and smcdeleg")
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

The rule included from auto.conf.cmd adds a dependency on every Kconfig
file, so these two Kconfig files do not need to be specified again here.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>

The .config file may be manually edited or copied from another location.
Since genconfig.py is responsible for generating auto.conf (the Makefile
fragment) and autoconf.h (the C header) from .config, it must be run any
time .config changes, not just when running menuconfig.

Fixes: 662e631c

 ("Makefile: Add initial kconfig support for each platform")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>

SCOUNTEREN and SENVCFG may not be supported on certain RISC-V core,
so check the existence of these CSRs via privilege spec version to
prevent illegal instructions.

Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Signed-off-by: Alvin Chang <alvinga@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Currently, all non-coldboot HARTs busy spin in wait_for_coldboot()
until the entire coldboot init sequence is completed.

This means:
1) On QEMU, all non-coldboot HARTs will eat host CPU time and
   also slow down the coldboot HART until the entire coldboot
   init sequence is completed.
2) On real HW, all non-coldboot HARTs will consume more CPU
   power until the entire coldboot init sequence is completed.

To address this, wake up all non-coldboot HARTs as early as
possible in the coldboot init sequence.

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

On QEMU virt machine with large number of HARTs, some of the HARTs
randomly fail to come out of wait_for_coldboot() due to one of the
following race-conditions:

1) Failing HARTs are not able to acquire the coldboot_lock and
   update the coldboot_hartmask in wait_for_coldboot() before
   the coldboot HART acquires the coldboot_lock and sends IPI
   in wake_coldboot_harts() hence the failing HARTs never
   receive IPI from the coldboot HART.

2) Failing HARTs acquire the coldbood_lock and update the
   coldboot_hartmask before coldboot HART does sbi_scratch_init()
   so the sbi_hartmask_set_hartid() does not update the
   coldboot_hartmask on the failing HARTs hence they never
   receive IPI from the coldboot HART.

To address this, use a simple busy-loop in wait_for_coldboot() for
polling on coldboot_done flag.

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

The address of the local scratch area is stored in each hart's mscratch
CSR. It is more efficient to read the CSR than to compute the address
from the hart ID.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

The address of the local scratch area is stored in each hart's mscratch
CSR. It is more efficient to read the CSR than to compute the address
from the hart ID.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Avoid using C types and casts if sbi/sbi_byteorder.h is included in
assembly code

Signed-off-by: Vivian Wang <dramforever@live.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Add SSE callbacks registration to PMU driver in order to disable
interrupt delegation for PMU interrupts. When interrupts are
undelegated send the PMU SSE event upon LCOFIP IRQ.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

The SBI SSE extension defines a set of function that can be called to
register and handle supervisor sofwtare events. This patch implements
all of the functionality defined in the specification.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

This extension [1] allows to deliver events from SBI to supervisor via
a software mechanism. This extension defines events (either local or
global) which are signaled by the SBI on specific signal sources (IRQ,
exceptions, etc) and are injected to be executed in supervisor mode.

[1] https://lists.riscv.org/g/tech-prs/message/798



Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Remove copy-base relocations that are no longer needed.

Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

All T-Head CSRs are already defined in thead/c9xx_encoding.h.
Let's reuse the values from there instead of redefining them with
a slightly different name.

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Anup Patel <anup@brainfault.org>

We should store test object files list in the `libsbi-objs-y` Makefile
variable, not in `libsbitests-objs-y`. Update the documentation
correspondingly.

Since we don't use the `console_dev` static variable directly in the
`sbi_console_test` unit test anymore, remove the paragraph which says
that we do.

Fixes: 86224ec3

 ("docs/writing_tests: Update tests paths")
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

The sbi_trap_error() should dump state of all in-flight traps upon
failure in a nested trap so extend it accordingly.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>

To be consistent with other trap handlers, pass trap context pointer
to sbi_ecall_handler().

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Clément Léger <cleger@rivosinc.com>

The trap irq handling functions no longer require regs parameter
so remove it.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>

The irqchip handlers will typically not need pointer to trap registers
so remove regs parameter of sbi_irqchip_process().

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Clément Léger <cleger@rivosinc.com>

The struct sbi_trap_context already has the information needed by
sbi_illegal_insn_handler() so directly pass struct sbi_trap_context
pointer to this function.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>

The struct sbi_trap_context already has the information needed by
misaligned load/store and access fault load/store handlers so directly
pass struct sbi_trap_context pointer to these functions.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Clément Léger <cleger@rivosinc.com>

Club the struct sbi_trap_regs and struct sbi_trap_info a new
struct sbi_trap_context (aka trap context) which must be saved
by low-level trap handler before calling sbi_trap_handler().

To track nested traps, the struct sbi_scratch points to the current
trap context and the trap context has pointer to pervious context
of previous trap.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>

To track nested traps, the struct sbi_scratch needs a pointer the
current trap context so add trap_context pointer in struct sbi_context.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>

Over the years, no uses of sbi_trap_exit() have been found so remove
it and also remove related code from fw_base.S and sbi_scratch.h.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>

In the only places this value is used, it duplicates mepc from
struct sbi_trap_regs.

Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Since the tests should be moved to the lib/sbi/tests directory, the
documentation should be updated correspondingly. So, update the paths
where they have to be changed.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Move all of the SBIUnit-related code into the lib/sbi/tests directory.
Update 'Makefile' to index objects from the tests subdirectory.

I don't think creating the full separate list of Makefile variables
(libsbitests-objs-path-y, libsbitests-object-mks, etc. as it is done for
libsbiutils) is necessary for the tests because:

1) `lib/sbi/tests/objects.mk` is already indexed into
'libsbi-objects-mks' since the find expression for the libsbi-object-mks
variable looks for objects.mk files in the nested directories as well).

2) Tests are tightly coupled with the `lib/sbi/` sources, therefore it
may be reasonable to store the list of lib/sbi and lib/sbi/tests object
files together in the libsbi-objs-path-y variable.

Additionally, update relative paths in the tests where necessary.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

sbi_load/store_access_handler now tries to call platform emulators
if defined. Otherwise, redirects the fault. If the platform code
returns failure, this means the H/S/U has accessed the emulated
devices in an unexpected manner, which is very likely caused by
buggy code in H/S/U. We redirect the fault, so lower privileged
level can get notified, and act accordingly. (E.g., oops in Linux)

We let the handler truly fail if the trap was originated from M mode.
In this case, something must be very wrong and we should just fail.

Signed-off-by: Bo Gan <ganboing@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

This patch allows the platform to define load/store emulators. This
enables a platform to trap-and-emulate special devices or filter
access to existing physical devices.

Signed-off-by: Bo Gan <ganboing@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

This patch abstracts out the instruction decoding part of misaligned ld/st
fault handlers, so it can be reused by ld/st access fault handlers.
Also Added lb/lbu/sb decoding. (previously unreachable by misaligned fault)

sbi_trap_emulate_load/store is now the common handler which takes a `emu`
parameter that is responsible for emulating the misaligned or access fault.
The `emu` callback is expected to fixup the fault, and based on the return
code of `emu`, sbi_trap_emulate_load/store will:

  r/wlen => the fixup is successful and regs/mepc needs to be updated.
  0      => the fixup is successful, but regs/mepc should be left untouched
            (this is usually used if `emu` does `sbi_trap_redirect`)
  -err   => failed, sbi_trap_error will be called

For now, load/store access faults are blindly redirected. It will be
enhanced in the following patches.

Signed-off-by: Bo Gan <ganboing@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>