We update reset drivers makefile to use kconfig for enabling/disabling
drivers. To avoid compile errors, we also enable appropriate reset
drivers for each platform.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>

We update serial drivers makefile to use kconfig for enabling/disabling
drivers. To avoid compile errors, we also enable appropriate serial
drivers for each platform.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>

Currently, if same build directory is used to compile two different
platforms then lib/utils objects are shared for these platforms.

We will be having platform specific configs to enable/disable drivers
in lib/utils and select compile time options for lib/utils sources.
This means lib/utils sources will now be compiled in a platform
specific way.

To tackle above, we update top-level Makefile as follows:
1) Don't create libsbiutils.a anymore because this can't be shared
   between platforms.
2) Compile lib/utils sources separately for each platform.
3) Add comments showing which make rules are for lib/sbi, lib/utils,
   firmware, and platform sources.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>

We extend the top-level makefile to allow kconfig based configuration
for each platform where each platform has it's own set of configs with
"defconfig" being the default config.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>

We adopt Kconfiglib v14.1.0 sources under scripts directory so that
top-level OpenSBI makefile can directly use Kconfiglib scripts without
expecting users to install a particular version of Kconfiglib on their
build system.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>

Read long long arguments directly using va_arg. Remove original hack for
RV32 that read a long long arg as two long args.

This un-breaks the case on RV64 where e.g. the long long is followed by
an odd number of ints:

    sbi_printf("%d %lld", (int) 1, (long long) 2LL);

Also remove the acnt variable, which is now unused.

Signed-off-by: dramforever <dramforever@live.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

RISC-V doesn't generate exceptions on divide-by-zero, but the result,
all bits set, is not likely what people expect either. In all cases
where we divide by baudrate there's a chance it's zero (when the DT
it came from is "bad"). To avoid difficult to debug situations, leave
baudrate dependent registers alone when baudrate is zero, as, also in
all cases, it appears we can skip initialization of those registers
and still [hopefully] have a functioning UART.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

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

While it doesn't look like there are any current cases of using
uninitialized data, let's zero all the UART data members to be
safe. Zero may not actually be better than a random number in
some cases, so all structure members should still be validated
before use, but at least zero is usually easier to debug than
some random stack garbage...

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Factor out the common code used by the fdt UART node parsers,
allowing us to drop duplicate code.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

fw_event_map represents array of firmware events. It should initialized
for maximum number of firmware events not counters.

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

The active_events array is accessed with counter ID passed from the supervisor
software before the counter ID bound check. This may cause a buffer overrun
if a supervisor passes an invalid counter ID.

Fix this by moving the access part after the bound check.

Reported-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Currently, there is no sanity check for firmware event code. We don't see
any issue as Linux kernel driver does a bound check on firmware events
already. However, OpenSBI can't assume sane supervisor mode software
always. Thus, an invalid event idx can cause a buffer overflow error.
For hardware events, the match will fail for invalid event code anyways.
However, a search is unecessary if event code is invalid.

Add a event ID validation function to solve the issue.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

The current implementation computes the possible counter range
by doing a left shift of counter base. However, this may overflow depending
on the counter base value. In case of overflow, the highest counter id
may be computed incorrectly. As per the SBI specification, the respective
function should return an error if any of the counter is not valid.

Fix the counter index check by avoiding left shifting while doing the
sanity checks. Without the shift, the implementation just iterates
over the counter mask and computes the correct counter index by adding
the base to it.

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

printc would happily write to 'out' even when 'out_len' was zero,
potentially overflowing buffers. Rework printc to not do that and
also ensure the null byte is written at the last position when
necessary, as stated in the snprintf man page. Also, panic if
sprintf or snprintf are called with NULL output strings (except
the special case of snprintf having a NULL output string and
a zero output size, allowing it to be used to get the number of
characters that would have been written). Finally, rename a
goto label which clashed with 'out'.

Fixes: 9e8ff05c

 ("Initial commit.")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

The age old version of Shakti UART was upgraded long back, but we missed
updating the driver in OpenSBI. The old version of UART is not supported
anymore, hence removed the inline comment which is also outdated now.

Signed-off-by: Prasanna T <ptprasanna@gmail.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>

MPV bit is set when the value of next_virt boolean variable equals
true. Since the value of next_virt is either 0 or 1, we can set
MPV bit without if-else logic.

Signed-off-by: Che-Chia Chang <alvinga@andestech.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

If the ecall SBI_EXT_HSM_HART_START is called it might try to wake the
secondary hart using sbi_ipi_raw_send() to send an IPI to the hart.
This can fail if there is no IPI device but no error is returned from
sbi_ipi_raw_send() so the ecall returns as if the action completed and
the caller continues without noticing (in the case of Linux it just hangs
waiting for the secondary hart to become active)

Fix this by changing sbi_ipi_raw_send() to return and error, and if an
error is returned, then return it via SBI_EXT_HSM_HART_START call.

Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Motivation: Suppose a peripheral needs to be configured to transmit
data. There is an SFR bit which indicates that the peripheral is ready
to transmit. The firmware should check the bit and will only transmit
data when the peripheral is ready. When the firmware starts polling the
SFR, the peripheral could be busy transmitting/receiving other data so
the firmware must wait till that completes. Assuming that there is no
other way, the firmware shouldn't wait indefinitely.

The function sbi_timer_waitms_until() will constantly check whether a
certain condition is satisfied, or timeout occurs. It can be used for
the cases when a timeout is required.

Signed-off-by: Adnan Rahman Chowdhury <adnan.chowdhury@sifive.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

This patch updates OpenSBI version to 1.1 as part of
release preparation.

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

OpenSBI explicitly assumes that there is no pmu hardware counter with
index 1: hardware uses that bit for TM control. So OpenSBI filters
out that index in sanity checks. However OpenSBI also excludes that
counter when reports total amount of hardware counters to Linux. As
a result, Linux uses incomplete counters mask excluding the highest
available counter.

Return accurate number of counters, update the firmware counter
starting index, fix range checks that include num_hw_ctrs.

The simple test is to make sure that there is no counter multiplexing
in the following command:

$ perf stat -e \
	r8000000000000000,r8000000000000001,r8000000000000002,r8000000000000003, \
	r8000000000000004,r8000000000000005,r8000000000000006,r8000000000000007, \
	r8000000000000008,r8000000000000009,r800000000000000a,r800000000000000b, \
	r800000000000000c,r800000000000000d,r800000000000000e,r800000000000000f  \
	ls

Note that 16 firmware events with 16 counters won't require multiplexing.

Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>

Now that SBI v1.0 specification is ratified, we change spec verion
implemented by OpenSBI to v1.0.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>

The allwinner,sun20i-d1-clint compatible string is not documented in any
official binding, so it should not be used by drivers.

The MSWI in the D1 CLINT is compatible with the ACLINT specification, so
it can take advantage of generic driver support. However, that is only
possible if the MSWI and MTIMER are split into separate DT nodes. This
means the final binding for this device is likely to be incompatible
with what is implemented here.

Remove this compatible string from the driver to prevent it from
appearing in a stable version and causing future issues.

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

The second invocation of plic_context_init() incorrectly calls the
function with m_cntx_id instead of s_cntx_id. This breaks systems which
only have 1 external interrupt per hart.

Fixes: 8c362e7d

 ("lib: irqchip/plic: Factor out a context init function")
Signed-off-by: Jan Remes <jan.remes@codasip.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Samuel Holland <samuel@sholland.org>

The CLINT in the Allwinner D1 SoC apparently does not support 64-bit
MMIO access. A property was added to support this quirk (and that
property was copied to the ACLINT MTIMER code). However, since this
difference in behavior makes the D1 CLINT incompatible with the SiFive
CLINT's programming interface, a better solution is to use a separate
compatible string.

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

Based on architecture review committee feedback, the [m|s|vs]seteienum,
[m|s|vs]clreienum, [m|s|vs]seteipnum, and [m|s|vs]clreipnum CSRs are
removed in the latest AIA draft v0.3.0 specification.
(Refer, https://github.com/riscv/riscv-aia/releases/tag/0.3.0-draft.31

)

These CSRs were mostly for software convenience and software can always
use [m|s|vs]iselect and [m|s|vs]ireg CSRs to update the IMSIC interrupt
file bits.

We update the IMSIC programming as-per above to match the latest AIA
draft specification.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>

We should not change trap->tval to mepc because mtval already points to
the faulting portion of the emulated instruction fetch, which is also
what stval is expected to be.

In addition, htinst is only allowed to be zero for instruction access
faults or page faults, and is only allowed to be zero or a
psuedoinstruction for instruction guest-page faults. Fix trap->tinst for
these cases.

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

If there is an exception while emulating a misaligned load/store, fixup
uptrap.tinst before redirecting. Otherwise, HS-mode software may receive
an htinst describing the lbu/sb instruction that faulted during
emulation[1].

[1]: https://github.com/riscv-software-src/opensbi/issues/258



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

Add psuedoinstruction encodings written to mtinst/htinst for faults
caused by implicit memory access for VS-stage address translation

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

Allwinner D1 contains a "PPU" power domain controller which can
automatically power down/up the CPU power domain. This power domain
includes the C906 core along with its CLINT and PLIC.

This HSM implementation supports non-retentive hart suspend by:
  1) Saving/restoring state that is lost during hart suspend,
  2) Performing cache maintenance before/after hart suspend,
  3) Configuring wakeup sources before hart suspend, and
  4) Asking the PPU to power down the hart when it enters WFI.

Since this HSM implementation is for a single-core SoC, it does not need
to worry about concurrency or saving multiple instances of state.

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

The delegation bit is lost along with the rest of the PLIC state when
the CPU power domain in the Allwinner D1 is powered down, so the PLIC
needs to be re-delegated to S-mode during the hart resume path.

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

These functions save/restore the state of the PLIC associated with the
current hart. The context save/restore functions only manipulate a
single context, since most likely the M-mode context is unused and does
not need to be saved.

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

These can be used by platform code to save the PLIC priority state, if
it would otherwise be lost during non-retentive suspend. The platform
is responsible for allocating all necessary storage.

As a space optimization, store the saved priority values as 8-bit
integers, since that is large enough to hold any priority value on the
relevant platforms.

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

These can be used by platform code to save the PLIC context state, if
it would otherwise be lost during non-retentive suspend. The platform
is responsible for allocating all necessary storage.

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

This simplifies both the callers and the callees by removing duplicated
code and consolidating the error handling. It also fixes two bugs in the
process:
  1) ie_words was one too large when plic->num_src was a multiple of 32.
  2) plic_set_ie takes a 32-bit mask, not a Boolean value, so the FPGA
     platforms previously only enabled one out of every 32 interrupts.

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

None of the functions modify the passed-in plic_data, so mark it const.

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

The suspend code needs to know the resume address for two reasons:
  1) Programming some hardware register or management firmware. Here we
     assume the hardware/firmware maintains its state between suspends,
     so it only needs to be programmed once at startup.
  2) When a non-retentive suspend request ends up being retentive, due
     to lack of hardware support, pending interrupt, or for some other
     reason. However, the behavior here is not platform-dependent, and
     this can be handled in the generic hart suspend function.

Since neither situation requires the platform-level suspend function to
know the resume address, stop passing it to that function. Instead,
handle the non-retentive to retentive situation generically.

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

Non-retentive suspend states may require platform-specific actions
during resume. For example, firmware may need to save and restore the
values of custom CSRs. Add a hook to support this.

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

Allow the vendor_ext_check and vendor_ext_provider APIs of the
generic platform to be overridden by other platforms

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

HS-mode software can choose what exceptions to delegate to VS-mode using
the hedeleg CSR. Synthetic VS/VU-mode exceptions should also honor
hedeleg. They should be redirected to VS-mode if and only if delegated
by HS-mode.

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